text: Radio programming charts in Sunday newspapers listed "The War of the Worlds". On October 30, 1938, "The New York Times" included the show in its "Leading Events of the Week" ("Tonight – Play: H. G. Wells' 'War of the Worlds'") and published a photograph of Welles with some of the Mercury players, captioned, "Tonight's show is H. G. Wells' 'War of the Worlds'".


title: The War of the Worlds (1938 radio drama)

text: Announcements that "The War of the Worlds" is a dramatization of a work of fiction were made on the full CBS network at four points during the broadcast: at the beginning, before the middle break, after the middle break, and at the end. The middle break was delayed 10 minutes to accommodate the dramatic content.


text: Another announcement was repeated on the full CBS network that same evening at 10:30 pm, 11:30 pm, and midnight: "For those listeners who tuned in to Orson Welles's "Mercury Theatre on the Air" broadcast from 8 to 9 pm Eastern Standard Time tonight and did not realize that the program was merely a modernized adaptation of H. G. Wells' famous novel "War of the Worlds", we are repeating the fact which was made clear four times on the program, that, while the names of some American cities were used, as in all novels and dramatizations, the entire story and all of its incidents were fictitious."


text: The show went on the air shortly after 8:00 pm ET. At 8:32, Houseman noticed Taylor step out of the studio to take a telephone call in the control room, who returned four minutes later looking "pale as death", as he had been ordered to immediately interrupt "The War of the Worlds" broadcast with an announcement of the program's fictional content. By the time the order was given, the fictional news reporter played by Ray Collins was choking on poison gas as the Martians overwhelmed New York and the program was less than a minute away from its first scheduled break, which proceeded as previously planned.


text: Actor Stefan Schnabel recalled sitting in the anteroom after finishing his on-air performance. "A few policemen trickled in, then a few more. Soon, the room was full of policemen and a massive struggle was going on between the police, page boys, and CBS executives, who were trying to prevent the cops from busting in and stopping the show. It was a show to witness."


text: During the sign-off theme, the phone began ringing. Houseman picked it up and the furious caller announced he was mayor of a Midwestern town, where mobs were in the streets. Houseman hung up quickly, "[f]or we were off the air now and the studio door had burst open."


text: The following hours were a nightmare. The building was suddenly full of people and dark-blue uniforms. Hustled out of the studio, we were locked into a small back office on another floor. Here we sat incommunicado while network employees were busily collecting, destroying, or locking up all scripts and records of the broadcast. Finally, the Press was let loose upon us, ravening for horror. How many deaths had "we" heard of? (Implying they knew of thousands.) What did "we" know of the fatal stampede in a Jersey hall? (Implying it was one of many.) What traffic deaths? (The ditches must be choked with corpses.) The suicides? (Haven't you heard about the one on Riverside Drive?) It is all quite vague in my memory and quite terrible.


text: Paul White, head of CBS News, was quickly summoned to the office, "and there bedlam reigned", he wrote:


text: The telephone switchboard, a vast sea of light, could handle only a fraction of incoming calls. The haggard Welles sat alone and despondent. "I'm through," he lamented, "washed up." I didn't bother to reply to this highly inaccurate self-appraisal. I was too busy writing explanations to put on the air, reassuring the audience that it was safe. I also answered my share of incessant telephone calls, many of them from as far away as the Pacific Coast.


text: Because of the crowd of newspaper reporters, photographers, and police, the cast left the CBS building by the rear entrance. Aware of the sensation the broadcast had made, but not its extent, Welles went to the Mercury Theatre where an all-night rehearsal of "Danton's Death" was in progress. Shortly after midnight, one of the cast, a late arrival, told Welles that news about "The War of the Worlds" was being flashed in Times Square. They immediately left the theatre, and standing on the corner of Broadway and 42nd Street, they read the lighted bulletin that circled the "New York Times" building: ORSON WELLES CAUSES PANIC.


text: Some listeners heard only a portion of the broadcast and, in the tension and anxiety prior to World War II, mistook it for a genuine news broadcast. Thousands of them shared the false reports with others or called CBS, newspapers, or the police to ask if the broadcast was real. Many newspapers assumed that the large number of phone calls and the scattered reports of listeners rushing about or fleeing their homes proved the existence of a mass panic, but such behavior was never widespread.


text: Future "Tonight Show" host Jack Paar had announcing duties that night for Cleveland CBS affiliate WGAR. As panicked listeners called the studio, he attempted to calm them on the phone and on air by saying: "The world is not coming to an end. Trust me. When have I ever lied to you?" When the listeners started to accuse Paar with "covering up the truth", he called WGAR's station manager for help. Oblivious to the situation, the manager advised Paar to calm down and said that it was "all a tempest in a teapot".


text: In a 1975 interview with radio historian Chuck Schaden, radio actor Alan Reed recalled being one of several actors recruited to answer phone calls at CBS's New York headquarters.


text: In Concrete, Washington, phone lines and electricity suffered a short circuit at the Superior Portland Cement Company's substation. Residents were unable to call neighbors, family, or friends to calm their fears. Reporters who heard of the coincidental blackout sent the story over the newswire, and Concrete was known worldwide.


text: Welles continued with the rehearsal of "Danton's Death", leaving shortly after the dawn of October 31. He was operating on three hours of sleep when CBS called him to a press conference. He read a statement that was later printed in newspapers nationwide and took questions from reporters:


text: In its October 31, 1938, edition, the "Tucson Citizen" reported that three Arizona affiliates of CBS (KOY in Phoenix, KTUC in Tucson and KSUN in Bisbee) had originally scheduled a delayed broadcast of "The War of the Worlds" that night; CBS had shifted "The Mercury Theater on the Air" from Monday nights to Sunday nights on September 11, but the three affiliates preferred to keep the series in its original Monday slot so that it would not compete with NBC's top-rated "Chase and Sanborn Hour". However, late that night, CBS contacted KOY and KTUC owner Burridge Butler and instructed him not to air the program the following night.


text: Within three weeks, newspapers had published at least 12,500 articles about the broadcast and its impact, but the story dropped from the front pages after a few days. Adolf Hitler referenced the broadcast in a speech in Munich on November 8, 1938. Welles later remarked that Hitler cited the effect of the broadcast on the American public as evidence of "the corrupt condition and decadent state of affairs in democracy".


text: Bob Sanders recalled looking outside the window and seeing a traffic jam in the normally quiet Grover's Mill, New Jersey, at the intersection of Cranbury and Clarksville Roads.


text: Later studies indicate that many people missed the repeated notices about the broadcast being fictional, partly because "The Mercury Theatre on the Air", an unsponsored CBS cultural program with a relatively small audience, ran at the same time as the NBC Red Network's popular "Chase and Sanborn Hour" featuring ventriloquist Edgar Bergen. At the time, many Americans assumed that a significant number of "Chase and Sanborn" listeners changed stations when the first comic sketch ended and a musical number by Nelson Eddy began, tuning in to "The War of the Worlds" after the opening announcements. Historian A. Brad Schwartz, after studying hundreds of letters from people who heard "The War of the Worlds" as well as contemporary audience surveys, concluded that very few people frightened by Welles's broadcast had tuned out Bergen's program. "All the hard evidence suggests that "The Chase & Sanborn Hour" was only a minor contributing factor to the Martian hysteria," he wrote. "...in truth, there was no mass exodus from Charlie McCarthy to Orson Welles that night." Because the broadcast was unsponsored, Welles and company could arbitrarily schedule breaks instead of arranging them around advertisements; as a result, the only notices that the broadcast was fictional came at the start of the broadcast and about 40 and 55 minutes into it.


text: A study by the Radio Project discovered that less than one third of frightened listeners understood the invaders to be aliens; most thought that they were listening to reports of a German invasion or of a natural catastrophe. "People were on edge", wrote Welles biographer Frank Brady. "For the entire month prior to 'The War of the Worlds', radio had kept the American public alert to the ominous happenings throughout the world. The Munich crisis was at its height... For the first time in history, the public could tune into their radios every night and hear, boot by boot, accusation by accusation, threat by threat, the rumblings that seemed inevitably leading to a world war."


text: CBS News chief Paul White wrote that he was convinced that the panic induced by the broadcast was a result of the public suspense generated before the Munich Pact. "Radio listeners had had their emotions played upon for days... Thus they believed the Welles production even though it was specifically stated that the whole thing was fiction".


text: "The supposed panic was so tiny as to be practically immeasurable on the night of the broadcast. ... Radio had siphoned off advertising revenue from print during the Depression, badly damaging the newspaper industry. So the papers seized the opportunity presented by Welles’ program to discredit radio as a source of news. The newspaper industry sensationalized the panic to prove to advertisers, and regulators, that radio management was irresponsible and not to be trusted."


text: Historical research suggests the panic was significantly less widespread than newspapers had indicated at the time. "[T]he panic and mass hysteria so readily associated with 'The War of the Worlds' did not occur on anything approaching a nationwide dimension", American University media historian W. Joseph Campbell wrote in 2003. He quoted Robert E. Bartholomew, an authority on mass panic outbreaks, as having said that "there is a growing consensus among sociologists that the extent of the panic... was greatly exaggerated".


text: That position is supported by contemporary accounts. "In the first place, most people didn't hear [the show]," said Frank Stanton, later president of CBS. Of the nearly 2,000 letters mailed to Welles and the Federal Communications Commission after "The War of the Worlds", currently held by the University of Michigan and the National Archives and Records Administration, roughly 27% came from frightened listeners or people who witnessed any panic. After analyzing those letters, Schwartz concluded that although the broadcast briefly misled a significant portion of its audience, not many of them fled their homes or otherwise panicked. The total number of protest letters sent to Welles and the FCC was also low in comparison with other controversial radio broadcasts of the period, suggesting that the audience was small and the fright severely limited.


text: 5,000 households were telephoned that night in a survey conducted by the C. E. Hooper company, the main radio ratings service at the time. Two percent of the respondents said they were listening to the radio play, and no one stated they were listening to a news broadcast. About 98% of respondents said they were listening to other radio programming ("The Chase and Sanborn Hour" was by far the most popular program in that timeslot) or not listening to the radio at all. Further shrinking the potential audience, some CBS network affiliates, including some in large markets such as Boston's WEEI, had pre-empted "The Mercury Theatre on the Air", in favor of local commercial programming.


text: Ben Gross, radio editor for the "New York Daily News", wrote in his 1954 memoir that the streets were nearly deserted as he made his way to the studio for the end of the program. Houseman reported that the Mercury Theatre staff was surprised when they were finally released from the CBS studios to find life going on as usual in the streets of New York. The writer of a letter that "The Washington Post" published later likewise recalled no panicked mobs in the capital's downtown streets at the time. "The supposed panic was so tiny as to be practically immeasurable on the night of the broadcast", media historians Jefferson Pooley and Michael J. Socolow wrote in "Slate" on its 75th anniversary in 2013; "Almost nobody was fooled".


text: According to Campbell, the most common response said to indicate a panic was calling the local newspaper or police to confirm the story or seek additional information. That, he writes, is an indicator that people were not generally panicking or hysterical. "The call volume perhaps is best understood as an altogether "rational" response..." Some New Jersey media and law enforcement agencies received up to 40% more telephone calls than normal during the broadcast. AT&T Corporation telephone operators in New York City recalled in 1988 that "every light" on the "half block long" switchboard lit up after the broadcast stated that the Martians were crossing the George Washington Bridge, while operators in Princeton and Missoula, Montana were asked what the invaders looked like. They described callers "crying and screaming", asking whether dead bodies were near the operators, "begging us to get connections to their families ... before the world came to an end". "The people believed it. They really believed it that night", one concluded.


text: As it was late on a Sunday night in the Eastern Time Zone, where the broadcast originated, few reporters and other staff were present in newsrooms. Most newspaper coverage thus took the form of Associated Press stories, which were largely anecdotal aggregates of reporting from its various bureaus, giving the impression that panic had indeed been widespread. Many newspapers led with the Associated Press's story the next day.


text: The "Twin City Sentinel" of Winston-Salem, North Carolina, pointed out that the situation could have been even worse if most people had not been listening to Bergen's show: "Charlie McCarthy last night saved the United States from a sudden and panicky death by hysteria."


text: On November 2, 1938, the Australian newspaper "The Age" characterized the incident as "mass hysteria" and stated that "never in the history of the United States had such a wave of terror and panic swept the continent". Unnamed observers quoted by "The Age" commented that "the panic could have only happened in America."


text: Editorialists chastised the radio industry for allowing that to happen. The response may have reflected newspaper publishers' fears that radio, to which they had lost some of the advertising revenue that was scarce enough during the Great Depression, would render them obsolete. In "The War of the Worlds", they saw an opportunity to cast aspersions on the newer medium: "The nation as a whole continues to face the danger of incomplete, misunderstood news over a medium which has yet to prove that it is competent to perform the news job," wrote "Editor & Publisher", the newspaper industry's trade journal.


text: William Randolph Hearst's papers called on broadcasters to police themselves, lest the government step in, as Iowa senator Clyde L. Herring proposed a bill that would have required all programming to be reviewed by the FCC prior to broadcast – it was never introduced. Others blamed the radio audience for its gullibility. Noting that any intelligent listener would have realized the broadcast was fictional, the "Chicago Tribune" opined, "it would be more tactful to say that some members of the radio audience are a trifle retarded mentally, and that many a program is prepared for their consumption." Other newspapers noted that anxious listeners had called their offices to learn if Martians were really attacking.


text: Few contemporary accounts exist outside newspaper coverage of the mass panic and hysteria supposedly induced by the broadcast. Justin Levine, a producer at KFI in Los Angeles, wrote that "the anecdotal nature of such reporting makes it difficult to objectively assess the true extent and intensity of the panic". Bartholomew saw it as more evidence that the panic was predominantly a creation of the newspaper industry.


text: In a study, published as "The Invasion from Mars" (1940), Princeton professor Hadley Cantril calculated around six million people heard "The War of the Worlds" broadcast. He estimated that 1.7 million listeners believed the broadcast was an actual news bulletin and, of those, 1.2 million people were frightened or disturbed. However, Pooley and Socolow have concluded that Cantril's study had serious flaws. Its estimate of the program's audience is more than twice as high as any other at the time. Cantril himself conceded that, but argued that unlike Hooper, his estimate had attempted to capture the significant portion of the audience that did not have home telephones at that time. Since those respondents were contacted only after the media frenzy, Cantril admitted that their recollections could have been influenced by what they read in the newspapers. Claims that "Chase and Sanborn" listeners, who missed the disclaimer at the beginning when they turned to CBS during a commercial break or musical performance on that show and thus mistook "The War of the Worlds" for a real broadcast inflated the show's audience and the ensuing panic, are impossible to substantiate.


text: Apart from his imperfect methods of estimating the audience and assessing the authenticity of their response, Pooley and Socolow found Cantril made another error in typing audience reaction. Respondents had indicated a variety of reactions to the program, among them "excited", "disturbed", and "frightened". However, he included all of them with "panicked", failing to account for the possibility that despite their reaction, they were still aware the broadcast was staged. "[T]hose who did hear it, looked at it as a prank and accepted it that way", recalled researcher Frank Stanton.


text: Bartholomew admitted that hundreds of thousands were frightened, but called evidence of people taking action based on their fear "scant" and "anecdotal". Contemporary news articles indicated that police received hundreds of calls in numerous locations, but stories of people doing anything more than calling authorities involved mostly only small groups; such stories were often reported by people who were panicking themselves.


text: Later investigations found many of the panicked responses to have been exaggerated or mistaken. Cantril's researchers found that contrary to what had been claimed, no admissions for shock were made at a Newark hospital during the broadcast; hospitals in New York City similarly reported no spike in admissions that night. A few suicide attempts seem to have been prevented when friends or family intervened, but no record of a successful one exists. A "Washington Post" claim that a man died of a heart attack brought on by listening to the program could not be verified. One woman filed a lawsuit against CBS, but it was soon dismissed.


text: The FCC also received letters from the public that advised against taking reprisals. Singer Eddie Cantor urged the commission not to overreact, as "censorship would retard radio immeasurably". The FCC decided to not punish Welles or CBS, and also barred complaints about "The War of the Worlds" from being brought up during license renewals. "Janet Jackson's 2004 'wardrobe malfunction' remains far more significant in the history of broadcast regulation than Orson Welles' trickery," wrote Pooley and Socolow.


text: H. G. Wells and Orson Welles met for the first and only time in late October 1940, shortly before the second anniversary of the "Mercury Theatre" broadcast, when they were both lecturing in San Antonio, Texas. On October 28, 1940, the two men visited the KTSA studio for an interview by Charles C. Shaw, who introduced them by characterizing the panic generated by "The War of the Worlds".


text: Wells was skeptic about the actual extent of the panic caused by "this sensational Halloween spree", saying: "Are you sure there was such a panic in America or wasn't it your Halloween fun?" Welles replied that "[i]t's supposed to show the corrupt condition and decadent state of affairs in democracy, that 'The War of the Worlds' went over as well as it did."


text: When Shaw mentioned that there was "some excitement" that he did not wish to belittle, Welles replied, "What kind of excitement? Mr. H. G. Wells wants to know if the excitement wasn't the same kind of excitement that we extract from a practical joke in which somebody puts a sheet over his head and says 'Boo!' I don't think anybody believes that that individual is a ghost, but we do scream and yell and rush down the hall. And that's just about what happened."


text: As the Mercury Theatre's second season began in 1938, Welles and Houseman were unable to write the "Mercury Theatre on the Air" broadcasts by themselves. They hired Koch, whose experience in having a play performed by the Federal Theatre Project in Chicago led him to leave his law practice and move to New York to become a writer. Koch was put to work at $50 a week, raised to $60 after he proved himself. "The Mercury Theatre on the Air" was a sustaining show, so in lieu of a more substantial salary, Houseman gave Koch the rights to any script he worked on.


text: A condensed version of the script for "The War of the Worlds" appeared in the debut issue of "Radio Digest" magazine (February 1939), in an article on the broadcast that credited "Orson Welles and his Mercury Theatre players". The complete script appeared in "The Invasion from Mars: A Study in the Psychology of Panic" (1940), the book publication of a Princeton University study directed by Cantril. Welles strongly protested Koch being listed as sole author since many others contributed to the script, but by the time the book was published, he had decided to end the dispute.


text: Welles sought legal redress after the CBS TV series "Studio One" presented its top-rated broadcast, "The Night America Trembled", on September 9, 1957. The live presentation of Nelson S. Bond's documentary play recreated the 1938 performance of "The War of the Worlds" in the CBS studio, using the script as a framework for a series of factual narratives about a cross-section of radio listeners. No member of the "Mercury Theatre" was named. The courts ruled against Welles, who was found to have abandoned any rights to the script after it was published in Cantril's book. Koch had granted CBS the right to use the script in its program.


text: "As it developed over the years, Koch took some cash and some credit," wrote biographer Frank Brady. "He wrote the story of how he created the adaptation, with a copy of his script being made into a paperback book enjoying large printings and an album of the broadcast selling over 500,000 copies, part of the income also going to him as copyright owner." Since his death in 1995, Koch's family has received royalties from adaptations or broadcasts.


text: The book, "The Panic Broadcast", was first published in 1970. The best-selling album was a sound recording of the broadcast titled "Orson Welles' War of the Worlds", "released by arrangement with Manheim Fox Enterprises, Inc." The source discs for the recording are unknown. Welles told Peter Bogdanovich that it was a poor-quality recording taken off the air at the time of broadcast – "a pirated record which people have made fortunes of money and have no right to play". Welles did not receive any compensation.


text: Initially apologetic about the supposed panic his broadcast had caused, and privately fuming that newspaper reports of lawsuits were either greatly exaggerated or totally fabricated, Welles later embraced the story as part of his personal myth: "Houses were emptying, churches were filling up; from Nashville to Minneapolis there was wailing in the streets and the rending of garments," he told Bogdanovich.


text: CBS also found reports ultimately useful in promoting the strength of its influence. It presented a fictionalized account of the panic in "The Night America Trembled", and included it prominently in its 2003 celebrations of CBS's 75th anniversary as a television broadcaster. "The legend of the panic," according to Jefferson and Socolow, "grew exponentially over the following years ... [It] persists because it so perfectly captures our unease with the media's power over our lives."


text: In 1975, ABC aired the television movie "The Night That Panicked America", depicting the effect the radio drama had on the public using fictional, but typical American families of the time.


text: West Windsor, New Jersey, where Grover's Mill is located, commemorated the 50th anniversary of the broadcast in 1988 with four days of festivities including art and planetarium shows, a panel discussion, a parade, burial of a time capsule, a dinner dance, film festivals devoted to H. G. Wells and Orson Welles, and the dedication of a bronze monument to the fictional Martian landings. Koch attended the 49th anniversary celebration as an honored guest.


text: The 75th anniversary of "The War of the Worlds" was marked by an episode of the PBS documentary series "American Experience".


text: Welles and "Mercury Theatre on the Air" were inducted into the Radio Hall of Fame in 1988. On January 27, 2003, "The War of the Worlds" was selected as one of the first 50 recordings to be added to the National Recording Registry of the Library of Congress. At the 72nd World Science Fiction Convention in August 2014, a Retrospective Hugo Award for "Best Dramatic Presentation, Short Form – 1938" was bestowed upon the broadcast.


text: Since the original "Mercury Theatre on the Air" broadcast of "The War of the Worlds", many re-airings, remakes, re-enactments, parodies, and new dramatizations have occurred. Many American radio stations, particularly those that regularly air old-time radio programs, re-air the original program as a Halloween tradition.


text: The first Spanish language version was produced and aired on November 12, 1944, by William Steele, and Raúl Zenteno in Radio Cooperativa Vitalicia, a radio station in Santiago, Chile. Even though the fictional nature of the drama was reported twice during the broadcast and once again in the end, "Newsweek" reported that an electrician named José Villaroel was so frightened that he died of a heart attack.


text: A second Spanish-language version produced in February 1949 by Leonardo Páez and Eduardo Alcaraz for Radio Quito in Quito, Ecuador, reportedly set off panic in the city. Police and fire brigades rushed out of town to engage the supposed alien invasion force. After it was revealed that the broadcast was fiction, the panic transformed into a riot. Hundreds of people attacked Radio Quito and "El Comercio", a local newspaper owner of the radio station that had participated in the hoax by publishing false reports of unidentified objects in the skies above Ecuador in the days preceding the broadcast. The riot resulted in at least seven deaths, including those of Paez's girlfriend and nephew. Radio Quito was off the air for two years until 1951. After the incident, Paez self-exiled to Venezuela, where he lived in Mérida until his death in 1991.


text: An updated version of the radio drama aired several times between 1968 and 1975 on WKBW radio in Buffalo, New York.


text: A Brazilian Portuguese version was aired in October 1971, by Rádio Difusora, from the Northeast state of Maranhão. This version remained faithful to Welles' adaptation, changing several American cities names to Brazilian state capitals. Also, foreign cities such as Los Angeles and Chicago were reported as engulfed by a poisonous smoke after several cylinders have fallen and tripods were defeating all human resistance.


text: During the transmission, the director of the radio station (also performing) proceeded to explain that many of the station employees were allowed to go home and join their families, but his speech is frequently interrupted by strange noises, which he explains as being result of a worldwide radio interference that was disturbing all transmissions on Earth (presumably caused by Martian machines).


text: Finally, a street reporter announces that gigantic machines were crossing Rio de Janeiro, before the city is algo attacked by the poison fog. Like in 1938, some listeners took the broadcast for a real news bulletin and shortly after, the Army (the event took place during Brazilian military dictatorship) shut down the radio station, only allowing it back on the air a few days later.


text: On the 50th anniversary of the radio play, on October 30, 1988, a remake was aired by WGBH and picked up by 150 National Public Radio stations. It was nominated for a Grammy Award for Best Spoken Word or Nonmusical Recording.


text: In 1994, L.A. Theatre Works and Pasadena, California, public radio station KPCC broadcast the original play before a live audience. Most of the cast for this production had appeared in one or more incarnations of "Star Trek", including Leonard Nimoy, John de Lancie, Dwight Schultz, Wil Wheaton, Gates McFadden, Brent Spiner, Armin Shimerman, Jerry Hardin, and Tom Virtue. It was accompanied by an original sequel called "When Welles Collide", co-written by de Lancie and Nat Segaloff featuring the same cast as themselves.


text: On October 30, 2002, XM Satellite Radio collaborated with conservative talk-show host Glenn Beck for a live recreation of the broadcast, using Koch's original script and airing on the Buzz XM channel, as well as on Beck's 100 AM/FM affiliates. In 2003, the parties were sued for copyright infringement by Koch's widow, but settled under undisclosed terms.


text: On October 30, 2013, KPCC re-aired the show, introduced by George Takei with a documentary on the 1938 radio show's production.


text: On November 12, 2017, a new opera based on "War of the Worlds" premiered at Walt Disney Concert Hall and outdoors in Los Angeles. The music was composed by Annie Gosfield, commissioned by the Los Angeles Philharmonic, directed by Yuval Sharon, and narrated by Sigourney Weaver.


title: Drosophila melanogaster

text: Drosophila melanogaster is a species of fly (the taxonomic order Diptera) in the family Drosophilidae. The species is often referred to as the fruit fly or lesser fruit fly, or less commonly the "vinegar fly" or "pomace fly". Starting with Charles W. Woodworth's 1901 proposal of the use of this species as a model organism, "D. melanogaster" continues to be widely used for biological research in genetics, physiology, microbial pathogenesis, and life history evolution. As of 2017, five Nobel Prizes have been awarded to drosophilists for their work using the insect.


title: Drosophila melanogaster

text: "D. melanogaster" is typically used in research owing to its rapid life cycle, relatively simple genetics with only four pairs of chromosomes, and large number of offspring per generation. It was originally an African species, with all non-African lineages having a common origin. Its geographic range includes all continents, including islands. "D. melanogaster" is a common pest in homes, restaurants, and other places where food is served.


title: Drosophila melanogaster

text: Flies belonging to the family Tephritidae are also called "fruit flies". This can cause confusion, especially in the Mediterranean, Australia, and South Africa, where the Mediterranean fruit fly "Ceratitis capitata" is an economic pest.


title: Drosophila melanogaster

text: Wild type fruit flies are yellow-brown, with brick-red eyes and transverse black rings across the abdomen. The brick-red color of the eyes of the wild type fly are due to two pigments: xanthommatin, which is brown and is derived from tryptophan, and drosopterins, which are red and are derived from guanosine triphosphate. They exhibit sexual dimorphism; females are about long; males are slightly smaller with darker backs. Males are easily distinguished from females based on colour differences, with a distinct black patch at the abdomen, less noticeable in recently emerged flies, and the sexcombs (a row of dark bristles on the tarsus of the first leg). Furthermore, males have a cluster of spiky hairs (claspers) surrounding the reproducing parts used to attach to the female during mating. Extensive images are found at FlyBase. "Drosophila melanogaster" flies can sense air currents with the hairs on their backs. Their eyes are sensitive to slight differences in light intensity and will instinctively fly away when a shadow or other movement is detected.


title: Drosophila melanogaster

text: Under optimal growth conditions at , the "D. melanogaster" lifespan is about 50 days from egg to death. The developmental period for "D. melanogaster" varies with temperature, as with many ectothermic species. The shortest development time (egg to adult), 7 days, is achieved at . Development times decrease at higher temperatures (11 days at ) due to heat stress. Under ideal conditions, the development time at is 8.5 days, at it takes 19 days and at it takes over 50 days. Under crowded conditions, development time increases, while the emerging flies are smaller. Females lay some 400 eggs (embryos), about five at a time, into rotting fruit or other suitable material such as decaying mushrooms and sap fluxes. "Drosophila melanogaster" is a holometabolous insect, so it undergoes a full metamorphosis. Their life cycle is broken down into 4 stages: embryo, larva, pupa, adult. The eggs, which are about 0.5 mm long, hatch after 12–15 hours (at ). The resulting larvae grow for about 4 days (at 25 °C) while molting twice (into second- and third-instar larvae), at about 24 and 48 h after hatching. During this time, they feed on the microorganisms that decompose the fruit, as well as on the sugar of the fruit itself. The mother puts feces on the egg sacs to establish the same microbial composition in the larvae's guts that has worked positively for herself. Then the larvae encapsulate in the puparium and undergo a 4-day-long metamorphosis (at 25 °C), after which the adults eclose (emerge).


title: Drosophila melanogaster

text: Males perform a sequence of five behavioral patterns to court females. First, males orient themselves while playing a courtship song by horizontally extending and vibrating their wings. Soon after, the male positions himself at the rear of the female's abdomen in a low posture to tap and lick the female genitalia. Finally, the male curls his abdomen and attempts copulation. Females can reject males by moving away, kicking, and extruding their ovipositor. Copulation lasts around 15–20 minutes, during which males transfer a few hundred, very long (1.76 mm) sperm cells in seminal fluid to the female. Females store the sperm in a tubular receptacle and in two mushroom-shaped spermathecae; sperm from multiple matings compete for fertilization. A last male precedence is believed to exist; the last male to mate with a female sires about 80% of her offspring. This precedence was found to occur through both displacement and incapacitation. The displacement is attributed to sperm handling by the female fly as multiple matings are conducted and is most significant during the first 1–2 days after copulation. Displacement from the seminal receptacle is more significant than displacement from the spermathecae. Incapacitation of first male sperm by second male sperm becomes significant 2–7 days after copulation. The seminal fluid of the second male is believed to be responsible for this incapacitation mechanism (without removal of first male sperm) which takes effect before fertilization occurs. The delay in effectiveness of the incapacitation mechanism is believed to be a protective mechanism that prevents a male fly from incapacitating his own sperm should he mate with the same female fly repetitively. Sensory neurons in the uterus of female "D. melanogaster" respond to a male protein, sex peptide, which is found in semen. This protein makes the female reluctant to copulate for about 10 days after insemination. The signal pathway leading to this change in behavior has been determined. The signal is sent to a brain region that is a homolog of the hypothalamus and the hypothalamus then controls sexual behavior and desire. Gonadotropic hormones in Drosophila maintain homeostasis and govern reproductive output via a cyclic interrelationship, not unlike the mammalian estrous cycle. Sex peptide perturbs this homeostasis and dramatically shifts the endocrine state of the female by inciting juvenile hormone synthesis in the corpus allatum.


title: Drosophila melanogaster

text: "D. melanogaster" is often used for life extension studies, such as to identify genes purported to increase lifespan when mutated. "D. melanogaster" is also used in studies of aging. Werner syndrome is a condition in humans characterized by accelerated aging. It is caused by mutations in the gene WRN that encodes a protein with essential roles in repair of DNA damage. Mutations in the "D. melanogaster" homolog of "WRN" also cause increased physiologic signs of aging, such as shorter lifespan, higher tumor incidence, muscle degeneration, reduced climbing ability, altered behavior and reduced locomotor activity.


title: Drosophila melanogaster

text: Females become receptive to courting males about 8–12 hours after emergence. Specific neuron groups in females have been found to affect copulation behavior and mate choice. One such group in the abdominal nerve cord allows the female fly to pause her body movements to copulate. Activation of these neurons induces the female to cease movement and orient herself towards the male to allow for mounting. If the group is inactivated, the female remains in motion and does not copulate. Various chemical signals such as male pheromones often are able to activate the group.


title: Drosophila melanogaster

text: Also, females exhibit mate choice copying. When virgin females are shown other females copulating with a certain type of male, they tend to copulate more with this type of male afterwards than naive females (which have not observed the copulation of others). This behavior is sensitive to environmental conditions, and females copulate less in bad weather conditions.


title: Drosophila melanogaster

text: "D. melanogaster" males exhibit a strong reproductive learning curve. That is, with sexual experience, these flies tend to modify their future mating behavior in multiple ways. These changes include increased selectivity for courting only intraspecifically, as well as decreased courtship times.


title: Drosophila melanogaster

text: Sexually naïve "D. melanogaster" males are known to spend significant time courting interspecifically, such as with "D. simulans" flies. Naïve "D. melanogaster" will also attempt to court females that are not yet sexually mature, and other males. "D. melanogaster" males show little to no preference for "D. melanogaster" females over females of other species or even other male flies. However, after "D. simulans" or other flies incapable of copulation have rejected the males' advances, "D. melanogaster" males are much less likely to spend time courting nonspecifically in the future. This apparent learned behavior modification seems to be evolutionarily significant, as it allows the males to avoid investing energy into futile sexual encounters.


title: Drosophila melanogaster

text: In addition, males with previous sexual experience modify their courtship dance when attempting to mate with new females—the experienced males spend less time courting, so have lower mating latencies, meaning that they are able to reproduce more quickly. This decreased mating latency leads to a greater mating efficiency for experienced males over naïve males. This modification also appears to have obvious evolutionary advantages, as increased mating efficiency is extremely important in the eyes of natural selection.


title: Drosophila melanogaster

text: Both male and female "D. melanogaster" flies act polygamously (having multiple sexual partners at the same time). In both males and females, polygamy results in a decrease in evening activity compared to virgin flies, more so in males than females. Evening activity consists of those in which the flies participate other than mating and finding partners, such as finding food. The reproductive success of males and females varies, because a female only needs to mate once to reach maximum fertility. Mating with multiple partners provides no advantage over mating with one partner, so females exhibit no difference in evening activity between polygamous and monogamous individuals. For males, however, mating with multiple partners increases their reproductive success by increasing the genetic diversity of their offspring. This benefit of genetic diversity is an evolutionary advantage because it increases the chance that some of the offspring will have traits that increase their fitness in their environment.


title: Drosophila melanogaster

text: The difference in evening activity between polygamous and monogamous male flies can be explained with courtship. For polygamous flies, their reproductive success increases by having offspring with multiple partners, and therefore they spend more time and energy on courting multiple females. On the other hand, monogamous flies only court one female, and expend less energy doing so. While it requires more energy for male flies to court multiple females, the overall reproductive benefits it produces has kept polygamy as the preferred sexual choice.


title: Drosophila melanogaster

text: The mechanism that affects courtship behavior in" Drosophila" is controlled by the oscillator neurons DN1s and LNDs. Oscillation of the DN1 neurons was found to be effected by sociosexual interactions, and is connected to mating-related decrease of evening activity.


title: Drosophila melanogaster

text: "D. melanogaster" remains one of the most studied organisms in biological research, particularly in genetics and developmental biology. It is also employed in studies of environmental mutagenesis.


title: Drosophila melanogaster

text: "D. melanogaster" was among the first organisms used for genetic analysis, and today it is one of the most widely used and genetically best-known of all eukaryotic organisms. All organisms use common genetic systems; therefore, comprehending processes such as transcription and replication in fruit flies helps in understanding these processes in other eukaryotes, including humans.


title: Drosophila melanogaster

text: Thomas Hunt Morgan began using fruit flies in experimental studies of heredity at Columbia University in 1910 in a laboratory known as the Fly Room. The Fly Room was cramped with eight desks, each occupied by students and their experiments. They started off experiments using milk bottles to rear the fruit flies and handheld lenses for observing their traits. The lenses were later replaced by microscopes, which enhanced their observations. Morgan and his students eventually elucidated many basic principles of heredity, including sex-linked inheritance, epistasis, multiple alleles, and gene mapping.


title: Drosophila melanogaster

text: "D. melanogaster" had historically been used in laboratories to study genetics and patterns of inheritance. However, "D. melanogaster" also has importance in environmental mutagenesis research, allowing researchers to study the effects of specific environmental mutagens.


title: Drosophila melanogaster

text: Genetic markers are commonly used in "Drosophila" research, for example within balancer chromosomes or P-element inserts, and most phenotypes are easily identifiable either with the naked eye or under a microscope. In the list of a few common markers below, the allele symbol is followed by the name of the gene affected and a description of its phenotype. "(Note: Recessive alleles are in lower case, while dominant alleles are capitalised.)"


title: Drosophila melanogaster

text: "Drosophila" genes are traditionally named after the phenotype they cause when mutated. For example, the absence of a particular gene in "Drosophila" will result in a mutant embryo that does not develop a heart. Scientists have thus called this gene "tinman", named after the Oz character of the same name. Likewise changes in the "Shavenbaby" gene cause the loss of dorsal cuticular hairs in "Drosophila sechellia" larvae. This system of nomenclature results in a wider range of gene names than in other organisms.


title: Drosophila melanogaster

text: The genome of "D. melanogaster" (sequenced in 2000, and curated at the FlyBase database) contains four pairs of chromosomes – an X/Y pair, and three autosomes labeled 2, 3, and 4. The fourth chromosome is relatively very small and therefore often ignored, aside from its important "eyeless" gene. The "D. melanogaster" sequenced genome of 139.5 million base pairs has been annotated and contains around 15,682 genes according to Ensemble release 73. More than 60% of the genome appears to be functional non-protein-coding DNA involved in gene expression control. Determination of sex in "Drosophila" occurs by the of X chromosomes to autosomes, not because of the presence of a Y chromosome as in human sex determination. Although the Y chromosome is entirely heterochromatic, it contains at least 16 genes, many of which are thought to have male-related functions.


title: Drosophila melanogaster

text: There are three transferrin orthologs, all of which are dramatically divergent from those known in chordate models.


title: Drosophila melanogaster

text: A March 2000 study by National Human Genome Research Institute comparing the fruit fly and human genome estimated that about 60% of genes are conserved between the two species. About 75% of known human disease genes have a recognizable match in the genome of fruit flies, and 50% of fly protein sequences have mammalian homologs . An online database called "Homophila" is available to search for human disease gene homologues in flies and vice versa.


title: Drosophila melanogaster

text: "Drosophila" is being used as a genetic model for several human diseases including the neurodegenerative disorders Parkinson's, Huntington's, spinocerebellar ataxia and Alzheimer's disease. The fly is also being used to study mechanisms underlying aging and oxidative stress, immunity, diabetes, and cancer, as well as drug abuse.


title: Drosophila melanogaster

text: "Drosophila" is one of the few animals ("C. elegans" being another) where detailed neural circuits (a connectome) are available.


title: Drosophila melanogaster

text: A high-level connectome, at the level of brain compartments and interconnecting tracts of neurons, exists for the full fly brain. A version of this is available online.


title: Drosophila melanogaster

text: Detailed circuit-level connectomes exist for the lamina and a medulla column, both in the visual system of the fruit fly, and the alpha lobe of the mushroom body.


title: Drosophila melanogaster

text: In May 2017 a paper published in bioRxiv presented an electron microscopy image stack of the whole adult female brain at synaptic resolution. The volume is available for sparse tracing of selected circuits.


title: Drosophila melanogaster

text: In 2020, a dense connectome of half the central brain of "Drosophila" was released, along with a web site that allows queries and exploration of this data. The methods used in reconstruction and initial analysis of the connectome followed.


title: Drosophila melanogaster

text: Embryogenesis in "Drosophila" has been extensively studied, as its small size, short generation time, and large brood size makes it ideal for genetic studies. It is also unique among model organisms in that cleavage occurs in a syncytium.


title: Drosophila melanogaster

text: During oogenesis, cytoplasmic bridges called "ring canals" connect the forming oocyte to nurse cells. Nutrients and developmental control molecules move from the nurse cells into the oocyte. In the figure to the left, the forming oocyte can be seen to be covered by follicular support cells.


title: Drosophila melanogaster

text: After fertilization of the oocyte, the early embryo (or syncytial embryo) undergoes rapid DNA replication and 13 nuclear divisions until about 5000 to 6000 nuclei accumulate in the unseparated cytoplasm of the embryo. By the end of the eighth division, most nuclei have migrated to the surface, surrounding the yolk sac (leaving behind only a few nuclei, which will become the yolk nuclei). After the 10th division, the pole cells form at the posterior end of the embryo, segregating the germ line from the syncytium. Finally, after the 13th division, cell membranes slowly invaginate, dividing the syncytium into individual somatic cells. Once this process is completed, gastrulation starts.


title: Drosophila melanogaster

text: Nuclear division in the early "Drosophila" embryo happens so quickly, no proper checkpoints exist, so mistakes may be made in division of the DNA. To get around this problem, the nuclei that have made a mistake detach from their centrosomes and fall into the centre of the embryo (yolk sac), which will not form part of the fly.


title: Drosophila melanogaster

text: The gene network (transcriptional and protein interactions) governing the early development of the fruit fly embryo is one of the best understood gene networks to date, especially the patterning along the anteroposterior (AP) and dorsoventral (DV) axes (See under morphogenesis).


title: Drosophila melanogaster

text: The embryo undergoes well-characterized morphogenetic movements during gastrulation and early development, including germ-band extension, formation of several furrows, ventral invagination of the mesoderm, and posterior and anterior invagination of endoderm (gut), as well as extensive body segmentation until finally hatching from the surrounding cuticle into a first-instar larva.


title: Drosophila melanogaster

text: During larval development, tissues known as imaginal discs grow inside the larva. Imaginal discs develop to form most structures of the adult body, such as the head, legs, wings, thorax, and genitalia. Cells of the imaginal disks are set aside during embryogenesis and continue to grow and divide during the larval stages—unlike most other cells of the larva, which have differentiated to perform specialized functions and grow without further cell division. At metamorphosis, the larva forms a pupa, inside which the larval tissues are reabsorbed and the imaginal tissues undergo extensive morphogenetic movements to form adult structures.


title: Drosophila melanogaster

text: Biotic and abiotic factors experienced during development will affect developmental resource allocation leading to phenotypic variation, also referred to as developmental plasticity. As in all insects, environmental factors can influence several aspects of development in "Drosophila melanogaster". Fruit flies reared under a hypoxia treatment experience decreased thorax length, while hyperoxia produces smaller flight muscles, suggesting negative developmental effects of extreme oxygen levels. Circadian rhythms are also subject to developmental plasticity. Light conditions during development affect daily activity patterns in "Drosophila melanogaster", where flies raised under constant dark or light are less active as adults than those raised under a 12-hour light/dark cycle.


title: Drosophila melanogaster

text: Temperature is one of the most pervasive factors influencing arthropod development. In "Drosophila melanogaster" temperature-induced developmental plasticity can be beneficial and/or detrimental. Most often lower developmental temperatures reduce growth rates which influence many other physiological factors. For example, development at 25 °C increases walking speed, thermal performance breadth, and territorial success, while development at 18 °C increases body mass, wing size, all of which are tied to fitness. Moreover, developing at certain low temperatures produces proportionally large wings which improve flight and reproductive performance at similarly low temperatures ("See" acclimation).


title: Drosophila melanogaster

text: While certain effects of developmental temperature, like body size, are irreversible in ectotherms, others can be reversible. When "Drosophila melanogaster" develop at cold temperatures they will have greater cold tolerance, but if cold-reared flies are maintained at warmer temperatures their cold tolerance decreases and heat tolerance increases over time. Because insects typically only mate in a specific range of temperatures, their cold/heat tolerance is an important trait in maximizing reproductive output.


title: Drosophila melanogaster

text: While the traits described above are expected to manifest similarly across sexes, developmental temperature can also produce sex-specific effects in "D. melanogaster" adults.


title: Drosophila melanogaster

text: "Drosophila" flies have both X and Y chromosomes, as well as autosomes. Unlike humans, the Y chromosome does not confer maleness; rather, it encodes genes necessary for making sperm. Sex is instead determined by the ratio of X chromosomes to autosomes. Furthermore, each cell "decides" whether to be male or female independently of the rest of the organism, resulting in the occasional occurrence of gynandromorphs.


title: Drosophila melanogaster

text: Three major genes are involved in determination of "Drosophila" sex. These are "sex-lethal, sisterless", and "deadpan". Deadpan is an autosomal gene which inhibits "sex-lethal", while "sisterless" is carried on the X chromosome and inhibits the action of "deadpan". An AAX cell has twice as much "deadpan" as "sisterless", so "sex-lethal" will be inhibited, creating a male. However, an AAXX cell will produce enough "sisterless" to inhibit the action of "deadpan", allowing the "sex-lethal" gene to be transcribed to create a female.


title: Drosophila melanogaster

text: Later, control by "deadpan" and "sisterless" disappears and what becomes important is the form of the "sex-lethal" gene. A secondary promoter causes transcription in both males and females. Analysis of the cDNA has shown that different forms are expressed in males and females. "Sex-lethal" has been shown to affect the splicing of its own mRNA. In males, the third exon is included which encodes a stop codon, causing a truncated form to be produced. In the female version, the presence of "sex-lethal" causes this exon to be missed out; the other seven amino acids are produced as a full peptide chain, again giving a difference between males and females.


title: Drosophila melanogaster

text: Presence or absence of functional sex-lethal proteins now go on to affect the transcription of another protein known as doublesex. In the absence of sex-lethal, doublesex will have the fourth exon removed and be translated up to and including exon 6 (DSX-M[ale]), while in its presence the fourth exon which encodes a stop codon will produce a truncated version of the protein (DSX-F[emale]). DSX-F causes transcription of Yolk proteins 1 and 2 in somatic cells, which will be pumped into the oocyte on its production.


title: Drosophila melanogaster

text: The "D. melanogaster" immune system can be divided into two responses: humoral and cell-mediated. The former is a systemic response mediated in large part through the "toll" and "Imd" pathways, which are parallel systems for detecting microbes. Other pathways including the stress response pathways JAK-STAT and P38, nutritional signalling via FOXO, and JNK cell death signalling are all involved in key physiological responses to infection. "D. melanogaster" has an organ called the "fat body", which is analogous to the human liver. The fat body is the primary secretory organ and produces key immune molecules upon infection, such as serine proteases and antimicrobial peptides (AMPs). AMPs are secreted into the hemolymph and bind infectious bacteria and fungi, killing them by forming pores in their cell walls or inhibiting intracellular processes. The cellular immune response instead refers to the direct activity of blood cells (hemocytes) in "Drosophila", which are analogous to mammalian monocytes/macrophages. Hemocytes also possess a significant role in mediating humoral immune responses such as the melanization reaction.


title: Drosophila melanogaster

text: The immune response to infection can involve up to 2,423 genes, or 13.7% of the genome. Although the fly's transcriptional response to microbial challenge is highly specific to individual pathogens, "Drosophila" differentially expresses a core group of 252 genes upon infection with most bacteria. This core group of genes is associated with gene ontology categories such as antimicrobial response, stress response, secretion, neuron-like, reproduction, and metabolism among others. "Drosophila" also possesses several immune mechanisms to both shape the microbiota and prevent excessive immune responses upon detection of microbial stimuli. For instance, secreted PGRPs with amidase activity scavenge and degrade immunostimulatory DAP-type PGN in order to block Imd activation.


title: Drosophila melanogaster

text: Unlike mammals, "Drosophila" have innate immunity but lack an adaptive immune response. However, the core elements of this innate immune response are conserved between humans and fruit flies. As a result, the fruit fly offers a useful model of innate immunity for disentangling genetic interactions of signalling and effector function, as flies do not have to contend with interference of adaptive immune mechanisms that could confuse results. Various genetic tools, protocols, and assays make "Drosophila" a classical model for studying the innate immune system, which has even included immune research on the international space station.


title: Drosophila melanogaster

text: The first description of toll-like receptors involved in the response to infection was performed in "Drosophila," culminating in a Nobel prize in 2011. The toll pathway in "Drosophila" is homologous to toll-like pathways in mammals. This regulatory cascade is initiated following pathogen recognition by pattern recognition receptors, particularly of Gram-positive bacteria, parasites, and fungal infection. This activation leads to serine protease signalling cascades ultimately activating the cytokine spätzle. Alternatively, microbial proteases can directly cleave serine proteases like Persephone that then propagate signalling. The cytokine spätzle then acts as the ligand for the toll pathway in flies. Upon infection, pro-spätzle is cleaved by the protease SPE () to become active spätzle, which binds to the toll receptor located on the cell surface of the fat body and dimerizes for activation of downstream NF-κB signaling pathways, including multiple death domain containing proteins and negative regulators such as the ankyrin repeat protein Cactus. The pathway culminates with the translocation of the NF-κB transcription factors Dorsal and Dif (Dorsal-related immunity factor) into the nucleus. Dudzic et al. find a large number of shared serine protease messengers and crosstalk between this pathway and immunity-related melanization pathways.


title: Drosophila melanogaster

text: The toll pathway was identified by its regulation of antimicrobial peptides (AMPs), including the antifungal peptide drosomycin. Upon infection, AMPs increase in expression sometimes by 1,000-fold, providing unmistakable readouts of pathway activation. Another group of toll-regulated AMP-like effectors includes the Bomanins, which appear to be responsible for the bulk of toll-mediated immune defence, however Bomanins alone do not exhibit antimicrobial activity.


title: Drosophila melanogaster

text: It has been proposed that a second SPE-like enzyme similarly acts to activate spätzle, as loss of SPE does not completely reduce the activity of toll signalling, however no second SPE has yet been identified. A number of serine proteases are yet to be characterized, including many with homology to SPE. The toll pathway also interacts with renal filtration of microbiota-derived peptidoglycan, maintaining immune homeostasis. Mechanistically, nephrocytes endocytose Lys-type PGN from systemic circulation and route it to lysosomes for degradation. Without this, toll signalling is constitutively activated, resulting in a severe drain on nutrient reserves and a significant stress on host physiology.


title: Drosophila melanogaster

text: The Imd pathway is orthologous to human TNF receptor superfamily signalling, and is triggered by Gram-negative bacteria through recognition by peptidoglycan recognition proteins (PGRP) including both soluble receptors and cell surface receptors (PGRP-LE and LC, respectively). Imd signalling culminates in the translocation of the NF-κB transcription factor Relish into the nucleus, leading to the upregulation of Imd-responsive genes including the AMP Diptericin. Consequently, flies deficient for AMPs resemble Imd pathway mutants in terms of susceptibility to bacterial infection. Imd signalling and Relish specifically are also involved in the regulation of immunity at surface epithelia including in the gut and respiratory tracts.


title: Drosophila melanogaster

text: The Relish transcription factor has also been implicated in processes regarding cell proliferation and neurodegeneration either through autophagy, or autoimmune toxicity. In neurodegenerative models relying on Imd signalling, expression of AMPs in the brain is correlated with brain tissue damage, lesions, and ultimately death. Relish-regulated AMPs such as Defensin and Diptericin also have anti-cancer properties promoting tumour clearance. The Imd-regulated AMP Diptericin B is also produced by the fat body specifically in the head, and Diptericin B is required for long-term memory formation.


title: Drosophila melanogaster

text: Multiple elements of the "Drosophila" JAK-STAT signalling pathway bear direct homology to human JAK-STAT pathway genes. JAK-STAT signalling is induced upon various organismal stresses such as heat stress, dehydration, or infection. JAK-STAT induction leads to the production of a number of stress response proteins including Thioester-containing proteins (TEPs), Turandots, and the putative antimicrobial peptide Listericin. The mechanisms through which many of these proteins act is still under investigation. For instance, the TEPs appear to promote phagocytosis of Gram-positive bacteria and the induction of the toll pathway. As a consequence, flies lacking TEPs are susceptible to infection by toll pathway challenges.


title: Drosophila melanogaster

text: Circulating hemocytes are key regulators of infection. This has been demonstrated both through genetic tools to generate flies lacking hemocytes, or through injecting microglass beads or lipid droplets that saturate hemocyte ability to phagocytose a secondary infection. Flies treated like this fail to phagocytose bacteria upon infection, and are correspondingly susceptible to infection. These hemocytes derive from two waves of hematopoiesis, one occurring in the early embryo and one occurring during development from larva to adult. However Drosophila hemocytes do not renew over the adult lifespan, and so the fly has a finite number of hemocytes that decrease over the course of its lifespan. Hemocytes are also involved in regulating cell-cycle events and apoptosis of aberrant tissue (e.g. cancerous cells) by producing Eiger, a tumor necrosis factor signalling molecule that promotes JNK signalling and ultimately cell death and apoptosis.


title: Drosophila melanogaster

text: In 1971, Ron Konopka and Seymour Benzer published "Clock mutants of "Drosophila melanogaster"", a paper describing the first mutations that affected an animal's behavior. Wild-type flies show an activity rhythm with a frequency of about a day (24 hours). They found mutants with faster and slower rhythms, as well as broken rhythms—flies that move and rest in random spurts. Work over the following 30 years has shown that these mutations (and others like them) affect a group of genes and their products that form a biochemical or biological clock. This clock is found in a wide range of fly cells, but the clock-bearing cells that control activity are several dozen neurons in the fly's central brain.


title: Drosophila melanogaster

text: Since then, Benzer and others have used behavioral screens to isolate genes involved in vision, olfaction, audition, learning/memory, courtship, pain, and other processes, such as longevity.


title: Drosophila melanogaster

text: Following the pioneering work of Alfred Henry Sturtevant and others, Benzer and colleagues used sexual mosaics to develop a novel fate mapping technique. This technique made it possible to assign a particular characteristic to a specific anatomical location. For example, this technique showed that male courtship behavior is controlled by the brain. Mosaic fate mapping also provided the first indication of the existence of pheromones in this species. Males distinguish between conspecific males and females and direct persistent courtship preferentially toward females thanks to a female-specific sex pheromone which is mostly produced by the female's tergites.


title: Drosophila melanogaster

text: The first learning and memory mutants ("dunce", "rutabaga", etc.) were isolated by William "Chip" Quinn while in Benzer's lab, and were eventually shown to encode components of an intracellular signaling pathway involving cyclic AMP, protein kinase A, and a transcription factor known as CREB. These molecules were shown to be also involved in synaptic plasticity in "Aplysia" and mammals.


title: Drosophila melanogaster

text: The Nobel Prize in Physiology or Medicine for 2017 was awarded to Jeffrey C. Hall, Michael Rosbash, Michael W. Young for their works using fruit flies in understanding the "molecular mechanisms controlling the circadian rhythm".


title: Drosophila melanogaster

text: Male flies sing to the females during courtship using their wings to generate sound, and some of the genetics of sexual behavior have been characterized. In particular, the "fruitless" gene has several different splice forms, and male flies expressing female splice forms have female-like behavior and vice versa. The TRP channels nompC, nanchung, and inactive are expressed in sound-sensitive Johnston's organ neurons and participate in the transduction of sound. Mutating the Genderblind gene, also known as CG6070, alters the sexual behavior of "Drosophila", turning the flies bisexual.


title: Drosophila melanogaster

text: Flies use a modified version of Bloom filters to detect novelty of odors, with additional features including similarity of novel odor to that of previously experienced examples, and time elapsed since previous experience of the same odor.


title: Drosophila melanogaster

text: As with most insects, aggressive behaviors between male flies commonly occur in the presence of courting a female and when competing for resources. Such behaviors often involve raising wings and legs towards the opponent and attacking with the whole body. Thus, it often causes wing damage, which reduces their fitness by removing their ability to fly and mate.


title: Drosophila melanogaster

text: In order for aggression to occur, male flies produce sounds to communicate their intent. A 2017 study found that songs promoting aggression contain pulses occurring at longer intervals. RNA sequencing from fly mutants displaying over-aggressive behaviors found more than 50 auditory-related genes (important for transient receptor potentials, Ca signaling, and mechanoreceptor potentials) to be upregulated in the AB neurons located in Johnston's organ. In addition, aggression levels were reduced when these genes were knocked out via RNA interference. This signifies the major role of hearing as a sensory modality in communicating aggression.


title: Drosophila melanogaster

text: Other than hearing, another sensory modality that regulates aggression is pheromone signaling, which operates through either the olfactory system or the gustatory system depending on the pheromone. An example is cVA, an anti-aphrodisiac pheromone used by males to mark females after copulation and to deter other males from mating. This male-specific pheromone causes an increase in male-male aggression when detected by another male's gustatory system. However, upon inserting a mutation that makes the flies irresponsive to cVA, no aggressive behaviors were seen. This shows how there are multiple modalities for promoting aggression in flies.


title: Drosophila melanogaster

text: Specifically, when competing for food, aggression occurs based on amount of food available and is independent of any social interactions between males. Specifically, sucrose was found to stimulate gustatory receptor neurons, which was necessary to stimulate aggression. However, once the amount of food becomes greater than a certain amount, the competition between males lowers. This is possibly due to an over-abundance of food resources. On a larger scale, food was found to determine the boundaries of a territory since flies were observed to be more aggressive at the food's physical perimeter.


title: Drosophila melanogaster

text: However, like most behaviors requiring arousal and wakefulness, aggression was found to be impaired via sleep deprivation. Specifically, this occurs through the impairment of Octopamine and dopamine signaling, which are important pathways for regulating arousal in insects. Due to reduced aggression, sleep-deprived male flies were found to be disadvantaged at mating compared to normal flies. However, when octopamine agonists were administered upon these sleep-deprived flies, aggression levels were seen to be increased and sexual fitness was subsequently restored. Therefore, this finding implicates the importance of sleep in aggression between male flies.


title: Drosophila melanogaster

text: It is now relatively simple to generate transgenic flies in Drosophila, relying on a variety of techniques. One approach of inserting foreign genes into the "Drosophila" genome involves P elements. The transposable P elements, also known as transposons, are segments of bacterial DNA that are transferred into the fly genome. Transgenic flies have already contributed to many scientific advances, e.g., modeling such human diseases as Parkinson's, neoplasia, obesity, and diabetes.


title: Drosophila melanogaster

text: The compound eye of the fruit fly contains 760 unit eyes or ommatidia, and are one of the most advanced among insects. Each ommatidium contains eight photoreceptor cells (R1-8), support cells, pigment cells, and a cornea. Wild-type flies have reddish pigment cells, which serve to absorb excess blue light so the fly is not blinded by ambient light. Eye color genes regulate cellular vesicular transport. The enzymes needed for pigment synthesis are then transported to the cell's pigment granule, which holds pigment precursor molecules.


title: Drosophila melanogaster

text: Each photoreceptor cell consists of two main sections, the cell body and the rhabdomere. The cell body contains the nucleus, while the 100-μm-long rhabdomere is made up of toothbrush-like stacks of membrane called microvilli. Each microvillus is 1–2 μm in length and about 60 nm in diameter. The membrane of the rhabdomere is packed with about 100 million opsin molecules, the visual protein that absorbs light. The other visual proteins are also tightly packed into the microvilli, leaving little room for cytoplasm.


title: Drosophila melanogaster

text: The genome of "Drosophila" encodes seven opsins, five of those are expressed in the omatidia of the eye. The photoreceptor cells R1-R6 express the opsin Rh1, which absorbs maximally blue light (around 480 nm), however the R1-R6 cells cover a broader range of the spectrum than an opsin would allow due to a sensitising pigment that adds two sensitivity maxima in the UV-range (355 and 370 nm). The R7 cells come in two types with yellow and pale rhabdomeres (R7y and R7p). The pale R7p cells express the opsin Rh3, which maximally absorbs UV-light (345 nm). The R7p cells are strictly paired with the R8p cells that express Rh5, which maximally absorbs violet light (437 nm). The other, the yellow R7y cells express a blue-absorbing screening pigment and the opsin Rh4, which maximally absorbs UV-light (375 nm). The R7y cells are strictly paired with R8y cells that express Rh6, which maximally absorbs UV-light (508 nm). In a subset of omatidia both R7 and R8 cells express the opsin Rh3.


title: Drosophila melanogaster

text: However, these absorption maxima of the opsins where measured in white eyed flies without screening pigments (Rh3-Rh6), or from the isolated opsin directly (Rh1). Those pigments reduce the light that reaches the opsins depending on the wavelength. Thus in fully pigmented flies, the effective absorption maxima of opsins differs and thus also the sensitivity of their photoreceptor cells. With screening pigment, the opsin Rh3 is short wave shifted from 345 nm to 330 nm and Rh4 from 375 nm to 355 nm. Whether screening pigment is present does not make a practical difference for the opsin Rh5 (435 nm and 437 nm), while the opsin R6 is long wave shifted by 92 nm from 508 nm to 600 nm.


title: Drosophila melanogaster

text: Additionally of the opsins of the eye, "Drosophila" has two more opsins: The ocelli express the opsin Rh2, which maximally absorbs violet light (~420 nm). And the opsin Rh7, which maximally absorbs UV-light (350 nm) with an unusually long wavelength tail up to 500 nm. The long tail disappears if a lysine at position 90 is replaced by glutamic acid. This mutant then absorbs maximally violet light (450 nm). The opsin Rh7 entrains with cryptochrome the circadian rhythm of "Drosophila" to the day-night-cycle in the central pacemaker neurons.


title: Drosophila melanogaster

text: Each "Drosophila" opsin binds the carotenoid chromophore 11-cis-3-hydroxyretinal via a lysine. This lysine is conserved in almost all opsins, only a few opsins have lost it during evolution. Opsins without it are not light sensitive. In particular, the Drosophila opsins Rh1, Rh4, and Rh7 function not only as photoreceptors, but also as chemoreceptors for aristolochic acid. These opsins still have the lysine like other opsins. However, if it is replaced by an arginine in Rh1, then Rh1 loses light sensitivity but still responds to aristolochic acid. Thus, the lysine is not needed for Rh1 to function as chemoreceptor.


title: Drosophila melanogaster

text: As in vertebrate vision, visual transduction in invertebrates occurs via a G protein-coupled pathway. However, in vertebrates, the G protein is transducin, while the G protein in invertebrates is Gq (dgq in "Drosophila"). When rhodopsin (Rh) absorbs a photon of light its chromophore, 11-cis-3-hydroxyretinal, is isomerized to all-trans-3-hydroxyretinal. Rh undergoes a conformational change into its active form, metarhodopsin. Metarhodopsin activates Gq, which in turn activates a phospholipase Cβ (PLCβ) known as NorpA.


title: Drosophila melanogaster

text: PLCβ hydrolyzes phosphatidylinositol (4,5)-bisphosphate (PIP), a phospholipid found in the cell membrane, into soluble inositol triphosphate (IP) and diacylglycerol (DAG), which stays in the cell membrane. DAG, a derivative of DAG, or PIP depletion cause a calcium-selective ion channel known as transient receptor potential (TRP) to open and calcium and sodium flows into the cell. IP is thought to bind to IP receptors in the subrhabdomeric cisternae, an extension of the endoplasmic reticulum, and cause release of calcium, but this process does not seem to be essential for normal vision.


title: Drosophila melanogaster

text: Calcium binds to proteins such as calmodulin (CaM) and an eye-specific protein kinase C (PKC) known as InaC. These proteins interact with other proteins and have been shown to be necessary for shut off of the light response. In addition, proteins called arrestins bind metarhodopsin and prevent it from activating more Gq. A sodium-calcium exchanger known as CalX pumps the calcium out of the cell. It uses the inward sodium gradient to export calcium at a stoichiometry of 3 Na/ 1 Ca.


title: Drosophila melanogaster

text: TRP, InaC, and PLC form a signaling complex by binding a scaffolding protein called InaD. InaD contains five binding domains called PDZ domain proteins, which specifically bind the C termini of target proteins. Disruption of the complex by mutations in either the PDZ domains or the target proteins reduces the efficiency of signaling. For example, disruption of the interaction between InaC, the protein kinase C, and InaD results in a delay in inactivation of the light response.


title: Drosophila melanogaster

text: Unlike vertebrate metarhodopsin, invertebrate metarhodopsin can be converted back into rhodopsin by absorbing a photon of orange light (580 nm).


title: Drosophila melanogaster

text: About two-thirds of the "Drosophila" brain is dedicated to visual processing. Although the spatial resolution of their vision is significantly worse than that of humans, their temporal resolution is around 10 times better.


title: Drosophila melanogaster

text: "Drosophila" are known to exhibit grooming behaviors that are executed in a predictable manner. "Drosophila" consistently begin a grooming sequence by using their front legs to clean the eyes, then the head and antennae. Using their hind legs, "Drosophila" proceed to groom their abdomen, and finally the wings and thorax. Throughout this sequence, "Drosophila" periodically rub their legs together to get rid of excess dust and debris that accumulates during the grooming process.


title: Drosophila melanogaster

text: Grooming behaviors have been shown to be executed in a suppression hierarchy. This means that grooming behaviors that occur at the beginning of the sequence prevent those that come later in the sequence from occurring simultaneously, as the grooming sequence consists of mutually exclusive behaviors. This hierarchy does not prevent "Drosophila" from returning to grooming behaviors that have already been accessed in the grooming sequence. The order of grooming behaviors in the suppression hierarchy is thought to be related to the priority of cleaning a specific body part. For example, the eyes and antennae are likely executed early on in the grooming sequence to prevent debris from interfering with the function of "D. melanogaster's" sensory organs.


title: Drosophila melanogaster

text: Like many other hexapod insects, "Drosophila" typically walk using a tripod gait. This means that three of the legs swing together while the other three remain stationary, or in stance. Variability around the tripod configuration appears to be continuous, meaning that flies do not exhibit distinct transitions between different gaits. At fast walking speeds (15–30 mm/s), the walking configuration is mostly tripod (3 legs in stance), but at low walking speeds (0–15 mm/s), flies are more likely to have four or five legs in stance. These transitions may help to optimize static stability. Because flies are so small, inertial forces are negligible compared with the elastic forces of their muscles and joints or the viscous forces of the surrounding air.


title: Drosophila melanogaster

text: In addition to stability, the robustness of a walking gait is also thought to be important in determining the gait of a fly at a particular walking speed. Robustness refers to how much offset in the timing of a legs stance can be tolerated before the fly becomes statically unstable. For instance, a robust gait may be particularly important when traversing uneven terrain, as it may cause unexpected disruptions in leg coordination. Using a robust gait would help the fly maintain stability in this case. Analyses suggest that "Drosophila" may exhibit a compromise between the most stable and most robust gait at a given walking speed.


title: Drosophila melanogaster

text: Flies fly via straight sequences of movement interspersed by rapid turns called saccades. During these turns, a fly is able to rotate 90° in less than 50 milliseconds.


title: Drosophila melanogaster

text: Characteristics of "Drosophila" flight may be dominated by the viscosity of the air, rather than the inertia of the fly body, but the opposite case with inertia as the dominant force may occur. However, subsequent work showed that while the viscous effects on the insect body during flight may be negligible, the aerodynamic forces on the wings themselves actually cause fruit flies' turns to be damped viscously.


title: Drosophila melanogaster

text: "Drosophila" is sometimes referred to as a pest due to its tendency to live in human settlements, where fermenting fruit is found. Flies may collect in homes, restaurants, stores, and other locations.


title: Drosophila melanogaster

text: The name and behavior of this species of fly has led to the misconception that it is a biological security risk in Australia. While other "fruit fly" species do pose a risk, "D. melanogaster" is attracted to fruit that is already rotting, rather than causing fruit to rot.


title: John Churchill, 1st Duke of Marlborough

text: General John Churchill, 1st Duke of Marlborough, 1st Prince of Mindelheim, 1st Count of Nellenburg, Prince of the Holy Roman Empire, (26 May 1650 – 16 June 1722 O.S.) was an English soldier and statesman whose career spanned the reigns of five monarchs. From a gentry family, he served first as a page at the court of the House of Stuart under James, Duke of York, through the 1670s and early 1680s, earning military and political advancement through his courage and diplomatic skill.


title: John Churchill, 1st Duke of Marlborough

text: Churchill's role in defeating the Monmouth Rebellion in 1685 helped secure James on the throne, but he was a key player in the military conspiracy that led to James being deposed during the Glorious Revolution. Rewarded by William III with the title Earl of Marlborough, persistent charges of Jacobitism led to his fall from office and temporary imprisonment in the Tower of London. William recognised his abilities by appointing him as his deputy in Southern Netherlands (modern-day Belgium) before the War of the Spanish Succession in 1701, but not until the accession of Queen Anne in 1702 did he secure his fame and fortune.


title: John Churchill, 1st Duke of Marlborough

text: Marriage to Sarah Jennings and her relationship with Anne ensured Marlborough's rise, first to the captain-generalcy of British forces, then to a dukedom. As de facto leader of Allied forces in the Low Countries, his victories at Blenheim (1704), Ramillies (1706), Oudenarde (1708), and Malplaquet (1709) ensured his place in history as one of Europe's great generals.


title: John Churchill, 1st Duke of Marlborough

text: His wife's stormy relationship with the Queen, and her subsequent dismissal from court, was central to his own fall. Incurring Anne's disfavour, and caught between Tory and Whig factions, Marlborough was forced from office and went into self-imposed exile. He returned to favour with the accession of George I to the British throne in 1714, but a stroke in 1716 ended his active career.


title: John Churchill, 1st Duke of Marlborough

text: Marlborough's leadership of the Allied armies fighting Louis XIV from 1701 to 1710 consolidated Britain's emergence as a front-rank power, while his ability to maintain unity in the fractious coalition demonstrated his diplomatic skills. He is often remembered by military historians as much for his organisational and logistic skills as his tactical abilities. However, he was also instrumental in moving away from the siege warfare that dominated the Nine Years' War, arguing one battle was worth ten sieges.


title: John Churchill, 1st Duke of Marlborough

text: Churchill was the second but eldest-surviving son of Sir Winston Churchill (1620–1688) of Glanvilles Wootton, Dorset, and Elizabeth Drake, whose family came from Ash, in Devon. Winston served with the Royalist Army in the Wars of the Three Kingdoms; he was heavily fined for doing so, forcing his family to live at Ash House with his mother-in-law.


title: John Churchill, 1st Duke of Marlborough

text: Only five of their children survived infancy: Arabella (1648–1730), who was the eldest; followed by John; George (1654–1710); and Charles (1656–1714). Another brother, Theobald, died in 1685.


title: John Churchill, 1st Duke of Marlborough

text: After the 1660 Restoration of Charles II, Winston became Member of Parliament for Weymouth and from 1662 served as Commissioner for Irish Land Claims in Dublin. On returning to London in 1663, he was knighted and received a position at Whitehall, with John attending St Paul's School.


title: John Churchill, 1st Duke of Marlborough

text: The family fortune was made in 1665 when Arabella Churchill became maid of honour to Anne Hyde and began an affair with her husband, James, Duke of York. This lasted over a decade; James had four acknowledged children by her, including the Duke of Berwick (1670–1734). Their relationship led to appointments for her brothers; John was appointed page to James, and in September 1667 made an ensign in the Foot Guards.


title: John Churchill, 1st Duke of Marlborough

text: Claims that Churchill served with the Tangier Garrison cannot be confirmed, but he is recorded as being with Sir Thomas Allin in the Mediterranean from March to November 1670. He returned to London, where in February 1671 he engaged in a duel with Sir John Fenwick. He allegedly had an affair with Barbara Villiers, a mistress of Charles II, and may have fathered her daughter Barbara Fitzroy, although he never formally acknowledged her.


title: John Churchill, 1st Duke of Marlborough

text: In the 1670 Treaty of Dover, Charles II agreed to support a French attack on the Dutch Republic and supply a British brigade of 6,000 troops for the French army. Louis XIV paid him £230,000 per year for this. When the Franco-Dutch War began in 1672, Churchill was present at the Battle of Solebay on 28 May, possibly aboard James' flagship, the "Prince", which was crippled in the action.


title: John Churchill, 1st Duke of Marlborough

text: Shortly thereafter, Churchill was commissioned Captain in the Duke of York's Admiralty Regiment, part of the British brigade, commanded by the Duke of Monmouth. The alliance with Catholic France was extremely unpopular and many doubted the brigade's reliability against the Protestant Dutch. As a result, it served in the Rhineland against the Holy Roman Empire, although Churchill, Monmouth and other volunteers took part in the French siege of Maastricht.


title: John Churchill, 1st Duke of Marlborough

text: England withdrew from the war with the 1674 Treaty of Westminster, but to keep his subsidies, Charles encouraged members of the Anglo-Scots force to remain in French service; many did so, including Monmouth and Churchill, who became Colonel of one such regiment, serving under Marshal Turenne. He was present at Sinsheim in June 1674, Enzheim in October, and possibly at Sasbach in July 1675, where Turenne was killed.


title: John Churchill, 1st Duke of Marlborough

text: Sometime around 1675, Churchill met the 15-year-old Sarah Jennings, who came from a similar background of minor Royalist gentry, ruined by the war. The family moved to London after her father died and in 1673, Sarah and her sister Frances joined the household of Mary of Modena, James' second Catholic wife. Despite opposition from his father, who wanted him to marry the wealthy Catherine Sedley, Churchill married Sarah in the winter of 1677–78, helped by Mary.


title: John Churchill, 1st Duke of Marlborough

text: The couple had five children who survived to adulthood: Henrietta Churchill, 2nd Duchess of Marlborough (1681–1733), Lady Anne Churchill (1683–1716), John Churchill, Marquess of Blandford (1686–1703), Elizabeth (1687–1714), and Mary (1689–1719).


title: John Churchill, 1st Duke of Marlborough

text: In November 1677, William of Orange married James's eldest daughter, Mary, and in March 1678, the Earl of Danby negotiated an Anglo-Dutch defensive alliance. Churchill was sent to the Hague to make arrangements for an expeditionary force, although English troops did not arrive in significant numbers until after the Peace of Nijmegen ended the war on 10 August.


title: John Churchill, 1st Duke of Marlborough

text: James publicly confirmed his conversion to Catholicism in 1673 and as heir to the throne, this led to a political crisis that dominated English politics from 1679 to 1681. In the 1679 General Election, Churchill was elected MP for Newtown; the majority supported James' exclusion and he spent the next three years in exile, Churchill acting as his liaison with the court.


title: John Churchill, 1st Duke of Marlborough

text: Charles defeated the Exclusionists and dismissed Parliament in 1681, allowing James to return to London. In 1682, Churchill was made Lord Churchill of Eyemouth in the peerage of Scotland and the following year, colonel of the King's Own Royal Regiment of Dragoons. These rewards allowed him to live in some style and comfort; in addition to a house in London, he purchased Holywell House, near St Albans. He also gained control of the Parliamentary constituency of St Albans; his brother George held the seat from 1685 to 1708.


title: John Churchill, 1st Duke of Marlborough

text: Charles Churchill served at the Danish court, where he became friends with Prince George of Denmark, who married James' younger daughter Anne in 1683. His senior aide was Colonel Charles Griffin, brother-in-law to Sarah, appointed Lady of the Bedchamber to Anne. The Churchills and their relatives formed a central part of the so-called 'Cockpit circle' of Anne's friends, named after her apartments in Whitehall. Churchill was reportedly concerned at being too closely associated with James, particularly since Sarah's sister Frances was married to Irish Catholic Richard Talbot, appointed Lord Deputy of Ireland in 1687. This was offset by their connection with the Protestant Anne, while Sarah herself was renowned for being virulently anti-Catholic.


title: John Churchill, 1st Duke of Marlborough

text: Despite his Catholicism, James succeeded Charles as king in February 1685 with widespread support. Many feared his exclusion would lead to a repetition of the 16381651 Wars of the Three Kingdoms but tolerance for his personal beliefs did not apply to Catholicism in general. His support collapsed when his policies appeared to threaten the primacy of the Church of England and created the very instability his supporters wished to avoid.


title: John Churchill, 1st Duke of Marlborough

text: This preference for stability led to the rapid defeat in June 1685 of Argyll's Rising in Scotland and the Monmouth Rebellion in western England. In the campaign against Monmouth, Churchill led the infantry, under the command of the Earl of Feversham, at Sedgemoor on 6 July 1685, defeating the rebels and effectively putting an end to the rebellion. Although subordinate to Feversham, Churchill's administrative capacity, tactical skill, and courage in battle were pivotal in the victory.


title: John Churchill, 1st Duke of Marlborough

text: In recognition of his contribution, he was promoted Major General and given the colonelcy of the Third Troop of Life Guards. In May, he had been made Baron Churchill of Sandridge, giving him a seat in the House of Lords, which led to the first open breach with James; Lord Delamere was accused of involvement in the rebellion and tried by 30 members of the House of Lords, including Churchill. As the most junior peer, he went first and his vote for acquittal was viewed as giving a lead to others; Delamere was set free, much to James' annoyance.


title: John Churchill, 1st Duke of Marlborough

text: As early as 1682, Churchill was recorded as being uneasy at James' obstinacy. The conviction he was always right often resulted in what many viewed as vindictive behaviour, including Monmouth's clumsy execution and the persecution of his followers by Judge Jeffreys. This provides the immediate context for Delamere's acquittal but shortly after the Coronation, Churchill reputedly told French Protestant Henri de Massue that "If the King should attempt to change our religion, I will instantly quit his service".


title: John Churchill, 1st Duke of Marlborough

text: Churchill emerged from the Sedgemoor campaign with great credit, but he was anxious not to be seen as sympathetic towards the King's growing religious ardour against the Protestant establishment. James II's promotion of Catholics in royal institutions – including the army – engendered first suspicion, and ultimately sedition in his mainly Protestant subjects; even members of his own family expressed alarm at the King's fanatic zeal for the Roman Catholic religion. When the queen gave birth to a son, James Francis Edward Stuart, it opened up the prospect of a line of successive Catholic monarchs. Some in the King's service, such as the Earl of Salisbury and the Earl of Melfort, converted to Catholicism and were seen as having betrayed their Protestant upbringing in order to gain favour at court. Churchill remained true to his conscience, telling the King, "I have been bred a Protestant, and intend to live and die in that communion", although he was also motivated by self-interest. Believing that the monarch's policy would either wreck his own career or generate a wider insurrection, he did not intend, like his unfortunate father before him, to be on the losing side.


title: John Churchill, 1st Duke of Marlborough

text: Seven men met to draft the invitation to the Protestant Dutch Stadtholder, William, Prince of Orange, to invade England and assume the throne. The signatories to the letter included Whigs, Tories, and the Bishop of London, Henry Compton, who assured the Prince that, "Nineteen parts of twenty of the people ... are desirous of change". William needed no further encouragement. Although the invitation was not signed by Churchill (he was not, as yet, of sufficient political rank to be a signatory), he declared his intention through William's principal English contact in The Hague – "If you think there is anything else that I ought to doe, you have but to command me".


title: John Churchill, 1st Duke of Marlborough

text: William landed at Brixham on 5 November 1688 (O.S.); from there, he moved his army to Exeter. James's forces – once again commanded by Lord Feversham – moved to Salisbury, but few of its senior officers were eager to fight – even Princess Anne wrote to William to wish him "good success in this so just an undertaking". Promoted to Lieutenant-General on 7 November (O.S.) Churchill was still at the King's side, but his displaying "the greatest transports of joy imaginable" at the desertion of Lord Cornbury led Feversham to call for his arrest. Churchill himself had openly encouraged defection to the Orangist cause, but James continued to hesitate. Soon it was too late to act. After the meeting of the council of war on the morning of 24 November (O.S.), Churchill, accompanied by some 400 officers and men, slipped from the royal camp and rode towards William in Axminster, leaving behind him a letter of apology and self-justification:


title: John Churchill, 1st Duke of Marlborough

text: ... I hope the great advantage I enjoy under Your Majesty, which I own I would never expect in any other change of government, may reasonably convince Your Majesty and the world that I am actuated by a higher principle ...


title: John Churchill, 1st Duke of Marlborough

text: When the King saw that he could not keep even Churchill – for so long his loyal and intimate servant – he despaired. James II, who in the words of the Archbishop of Rheims, had "given up three kingdoms for a Mass", fled to France, taking with him his son and heir.


title: John Churchill, 1st Duke of Marlborough

text: As part of William III and Mary II's coronation honours, Churchill was created Earl of Marlborough on 9 April 1689 (O.S.); he was also sworn as a member of the Privy Council and made a Gentleman of the King's Bedchamber. His elevation, however, led to accusatory rumours from King James's supporters that Marlborough had disgracefully betrayed his erstwhile king for personal gain; William himself entertained reservations about the man who had deserted James. Marlborough's apologists, including his biographer and most notable descendant Winston Churchill, have been at pains to attribute patriotic, religious, and moral motives to his action; but in the words of David G. Chandler, it is difficult to absolve Marlborough of ruthlessness, ingratitude, intrigue and treachery against a man to whom he owed virtually everything in his life and career to date.


title: John Churchill, 1st Duke of Marlborough

text: Marlborough's first official act was to assist in the remodelling of the army – the power of confirming or purging officers and men gave the Earl the opportunity to build a new patronage network which would prove beneficial over the next two decades. His task was urgent, for less than six months after James II's departure, England joined the war against France as part of a powerful coalition aimed at curtailing the ambitions of Louis XIV. With his experience it was logical that Marlborough took charge of the 8,000 English troops sent to the Low Countries in the spring of 1689; yet throughout the Nine Years' War (1688–97) he saw only three years service in the field, and then mostly in subordinate commands. However, at the Battle of Walcourt on 25 August 1689 Marlborough won praise from the Allied commander, Prince Waldeck – "... despite his youth he displayed greater military capacity than do most generals after a long series of wars ... He is assuredly one of the most gallant men I know".