In the 2006 animated comedy Flushed Away, Roddy St. James, a spoiled pet mouse voiced by Hugh Jackman, is flushed down the toilet and into the sewage city of Ratropolis. In his attempt to get home, he uncovers a plot by the animal mob boss, The Toad, to flood Ratropolis with a wave of excrement during the halftime toilet break of the FIFA World Cup. See, the toad used to be Prince Charles’ pet, but then Charles got a rat and flushed it down the toilet, so now he hates rats and… it’s a whole thing.
Humans have also been known throughout our history for making intricate mousetraps. We’re not normally driven by a perceived offense from all rodents, but mice and rats have posed a threat to health and resources over time, and in response we’ve come up with all sorts of ways to get rid of them. Now, thanks to scientists from the University of Adelaide, we may have the mousetrap to end all mousetraps. According to a recent article in the Proceedings of the National Academy of Sciences, we’re taking the fight straight to their DNA.
For many of us, rodents are little more than an occasional nuisance or even a beloved pet, but in some places they are invasive, causing harm to both humans and other species. This is especially true in closed environments such as islands, where particularly harmful rodents can spread so quickly that they crowd out native species. Faced with this problem, the Adelaide researchers developed a modified version of CRISPR, which they call t-CRISPR, to spread a mutation throughout the population.
This form of genetic engineering is often referred to as gene drive and differs from conventional gene editing in one important respect. Traditionally, gene editing modifies a trait or set of traits in an individual, but these changes are not necessarily passed on to offspring. A gene drive increases the likelihood that a trait or set of traits will be passed on to the next generation. For this work, the scientists relied on a naturally occurring mutation in mice that renders them infertile. By targeting that mutation and increasing the likelihood of inheritance, you get an ever larger population of infertile mice, and the overall population decreases. At least that’s what the models show.
The team used advanced computer modeling to simulate an environment with an invasive population of 200,000 mice. Then they just introduced 250 modified mice with the desired mutation in the fertility gene and got the simulation to work. They found that their gene drive could ramp up the inheritance of this mutation and wipe out the entire population in just 20 years.
Of course, a simulation is only as good as its real-world results, and that depended on actually being able to get transgenic mice to pass on the faulty genes. To find out, the team engineered genetically engineered mice with t-CRISPR and confirmed that they had biased transmission – which increased inheritance – of the target mutation at levels that successfully wiped out the population in the simulation.
It’s worth noting that genetic engineering of a population on this scale involves some ethical and moral considerations that need to be worked out before we go full speed ahead. These talks are ongoing as similar efforts to use gene drives in insect populations are being developed. It can be argued that this type of genetic population control is the humane solution. It does not involve any painful traps or chemicals of any kind. The mice that are born will go on with their lives as usual, they will just have fewer and fewer offspring in each succeeding generation until they perish.
Instead of snares and poisons, we turn their gene pool into a slowly tightening noose. It’s the kind of mousetrap you can’t escape from because you don’t even know you’re in it.
It’s a fan thing
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Katika filamu ya 2006 ya Flushed Away, Roddy St. James, panya aliyetengenezwa na Hugh Jackman, anaanguka chini ya choo na kuingia katika jiji la mifereji ya maji ya Ratopolis. Katika jaribio lake la kurudi nyumbani, anafunua njama ya bosi wa mafia ya wanyama, Toad, kufurika Ratopolis na wimbi la uchafu wakati wa mapumziko ya choo ya nusu ya Kombe la Dunia la FIFA. Angalia, toad kutumika kuwa Prince Charles'mnyama wa kufugwa, lakini kisha Charles got panya na flushed ni chini ya choo, hivyo sasa yeye anachukia panya na... ni kitu nzima. Wanadamu pia wamejulikana katika historia yetu kwa kutengeneza mitego ya panya yenye kutatanisha. Kwa kawaida hatuendeshwi na kosa linalotambuliwa kutoka kwa panya wote, lakini panya na panya wameweka tishio kwa afya na rasilimali kwa muda, na kwa kujibu tumekuja na njia zote za kuondoa. Sasa, shukrani kwa wanasayansi kutoka Chuo Kikuu cha Adelaide, tunaweza kuwa na mtego wa panya wa kumaliza mtego wote wa panya. Kulingana na makala ya hivi karibuni katika Majarida ya Chuo Kikuu cha Kitaifa cha Sayansi, tunachukua mapigano moja kwa moja kwa DNA yao. Kwa wengi wetu, panya ni tu msukosuko wa mara kwa mara au hata mnyama mpendwa, lakini katika maeneo fulani wao ni wavamizi, wakisababisha madhara kwa wanadamu na spishi nyingine. Hii ni kweli hasa katika mazingira ya kufungwa kama vile visiwa, ambapo hasa wadudu hatari wanaweza kuenea haraka sana kwamba wao crowd nje spishi za asili. Kwa sababu hiyo, watafiti wa Adelaide waliunda t-CRISPR, ambayo ni njia ya kueneza mabadiliko katika jamii. Aina hii ya uhandisi wa maumbile mara nyingi huitwa uendeshaji wa jeni na inatofautiana na uhariri wa kawaida wa jeni katika jambo moja muhimu. Kwa kawaida, uhariri wa chembe za urithi hubadilisha tabia au seti ya tabia katika mtu, lakini mabadiliko haya hayapitishwi kwa wazao. Uendeshaji wa chembe za urithi huongeza uwezekano wa kwamba sifa au seti ya sifa itapitishwa kwa kizazi kifuatacho. Kwa ajili ya kazi hii, wanasayansi walitegemea mabadiliko ya asili katika panya ambayo huwafanya wawe wasiozaa. Kwa kulenga mabadiliko hayo na kuongeza uwezekano wa urithi, unapata idadi kubwa ya panya wasiozaa, na idadi ya jumla hupungua. Angalau hivyo ndivyo mifano inavyoonyesha. Timu hiyo ilitumia kompyuta kuiga mazingira yenye wadudu 200,000. Kwa mfano, mnyama mmoja aliweza kuunda panya 250 na kugeuza chembe za urithi za panya hao na kufanya simulation hiyo ifanye kazi. "Walipata kwamba ""gene drive"" yao inaweza kuongeza urithi wa mabadiliko haya na kuharibu idadi nzima ya watu katika miaka 20 tu." "Hata hivyo, simulation ni nzuri tu kama matokeo yake halisi, na hiyo inategemea kuwa kweli kuwa na uwezo wa kupata panya transgenic kupitisha juu ya jeni kosa. """ Ili kujua, timu hiyo ilibuni panya waliobadilishwa kwa jeni na t-CRISPR na kuthibitisha kuwa walikuwa na maambukizi ya upendeleo - ambayo iliongeza urithi - wa mabadiliko ya lengo kwa viwango ambavyo vilifaulu kufuta idadi katika simulation. Ni muhimu kutambua kwamba uhandisi wa maumbile ya idadi ya watu katika kiwango hiki unahusisha baadhi ya kuzingatia maadili na maadili ambayo yanahitaji kufanywa kabla ya kwenda kasi kamili mbele. Mazungumzo hayo yanaendelea huku jitihada kama hizo za kutumia mbinu za kuchochea chembe za urithi katika idadi ya wadudu zikiendelea. Inaweza kusemwa kwamba aina hii ya udhibiti wa idadi ya watu wa urithi ni suluhisho la kibinadamu. Haihusishi mitego yoyote yenye kuumiza au kemikali za aina yoyote. Panya wanaozaliwa wataendelea na maisha yao kama kawaida, watakuwa na watoto wachache na wachache katika kila kizazi kinachofuata mpaka watapotea. Badala ya mitego na sumu, tunageuza hifadhi yao ya chembe za urithi kuwa kamba inayokandamizwa polepole. Ni aina ya mtego wa panya ambao huwezi kuukimbia kwa sababu hujui hata uko ndani yake. Ni kitu mashabiki Kujiunga SYFY Insiders kwa ajili ya upatikanaji wa video ya kipekee na mahojiano, kuvunja habari, sweepstakes na zaidi! Jiandikishe bila malipo