
heterochromatin

heterochromatin anedi dna ledhaa "ghaneebhavinchina dna" yokka kathinamgaa pyaak cheyabadina roopam, idhi bahula rakaalalo vastundi. eee rakalu constitutive heterochromatin mariyu facultative heterochromatin yokka rendu teevratala madhya konasaagimpupai untaayi. janyuvula vyakteekaranalo rendoo paatra poeshistaayi. idhi gattiga pyaak cheyabadinanduna, idhi polymeraselaku andubaatulo ledani bhaavinchabadindi, anduvalla lipyantareekarinchabadaledu; ayithe, volp mariyu itarula prakaram. (2002), mariyu appati nundi aneka itara patraalu, eee dnalo ekkuva bhaagam vaastavaaniki lipyantareekarana cheyabadindi, conny idhi rna-prerita lipyantareekarana nissabdam (rits) dwara nirantaram maarchabadutundi. electron microscopy mariyu oso4 steiningtho iteevali adhyayanalu dattamaina packing chromatin kaaranamgaa kaadani velladistunnaayi.
constitutive heterochromatin thana daggari janyuvulanu prabhaavitam chestundi (udhaa.zii. sthaanam-prabhavam vaividhyata). idhi saadhaaranamgaa punaraavrutamavutundi mariyu itara janyu-vyakteekarana ledhaa anachiveta sankethaalaku aakarshanheeyamgaa vyavaharinchadamtho paatu centromers ledhaa telomeres vanti nirmaanaatmaka vidhulanu yerparustundi.
facultative heterochromatin anedi histone decitylation ledhaa pivi-interacting rna (pirna) vanti yantraangam dwara arnai dwara nissabdam cheyabadina janyuvula phalitam. idhi punaraavrutamayyedi kaadu mariyu constitutive heterochromatin yokka compact nirmaanaanni panchukuntundi. ayithe, nirdishta abhivruddhi ledhaa paryaavarana sankethaala suuchanala krinda, idhi daani ghaneebhavinchina nirmaanaanni kolpoyi, pratilekhanamgaa churukuga maaravacchu.
heterochromatin maanava janyuvulooni konni bhagalalo hetch3keey9 yokka dii-mariyu trai-methylationtho mudipadi undhi. organogenesis praarambhamlo vamsa nibaddhata samayamlo heterochromatin nuu savarinchadamlo mariyu vamsa viswasaneeyatanu konasaginchadamlo hetch3keey9mea3-sambandhita methyl transferrages keelaka paatra pooshistunnatlu telustondi.
nirmaanam.
chromatin rendu rakaluga kanipistundihi eukromatin mariyu heterochromatin. modata, rendu roopaalu entha teevramgaa tadisiveyabadatayo daani dwara cytologicalga vaeru cheyabaddaayi-eukromatin takkuva teevramgaa untundi, ayithe heterochromatin marakalu teevramgaa untaayi, idhi kathinamaina packingnu suuchistumdi. heterochromatin saadhaaranamgaa kendrakam yokka anchuku sthaanikeekarinchabadutundi.
eee prarambha dwaipaakshikata unnappatikee, jantuvulu mariyu mokkalu rendintiloonuu iteevali aadharalu rendu kante ekkuva vibhina heterochromatin sthithulu unnayani suuchimchaayi, mariyu idhi vaastavaaniki naalugu ledhaa aidu 'sthithulalo' undavacchu, prati okkati epigenetic gurtula yokka vibhina kalayikalatho gurtinchabadindi.
heterochromatin pradhanamgaa janyuparamgaa kriyaarahita upagraha shrenulanu kaligi untundi, mariyu aneka janyuvulu vividha sthaayilaku anachiveyabadataayi, ayithe konni eukromatinlo assalu vyakteekarinchabadavu. centromeres mariyu telomeres rendoo binna varnaalu, alaage rendavadi yokka baar boddy, streelo kriyaarahitam cheyabadina x-chromosome.
function.
heterochromatin janyu niyantrana nundi chromosome samagrata rakshana varaku aneka vidhulatho mudipadi undhi; eee paatralalo konni DNA yokka dattamaina packingku aapaadinchavachchu, idhi saadhaaranamgaa DNA ledhaa daani anubandha kaarakaalanu bandhinche protein kaarakaalaku takkuva andubaatulo undela chestundi. udaaharanaku, nagna double-stranded dna chivaralanu saadhaaranamgaa kanaalu debbatinna ledhaa viral dnaga ardham chesukuntaayi, idhi kana chakram arrest, dna marammattu ledhaa bacterialoni endonucleusla dwara sakalam naasanam cheyadaanni prerepistundi.
chromatin yokka konni praantaalu chaalaa dattamgaa fibersto nindi untaayi, ivi mytosis vadda chromosometho polchadagina paristhitini pradarsistaayi. heterochromatin saadhaaranamgaa clonallyga vaarasatvamgaa vastundi; oka kanam vibhajinchinappudu, rendu kumarte kanaalu saadhaaranamgaa dna yokka oke praantaalalo heterochromatin kaligi untaayi, phalitamgaa epigenetic vaarasatvam vastundi. vaividhyaalu heterochromatin prakkane unna janyuvulanu aakraminchadaaniki ledhaa domainla yokka teevratala vadda janyuvula nundi vaidolagadaaniki kaaranamavutaayi. eee sarihaddu domainlalo ("sis" loe) unchadam dwara lipyantareekarinchadagina padaarthaanni anachiveyavachhu. idhi oka kanam nundi maroka kanam varaku maarutuu unde vyakteekarana sthaayilaku daariteestundi, idhi sthaanam-prabhavam vaividhyeekarana dwara pradarsinchabadutundi. constitutive heterochromatin mariyu atyanta churukaina janyuvulu jatacheyabadina arudaina sandarbhaallo insulator sequencelu avarodhamgaa panicheestaayi (udhaa.zii. chiken β-globin locus yokka eguva bhaagamlo 5 'hchs4 insulator, mariyu rendu "saccaromyces" esppi loe lokey.).
constitutive heterochromatin.
icchina jaatula yokka anni kanaalu dna yokka oke praantaalanu constitutive heterochromatinlo packagy chestaayi, anduvalla anni kanaalalo, constitutive heterochromatinlo unna edainaa janyuvulu paelavamgaa vyakteekarinchabadataayi. udaaharanaku, anni maanava chromosomelu 1,9,16, mariyu vai-chromosomelu constitutive heterochromatin yokka pedda praantaalanu kaligi untaayi. chaalaa jeevulalo, chromosome centromere chuttoo mariyu telomirla sameepamlo constitutive heterochromatin sambhavistundi.
adhyapaka heterochromatin.
facultative heterochromatinlo pyaak cheyabadina dna praantaalu oka jaatilooni kana rakaala madhya sthiramgaa undavu, anduvalla facultative heterochromatinlo pyaak cheyabadina oka kanamlo oka kramam (mariyu lopala unna janyuvulu paelavamgaa vyakteekarinchabadataayi) maroka kanamlo eukromatinlo pyaak cheyabadavachhu (mariyu lopala unna janyuvulu ikapai nissabdam cheyabadavu). ayithe, facultative heterochromatin erpadatam niyantrinchabadutundi, mariyu tarachugaa padanirmaanam ledhaa bhedamto mudipadi untundi. facultative heterochromatineku oka udaaharana stree ksheeradaalalo x chromosome nishkriyaatmakatah oka x chromosome facultative heterochromatinga pyaak cheyabadutundi mariyu nissabdam cheyabadutundi, maroka x chromosome eukromatinga pyaak cheyabadutundi mariyu vyakteekarinchabadutundi.
heterochromatin vyaaptini niyantrinche paramaanu bhagalalo polycomb-group proteins mariyu gist vanti naan-coding janyuvulu unnaayi. atuvanti vyaaptiki gala vidhanam ippatikee vivaadaaspadamaina vishayam. polycomb anachiveta sanklishtatalu prc1 mariyu prc2 chromatin sampeedanaanni mariyu janyu vyakteekarananu niyantristaayi mariyu abhivruddhi prakriyalalo praathamika paatranu kaligi untaayi. prc-madhyavartitva epigenetic apavartanalu janyuvu asthirata mariyu praanaantakatatoo mudipadi untaayi mariyu dna nashtam pratispandana, dna marammattu mariyu pratiroopam yokka viswasaneeyatalo paatra poeshistaayi.
eest heterochromatin.
"saccaromysis serevisia" ledhaa budding eest anedi oka namuunaa eucariot mariyu daani heterochromatin puurtigaa nirvachinchabadindi. daani janyuvulo ekkuva bhaganni eukromatinluga vargeekarinchavachhu. serivisia "loe chaalaa paelavamgaa lipyantareekarana cheyabadina dna praantaalu unnaayi. eee lokilu nissabda samyoga rakam lokey (hchml mariyu hcmr), rdna (encoding ribosomal rna) mariyu sub-telomeric praantaalu anie pilavabadataayi.
vichchitti eest ("schizosacharomysis pombe") daani centromers vadda heterochromatin erpadataaniki maroka yantraamgaanni upayogistundi. eee pradaesamloe janyu nissabdam anedi raie maargamloni bhagalapai aadharapadi untundi. double-stranded rna varusa dasala dwara eee praantaanni nissabdam chestundani nammutaaru.
vichchitti eest "schizosacharomysis pombe" loe, rendu raine complexelu, rits complexes mariyu rna-directed rna polymerase complexes (rdrc), heterochromatin assembly praarambhinchadam, pracharam mariyu nirvahanalo palgone raine yantramlo bhaagam. eee rendu sanklishtatalu heterochromatin assembly unna pradaesamloe chromosomelapy sirna-aadhaarita paddhatiloo sthaanikeekarinchabadathaayi. rna polymerase II anedi heterochromatin assembleaki avasaramaina rits, rdrc mariyu bahusha itara complexelanu niyaminchadaaniki oka vaedikagaa panichese transcriptnu samslaeshanha chestundi. raie mariyu exosome-aadhaarita rna ksheenata prakriya rendoo binna varna janyuvu nissabdaaniki dohadam chestaayi. schizosacharomysis pombe" yokka eee vidhanalu itara eukariotlalo sambhavinchavachhu. konni vichchitti eest loe heterochromatin erpadataaniki madhyavartitvam cheyadaaniki sirnas utpattilo revsen anie piluvabade pedda rna nirmaanam kooda chikkukundi.

