Karolo ea Chromosome: Ho Utloisisa Sebopeho le Mosebetsi oa Liphatsa tsa Lefutso
Li-chromosome ke meaho e rarahaneng e fumanoang ka har'a khubu ea lisele tsa eukaryotic. Li jara tlhahisoleseling ea liphatsa tsa lefutso ka mokhoa oa DNA le liprotheine, li bapala karolo ea bohlokoa phetisong ea litšobotsi ho tloha molokong o mong ho ea ho o mong. Ho utloisisa hore na li-chromosome li sebetsa joang, ho bohlokoa ho hlahlobisisa likarolo tsa tsona ka botebo le hore na li kenya letsoho joang mosebetsing oa liphatsa tsa lefutso. Sehloohong sena, re tla hlahloba likarolo tse kholo tsa li-chromosome, ho kenyeletsoa li-centromere, li-telomere, li-chromatids le tse ling, le mesebetsi ea tsona.
Sebopeho sa Motheo sa Li-chromosome
Li-chromosome li entsoe ka DNA e kopantsoeng ka thata ho potoloha limolek'hule tsa protheine tse bitsoang histones, tse etsang sebopeho se tsejoang e le chromatin. Liseleng tsa eukaryotic, li-chromosome lia bonahala 'me li hlophisoa nakong ea mekhahlelo ea karohano ea sele, mitosis le meiosis. Chromatin e kobehileng e theha li-chromatids, tse shebahalang joaloka likhoele tse kobehileng, 'me chromosome ka' ngoe e na le li-chromatids tse peli tse tšoanang tse bitsoang li-chromatids tsa khaitseli.
Setsi sa bohareng
E 'ngoe ea likarolo tsa bohlokoa ka ho fetisisa tsa chromosome ke centromere. Centromere ke karolo ea chromosome e sebetsang e le ntlha ea ho khomarela li-chromatids tse peli tsa khaitseli 'me ke sebaka sa ho khomarela kinetochore. Kinetochore ke sebopeho se rarahaneng sa protheine seo likhoele tsa spindle li khomarelang ho sona nakong ea karohano ea sele, e thusang ho arola li-chromatids ka ho nepahetseng ho ea ho lisele tsa morali.
Sentromere ha se kamehla e leng bohareng ba chromosome; boemo ba yona bo ka fapana. Ho latela boemo ba centromere, di-chromosome di ka arolwa ka mefuta e mmalwa: metacentric (centromere bohareng), submetacentric (centromere e ka hodimo hanyane bohareng), acrocentric (centromere haufi le pheletso), le telocentric (centromere qetellong).
Telomer
Li-telomere ke lipheletso tsa li-chromosome tse otlolohileng, tse entsoeng ka tatellano ea DNA e pheta-phetoang. Li-telomere li sireletsa lipheletso tsa li-chromosome hore li se ke tsa senyeha le ho kopana le li-chromosome tse ling. Nako le nako ha sele e arohana, li-telomere lia khutsufala, e leng se amanang le botsofali ba sele le botsofali ka kakaretso. Enzyme ea telomerase e ka eketsa bolelele ba telomere, e bapala karolo ea bohlokoa liseleng tse lokelang ho arohana khafetsa, joalo ka lisele tsa kutu le lisele tsa mofetše.
Li-telomere le tsona li bapala karolo ea bohlokoa ho khetholleng nako ea bophelo ba sele. Ha li-telomere li ba khutšoanyane haholo, lisele li kena mohatong o tsejoang e le botsofali, moo li khaotsang ho arohana empa li lula li sebetsa ka mokhoa oa metabolism. Ena ke mokhoa oa bohlokoa oa ho thibela kholo e sa laoleheng ea lisele le mofetše.
Chromatid
Chromatide ke sete e tšoanang ea likarolo tse peli tse otlolohileng tse etsang chromosome e iphetang. Pele ho karohano ea sele, chromosome e na le li-chromatid tse peli tse hokahaneng sebakeng se bitsoang centromere. Chromatide ka 'ngoe e na le kopi e nepahetseng ea DNA, e netefatsang hore sele e 'ngoe le e 'ngoe ea morali e fumana thepa e felletseng ea lefutso e hlokahalang bakeng sa ts'ebetso e tloaelehileng.
Matsoho a P le Q
Li-chromosome li ka aroloa likarolo tse peli tse kholo tse bitsoang matsoho. Letsoho le lekhutšoanyane le tsejoa e le letsoho la P, ha letsoho le lelelele le bitsoa letsoho la Q. Lebitso lena le tsoa ho Sefora, 'petit' e bolelang e nyane bakeng sa letsoho la P. Karohano ena e thusa ho etsa 'mapa oa li-chromosome le ho khetholla sebaka sa liphatsa tsa lefutso tse itseng.
Mekhoa e fapaneng ea ho etsa 'mapa oa li-chromosome, joalo ka ho taka mabanta le ho kopanya li-fluorescein in situ (FISH), e sebelisa likarohano tsena ho khetholla ka nepo sebaka sa liphatsa tsa lefutso kapa lintho tse sa tloaelehang ka har'a genome. Sena se thusa lipatlisisong tsa liphatsa tsa lefutso le ho hlahloba maemo a amanang le genome.
Mosebetsi le Bohlokoa ba Li-chromosome
Li-chromosome ha li na feela liphatsa tsa lefutso; li boetse li laola tlhahiso ea liphatsa tsa lefutso le ho netefatsa botsitso ba liphatsa tsa lefutso ka karohano ea sele e laoloang. Tse ling tsa mesebetsi le bohlokoa ba li-chromosome ke tsena:
1. Phetiso ea Liphatsa tsa Lefutso: Li-chromosome li lumella ho rua lintho tsa lefutso ho tloha molokong o mong ho ea ho o mong, ho netefatsa hore bana ba fumana tlhahisoleseling ea liphatsa tsa lefutso e hlokahalang bakeng sa nts'etsopele le ts'ebetso.
2. Taolo ea Liphatsa tsa Lefutso: Sebaka sa liphatsa tsa lefutso ho li-chromosome le tšebelisano ea tsona le liprotheine tsa histone le balaoli ba bang ba susumetsa tlhahiso ea liphatsa tsa lefutso. Sebopeho sa chromatin se ka ba se senyenyane kapa se hlephileng, e leng se etsang qeto ea hore na phatsa ea lefutso e sebetsa kapa ha e sebetse.
3. Taolo ea Mefuta-futa ea Liphatsa tsa Lefutso: Nakong ea meiosis, liketsahalo tse kang ho tšela le ho fapanyetsana lintho tsa lefutso pakeng tsa li-chromosome tse tšoanang li eketsa mefuta-futa ea liphatsa tsa lefutso, sena se bohlokoa bakeng sa ho iphetola ha lintho le ho ikamahanya le maemo.
4. Ho Tsitsisa ha Genome: Sebopeho se otlolohileng le se kobehileng sa li-telomere se thusa ho sireletsa tlhahisoleseling ea liphatsa tsa lefutso nakong ea ts'ebetso ea ho ikatisa ha DNA, ho thibela tšenyo kapa tahlehelo ea tlhahisoleseling ea liphatsa tsa lefutso.
Qetello
Ho utloisisa likarolo tsa li-chromosome le mesebetsi ea tsona ho fana ka temohisiso e tebileng mabapi le mekhoa ea lefutso le matla a liphatsa tsa lefutso linthong tse phelang. Karolo e 'ngoe le e 'ngoe ea chromosome e na le karolo e ikhethang le ea bohlokoa ho bolokeng botšepehi le ho tsoela pele ha lintho tsa lefutso, e leng se nolofalletsang lintho tse phelang ho hola, ho hola le ho ikatisa ka katleho. Ho tloha ho li-centromere ho ea ho li-telomere, karolo e 'ngoe le e 'ngoe e sebetsa 'moho ho netefatsa hore tlhahisoleseling ea liphatsa tsa lefutso e bolokoa le ho hlahisoa ka mokhoa o hlophisehileng, e totobatsang mohlolo le ho rarahana ha bophelo boemong ba microscope. Lipatlisiso tse ling li ntse li tsoela pele ho senola liphiri ka li-chromosome, tse ka tlatsetsang kutloisisong ea rona ea mafu a liphatsa tsa lefutso le mekhoa e mecha ea phekolo.
