Qhov qhov tseem ceeb sib txawv ntawm polytene thiab lampbrush chromosome yog tias polytene chromosome yog ib tug loj, rau armed thiab banded chromosome tam sim no nyob rau hauv ntau hom dipteron ya thaum lub teeb ci chromosome yog ib tug loj chromosome tam sim no nyob rau hauv oocytes ntawm vertebrates uas muaj ib tug zoo nkaus li ntawm ib tug lampbrush
Ib chromosome hais txog cov xov zoo li cov qauv tsim los ntawm nruj ntim DNA molecule thiab histone proteins. Nws kuj muaj cov qauv zoo thiab qhov nruab nrab loj. Txawm li cas los xij, muaj cov chromosomes loj heev nyob rau hauv qee cov tsiaj hlwb. Raws li txoj cai, lawv yog cov chromosomes loj heev. Ntawm cov chromosomes loj, polytene thiab lampbrush chromosome yog ob qho piv txwv.
Polytene Chromosome yog dab tsi?
Polytene chromosome yog ib tug loj chromosome nrhiav tau los ntawm E. G. Balbiani thawj zaug nyob rau hauv 1881. Feem ntau, lawv muaj nyob rau hauv dipteron ya hom, tshwj xeeb tshaj yog nyob rau hauv lawv cov qog nqaij hlav qog. Yog li ntawd, thaum xub thawj, lawv tau raug xa mus rau lub caj pas salivary chromosomes. Raws li kev kwv yees, polytene chromosomes ntau zaus loj dua thiab tuab dua li cov chromosomes ib txwm.
Daim duab 01: Polytene Chromosome
Tsis zoo li cov chromosomes ib txwm, lawv muaj ntau cov kab ntev ntev thiab 1000 npaug ntau DNA. Tsis tas li ntawd, polytene chromosome strands muaj ob hom bands uas yog tsaus bands thiab interbands. Piv txwv li, cov bands tsaus muaj ntau DNA ntau dua li cov interbands. Yog li ntawd, thaum peb siv ib tug nuclear stains, dub bands stain tsaus nyob rau hauv kev sib piv rau cov interband raws li qhia saum toj no nyob rau hauv daim duab 1.
Lampbrush Chromosome yog dab tsi?
Lampbrush chromosome yog lwm cov chromosome loj uas muaj nyob hauv oocytes ntawm amphibians thiab hauv qee cov kab. Xyoo 1882, W alther Flemming tau soj ntsuam thiab sau cov chromosome loj no thawj zaug thaum nws txheeb xyuas cov seem ntawm salamander oocytes. Structurally no chromosome tshwm raws li ib tug lampbrush. Qhov zoo li no yog vim muaj lub ntsiab chromosomal axis thiab thoob plaws hauv lub axis, khub ntawm loops tshwm sim nyob rau hauv lub opposite lus qhia ntsug mus rau lub ntsiab chromosomal axis. Qhov tshwj xeeb ntawm lub teeb chromosome yog tias nws tsis muaj nyob rau hauv cov tsiaj nyeg txawm tias nws muaj nyob rau hauv cov oocytes loj hlob ntawm cov tsiaj feem ntau.
Daim duab 02: Lampbrush Chromosome
Lampbrush chromosome yog qhov muaj txiaj ntsig zoo li tus qauv chromosome thaum kawm lub koom haum ntawm chromosomes, kev ua haujlwm ntawm genome thiab kev qhia ntawm cov noob hauv kev faib meiotic thiab lwm yam. Nws yog vim muaj ib tug neeg transcription units nyob rau hauv txhua tus neeg lub voj ntawm lub lampbrush chromosome, uas yog yooj yim pom. Tsis tas li ntawd, lampbrush chromosome yog ib qho tseem ceeb nyob rau hauv high-resolution mapping DNA sequences thiab kev tsim kho ntawm nthuav dav cytological maps ntawm ib tug chromosomes.
Dab tsi yog qhov zoo sib xws ntawm Polytene thiab Lampbrush Chromosome?
- Ob leeg polytene thiab lampbrush chromosome yog loj chromosomes.
- Yog li, lawv loj heev piv rau cov chromosomes ib txwm.
- Tsis tas li ntawd, lawv tshwm sim hauv qee lub hlwb.
- Cov chromosomes tuaj yeem pom hauv qab lub teeb tsom iav.
Qhov txawv ntawm Polytene thiab Lampbrush Chromosome yog dab tsi?
Hauv kev sib piv rau cov chromosomes ib txwm, qee cov chromosomes tuab dua thiab loj dua. Tsis tas li ntawd, lawv muaj DNA ntau dua li cov chromosomes li qub, yog li lawv pom tau txawm tias nyob hauv lub teeb pom kev zoo. Polytene thiab lampbrush yog ob lub chromosomes loj heev tam sim no nyob rau hauv cov qog ua kua qaub ntawm dipteron ya hom thiab loj hlob oocytes ntawm vertebrates feem. Qhov sib txawv tseem ceeb ntawm polytene thiab lampbrush chromosome yog tias polytene chromosome muaj ntau cov strands thaum lub teeb txhuam chromosome muaj lub teeb pom kev zoo. Lwm qhov sib txawv ntawm polytene thiab lampbrush chromosome yog tias polytene chromosome muaj ob hom bands ntawm DNA strands thaum lub teeb txhuam chromosome tsis muaj cov qauv banding. Tsis tas li ntawd, peb tuaj yeem txheeb xyuas qhov sib txawv ntawm polytene thiab lampbrush chromosome raws li qhov loj me thiab. Lub lampbrush chromosome yog cov chromosome loj tshaj plaws uas tau sau tseg txog tam sim no thaum lub polytene chromosome kuj me dua li cov teeb ci chromosome.
Infographic ntawm qhov sib txawv ntawm polytene thiab lampbrush chromosome hauv qab no qhia cov ntsiab lus ntxiv hauv daim ntawv teev npe.
Summary – Polytene vs Lampbrush Chromosome
Polytene thiab lampbrush chromosome yog ob lub chromosome loj. Raws li lub npe qhia, lawv yog cov chromosomes uas loj heev. Lawv tshwm sim nyob rau hauv tej theem ntawm lub neej voj voog ntawm ib co tsiaj hlwb. Raws li, polytene chromosome muaj nyob rau hauv cov qog ua kua qaub ntawm dipteron yoov thaum lub teeb chromosome muaj nyob rau hauv loj hlob oocytes ntawm vertebrates. Tsis tas li ntawd, polytene chromosome muaj ntau DNA strands uas muaj cov kab tsaus nti thiab interbands. Ntawm qhov tod tes, lampbrush chromosome muaj lub ntsiab chromosomal axis thiab raws li axis, muaj vertically khiav khub ntawm loops. Yog li, qhov no qhia txog qhov sib txawv ntawm polytene thiab lampbrush chromosome.
