Qhov sib txawv tseem ceeb ntawm centromere thiab kinetochore yog qhov centromere yog thaj tsam ntawm chromosome uas tuav ob tus muam chromatids ua ke tom qab kev rov ua dua ntawm chromosome thaum kinetochore yog cov disc-zoo li protein complex ntawm chromosome uas tso cai rau spindle fibers txuas. thaum lub sij hawm faib cell.
Txoj kev hloov pauv ntawm cov ntaub ntawv caj ces yog nyob ntawm kev sib cais ntawm cov chromosomes hauv cov txheej txheem ntawm mitosis thiab meiosis. Mitosis yog kev tsim cov noob qes zoo ib yam, thaum meiosis yog tsim cov menyuam ntxhais uas muaj ib khub ntawm txhua tus chromosome uas muaj nyob rau hauv niam txiv cell. Tsis tas li ntawd, kev sib cais ntawm chromosome yog cov txheej txheem muaj tseeb heev. Nws microstructure thiab cov duab yog qhov tseem ceeb heev rau txoj kev sib cais. Tsis tas li ntawd, cov txheej txheem no tag nrho nyob ntawm kev ncaj ncees ntawm microtubules. Cov chaw ntawm kev txuas ntawm microtubules, yog li ntawd, yuav tsum muaj qee yam khoom tshwj xeeb. Centromere thiab kinetochore yog ob thaj tsam ntawm chromosomes uas ua lub luag haujlwm tseem ceeb thaum lub sijhawm faib ntawm tes. Lub hom phiaj tseem ceeb ntawm tsab xov xwm no yog qhia txog qhov sib txawv ntawm centromere thiab kinetochore.
Centromere yog dab tsi?
A centromere yog thaj chaw nruj heev ntawm chromosome uas tuav ob tus viv ncaus chromatids ua ke hauv ib chromosome. Nws kuj tso cai rau spindle fibers txuas rau nws thaum lub sij hawm tus txheej txheem ntawm mitosis thiab meiosis. Cov cheeb tsam tshwj xeeb no muaj cov proteins uas tsis yog histone uas tiv thaiv lawv los ntawm kev zom zaub mov endonuclease thiab lawv tsis muaj nucleosomes. Lub luag haujlwm tseem ceeb ntawm centromere yog muab qhov chaw rau kinetochores.
Daim duab 01: Centromere
Nyob rau hauv eukaryotes, qhov ntau thiab tsawg ntawm cov centromeres sib txawv, tab sis txhua yam muaj tib txoj haujlwm. Feem ntau cov eukaryotes muaj monocentric centromeres, qhov twg cov centromere-kinetochore complex cov ntaub ntawv ntawm ib tug taw tes ntawm chromosome tsuas yog nyob rau hauv ib co nematodes. Tsis zoo li hauv cov kab mob unicellular, centromeres ntawm ntau cov kab mob muaj nyob rau hauv cov khoom tsim centric heterochromatin. Centromere muaj qhov tshwj xeeb rov ua dua DNA ua ntu zus. Tsis tas li ntawd, nws tsuas yog khi nrog ib qho tshwj xeeb ntawm cov proteins. Cov cheeb tsam no, yog li ntawd, tshuaj sib txawv ntawm tus so ntawm chromosome.
Kinetochore yog dab tsi?
Kinetochore yog ib qho disc-zoo li protein complex tam sim no nyob rau hauv cheeb tsam centromere ntawm ib chromosome uas yog nyob rau hauv lub mitotic los yog meiotic division. Txhua chromosome muaj ib tug kinetochore. Lub luag haujlwm ntawm cov complexes no yog khi microtubules ntawm spindle bundle thiab depolarize lawv thaum lub sij hawm cell faib. Ntau lub hlwb muaj cov disc zoo li kinetochore nrog peb txheej sib txawv uas tsim ntawm ib sab ntawm txhua chromatid. Sab hauv txheej ntawm kinetochore yog txuam nrog centromere thaum txheej txheej sab nrauv cuam tshuam nrog microtubules. Kev ua haujlwm ntawm nruab nrab txheej tsis paub. Tus naj npawb ntawm cov microtubules khi rau ib lub kinetochore sib txawv nrog cov hom. Piv txwv li, tib neeg kinetochore khi kwv yees li ntawm 15 microtubules whereas kinetochore ntawm Saccharomyces khi nrog tib lub microtubules.
Daim duab 02: Kinetochore
Nyob rau hauv qee yam kab mob xws li protozoa, qee cov fungi, thiab kab, kinetochore tsis tuaj yeem pom tau tias cov proteins tawg thaum npaj. Unattached kinetochores muaj cov fibers uas muaj ntau cov proteins hu ua corona. Cov kab mob corona no pab txhawm rau ntes microtubules thaum lub sijhawm faib ntawm tes. Cov microtubules cuam tshuam nrog kinetochores muaj lub neej ntev, thaum cov neeg nyob hauv qhov seem ntawm cov ntxaiv muaj lub neej luv heev.
Dab tsi yog qhov zoo sib xws ntawm Centromere thiab Kinetochore?
- Ob lub centromere thiab kinetochore muaj nyob rau hauv chromosomes.
- Lawv tseem ceeb heev rau kev faib cell.
- Thiab, lawv pom thaum lub sijhawm faib cell.
Qhov txawv ntawm Centromere thiab Kinetochore yog dab tsi?
A centromere yog thaj chaw txwv tsis pub muaj nyob ntawm chromosome nrog tshwj xeeb, rov ua dua DNA ua ntu zus. Txawm li cas los xij, kinetochore yog ib qho disc-zoo li protein complex pom nyob rau hauv cheeb tsam centromere ntawm chromosome. Yog li, qhov no yog qhov sib txawv tseem ceeb ntawm centromere thiab kinetochore. Tsis tas li ntawd, qhov sib txawv tseem ceeb ntawm centromere thiab kinetochore yog tias centromeres pom meej meej nyob rau hauv lub teeb tsom iav raws li thaj chaw txwv ntawm cov chromosome condensed thaum kinetochore tsuas tuaj yeem pom nrog kev pab ntawm lub tshuab ntsuas hluav taws xob. Tsis tas li ntawd, tsis zoo li hauv centromeres, muaj peb txheej sib txawv hauv lub kinetochore. Li no, qhov no kuj yog qhov txawv ntawm centromere thiab kinetochore.
Ntxiv mus, qhov sib txawv ntxiv ntawm centromere thiab kinetochore yog tias kinetochore muaj corona thaum tsis muaj cov qauv zoo li no pom hauv centromeres. Tsis tas li ntawd, cov centromeres tsis tuaj yeem khi nrog cov microtubules. Tsuas yog cov kinetochores uas cuam tshuam nrog centromeres muaj peev xwm khi microtubules. Yog li, peb tuaj yeem xav txog qhov no kuj yog qhov sib txawv ntawm centromere thiab kinetochore.
Hauv qab infographic qhia txog qhov sib txawv ntawm centromere thiab kinetochore.
Summary – Centromere vs Kinetochore
A centromere yog ib qho kev txwv ntawm chromosome. Nws muaj ntau condensed chromatin nyob ib ncig ntawm histone proteins. Nws tuav ob tug muam chromatids ntawm ib chromosome ua ke. Ntawm qhov tod tes, kinetochore yog ib qho protein complex sib sau ua ke nyob ib ncig ntawm lub centromere ntawm chromosome. Nws muab cov chaw rau kev txuas ntawm microtubules thaum lub sijhawm faib ntawm tes. Ob leeg centromere thiab kinetochore xyuas kom meej qhov kev faib tawm thiab kev sib cais ntawm chromosomes thiab chromatids thaum lub sijhawm faib ntawm tes. Yog li, qhov no yog cov ntsiab lus ntawm qhov sib txawv ntawm centromere thiab kinetochore.
