Nyob hauv tib neeg, cov hlwb polyploid yog pom nyob rau hauv cov ntaub so ntswg tseem ceeb, xws li daim siab thiab placenta. Ib lo lus dav dav feem ntau siv los piav txog tiam ntawm cov hlwb polyploid yog endoreplication, uas yog hais txog ntau yam genome duplications yam tsis muaj kev cuam tshuam kev faib / cytokinesis.
Puas polyploidy tuag rau tib neeg?
Ntxim qab kawg, polyploidy yog qhov tuag tsis hais txogntawm kev sib deev phenotype ntawm embryo (piv txwv li, triploid XXX tib neeg, uas loj hlob li poj niam, tuag, zoo li triploid ZZZ qaib, uas loj hlob Raws li cov txiv neej), thiab polyploidy ua rau muaj qhov tsis xws luag hnyav dua li trisomy cuam tshuam nrog kev sib deev chromosomes (diploids nrog X lossis Y ntxiv …
Puas yog tib neeg diploid lossis polyploid?
Tib neeg yog diploid kab mob, ib txwm nqa ob pawg chromosomes tiav hauv lawv cov hlwb somatic: ob daim ntawv ntawm leej txiv thiab leej niam chromosomes, raws li, hauv txhua 23 homologous khub ntawm chromosomes uas tib neeg ib txwm muaj.
Dab tsi ua rau polyploidy hauv tib neeg?
Polyploids tshwm sim thaum muaj qhov tsis tshua muaj mitotic lossis meiotic kev puas tsuaj, xws li kev tsis sib haum xeeb, ua rau tsim cov gametes uas muaj tag nrho cov chromosomes duplicate… Thaum lub diploid gamete fuses nrog a haploid gamete, ib daim ntawv triploid zygote, txawm hais tias cov triploids no feem ntau tsis ruaj khov thiab feem ntau tuaj yeem ua rau tsis muaj menyuam.
polyploidy ua li cas puas tsim nyog?
Kev nce hauv DNA cov ntsiab lus, ib yam li cov ntaub ntawv hauv polyploids, feem ntau ua rau cov cell thiab lub cev loj dua(Müntzing, 1936). … Qhov tshwm sim no tau raug postulated ua ntej raws li "high-ploidy syndrome," qhov twg ntau ploidy theem nthuav tawm kev nthuav dav ntawm tes tab sis txo qis ntawm tes (Tsukaya, 2008).
