Department of Biology, University of Pennsylvania, Philadelphia, PA, United States; Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, United States.
Curr Top Dev Biol. 2020;140:35-54. doi: 10.1016/bs.ctdb.2020.03.004. Epub 2020 Apr 25.
The centromere directs chromosome segregation but is not itself genetically encoded. In most species, centromeres are epigenetically defined by the presence of a histone H3 variant CENP-A, independent of the underlying DNA sequence. Therefore, to maintain centromeres and ensure accurate chromosome segregation, CENP-A nucleosomes must be inherited across generations through the germline. In this chapter we discuss three aspects of maternal centromere inheritance. First, we propose mechanisms for maintaining CENP-A nucleosomes through the prolonged prophase arrest in mammalian oocytes. Second, we review mechanisms by which selfish centromeres bias their transmission through female meiosis. Third, we discuss regulation of centromere size through early embryonic development.
着丝粒指导染色体分离,但本身并非遗传编码。在大多数物种中,着丝粒通过组蛋白 H3 变体 CENP-A 的存在在表观遗传上定义,与潜在的 DNA 序列无关。因此,为了维持着丝粒并确保染色体的准确分离,CENP-A 核小体必须通过生殖系世代相传。在本章中,我们讨论了母系着丝粒遗传的三个方面。首先,我们提出了在哺乳动物卵母细胞中通过延长前期阻滞来维持 CENP-A 核小体的机制。其次,我们回顾了自私着丝粒通过雌性减数分裂偏向其传递的机制。最后,我们讨论了通过早期胚胎发育调节着丝粒大小的机制。