Steiner Florian A, Henikoff Steven
Basic Sciences Division and Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
Basic Sciences Division and Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
Curr Opin Genet Dev. 2015 Apr;31:28-35. doi: 10.1016/j.gde.2015.03.010. Epub 2015 May 16.
Centromeric chromatin is distinguished primarily by nucleosomes containing the histone variant cenH3, which organizes the kinetochore that links the chromosome to the spindle apparatus. Whereas budding yeast have simple 'point' centromeres with single cenH3 nucleosomes, and fission yeast have 'regional' centromeres without obvious sequence specificity, the centromeres of most organisms are embedded in highly repetitive 'satellite' DNA. Recent studies have revealed a remarkable diversity in centromere chromatin organization among different lineages, including some that have lost cenH3 altogether. We review recent progress in understanding point, regional and satellite centromeres, as well as less well-studied centromere types, such as holocentromeres. We also discuss the formation of neocentromeres, the role of pericentric heterochromatin, and the structure and composition of the cenH3 nucleosome.
着丝粒染色质主要由包含组蛋白变体cenH3的核小体所区分，cenH3组织形成将染色体与纺锤体装置相连的动粒。芽殖酵母具有带有单个cenH3核小体的简单“点”着丝粒，裂殖酵母具有无明显序列特异性的“区域”着丝粒，而大多数生物的着丝粒则嵌入高度重复的“卫星”DNA中。最近的研究揭示了不同谱系之间着丝粒染色质组织的显著多样性，包括一些完全失去cenH3的谱系。我们综述了在理解点着丝粒、区域着丝粒和卫星着丝粒以及研究较少的着丝粒类型（如全着丝粒）方面的最新进展。我们还讨论了新着丝粒的形成、着丝粒周围异染色质的作用以及cenH3核小体的结构和组成。
