Histone H2A insufficiency causes chromosomal segregation defects due to anaphase chromosome bridge formation at rDNA repeats in fission yeast.
Histone H2A insufficiency causes chromosomal segregation defects due to anaphase chromosome bridge formation at rDNA repeats in fission yeast.
复制标题
组蛋白 H2A 不足会因裂殖酵母中 rDNA 重复序列处形成后期染色体桥而导致染色体分离缺陷。
DOI：
10.1038/s41598-019-43633-5
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发表时间：
2019
影响因子：
4.6
通讯作者：
Hiraoka Y.
中科院分区：
文献类型：
--
作者：
Yamamoto TG;Ding DQ;Nagahama Y;Chikashige Y;Haraguchi T;Hiraoka Y.
核小体是染色质的基本结构单位，由DNA和组蛋白核心组成。裂殖酵母含有组蛋白H_2A、HTA~(1+)和H_(ta2+)两个基因，这两个基因分别编码三个氨基酸残基不同的组蛋白H_2A(H_2A_α和H_2A_β)，在减数分裂过程中只上调H_(ta2+)。然而，目前还不清楚S。PombeH_2Aα和H_2A_β在功能上存在差异。因此，在本研究中，我们研究了在INS减数分裂过程中，H_2Aα和H_2Aβ之间可能的功能差异。庞贝。我们发现hta2+的缺失，而不是hta1+的缺失，会导致减数分裂过程中染色体分离和孢子形成的缺陷。Hta2+缺失细胞中的减数分裂缺陷可通过表达额外的hta1+拷贝或表达hta2启动子中的hta1+来挽救。这表明缺陷是由于组蛋白H_2A含量不足引起的，而不是由于H_2Aα和H_2Aβ之间的氨基酸残基差异所致。显微镜观察将染色体分离缺陷归因于核糖体RNA基因重复序列(rDNA重复序列)染色体区域后期桥的形成。这些结果表明，组蛋白H_2A缺乏影响rDNA重复序列的染色质结构，导致染色体错误分离INS。庞贝。
The nucleosome, composed of DNA and a histone core, is the basic structural unit of chromatin. The fission yeastSchizosaccharomyces pombehas two genes of histone H2A,hta1+andhta2+; these genes encode two protein species of histone H2A (H2Aα and H2Aβ, respectively), which differ in three amino acid residues, and onlyhta2+is upregulated during meiosis. However, it is unknown whetherS. pombeH2Aα and H2Aβ have functional differences. Therefore, in this study, we examined the possible functional differences between H2Aα and H2Aβ during meiosis inS. pombe. We found that deletion ofhta2+, but nothta1+, causes defects in chromosome segregation and spore formation during meiosis. Meiotic defects inhta2+deletion cells were rescued by expressing additional copies ofhta1+or by expressinghta1+from thehta2promoter. This indicated that the defects were caused by insufficient amounts of histone H2A, and not by the amino acid residue differences between H2Aα and H2Aβ. Microscopic observation attributed the chromosome segregation defects to anaphase bridge formation in a chromosomal region at the repeats of ribosomal RNA genes (rDNA repeats). These results suggest that histone H2A insufficiency affects the chromatin structures of rDNA repeats, leading to chromosome missegregation inS. pombe.