Histone modifications associated with both A and B chromosomes of maize
Histone modifications associated with both A and B chromosomes of maize
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DOI：
10.1007/s10577-008-1269-8
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发表时间：
2008-12-01
影响因子：
2.6
通讯作者：
Jiang, Jiming
中科院分区：
文献类型：
--
作者：
Jin, Weiwei;Lamb, Jonathan C.;Jiang, Jiming
我们报告了几个组蛋白修饰沿着臂和在着丝粒区的玉米体细胞染色体，包括额外的B染色体的分布。乙酰化的H3和H4以及H3 K4 me2，与常染色质相关的修饰，在A染色体的远端部分富集，但向A染色体的着丝粒逐渐耗尽，并在B染色体的异染色质部分耗尽。与异染色质相关的经典组蛋白修饰，包括H3 K9 me2、H3 K27 me1和H3 K27 me2，分布在A和B染色体上。然而，与A染色体相比，H3 K27 me2在B染色体上的水平降低，并且与某些类型的组成性异染色质无关。我们使用YFP标记的着丝粒特异性组蛋白CENH3监测着丝粒区域中每个组蛋白修饰的存在。我们观察到在玉米的A和B染色体的着丝粒区域中存在H3 K9me2而不存在H3 K4me2，这与在动物的着丝粒中存在H3 K4me2而不存在H3 K9me2相反。这些结果表明，在不同的真核生物与着丝粒染色质的表观遗传修饰的多样性。
We report the distribution of several histone modifications along the arms and in centromeric regions of somatic chromosomes of maize, including the supernumerary B chromosome. Acetylated H3 and H4 as well as H3K4me2, modifications associated with euchromatin, were enriched in the distal parts of the A chromosomes, but were progressively depleted toward the centromeres of the A chromosomes and were depleted in the heterochromatic portions of the B chromosome. Classical histone modifications associated with heterochromatin, including H3K9me2, H3K27me1 and H3K27me2, were distributed throughout both A and B chromosomes. However, H3K27me2 showed a reduced level on the B chromosome compared with the A chromosomes and was not associated with some classes of constitutive heterochromatin. We monitored the presence of each histone modification in the centromeric regions using a YFP-tagged centromere-specific histone, CENH3. We observed the presence of H3K9me2 and absence of H3K4me2 in the centromeric regions of both A and B chromosomes of maize, which is in contrast to the presence of H3K4me2 and absence of H3K9me2 in animal centromeres. These results show a diversity of epigenetic modifications associated with centromeric chromatin in different eukaryotes.