Early disruption of centromeric chromatin organization in centromere protein A (Cenpa) null mice
Early disruption of centromeric chromatin organization in centromere protein A (Cenpa) null mice
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DOI：
10.1073/pnas.97.3.1148
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发表时间：
2000-02-01
影响因子：
11.1
通讯作者：
Choo, KHA
中科院分区：
文献类型：
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作者：
Howman, EV;Fowler, KJ;Choo, KHA
着丝粒蛋白 A（小鼠为 Cenpa，其他物种为 CENP-A）是一种组蛋白 H3 样蛋白，被认为参与着丝粒 DNA 的核小体包装。通过基因打靶，我们破坏了小鼠 Cenpa 基因，并证明该基因是必需的。杂合子小鼠健康且具有生育能力，而无效突变体在受孕后无法存活超过 6.5 天，受影响的胚胎表现出严重的有丝分裂问题，包括微核和大核形成、核桥接和起泡以及染色质碎片和超浓缩，第 5.5 天时间期细胞的免疫荧光分析显示 Cenpa 完全耗尽，弥散性 Cenpb 焦点，着丝粒上缺乏离散的 Cenpc 信号，Cenpb 和 Cenpc 分散在整个细胞核中。这些结果表明，Cenpa 对于 Cenpc 的着丝粒靶向至关重要，并且在间期组织着丝粒染色质中发挥早期作用。该证据与 CENP-A 在标记着丝粒形成的染色体区域中具有关键表观遗传功能的提议一致。
Centromere protein A (Cenpa for mouse, CENP-A for other species) is a histone H3-like protein that is thought to be involved in the nucleosomal packaging of centromeric DNA. Using gene targeting, we have disrupted the mouse Cenpa gene and demonstrated that the gene is essential. Heterozygous mice are healthy and fertile whereas null mutants fail to survive beyond 6.5 days postconception, Affected embryos show severe mitotic problems, including micronuclei and macronuclei formation, nuclear bridging and blebbing, and chromatin fragmentation and hypercondensation, Immunofluorescence analysis of interphase cells at day 5.5 reveals complete Cenpa depletion, diffuse Cenpb foci, absence of discrete Cenpc signal on centromeres, and dispersion of Cenpb and Cenpc throughout the nucleus. These results suggest that Cenpa is essential for kinetochore targeting of Cenpc and plays an early role in organizing centromeric chromatin at interphase, The evidence is consistent with the proposal of a critical epigenetic function for CENP-A in marking a chromosomal region for centromere formation.