Leibniz Institute of Plant Genetics and Crop Plant Research, 06466 Gatersleben, Germany.
Proc Natl Acad Sci U S A. 2011 Aug 16;108(33):E498-505. doi: 10.1073/pnas.1103190108. Epub 2011 Jul 11.
Uniparental chromosome elimination occurs in several interspecific hybrids of plants. We studied the mechanism underlying selective elimination of the paternal chromosomes during the early development of Hordeum vulgare × Hordeum bulbosum embryos. The following conclusions regarding the role of the centromere-specific histone H3 variant (CENH3) in the process of chromosome elimination were drawn: (i) centromere inactivity of H. bulbosum chromosomes triggers the mitosis-dependent process of uniparental chromosome elimination in unstable H. vulgare × H. bulbosum hybrids; (ii) centromeric loss of CENH3 protein rather than uniparental silencing of CENH3 genes causes centromere inactivity; (iii) in stable species combinations, cross-species incorporation of CENH3 occurs despite centromere-sequence differences, and not all CENH3 variants get incorporated into centromeres if multiple CENH3s are present in species combinations; and (iv) diploid barley species encode two CENH3 variants, the proteins of which are intermingled within centromeres throughout mitosis and meiosis.
单亲染色体消除发生在植物的几个种间杂种中。我们研究了大麦与球茎大麦胚胎早期发育过程中父本染色体选择性消除的机制。关于着丝粒特异性组蛋白 H3 变体（CENH3）在染色体消除过程中的作用得出以下结论：（i） 球茎大麦染色体着丝粒失活引发不稳定的大麦与球茎大麦杂种中依赖有丝分裂的单亲染色体消除过程；（ii） 是 CENH3 蛋白的着丝粒丢失而不是 CENH3 基因的单亲沉默导致着丝粒失活；（iii） 在稳定的种间组合中，尽管存在着丝粒序列差异，但仍会发生 CENH3 的种间掺入，并且如果种间组合中存在多个 CENH3，则并非所有 CENH3 变体都会掺入到着丝粒中；（iv） 二倍体大麦物种编码两种 CENH3 变体，其蛋白在整个有丝分裂和减数分裂过程中交织在着丝粒内。
