Zalenskaya I A, Bradbury E M, Zalensky A O
Department of Biological Chemistry, School of Medicine, University of California Davis, 95616, USA.
Biochem Biophys Res Commun. 2000 Dec 9;279(1):213-8. doi: 10.1006/bbrc.2000.3917.
Telomeres in human sperm nucleus are clustered at the nuclear periphery. Chromosomes in the sperm are highly condensed with protamines, however, a small portion of DNA remains associated with histones; the role of the nucleohistone is unknown. To examine structure of the telomeric chromatin, the sperm nuclei were treated with micrococcal nuclease. Chromatin released by the digestion was free from protamines, but contained histones and revealed nucleosomal organization. It was enriched with telomeric DNA organized into closely spaced nucleosomes with a periodicity of 148 +/- bp. Thus, while the most of the sperm genome is packed into extremely dense nucleoprotamine structure, at least a part of the telomeric DNA is arranged into nucleosomes and can be released by the nuclease. We suggest that telomeres might be among the first structures in the sperm nucleus that respond to oocyte signals for male pronucleus development at fertilization.
人类精子细胞核中的端粒聚集在核周边。精子中的染色体与鱼精蛋白高度浓缩在一起，然而，一小部分DNA仍与组蛋白相关联；核组蛋白的作用尚不清楚。为了研究端粒染色质的结构，用微球菌核酸酶处理精子细胞核。消化释放出的染色质不含鱼精蛋白，但含有组蛋白，并显示出核小体结构。它富含端粒DNA，这些端粒DNA被组织成紧密排列的核小体，周期为148±碱基对。因此，虽然精子基因组的大部分被包装成极其致密的核鱼精蛋白结构，但至少一部分端粒DNA被排列成核小体，并可被核酸酶释放。我们认为，端粒可能是精子细胞核中最早对受精时卵母细胞发出的雄性原核发育信号作出反应的结构之一。
