Gatewood J M, Cook G R, Balhorn R, Bradbury E M, Schmid C W
Science. 1987 May 22;236(4804):962-4. doi: 10.1126/science.3576213.
The DNA in human sperm chromatin is packaged into nucleoprotamine (approximately 85%) and nucleohistone (approximately 15%). Whether these two chromatin fractions are sequence-specific subsets of the spermatozoon genome is the question addressed in this report. Sequence-specific packaging would suggest distinct structural and functional roles for the nucleohistone and nucleoprotamine in late spermatogenesis or early development or both. After removal of histones with 0.65M NaCl, exposed DNA was cleaved with Bam HI restriction endonuclease and separated by centrifugation from insoluble nucleoprotamine. The DNA sequence distribution of nucleohistone DNA in the supernatant and nucleoprotamine DNA in the pellet was compared by cloning size-selected single-copy sequences and by using the derived clones as probes of nucleohistone DNA and nucleoprotamine DNA. Two clones derived from nucleohistone DNA preferentially hybridized to nucleohistone DNA, and two clones derived from nucleoprotamine DNA preferentially hybridized to nucleoprotamine DNA, which demonstrated the existence of sequence-specific nucleohistone and nucleoprotamine components within the human spermatozoon.
人类精子染色质中的DNA被包装成核精蛋白（约85%）和核组蛋白（约15%）。这两种染色质组分是否是精子基因组的序列特异性亚集，是本报告所探讨的问题。序列特异性包装表明核组蛋白和核精蛋白在精子发生后期或早期发育或两者中具有不同的结构和功能作用。用0.65M NaCl去除组蛋白后，将暴露的DNA用Bam HI限制性内切酶切割，并用离心法与不溶性核精蛋白分离。通过克隆大小选择的单拷贝序列，并将得到的克隆用作核组蛋白DNA和核精蛋白DNA的探针，比较了上清液中核组蛋白DNA和沉淀中核精蛋白DNA的DNA序列分布。来自核组蛋白DNA的两个克隆优先与核组蛋白DNA杂交，来自核精蛋白DNA的两个克隆优先与核精蛋白DNA杂交，这证明了人类精子中存在序列特异性的核组蛋白和核精蛋白成分。
