Trostle-Weige P K, Meistrich M L, Brock W A, Nishioka K
J Biol Chem. 1984 Jul 25;259(14):8769-76.
We have identified and purified TH3, a germ cell-specific histone. It has been characterized by amino acid analysis, tryptic peptide mapping, labeling with cystine, and by electrophoretic mobility as a variant of H3. On fully reduced Triton/acid/urea gels its mobility is retarded more than that of the somatic variants H3.2 and H3.3, but less than that of H3.1; it migrates between the H2As and H1s. Germinal cells from adult and sexually immature testes were purified by centrifugal elutriation followed by Percoll density gradient separation in order to study the distribution and synthesis of TH3. TH3 is found in significant levels in spermatogonia and in similar or slightly higher amounts in spermatocytes and round spermatids. The synthesis of TH3 takes place in the spermatogonia but not in spermatocytes, in contrast to the other testis-specific histones, TH2A, H1t, and TH2B. Therefore, TH3 may have a different role in spermatogenesis than do the other testis-specific histone variants.
我们已经鉴定并纯化了TH3，一种生殖细胞特异性组蛋白。它已通过氨基酸分析、胰蛋白酶肽图谱分析、用胱氨酸标记以及作为H3变体的电泳迁移率进行了表征。在完全还原的Triton/酸/尿素凝胶上，其迁移率比体细胞变体H3.2和H3.3的迁移率受到更大的阻碍，但比H3.1的迁移率受到的阻碍小；它在H2A和H1之间迁移。为了研究TH3的分布和合成，通过离心淘析，然后进行Percoll密度梯度分离，从成年和性未成熟睾丸中纯化生殖细胞。在精原细胞中发现TH3的含量很高，在精母细胞和圆形精子细胞中的含量相似或略高。与其他睾丸特异性组蛋白TH2A、H1t和TH2B不同，TH3的合成发生在精原细胞中，而不是在精母细胞中。因此，TH3在精子发生中的作用可能与其他睾丸特异性组蛋白变体不同。
