Steger K, Klonisch T, Gavenis K, Drabent B, Doenecke D, Bergmann M
Institut für Anatomie und Zellbiologie, Halle (Saale), Germany.
Mol Hum Reprod. 1998 Oct;4(10):939-45. doi: 10.1093/molehr/4.10.939.
The most important event determining the nuclear status of sperm cells is the replacement of histones by protamines, which are the basic nuclear proteins of mature spermatozoa. A first step in this exchange is the displacement of histones by transition proteins (TP). Our study demonstrates, for the first time, the sequential expression of the testis-specific histone (H1t) and the transition proteins (TP1 and TP2) during normal human spermatogenesis. H1t mRNA could only be detected in the cytoplasm of mid and late pachytene spermatocytes. Concomitant with the onset of H1t transcription, the H1t protein appeared in the nuclei of pachytene spermatocytes and remain as a nuclear protein constituent up to step 5 spermatids. While transition protein 1 gene TNP-1 mRNA was present in spermatids from step 2 to early step 4, the TP1 protein occured, with temporal delay, in the nuclei of step 3 and step 4 spermatids. The TP2 protein was observed in the nuclei of spermatids from step 1 to step 5. The transition protein 2 gene TNP-2 mRNA was only detected by reverse transcription-polymerase chain reaction, but not on paraffin sections. These data demonstrate a strong temporal association between H1t gene transcription and synthesis of the H1t protein. Since the TP1 protein appeared with temporal delay we can assume that the corresponding TNP-1 mRNA is translationally delayed.
决定精子细胞核状态的最重要事件是组蛋白被鱼精蛋白取代，鱼精蛋白是成熟精子的碱性核蛋白。这种交换的第一步是组蛋白被过渡蛋白（TP）取代。我们的研究首次证明了在正常人类精子发生过程中睾丸特异性组蛋白（H1t）和过渡蛋白（TP1和TP2）的顺序表达。H1t mRNA仅在粗线期精母细胞中期和后期的细胞质中检测到。随着H1t转录的开始，H1t蛋白出现在粗线期精母细胞的细胞核中，并作为核蛋白成分一直保留到第5步精子细胞。虽然过渡蛋白1基因TNP-1 mRNA在第2步到第4步早期的精子细胞中存在，但TP1蛋白在第3步和第4步精子细胞的细胞核中出现有时间延迟。TP2蛋白在第1步到第5步的精子细胞核中观察到。过渡蛋白2基因TNP-2 mRNA仅通过逆转录-聚合酶链反应检测到，而在石蜡切片上未检测到。这些数据表明H1t基因转录与H1t蛋白合成之间存在很强的时间关联。由于TP1蛋白出现有时间延迟，我们可以假设相应的TNP-1 mRNA翻译延迟。
