停服棉酚后恢复的大鼠精母细胞蛋白质合成的研究

A STUDY ON THE SYNTHESIS OF CELLULAR PROTEINS OF THE REPOPULATING RAT SPERMATOCYTE AFTER THE WITHDRAWAL OF GOSSYPOL TREATMENT

经不同时间(3～12周)给大鼠喂服棉酚后应用~3H-精氨酸参入技术,测定睾丸内恢复的第一世代粗线期精母细胞(RPS)的细胞蛋白和核内碱性蛋白合成量的变化。结果表明,与未服棉酚的对照组粗线期精母细胞(CPS)相比较,RPS的细胞蛋白~3H-精氨酸参入量有轻度的抑制,抑制程度从12％到26％;而核碱性蛋白合成活性有明显减少,其减少程度从46％到61％。从正常的粗线期精母细胞提取的碱性蛋白作凝胶电泳分离,表明大部分碱性蛋白是核小体联接蛋白和核心蛋白,即组蛋白H_1、H_(2A)、H_(2B)、H_3和H_4,还有少量精子特异蛋白BP和X_1。喂服棉酚后的RPS,其精子特异蛋白BP和X_1以及核心组蛋白H_(2A)和H_4有明显的减少。这表明棉酚影响了PRS核碱性蛋白与BNA量之间的比例,从而改变了细胞的正常生理功能。本文讨论了这种比例与核小体联接和染色质结构的直接关系。

The synthesis of cellular and nuclear basic proteins in the first generation of the repopulated pachytene spermatocytes (RPS) after the withdrawal of gossypol treatment and the normal control pachytene spermatocyte (CPS) were studied by the incorporation of ~3H-arginine into proteins. After treatment with gossypol for various periods of time, the synthetic activity for cellular protein in the RPS was slightly inhibited. In comparison to CPS, the inhibitory rate ranged from 12% to 26% (gossypol treatment for 3 to 12 weeks, respectively). However, the synthetic activity for nuclear basic protein in the RPS was drastically reduced in comparison to that of the CPS. The reductive rate ranged from 46％ to 61％ in RPS (gossypol treatment for 3 to 12 weeks, respectively).Gel electrophoretic separation of the basic protein extracted from normal pachytene cell indicated that the major basic proteins were nucleosomal linker and core proteins, i. e., histone H_1, H_(2a), H_(2b), H_3 and H_4, and with a lesser amount of spermspecific BP and X_1 proteins. In the RPS, the synthesis of sperm-specific proteins(BP and X_1) and core histones (H_(2a) and H_4) reduced markedly.Finally, the effect of gossypol on the ratio change of nuclear basic protein to DNA in RPS and its relation to nucleosomal spacing and chromatin structure are discussed.