中心体蛋白centrin在大鼠精子发生过程中的表达

目的：研究中心体蛋白centrin在大鼠生精细胞中的表达情况，以深入了解centrin在精子发生过程中的作用。方法：通过重力沉降法分离大鼠不同发育阶段的生精细胞，用免疫荧光和蛋白印迹实验检测各级生精细胞中centrin蛋白的表达，用定量RT－PCR检测centrin同源基因centrin1和centrin2mRNA的表达水平。结果：间接免疫荧光和蛋白印迹显示精母细胞、圆形、长形精子细胞均有centrin蛋白存在，位于中心粒上，而在附睾的成熟精子中centrin则消失。RT－PCR研究发现，centrin在睾丸组织中特异性表达，centrin2在多种组织中均有表达。在睾丸中，centrin1仅在生精细胞进入减数分裂后转录，其mRNA水平在圆形精子细胞中最高，而centrin2在精原细胞中即有表达，减数分裂后其mRNA难以检测到。结论centrin蛋白在大鼠雄性配子的发育过程中最终丢失；该基因家族中同源基因centrin1和centrin2表达呈现组织特异性和发育阶段特性，在精子发生过程中发挥不同功能，centrin1蛋白可能与减数分裂及鞭毛生成相关，centrin2则参与细胞有丝分裂过程。

THE EXPRESSION OF CENTRIN IN RAT SPERMATOGENESIS

Objective To study the expression of centrin at different stages of rat spermatogenesis. Methods The Wistar male rat germ cells at different stages of spermatogenesis were isolated by gravity sedimentation.The centrin protein,centrin1 and centrin2 mRNA were estimated by indirect immunofluorescence staining,Western blot and RT\|PCR. Results The centrin protein was expressed in spermatocyte,round spermatid and elongating spermatid,but not detected in mature epididymal sperm.The results from RT\|PCR showed that the rat centrin1 gene was exclusively expressed in testis.While,rat centrin2 mRNA was detected in various tissues examined,including testis,kidney,spleen,brain,heart and ovary.In testis,the mRNA of centrin1 gene was not detected until the male germ cells had developed into spermatocytes and the amount of its mRNA reached the highest level in round spermatid.However,the expression of centrin2 gene was showed in spermatogonia and then decreased to undetectable level. Conclusion Centrin protein is lost in the development of rat male germ cells.The isoforms of centrin play different roles in rat spermatogenesis.Centrin1 might be involved in meiosis and the flagellum formation and centrin2 may play a role in mitosis.