中心体蛋白Cenexin在大鼠精子发生过程中的表达特征

中心体蛋白Cenexin是成熟中心粒的唯一标志分子。为阐明中心粒在大鼠精子发生中的成熟以及功能，我们首先通过RT－PCR技术从大鼠睾丸组织中扩增出了Cenexin cDNA片段，原核表达重组蛋白后，用其免疫小鼠制备了高滴度的抗Cenexin的多克隆抗体，然后利用免疫荧光染色、Western Blot和半定量RT－PCR方法，研究了大鼠精子发生过程中Cenexin蛋白和基因的表达特征。结果显示Cenexin mRNA水平在精原细胞和精母细胞中较高，随后表达水平下降，而蛋白质分子在精原细胞到精子细胞中都定位于细胞的一个中心粒上，表示有成熟中心粒的存在，在长形精子细胞中该蛋白位于鞭毛的基体部。附睾的绝大多数成熟精子中Cenexin免疫染色消失。中心体蛋白Cenexin在精子变态期的表达变化可能与精子鞭毛形成的起始有关。

Characterization of expression of the centrosomal protein, Cenexin, in rat spermatogenesis]

The centrosomal protein, Cenexin, is a molecular marker of mature centriole. To elucidate the variability and function of mature centriole in spermatogenesis, the high titer polyclonal antibody against rat cenexin was obtained by immunizing mice with recombinant cenexin which was made up in this study. The expression of cenexin in rat spermatogenesis was carried out by semi-quantitative RT-PCR, immunofluorescence and Western Blot. The results demonstrated that the level of Cenexin mRNA was higher in spermatogonia and spermatocytes, then decreased in following stages, while Cenexin protein was located on one centriole from spermatogonia to spermatids, showing mature centriole existed in these stages. Cenexin protein was localized to the basal body of the flagellum in elongated spermatids and the stained signal disappeared in the most of epidydimal sperms. These results suggested that the expression pattern of cenexin in rat spermatogenesis might be related to the initiation of the flagella formation.