健康人成熟精子中mRNA的种类特征

Characterization of mRNA in ejaculated spermatozoa from healthy fertile men

目的分析具有正常生育能力男性成熟精子mRNA的种类特征。方法健康并育有后代的成年男性11例,禁欲3～5d后取精液,上游法纯化精子,Trizol试剂提取精子总RNA。混合所有总RNA进行基因表达系列分析(SAGE),随后对所得SAGE文库进行功能聚类性分析。结果所建SAGE文库共获877个克隆,测序得到21052个标签,出现两次以上的独特性标签有2712种。SAGE文库用DAVID软件进行功能性聚类分析,高丰度的389个基因能聚合成25组功能性的基因。最突出的是一组核蛋白基因、参与DNA依赖的基因转录和转录调节;其次是与胞质,核糖体蛋白以及蛋白质合成相关的基因;其他基因类别还包括蛋白多肽水解相关蛋白;具有蛋白激酶活性,蛋白氨基酸磷酸化、蛋白修饰相关蛋白;免疫相关蛋白等。结论人成熟精子中存在数量庞大、种类繁多的mRNA,这些mRNA可能并不仅仅是在精子形成过程中残留下来的,它的功能可能包括重新翻译以替代降解的蛋白、染色质的重组装,受精过程中传递一些父系必须的RNAs到卵子中以进行表观遗传。

Objective To explore the characterization of mRNA in the ejaculated sperm from healthy fertile men. Methods Semen samples were collected from 11 healthy fathers. The swim-up method was adopted to purify the spermatozoa from possible contamination of somatic cells and the spermatozoa total RNA extracted by Trizol was used for SAGE library analysis. The data was analyzed by DAVID 2.1 software （http：//david.abcc.ncifcrf.gov/）. Results A total of 21 052 SAGE raw tags were sequenced from 877 clones and 2 712 unique tags that occurred at least twice in the library were given further analysis. When the SAGE library of spermatozoa was analyzed by the DAVID software, 389 genes could be clustered as 25 function groups. The first obvious group was nucleus proteins related to transcription and transcription regulation （DNA-dependent）, and the second big gene groups were ribosomal subunit involving protein biosynthesis. The rest of gene groups pointed to functions were similar to proteolysis and peptidolysis; protein kinase; antigen presentation, cell adhesion and immunity etc. Conclusion There exists a complex repertoire of mRNAs in the ejaculated spermatozoa from fertile men. These mRNAs probably were not only the remains in the spermiogenesis, but also maybe have other important functions, such as being retranslated to replace the degraded proteins, selective chromatin repackaging, and bringing some father＇s necessary RNAs to the oocyte mediating epigenetic change of inheritance.