小鼠睾丸生精细胞凋亡相关基因SRG2的分子克隆及其在隐睾中的表达特征

Molecular Cloning and Expression in Cryptorchid Testis of SRG2 from a Mouse Testis Spermatocyte Apoptosis-related Gene

从已获得的在隐睾和正常睾丸对照中表达量有明显差异的EST片段 (BE6 4 4 5 4 2 )入手 ,利用网上生物信息学克隆了SRG2基因全长 ,GenBank登录号为AF395 0 83。从小鼠睾丸cDNA文库中分离出该基因完整阅读框cDNA ,SRG2基因的cDNA全长为 10 88bp ,为编码 2 95个氨基酸、分子量为 335 79kD、等电点为 9 6 4的蛋白质 ,与人类同源基因TSARG2相似性为 78% ,而与其他已知蛋白质无明显同源性。RT PCR结果表明 :该基因只在睾丸中有高表达。应用新型的分子信标检测该基因在不同时期隐睾中的mRNA表达水平 ,发现该基因呈明显上调 。

It was observed that the spermatogenic cells apop to sis dramatically increased in infertile man.Cloning of novel spermatogenic cell -specific gene related to apoptosis is of momentous physiological and pathologi cal significance to illustrate the apoptosis mechanism and the biology process o f spermatogenic cells.A novel mouse gene full-length cDNA sequence- SRG2 was identified (GenBank accession number AF395083),which was significantly changed in cryptorchidism,from a mouse testis cDNA library us ing a cDNA fragment (GenBank accession number BE644542) as an electronic probe. SRG2 was 1 088 bp in length.The putative protein enc oded by this gene was 295 amino acids with a theoretical molecular weight of 33 579 kDa and isoelectric point of 9.64.The sequence shared no significant homolo gy with any known protein in databases except TSARG2 ,with which its homology was 78%.RT-PCR showed that SRG2 was expressed significantly in testis.Using molecular beacon probe to exa mine the mRNA expression level of SRG2 gene in crypt orchid testis of various stages,we found that the gene was up-regulated distinc tly.Therefore,we conclude that this gene plays an important role in cryptorchid testis.