性别判定基因突变与男性不育症相关性的研究

Correlativity of SRY Gene Mutation with Male Sterility.

采用两对引物的多重聚合酶链反应(mPCR)技术,对28例镜下无精子、先天性睾丸发育不良男性不育症患者性别决定基因(SRY基因)扩增。一对引物特异于SRY基因序列称为引物对A,扩增片段长为280bp,另一对引物B,可从X染色体及Y染色体分别扩增出两个DNA片段,分别为590bp、355bp。在确定SRY基因无大缺失情况下,用引物对A行单链构象多态性分析(PCR/SSCP),检测有无基因突变。结果发现有7例患者SSCP与正常男性不同,可能有突变。进而用Sanger氏的双脱氧末端终止法测该7例患者280bp片段DNA序列,有3例在128密码子发现A→T突变;使原赖氨酸的密码子突变为终止密码(AAG→TAG)。结果提示部分镜下无精子、先天睾丸发育不良男性不育症患者可能与性别决定基因突变有一定的相关。

This investigation adapted multiple polymerase chain reactions (PCR) with primers (A) from a sex-determining region of the Y chromosome and X - Y homologous primers (B). A 280bp (Y) fragment was amplified with primers (A). The fragment of 355bp(Y) and 590bp(X) was amplified with primers(B) as an inner control. We detected 28 male sterility patients who had congenital testis dysplasia and were not found sperms by the microscope. The amplificated products were showed 280, 355 and 590bp bands. The results indicated the samples did not carry homozygous deletions in the SRY gene. The samples were further analyzed for the presence of subtle mutations by the PCR - SSCP (single strand conformation polymerphism)method with primers A. Abnormal mobility shifts were observed in 7 patients. Since the results suggest that gene mutations occurred, we performed sequence analysis by the dideoxy chain termination method. Identical nonsense mutations ( AAGLys-TAGstop)at the codon 128 were observed in 3 patients. The mutations changed lysine codons into premature stop codons in the SRY gene. The results suggest mutations of the SRY gene correlate with male sterility.