mt ND2基因多态性与弱精子症的相关性分析

Analysis of the mt ND2 Gene Polymorphisms Associated with Asthenospermia Patients

为了探讨线粒体ND2(mt ND2)基因多态性与弱精子症的相关性,按WHO标准收集了134例弱精子症和1 12例精子活力正常的精液标本,PCR测序或双向等位基因PCR(Bi-PASA)技术分析ND2基因多态性,统计ND2基因4个位点多态性在两组间的差异。应用变性高效液相色谱(DHPLC)分析m.5442T>C和m.5466A>G多态性变异的异质性。结果发现了34个变异位点,其中6个位点未曾报道;ND2基因m.5351A>G、m.5460G>A和m.5466A>G变异率弱精子症组显著高于对照组(P<0.05),m.5442T>C变异率对照组显著高于弱精子症组(P<0.05);进一步分析m.5460G>A和m.5466A>G突变阳性标本精子活力显著低于突变阴性标本(P<0.001),m.5442T>C突变阳性标本精子活力显著高于突变阴性标本(P<0.001)。提示:ND2基因一些核苷酸变异(m.5351A>G、m.5460G>A和m.5466A>G)可能与弱精子症有关,m.5460G>A和m.5466A>G错义突变可能是精子活力的有害因素,而m.5442T>C多态性可能对精子活力具有一定的帮助。

This research attempted to investigate whether there was correlationship between mt ND2 gene polymorphisms in sperms and asthenospermia. After 134 asthenospermia cases and 112 control cases were collected under the WHO criterion, the ND2 gene variation of them were detected by using sequencing or bidirectional PCR amplification of specific alleles（Bi-PASA） technology. Consequently, We analyze ND2 gene polymorphisms in the asthenospermia and controls. Heteroplasmic mutation of m.5442T〉C and m.5466A〉G were detected by DHPLC. Then, a total of 34 nucleotide variations were found in ND2 genes in asthenospermia and controls, six of them were the reported for the first time in this study. The frequencies of single point mutation of m.5351A〉G, m.5460G〉A and m.5466A〉G in asthenospermia were significantly higher than those in the controls （P〈0.05）. However, frequencies of m.5442T〉C mutation in the controls was significantly higher than those in the asthenospermia（P〈0.05）. The percents of grade a and grade （a＋b） sperm in mutation samples（with m.5460G〉A or m.5466A〉G mutation） were significantly lower than that in non-mutation samples（P〈0.001）. However, the percents of grade a and grade （a＋b） sperm in m.5442T〉C mutation samples were significantly higher than that in non-mutation samples （P〈0.001）. ND2 gene polymorphisms may have some correlation with sperm motility. The m.5460G〉A and m.5466A〉 G mutation may impair sperm motility,whereas the m.5442T〉C polymorphisms may have benefit for sperm motility.