摘要目的:比较正常生育男性及少弱精子症患者 DAZL基因启动子区域DNA甲基化水平的差异。 方法:采用病例对照研究，回顾性分析2018年6月至2019年6月期间于徐州医科大学附属连云港医院就诊的具有正常生育男性（对照组）15例和少弱精子症患者35例（少弱精子症组）的临床资料，对精液标本进行精子形态与精子浓度、活力分析。提取精液基因组DNA行亚硫酸氢盐处理，利用PCR体外扩增并将PCR产物经纯化后与pCR2.1载体连接及酶切验证，挑选阳性克隆进行测序和DNA甲基化程度差异比较。结果:对照组 DAZL基因启动子均呈低甲基化水平，甲基化率为0.96%±0.46%，少弱精子症组甲基化率为12.15%±11.35%，组间差异有统计学意义（ P=0.000 4）； DAZL基因甲基化率在少弱精子症组患者中个体差异明显，有12例（34.3%）患者DNA甲基化水平超过10%。 结论:DAZL基因启动子区域甲基化异常可能和少弱精子症有关，有望成为男性生精缺陷的生物学标志之一。

abstractsObjective:To compare the DNA methylation levels of DAZL promoter regions in spermatozoa between the normozoospermic and oligoasthenozoospermic males. Methods:A case-control study was performed. Routine semen analysis and morphological analysis were performed in 15 normozoospermic individuals (control group) and 35 subfertile patients with oligoasthenozoospermia(oligoasthenozoospermia group). Semen were purified by density gradient centrifugation. DNA was extracted, treated with bisulfite, amplified by PCR and the purified PCR products were cloned into pCR2.1 vector and then proceeded to chemical transformation, restriction enzyme reaction. The positive clones of each sample were selected for sequencing analysis and DNA methylation analysis.Results:The DNA methylation rate of DAZL promoters was increased significantly in oligoasthenozoospermia group (12.15%±11.35%) compared with control group (0.96%±0.46%) ( P=0.000 4). There was also an obvious difference in the DNA methylation status among oligoasthenozoospermia males. DNA methylation levels were significantly increased in 12 (34.3%) patients with oligoasthenozoospermia. Conclusion:Aberrant methylation of DAZL gene promoters is associated with male infertility, and it may be a biomarker of human spermatogenesis defect.