无精子症患者减数分裂遗传重组的研究

摘要

[Objectives] To analyze defective homologous chromosomal recombination in Han Chinese azoospermic patients.[Methods] Testicular biopsy samples from 7 healthy controls and 7 Han Chinese azoospermic patients including 2 obstructive azoospermia (OA group) and 5 non-obstructive azoospermia (NOA group) were analyzed.Immunofluorescence staining was performed to categorize early stage cells at meiosis prophase and to analyze chromosome pairing and recombination of pachytene spermatocyte.Newly developed meiotic proteins antibodies (anti-SCP3,anti-synaptonemal complex proteins 3;anti-MLH1,antiMut-L Homolog I;anti-CREST,chromosome centromere antibody) were used to identify synaptonemal complex (anti-SCP3),recombination sites (anti-MLH1) and centromere (anti-CREST),respectively.Staging of spermatocyte was determined according to SCP3 formation progression.Qualitative data were compared by a Chi-square test,and ANOVA was used to analyze quantitative data.[Results] Respectively,2346 and 2932 spermatocytes were categorized in the controls and azoospermic patients.The proportions of zygotene cells in both OA group and NOA group were significantly higher than that of the control group.Investigation of 1967 pachytene cells from the controls and 354 pachytene cells from azoospermic patients indicated that the mean MLHI loci per pachytene cell of NOA group was statistically lower than that of the controls.Compared with the controls,incomplete synaptonemal complexes cells (containing gap and/orsplit) were significantly increased in the NOA group.[Conclusion] Delayed meiosis prophase is relatively common in azoospermic patients,and changes in quantity and distribution of recombination foci may be the cause for spermatogenesis arrest in Han Chinese population.%目的 探讨无精子症患者精母细胞减数分裂过程中染色体联会与遗传重组的情况.方法 对7名汉族正常人(对照组)和7例汉族无精子症患者,包括2例梗阻性无精子症(obstructive azoospermia,OA)和5例非梗阻性无精子症(non-obstructive azoospermia,NOA)进行睾丸组织精母细胞免疫荧光染色.联会复合体蛋白3(synaptonemal complex protein 3,SCP3)抗体标记联会复合体,DNA修复蛋白(human mutL homologl,MLHl)抗体定位遗传重组位点.结果 OA组和NOA组偶线期细胞比例较对照组均显著增加,差异具有统计学意义(P＜0.05).详细分析粗线期精母细胞MLH1位点数目及分布情况,发现NOA组患者中每个细胞MLH1位点数较对照组显著减少(P＜0.05),常染色体上无MLH1位点的染色体数目较对照组显著增加(P＜0.01),含有至少1条染色体臂上无MLH1位点的细胞比例较对照组增高.分析粗线期精母细胞中SCP3形态时发现,NOA患者中SCP3不完全联会的粗线期精母细胞比例显著高于对照组(P＜0.01).结论 无精子症患者减数分裂过程有延迟现象；NOA患者精母细胞遗传重组MLH1位点的数目和分布出现异常,染色体联会不完全现象增加,这些异常事件可能与NOA患者精子发生障碍有关.