中文摘要：

目的探讨生殖细胞高度特异性基因VASA和信号分子BMP-4在精子发生中的作用和相关机制.方法正常和少精子症患者精液通过Percoll梯度分离获得精子和未成熟生精细胞,采用RT-PCR、real-time PCR、Western Blot和免疫荧光方法分析基因转录产物表达.结果少精子症精子VASA基因转录产物是正常精子的1/5;两种样本精子中均检测到荧光信号,正常组信号强,与Western blot结果相一致;两种样本精子RT-PCR均未检测到BMP-4及其Ⅰ型受体Alk-3表达,但在分离的未成熟生精细胞中均表达.人正常睾丸组织可检测到BMP-4及其Alk-3表达.结论少精子症患者精子发生过程中VASA基因及其产物发生变化;BMP-4及其受体Alk-3并不直接上调VASA表达;睾丸组织包括精子所存在的部分转录产物,而精子转录产物并不完全等同于睾丸组织;睾丸组织内表达BMP-4和Alk-3的可能主要是精原和精母细胞.

英文摘要：

Objective The current study was designed to identify whether transcript of VASA was changed in oligospermatism compared to normal fertile men, and to determine whether VASA and BMP-4 affect spermatogenesis, as well as the relationship between VASA and BMP-4, I type receptor Alk-3 on spermatogenesis. Methods Ejacu- lates of normal and oligospermatism were collected by masturbation and subsequently segregation through discontinuous gradient of Percoll to remove the residual somatic cells and purified spermatozoa, immature spermatogenic cells （spermatogonium and spermatocyte）. Total RNA was extracted, and RT-PCR, Real-time PCR, immunofluorescence and Western Blot （WB） were used to assess the gene transcript. Results VASA expression was significantly reduced in oligospermatism. Real-time PCR analysis to indicate that transcription of VASA was greater by approximately five fold in normal spermatozoa than in oligospermatism group. VASA protein was detected on spermatozoa of both normal and abnormal groups by immunofluorescence and Western Blot, lower level was detected on the oligospermatism group. BMP-4 and Alk-3 were undetectable by RT-PCR in both normal and abnormal spermatozoa, but expressed on the immature spermatogenic cells. Normal human testis expressed BMP-4 and Alk-3. Conclusion Identification of VASA various expression profile in normal and oligospermatism reveals that VASA was associated with spermatogenesis. BMP-4 and receptor Alk-3 do not directly upregulate expression of VASA. Testes transcript included the counterpart of spermatozoa. The expression of BMP-4 and Alk-3 from the testes may be due to spermatogonium and spermatocyte. Our findings suggest VASA play a role in the spermatogenesis or serve as valuable markers of fertility status and provide a genetic fingerprint of normal fertile men.