中文摘要：

研究小鼠生精新基因SRG4在出生后小鼠睾丸及手术隐睾中的表达特性,为了解SRG4在精子发生中的作用奠定基础。取出生后1,3,12w小鼠睾丸进行免疫组化检测,观察SRG4蛋白在出生后小鼠不同发育阶段睾丸中的表达;制备单侧手术隐睾模型,取术后0～18d的隐睾组织进行半定量RT-PCR检测,观察SRG4 mRNA在隐睾病变过程中的表达变化,并对隐睾术后18d睾丸进行组织原位杂交分析。免疫组化分析结果表明,SRG4蛋白在出生1w的小鼠睾丸中几乎检测不到,在出生3w的小鼠睾丸中有明显表达,在出生12w的小鼠中大量表达,主要分布在精母细胞和圆形精子细胞胞浆及胞膜,呈不均匀分布。半定量RT-PCR结果发现,SRG4 mRNA在小鼠隐睾术后0～6d表达没有明显下调,9d开始表达下调,第18d表达最低。组织原位杂交结果表明,术后18d隐睾睾丸生殖细胞大量凋亡,精曲小管中仅见到个别的SRG4阳性信号,而对照则不受影响。上述结果说明,SRG4蛋白表达受小鼠生长发育调控;隐睾模型中,随着生殖细胞的大量凋亡,SRG4基因表达下调,提示SRG4基因可作为一个精子发生特定阶段的分子标记用以研究精子发生过程。

英文摘要：

To understand the function of SRG4, a novel spermatogenesis gene, we studied its expression pattern during normal mouse development and in experimental cryptorchidism. Testis tissues were collected from 1-, 3-, and 12-week-old normal mice and immunohistochemistry was used to detect the expression of SRG4. We performed surgery on mice to create unilateral cryptorchidism and monitored SRG4 mRNA levels by semi-quantitative RT-PCR in the cryptorchid testis from day 0-18. At post-operative day 18, the cryptorchid testis and the contralateral control testis were harvested and assayed for SRG4 expression by in situ hybridization. Immunohistochemistry results showed that SRG4 protein was hardly detected in 1-week-old mouse testis, but the expression was present in 3-week-old mouse and abundant in 12-week-old mouse testis. SRG4 immunostaining was mainly localized to the cytoplasm and membrane of spermatocytes and round spermatids. Moreover, semi-quantitative RT-PCR result showed the expression of SRG4 mRNA did not decrease until 9 d after cryptorchid surgery, and continued to decline thereafter. In situ hybridization revealed that in contrast to the abundant SRG4 expression in the control side, few remaining germ cells in the crytorchid testis were positive for SRG4 at d 18 after surgery. The results indicated that the expression of SRG4 was regulated by development, and SRG4 was mainly expressed in the cytoplasm of spermatocytes and round spermatids. However, in cryptorchid testis, in which most germ cells undergo apoptosis, only a few of SRG4 is observed, suggesting that SRG4 may be as a specific marker to evaluate the process of spermatogenesis.