Modi D, Shah C, Sachdeva G, Gadkar S, Bhartiya D, Puri C
Stem Cell Biology Department, National Institute for Research in Reproductive Health, Indian Council of Medical Research, Mumbai, Maharashtra, India.
Reproduction. 2005 Nov;130(5):603-13. doi: 10.1530/rep.1.00413.
The sex-determining region on the Y (SRY) gene is unequivocally designated as the testis-determining factor in mammals; however, its roles beyond sex determination, if any, have been hitherto unknown. To determine whether SRY has any roles beyond sex determination, herein the expression of SRY mRNA was investigated in the midtrimester human fetal, infantile and adult testes as well as in ejaculated spermatozoa. High levels of SRY transcripts were in situ localized to the Sertoli cells of the developing testis at 9 weeks of gestation, and the expression persisted at comparable levels throughout the midtrimester (until 22 weeks) and also in the testis of an infant at 3 months of age. The germ cells and other somatic cells in the testes of fetuses and the infant were negative for SRY expression. The mRNA for SRY was detected in the spermatogenic cells, particularly the spermatogonia and the round spermatids; the expression was negligible in the meiotic stages. A single transcript of approximately 1.2 kb was detected in the adult testes and isolated spermatogonial cells. In the adult testis, in situ hybridization (ISH) studies revealed a switch in the cellular localization of SRY transcripts. SRY transcripts were also demonstrable by RT-PCR of RNA from ejaculated human spermatozoa. ISH revealed the presence of SRY transcripts in the midpiece of 50% of ejaculated sperm. These results suggest that SRY may have extensive roles in male reproductive physiology, such as maturation of fetal testis, spermatogenesis, sperm maturation and early embryonic development.
Y染色体性别决定区（SRY）基因被明确认定为哺乳动物的睾丸决定因子；然而，其在性别决定之外的作用（若有的话），迄今仍不为人知。为了确定SRY在性别决定之外是否具有任何作用，本文研究了SRY mRNA在孕中期人类胎儿、婴儿及成人睾丸以及射出精子中的表达情况。高水平的SRY转录本在妊娠9周时原位定位于发育中睾丸的支持细胞，并且在整个孕中期（直至22周）以及3个月大婴儿的睾丸中，该表达持续维持在相当水平。胎儿和婴儿睾丸中的生殖细胞及其他体细胞SRY表达均为阴性。在生精细胞中检测到了SRY的mRNA，尤其是精原细胞和圆形精子细胞；在减数分裂阶段表达可忽略不计。在成人睾丸和分离的精原细胞中检测到了一条约1.2 kb的单一转录本。在成人睾丸中，原位杂交（ISH）研究显示SRY转录本的细胞定位发生了转变。通过对射出人类精子RNA进行RT-PCR也证实了SRY转录本的存在。ISH显示50%射出精子的中段存在SRY转录本。这些结果表明，SRY可能在男性生殖生理学中具有广泛作用，如胎儿睾丸成熟、精子发生、精子成熟及早期胚胎发育。
