一个人类精子发生相关新基因TSARG7的克隆和初步功能研究

精子发生是一个多基因参与的复杂的生理过程，虽然人们克隆了一些与精子发生相关的基因，但迄今为止，人们对精子发生的分子机制了解有限，因而克隆相关的新基因，并研究其在理论上和实践上的功能仍然十分重要。该文从人类睾丸cDNA文库出发，以小鼠精子发生相关基因mTSARG7基因为电子探针，得到1个与人类的精子发生相关的新基因TSARG7（GenBank登录号为AY513610）,该基因的cDNA全长为2463bp，含有12个外显子和11个内含子，定位在人类8号染色体8p11.21上。TSARG7编码的蛋白质含有456个氨基酸，分子量为56．295kDa，等电点为9．13，为胞浆中非分泌性蛋白，具有磷酸酰基转移酶（Hsc）的结构域，属于酰基转移酶家族的新成员，该家族成员具有脂质合成的功能。TSARG7和mTSARG7，TSARG7和Au041707分别具有97％的同源性。该基因在睾丸中特异表达，亚细胞定位在胞浆中表达。TSARG7 mRNA在13岁的睾丸中开始表达，并且随着精子的发生和性成熟而稳定增加，热应急实验显示该基因的表达与温度相关。综上所述，该文克隆了人的1个新基因，该基因与精子的发生和性成熟相关。

Molecular Cloning and Preliminary Function Study of a Novel Human Gene, TSARG7, Related to Spermatogenesis

A novel human gene TSARG7 (GenBank accession No. AY513610) was identified from a human testis cDNA library by using the mTSARG7 gene (GenBank accession No. AY489184) as an electronic probe. The gene whose full cDNA length is 2 463 bp containing 12 exons and 11 introns is located in the human chromosome 8p11.21. The predicted protein encoded by this gene contains 456 amino acids with a theoretical molecular weight of 56 295 dalton and isoelectric point of 9.13. It is a new member of the acyltransferase family since its sequence possesses the highly conserved PlsC domain existing in all acyltransferase-like pro-teins. Two groups, the TSARG7 and mTSARG7, the TSARG7 and Au041707, share 97% identity in the 456 amino acids. Expres-sion of the TSARG7 gene is restricted to the testis. Subcellular localization studies show that the EGFP-tagged TSARG7 protein was localized in the cytoplasm of GC-1 cells. The TSARG7 mRNA expression was initiated in the testis of a 13-year-old boy, and its level increased steadily along with spermatogenesis and sexual maturation of the human. The results of heat stress experiment demonstrate that TSARG7 expression has a relation with temperature. In conclusion, our study suggests that we have cloned a novel human gene and this gene may play an important role in human spermatogenesis and sexual maturation.