Karwacki Violetta, Kovac Judit, Mauceri Grazia, Backhaus Arne, Föhse Lisa, Schmidtke Jörg, Schubert Stephanie
Institute of Human Genetics, Medical School Hannover, Carl-Neuberg-Strasse 1, D-30625 Hannover, Germany.
Genomics. 2006 Jul;88(1):65-73. doi: 10.1016/j.ygeno.2006.03.006. Epub 2006 Apr 19.
The TSPY gene is conserved in placental mammals and encodes the testis-specific protein, Y encoded. Within the testis, TSPY expression is restricted to germ cells, and it is assumed that TSPY plays a role in the proliferation of germ cells. Since it was first discovered in humans, TSPY orthologous gene families have been subsequently characterized in many mammalian lineages. In contrast to the situation in cattle and primates, in which TSPY is organized in a moderately repetitive cluster, including functional members and pseudogenes, a peculiar situation is observed in rodents, in which Tspy has been become low or single copy and degenerated to a pseudogene in some species of the subgenus Mus. We have extended this approach and investigated Tspy gene evolution in the Syrian hamster (Mesocricetus auratus) and the Mongolian gerbil (Meriones unguiculatus). Whereas the Syrian hamster Tspy is functionally conserved, organized in multiple copies, and expressed only in testis, the closely related Mongolian gerbil possesses a single-copy pseudogene that is unable to generate a functional transcript. Thus, the Tspy locus has degenerated at least twice at different points of rodent evolution, strongly supporting the hypothesis that the decay of Y-chromosomal genes is an intrinsic evolutionary process. TSPY is the first example of a Y-chromosomal tandem repetitive gene whose decay could be studied in two independent mammalian lineages.
TSPY基因在胎盘哺乳动物中保守，编码Y染色体编码的睾丸特异性蛋白。在睾丸内，TSPY表达仅限于生殖细胞，推测TSPY在生殖细胞增殖中起作用。自首次在人类中发现以来，TSPY直系同源基因家族随后在许多哺乳动物谱系中得到了表征。与牛和灵长类动物不同，在牛和灵长类动物中TSPY以中度重复簇的形式组织，包括功能成员和假基因，在啮齿动物中观察到一种特殊情况，在小家鼠亚属的一些物种中，Tspy已变得低拷贝或单拷贝并退化为假基因。我们扩展了这种方法，研究了叙利亚仓鼠（金仓鼠）和蒙古沙鼠（长爪沙鼠）中Tspy基因的进化。叙利亚仓鼠的Tspy功能保守，以多拷贝形式组织，且仅在睾丸中表达，而亲缘关系密切的蒙古沙鼠拥有一个单拷贝假基因，无法产生功能性转录本。因此，Tspy基因座在啮齿动物进化的不同点至少退化了两次，有力地支持了Y染色体基因衰变是一个内在进化过程的假说。TSPY是第一个可以在两个独立的哺乳动物谱系中研究其衰变的Y染色体串联重复基因的例子。
