The functional analysis of microtubule-associated protein, Spag5, and the rescue experiment of hypogonadic phenotype by gene transfer of wild type Spag5 cDNA.

微管相关蛋白Spag5被认为是有丝分裂中期进程所必需的。然而，据报道，spag5基因敲除小鼠表型正常。为了揭示Spag5在体内的功能，我们制作了Spag5转基因大鼠，并将其与性腺功能低下（hgn）品系大鼠交配。hgn/hgn表型与Spag5的自发突变有关。雄性hgn/hgn不育，其睾丸支持细胞有丝分裂异常。经Spag5转基因的hgn/hgn雄性睾丸和生殖力正常。因此，Spag5是睾丸正常发育所必需的。

Microtubule-associated protein Spag5 is believed to be required for the progression of mitotic metaphase. However, it has been reported that Spag5-knockout mice had normal phenotype. To reveal in vivo-function of Spag5, we made Spag5-transgenic rats, and mated them to the rats from hypogonadic (hgn) strain. The hgn/hgn phenotype is associated with spontaneous mutation of Spag5. Male hgn/hgn is infertile, and abnormal mitosis is found in Sertoli cells of their testes. The hgn/hgn males with Spag5 transgene showed normal testis and fertility. Therefore, Spag5 is required for normal testicular development.