Animal Model of Male Sterility ; Differentiation of Germ Cell in Sl, W Mutant Mice.

本文采用实验性隐睾及其手术逆转的方法研究了Steel-Dickie （Sl^d）突变和W突变对睾丸生殖细胞分化的影响。Sl^d/+型隐睾未分化a型精原细胞的维持功能受损，数量减少。相比之下，突变小鼠隐睾中a型精原细胞的增殖活性通过细胞周期的进展来判断是正常的。手术逆转隐睾导致保留在Sl^d/+隐睾的a型精原细胞的再生分化受到严重损害，特别是在细胞分化的两个步骤，从a型精原细胞到中间或b型精原细胞和减数分裂。通过实验隐睾及其手术逆转，研究了W、W^f、W^<sh>和W^v突变对小鼠精子发生的影响。结果表明，W基因对生精细胞分化的影响与SI基因相同。这两种突变小鼠睾丸生殖细胞的再生分化结果表明，Sl（配体）和W （c-kit受体）基因产物之间的信号转导在成年小鼠精子发生中起重要作用。

The effects of Steel-Dickie (Sl^d) mutation and W mutations on testicular germ cell differentiation were investigated using experimental cryptorchidism and its surgical reversal. In Sl^d/+ cryptorchid testes the maintenance of undifferentiated type-A spermatogonia was impaired and their numbers decreased. In contrast, the proliferative activity of type-A spermatogonia in the cryptorchid testis of mutant mice appeared normal as judged by their progression through the cell cycle. Surgical reversal of cryptorchidism resulted in regenerative differentiation of type-A spermatogonia which remained in Sl^d/+ cryptorchid testes was strongly impaired, particularly at two steps of cellular differentiation, from type-A spermatogonia to intermediate or type-B spermatogonia and at meiotic division.The effect of W, W^f, W^<sh>, and W^v mutations on spermatogenesis in mice was also examined by using experimental cryptorchidism and its surgical reversal. The results indicate that the W gene also exerts its effect on spermatogenic cell differentiation at the same steps as SI gene does. These results of regenerative differentiation of testicular germ cells in both mutant mice indicate that signal transduction between Sl (ligand) and W (c-kit receptor) gene products is important in spermatogenesis of adult mouse.