Kojima Y, Kominami K, Dohmae K, Nonomura N, Miki T, Okuyama A, Nishimune Y, Okabe M
Department of Urology, Osaka University Medical School, Suita, Japan.
Int J Urol. 1997 Sep;4(5):500-7. doi: 10.1111/j.1442-2042.1997.tb00293.x.
Mice homozygous for the jsd (juvenile spermatogonial depletion) allele are sterile because they become azoospermic. The onset of such azoospermia was investigated by histologic analysis of sections of testes from jsd/jsd mice.
The testes removed from C57BL/6-jsd/jsd mice aged 3 to 10 weeks were examined microscopically.
At 3 weeks of age, spermatocytes were seen in most of the seminiferous tubules of jsd/jsd mice. However, the number of tubules that contained spermatids was significantly smaller than that counted in the wild-type mice. Since degenerative figures were not abundant in the jsd/jsd testes, the decreased number of spermatids found in the tubules suggested a longer duration of development from spermatocyte to spermatid in jsd/jsd mice. The abnormality extended to the development of type B spermatogonia, and a decrease in their number became apparent after 6 weeks of age in most of the jsd/jsd tubules. However, as early as 3 weeks of age, a few seminiferous tubules in jsd/jsd mice already contained only Sertoli cells and type A spermatogonia.
It is assumed that the decrease in type B spermatogonia occurred at various ages and locations. The defect of spermatogenesis in jsd/jsd mice was attributable to aberrations in multiple steps of spermatogenesis.
jsd（幼年精原细胞耗竭）等位基因纯合的小鼠不育，因为它们会出现无精子症。通过对jsd/jsd小鼠睾丸切片进行组织学分析，研究了这种无精子症的发病情况。
对3至10周龄的C57BL/6-jsd/jsd小鼠摘除的睾丸进行显微镜检查。
在3周龄时，jsd/jsd小鼠的大多数生精小管中可见精母细胞。然而，含有精子细胞的小管数量明显少于野生型小鼠。由于jsd/jsd睾丸中退化形态并不多见，小管中精子细胞数量减少表明jsd/jsd小鼠从精母细胞发育到精子细胞的时间更长。这种异常扩展到B型精原细胞的发育，在大多数jsd/jsd小管中，6周龄后其数量减少明显。然而，早在3周龄时，jsd/jsd小鼠的一些生精小管就仅含有支持细胞和A型精原细胞。
推测B型精原细胞数量减少发生在不同年龄和部位。jsd/jsd小鼠精子发生缺陷归因于精子发生多个步骤的异常。
