Rosenstrauch A, Degen A A, Friedländer M
Department of Life Sciences, Ben-Gurion University of the Negev, Beer Sheva, Israel.
Biol Reprod. 1994 Jan;50(1):129-36. doi: 10.1095/biolreprod50.1.129.
Fertility of domestic roosters peaked and then began a steep decline within the first year of life. The decline was concomitant with a steady reduction in total number of spermatozoa per ejaculate. We found that 1) the decline was neither related to germinal epithelium regression nor to spermatozoa abnormalities, as reported for aging males of nonseasonal breeders and for fertile seasonal breeders during the nonmating period and 2) seminiferous tubules of extremely low-fertility aging roosters contained more Sertoli cell-spermatozoa complexes than did more fertile roosters, which is in sharp contrast to what occurs in other domestic males. We further observed that Sertoli cells of low-fertility roosters had smaller diameters, cytoplasm that stained deeper, and more crowded cytoplasmic inclusions than did Sertoli cells of high-fertility roosters. We conclude that the decline of fertility in aging roosters is related to changes in Sertoli cells that impair the regular release of spermatozoa. Spermatozoa remain within the testicular tubules and thus fewer spermatozoa are available for insemination.
家鸡的生育能力在出生后的第一年内达到峰值，随后便开始急剧下降。这种下降与每次射精的精子总数稳步减少相伴。我们发现：1）这种下降既与生殖上皮退化无关，也与精子异常无关，这与非季节性繁殖雄性动物衰老时以及繁殖季节之外的可育季节性繁殖雄性动物的情况相同；2）极低生育能力的老龄公鸡的生精小管中，支持细胞-精子复合体比生育能力较强的公鸡更多，这与其他家养雄性动物的情况形成鲜明对比。我们进一步观察到，生育能力低的公鸡的支持细胞直径较小，细胞质染色更深，细胞质内含物比生育能力高的公鸡更密集。我们得出结论，老龄公鸡生育能力的下降与支持细胞的变化有关，这些变化会损害精子的正常释放。精子滞留在睾丸小管内，因此可用于授精的精子减少。
