Functional testicular tissue does not masculinize development of the zebra finch song system.
Functional testicular tissue does not masculinize development of the zebra finch song system.
复制标题
DOI：
10.1073/pnas.93.11.5264
复制
发表时间：
1996-05
影响因子：
11.1
通讯作者：
J. Wade;A. Arnold
中科院分区：
文献类型：
--
作者：
J. Wade;A. Arnold
目前的性分化理论认为，卵巢雌激素阻止鸟类交配系统的男性化发展，而来自睾丸雄激素的雌激素促进哺乳动物神经解剖学和性行为的男性化。奇怪的是，一些数据表明，斑胸草雀的神经鸣唱系统遵循哺乳动物的模式，睾丸分泌物的雌激素代谢产物引起雄性发育。为了测试在早期发育过程中去除雄性的雌激素是否会阻止雄性鸣唱系统的发展，斑马雀在胚胎中接受了雌激素合成抑制剂的治疗。此外，在遗传雌性斑胸草雀中的这种治疗诱导功能性卵巢和睾丸组织发育，从而允许评估睾丸分泌物对歌曲系统发育的直接影响。在雄性中，在孵化前抑制雌激素的合成，在使神经鸣唱系统的一个方面去男性化方面有一个小但显著的效果。在治疗的女性，歌曲系统保持形态女性化。这些结果表明，男性化的歌曲系统并不完全由睾丸雄激素或其雌激素代谢产物。
Current theories of sexual differentiation maintain that ovarian estrogen prevents masculine development of the copulatory system in birds, whereas estrogen derived from testicular androgens promotes masculine sexual differentiation of neuroanatomy and sexual behavior in mammals. Paradoxically, some data suggest that the neural song system in zebra finches follows the mammalian pattern with estrogenic metabolites of testicular secretions causing masculine development. To test whether the removal of estrogen from males during early development would prevent the development of masculine song systems, zebra finches were treated embryonically with an inhibitor of estrogen synthesis. In addition, this treatment in genetic female zebra finches induced both functional ovarian and testicular tissue to develop, thus allowing the assessment of the direct effects of testicular secretions on song system development. In males, the inhibition of estrogen synthesis before hatching had a small but significant effect in demasculinizing one aspect of the neural song system. In treated females, the song systems remained morphologically feminine. These results suggest that masculinization of the song system is not determined solely by testicular androgens or their estrogenic metabolites.