Adkins-Regan E, Abdelnabi M, Mobarak M, Ottinger M A
Department of Psychology, Cornell University, Ithaca, New York 14853-7601.
Gen Comp Endocrinol. 1990 Apr;78(1):93-109. doi: 10.1016/0016-6480(90)90051-m.
Serum samples from male and female zebra finches ranging in age from 1 day before hatch to 54 days posthatch were assayed for 17 beta-estradiol (E), androgen, testosterone (T), or 5 alpha-dihydrotestosterone (DHT). Additional samples were assayed from intact and gonadectomized adults, gonadectomized adults with intraperitoneal implants of testosterone propionate (TP) or estradiol benzoate (EB), gonadectomized nestlings, and nestlings injected subcutaneously with EB. DHT levels of developing birds did not vary as a function of either sex or age. During development, average androgen and T levels were highest during the nestling period, prior to sexual maturation, and were higher in females than in males. Endogenous androgen levels of most subjects that were sampled repeatedly rose and then declined between 24 and 49 days. TP implants produced higher T levels in adult females than in adult males. Levels of E were higher in both sexes during the hatching period (Days -1 through 0) than during the nestling period (Days 2 through 14). A greater number of males than females had relatively high E levels on Days 12 and 14 and during the second week overall. There was no sex difference in levels of E in adults, and gonadectomized adults had markedly higher E levels than intact adults. Gonadectomized nestlings had the same androgen and E levels as intact nestlings of the same age; EB injected nestlings had elevated E levels. The present results indicate specific endocrine changes that mirror events crucial to sexual differentiation of endocrine and behavioral components of reproduction, and have important implications for models of sexual differentiation in zebra finches.
对年龄从孵化前1天到孵化后54天的雄性和雌性斑胸草雀的血清样本进行了17β - 雌二醇（E）、雄激素、睾酮（T）或5α - 双氢睾酮（DHT）的检测。还对完整的成年鸟、性腺切除的成年鸟、植入丙酸睾酮（TP）或苯甲酸雌二醇（EB）的性腺切除成年鸟、性腺切除的雏鸟以及皮下注射EB的雏鸟进行了额外样本检测。发育中的鸟类的DHT水平不会因性别或年龄而变化。在发育过程中，平均雄激素和T水平在雏鸟期、性成熟之前最高，且雌性高于雄性。大多数被重复采样的受试者的内源性雄激素水平在24至49天之间先上升后下降。TP植入物在成年雌性中产生的T水平高于成年雄性。孵化期（-1天至0天）两性的E水平均高于雏鸟期（2天至14天）。在第12天和第14天以及整个第二周，具有相对较高E水平的雄性比雌性更多。成年鸟的E水平没有性别差异，性腺切除的成年鸟的E水平明显高于完整的成年鸟。性腺切除的雏鸟与同龄完整雏鸟的雄激素和E水平相同；注射EB的雏鸟的E水平升高。目前的结果表明了特定的内分泌变化，这些变化反映了对生殖的内分泌和行为成分的性别分化至关重要的事件，并且对斑胸草雀的性别分化模型具有重要意义。
