A critical period for the organization of alternative male phenotypes of tree lizards by exogenous testosterone?
A critical period for the organization of alternative male phenotypes of tree lizards by exogenous testosterone?
复制标题
外源睾酮形成树蜥另类雄性表型的关键时期？
DOI：
10.1016/s0031-9384(96)80014-x
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发表时间：
1996
影响因子：
2.9
通讯作者：
Moore,MC
中科院分区：
文献类型：
--
作者：
Hews,DK;Moore,MC
雄性树蜥蜴（Urosaurus ornatus）在颜色和大小上表现出永久性的成年差异，这些差异与行为差异有功能上的联系：中央有蓝色喉咙补丁的雄性比没有补丁的雄性更具有领土性，更具侵略性，并且比没有补丁的雄性更小，后者是游牧民族或卫星。性腺切除术或长期激素植入幼龟影响这些永久性成人差异的发展，但在成人类似的操作是无效的。脊椎动物性分化中类似的早期激素作用通常必须发生在关键时期。影响树蜥蜴雄性类型发育的早期激素作用是否存在一个关键时期尚不清楚。我们遵循了与我们以前对孵化的实验相同的协议，但我们操纵了年龄较大的青少年的睾酮（T），以确定他们是否对这种激素操纵保持敏感。在孵化后60天（第60天）给予的Teptide植入物没有改变成年人的喉咙颜色，表明喉咙颜色对T的敏感性在第60天下降。这与我们早期的工作形成对比，其中成人颜色在第30天受到T操纵的影响。然而，大小和喉咙的颜色响应不同的外源性T，作为青少年给予T植入物在第60天的增长低于控制植入的男性。
Male tree lizards (Urosaurus ornatus) exhibit permanent adult differences in color and size that are functionally linked with behavioral differences: males with a central blue throat patch are territorial, more aggressive, and smaller than males lacking the patch, who are nomads or satellites foregoing territory defense. Gonadectomy or long-lasting hormone implants in hatchlings affect the development of these permanent adult differences, but similar manipulations in adults are ineffective. Analogous early hormone actions in vertebrate sexual differentiation typically must occur during a critical period. Whether there is a critical period for early hormone actions affecting development of male types in tree lizards is unclear. We followed a protocol identical to our previous experiments on hatchlings, but we manipulated testosterone (T) in later-aged juveniles to determine if they remained sensitive to such hormone manipulations. Testosterone implants given at 60 days posthatching (day 60) did not alter adult throat color, indicating that sensitivity of throat color to T declines by day 60. This contrasts to our earlier work where adult color was affected by T manipulations on day 30. However, size and throat color responded differently to exogenous T, as juveniles given T implants at day 60 grew less than control-implanted males.