Shield characteristics are testosterone-dependent in both male and female moorhens
Shield characteristics are testosterone-dependent in both male and female moorhens
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DOI：
10.1006/hbeh.1999.1569
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发表时间：
2000-03-01
影响因子：
3.5
通讯作者：
Pinxten, R
中科院分区：
文献类型：
--
作者：
Eens, M;Van Duyse, E;Pinxten, R
免疫功能障碍假说提出，第二性征的表达与睾酮水平呈正相关，但睾酮水平升高也会带来免疫抑制的代价。因此，睾丸激素依赖的特征应该准确地反映男性的质量，因为只有高质量的男性才能够投资于大的性特征，而不会对自己的免疫系统产生不利影响。迄今为止，大多数研究都集中在睾丸激素在表达配偶饰品中的作用以及雄激素在男性中可能的免疫抑制作用上。在黑水鸡（Gallinula chloropus）中，一种性单态的一夫一妻制鸟类表现出部分的性别角色逆转，两性都有一个突出的前盾。我们植入两种性别的睾丸激素填充植入物，以检查睾丸激素对盾牌特征和免疫功能的影响。盾的大小，厚度和颜色显着增加了实验中增加睾酮浓度在男性和女性。同样，移除植入物导致雄性和雌性的盾大小和厚度迅速减少，这表明两性对睾丸激素的增加或减少反应迅速。植入睾酮的黑水鸡体外寄生虫感染的强度高于对照鸟，但其他间接措施的免疫能力没有显着差异的两类鸟类。(C)北京大学出版社.
The immunocompetence handicap hypothesis proposes that the expression of secondary sexual characteristics is positively related to testosterone levels, but that elevated testosterone levels also impose costs from immune suppression. Hence, testosterone-de pendent characteristics should accurately reflect male quality because only high-quality males are able to invest in large sexual characteristics without detrimental effects upon their own immune system. Most studies to date have focused on the role of testosterone in the expression of mate ornaments and on the possible immunosuppressant effects of androgens in males. in the moorhen (Gallinula chloropus), a sexually monomorphic monogamous bird species showing a partial sex-role reversal, both sexes have a prominent frontal shield. We implanted both sexes with testosterone-filled implants to examine the effects of testosterone on shield characteristics and immune function. Shield size, thickness, and color were significantly increased by an experimental increase in testosterone concentrations in both males and females. Likewise, removal of the implants led to a rapid decrease in shield size and thickness in both males and females, suggesting that both sexes responded quickly to an increase or a decrease in testosterone. Moorhens implanted with testosterone had higher intensities of ectoparasite infestations than control birds, but other indirect measures of immunocompetence did not differ significantly between the two categories of birds. (C) 2000 Academic Press.