Hale M L, Verduijn M H, Møller A P, Wolff K, Petrie M
School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
J Evol Biol. 2009 Jun;22(6):1284-94. doi: 10.1111/j.1420-9101.2009.01746.x. Epub 2009 Apr 21.
Peacocks are a classic example of sexual selection, where females preferentially mate with males who have longer, more elaborate trains. One of the central hypotheses of sexual selection theory is that large or elaborate male 'ornaments' may signal high genetic quality (good genes). Good genes are thought to be those associated with disease resistance and as diversity at the major histocompatibility complex (MHC) has been shown to equate to superior immune responses, we test whether the peacock's train reveals genetic diversity at the MHC. We demonstrate via a captive breeding experiment that train length of adult males reflects genetic diversity at the MHC while controlling for genome-wide diversity and that peahens lay more, and larger, eggs for males with a more diverse MHC, but not for males with longer trains. Our results suggest that females are assessing and responding to male quality in terms of MHC diversity, but this assessment does not appear to be via train length, despite the fact that train length reflects MHC diversity.
孔雀是性选择的经典例子，雌性会优先与拥有更长、更精致尾羽的雄性交配。性选择理论的核心假设之一是，大型或精致的雄性“装饰物”可能标志着高遗传质量（优质基因）。优质基因被认为是那些与抗病性相关的基因，并且由于主要组织相容性复合体（MHC）的多样性已被证明等同于卓越的免疫反应，我们测试了孔雀的尾羽是否揭示了MHC的遗传多样性。我们通过圈养繁殖实验证明，成年雄性的尾羽长度反映了MHC的遗传多样性，同时控制了全基因组的多样性，并且雌孔雀会为MHC更多样化的雄性产下更多、更大的蛋，但不会为尾羽更长的雄性这样做。我们的结果表明，雌性正在根据MHC的多样性评估并回应雄性的质量，但尽管尾羽长度反映了MHC的多样性，这种评估似乎并不是通过尾羽长度进行的。
