Evolutionary Ecology of Marine Fishes, GEOMAR Helmholtz Centre for Ocean Research Kiel, Kiel, Germany.
J Evol Biol. 2014 May;27(5):929-38. doi: 10.1111/jeb.12365. Epub 2014 Apr 12.
Mate choice for compatible genes is often based on genes of the major histocompatibility complex (MHC). Although MHC-based mate choice is commonly observed in female choice, male mate choice remains elusive. In particular, if males have intense paternal care and are thus the choosing sex, male choice for females with dissimilar MHC can be expected. Here, we investigated whether male mate choice relies on MHC class I genes in the sex-role reversed pipefish Syngnathus typhle. In a mate choice experiment, we determined the relative importance of visual and olfactory cues by manipulating visibility and olfaction. We found that pipefish males chose females that maximize sequence-based amino acid distance between MHC class I genotypes in the offspring when olfactory cues were present. Under visual cues, large females were chosen, but in the absence of visual cues, the choice pattern was reversed. The use of sex-role reversed species thus revealed that sexual selection can lead to the evolution of male mate choice for MHC class I genes.
基于相容基因的配偶选择通常基于主要组织相容性复合体 (MHC) 的基因。尽管 MHC 为基础的配偶选择在雌性选择中很常见，但雄性选择仍然难以捉摸。特别是，如果雄性具有强烈的父爱并且是选择性别，那么具有不同 MHC 的雌性可能会受到雄性的选择。在这里，我们研究了性别反转的海龙 Syngnathus typhle 中雄性是否依赖 MHC 类 I 基因进行配偶选择。在一项配偶选择实验中，我们通过操纵可见度和嗅觉来确定视觉和嗅觉线索的相对重要性。我们发现，当存在嗅觉线索时，海龙雄性会选择那些能够使后代 MHC 类 I 基因型之间的基于序列的氨基酸差异最大化的雌性。在视觉线索下，体型较大的雌性被选择，但在没有视觉线索的情况下，选择模式会反转。因此，使用性别反转的物种揭示了性选择可以导致雄性对 MHC 类 I 基因的配偶选择的进化。
