Max Planck Institute for Evolutionary Biology, Department of Evolutionary Ecology, August-Thienemann-Str. 2, 24306 Plön, Germany.
J Fish Biol. 2009 Nov;75(8):2122-42. doi: 10.1111/j.1095-8649.2009.02410.x.
To investigate and disentangle the role of major histocompatibility complex (MHC)-based 'good genes' and 'compatible genes' in mate choice, three-spined sticklebacks Gasterosteus aculeatus with specific MHC IIB genotypes were allowed to reproduce in an outdoor enclosure system. Here, fish were protected from predators but encountered their natural parasites. Mate choice for an intermediate genetic distance between parental MHC genotypes was observed, which would result in intermediate diversity in the offspring, but no mate choice based on good genes was found under the current semi-natural conditions. Investigation of immunological variables revealed that the less-specific innate immune system was more active in individuals with a genetically more divergent MHC allele repertoire. This suggests the need to compensate for an MHC-diminished T-cell repertoire and potentially explains the observed mate choice for intermediate MHC genetic distance. The present findings support a general pattern of mate choice for intermediate MHC diversity (i.e. compatible genes). In addition, the potentially dynamic role of MHC good genes in mate choice under different parasite pressures is discussed in the light of present and previous results.
为了研究和厘清主要组织相容性复合体（MHC）为基础的“优质基因”和“相容基因”在配偶选择中的作用，我们让具有特定 MHC IIB 基因型的三刺鱼（Gasterosteus aculeatus）在户外围场系统中繁殖。在这种情况下，鱼类受到保护免受捕食者的侵害，但会遇到它们的天然寄生虫。我们观察到了对父母 MHC 基因型之间中间遗传距离的选择，这将导致后代的中间多样性，但在当前的半自然条件下，没有发现基于优质基因的选择。对免疫变量的调查显示，具有遗传上更具差异 MHC 等位基因库的个体中，非特异性先天免疫系统更活跃。这表明需要补偿 MHC 减少的 T 细胞库，这可能解释了观察到的对中间 MHC 遗传距离的选择。目前的研究结果支持了配偶选择中间 MHC 多样性（即相容基因）的一般模式。此外，根据目前和以前的结果，还讨论了 MHC 优质基因在不同寄生虫压力下配偶选择中潜在的动态作用。
