Grob B, Knapp L A, Martin R D, Anzenberger G
Anthropologisches Institut und Museum der Universität Zürich, Switzerland.
Exp Clin Immunogenet. 1998;15(3):119-29. doi: 10.1159/000019063.
It has been known for decades that MHC genes play a critical role in the cellular immune response, but only recent research has provided a better understanding of how these molecules might affect mate choice. Original studies in inbred mouse strains revealed that mate choice was influenced by MHC dissimilarity. Detection of MHC differences between individuals in these experiments was related to olfactory cues, primarily in urine. Recent studies in humans have shown an analogous picture of MHC-based mating. Taken together, these findings could support either the hypothesis of MHC-based inbreeding avoidance or the hypothesis of MHC-related avoidance of reproductive failure, since studies in mice, humans and pigtailed macaques have shown that parental sharing of certain MHC alleles correlates with frequent spontaneous abortion or prolonged intergestational intervals. Data from many mammalian species clearly demonstrate that reproductive failure occurs as a result of inbreeding. Therefore, MHC similarity might serve as an indicator of genome-wide relatedness. In contrast, increased fitness due to the presence of individual MHC alleles in a pathogenic environment could explain MHC-based selection of currently good genes. Specifically, the physical condition of long-living animals depends on the ability to respond to immunological challenge and an individual's MHC alleles determine the response, since, unlike the T cell receptors, MHC alleles are not somatically recombined. Therefore, sexual selection of condition-dependent traits during mate choice could be used to select successful MHC alleles, thereby providing offspring with a higher relative immunity in their pathogenic environment.
几十年来，人们已经知道主要组织相容性复合体（MHC）基因在细胞免疫反应中起关键作用，但直到最近的研究才让我们更好地理解这些分子可能如何影响配偶选择。对近交系小鼠品系的早期研究表明，配偶选择受MHC差异的影响。在这些实验中，个体之间MHC差异的检测与嗅觉线索有关，主要是尿液中的线索。最近对人类的研究也呈现出基于MHC的交配情况。综合来看，这些发现可能支持基于MHC的近亲繁殖回避假说，或者基于MHC的生殖失败回避假说，因为对小鼠、人类和豚尾猕猴的研究表明，父母共享某些MHC等位基因与频繁自然流产或妊娠期延长有关。来自许多哺乳动物物种的数据清楚地表明，近亲繁殖会导致生殖失败。因此，MHC相似性可能作为全基因组相关性的一个指标。相比之下，在致病环境中由于个体MHC等位基因的存在而提高的适应性，可以解释基于MHC的当前优良基因选择。具体而言，长寿动物的身体状况取决于对免疫挑战作出反应的能力，而个体的MHC等位基因决定这种反应，因为与T细胞受体不同，MHC等位基因不会进行体细胞重组。因此，在配偶选择过程中对依赖于身体状况的性状进行性选择，可以用来选择成功的MHC等位基因，从而为后代在其致病环境中提供更高的相对免疫力。
