Genomic evidence for MHC disassortative mating in humans

Abstract

Although pervasive in many animal species, the evidence for major histocompatibility complex (MHC) disassortative mating in humans remains inconsistent across studies. Here, to revisit this issue, we analyse dense genotype data for 883 European and Middle Eastern couples. To distinguish MHC-specific effects from socio-cultural confounders, the pattern of relatedness between spouses in the MHC region is compared to the rest of the genome. Couples from Israel exhibit no significant pattern of relatedness across the MHC region, whereas across the genome, they are more similar than random pairs of individuals, which may reflect social homogamy and/or cousin marriages. On the other hand, couples from The Netherlands and more generally from Northern Europe are significantly more MHC-dissimilar than random pairs of individuals, and this pattern of dissimilarity is extreme when compared with the rest of the genome. Our findings support the hypothesis that the MHC influences mate choice in humans in a context-dependent way: MHC-driven preferences may exist in all populations but, in some populations, social constraints over mate choice may reduce the ability of individuals to rely on such biological cues when choosing their mates.

Gamete-level immunogenetic incompatibility in humans–towards deeper understanding of fertilization and infertility?

“…Together, these results indicate that the functional (fertilization) competence of sperm is shaped by the HLA combination (dissimilarity) of males and females. Although previous studies have demonstrated the importance of HLA genes in human mate choice prior to copulation (Milinski et al 2013;Kromer et al 2016;Winternitz et al 2017;Dandine-Roulland et al 2019), the function of these genes in gamete-level mate choice has not earlier been demonstrated in humans. However, Scofield et al (1982) have hypothesized that self-nonself recognition of the gametes may be the original adaptive function of ancestral MHC genes.…”

Sex differences in main olfactory system pathways involved in psychosexual function

“…Since the original demonstration that women preferred the odors of men with MHC antigens dissimilar to their own, 168 there have been reports both in support of the hypothesis for MHC-correlated mate choice, [169][170][171] and other studies failing to find such evidence. Since the original demonstration that women preferred the odors of men with MHC antigens dissimilar to their own, 168 there have been reports both in support of the hypothesis for MHC-correlated mate choice, [169][170][171] and other studies failing to find such evidence.…”

“…Finally, we recall the long-standing hypothesis that body odors associated with an individual's MHC signature can drive odor preferences and mate selection in humans. Since the original demonstration that women preferred the odors of men with MHC antigens dissimilar to their own, 168 there have been reports both in support of the hypothesis for MHC-correlated mate choice, [169][170][171] and other studies failing to find such evidence. 172,173 Thus, like the human pheromone data summarized above, results are conflicting and sometimes controversial.…”

Gonadal suppression alters axillary steroid secretions in men, but does that affect olfactory social signaling?

“…In most mammals, olfaction is the dominant sensory modality in social communication [14,15]. Humans possess the ability to perceive socially relevant information from chemical signaling, which varies from individual to individual [16]. Different areas of the human body have characteristic odors.…”