MHC spreading and its consequences on social structure of European rabbits
Philipp Rausch, Claus Oppelt, Anett Strakloff, Heiko Rödel, Dietrich v. Holst
Tierphysiologie, Universität Bayreuth
Genes of the high polymorphic MHC play a crucial role in immune recognition of pathogens and parasites. Natural and sexual selection on these genes should influence their distribution in a population. In this work, the MHC II- DRB exon 2 of Oryctolagus cuniculus L. and its effects on the social structure of this species were examined. For this aim all adult individuals from a seminatural population were genotyped for MHC II DRB Exon 2. Analyses of the allel- spreading in the population showed a significant deviation from the Hardy- Weinberg- equilibrium to an excess of homozygotes. This contradicts heterozygote advantage and MHC dependent disassortative mating- strategies. Furthermore, one allele was much more present in the population than others, what may mediate a selective advantage for carriers of this allele. In the mating groups and over the whole population was an increase of homozygosity. So there seems to be no selective advantage of heterozygous individuals. Mating- groups showed a higher polymorphism of the MHC- locus than measured for the whole population, at this, genetic distances to females of all to the group belonging males overcome the distances of dominant group males. Nevertheless the distance between males and females of a group is greater than expected by chance, which could be an effect of MHC dependent dispersal. That gives the possibility, that dominant males are not the matter for grouping females, but the whole males belonging to the mating-groups.