Data from: Specific MHC class I supertype associated with parasite infection and colour morph in a wild lizard population

The major histocompatibility complex (MHC) is a large gene family that
plays a central role in the immune system of all jawed vertebrates.
Non-avian reptiles are under-represented within the MHC literature and
little is understood regarding the mechanisms maintaining MHC diversity in
this vertebrate group. Here, we examined the relative roles of
parasite-mediated selection and sexual selection in maintaining MHC class
I diversity of a colour polymorphic lizard. We discovered evidence for
parasite-mediated selection acting via rare-allele advantage or
fluctuating selection as ectoparasite load was significantly lower in the
presence of a specific MHC supertype (functional clustering of alleles);
supertype four. Based on comparisons between ectoparasite prevalence and
load, and assessment of the impact of ectoparasite load on host fitness,
we suggest that supertype four confers quantitative resistance to ticks or
an intracellular tick-borne parasite. We found no evidence for
MHC-associated mating in terms of pair genetic distance, number of alleles
or specific supertypes . An association was uncovered between supertype
four and male throat colour morph. However, it is unlikely that male
throat colouration acts as a signal of MHC genotype to conspecifics
because we found no evidence to suggest that male throat colouration
predicts male mating status. Overall, our results suggest that
parasite-mediated selection plays a role in maintaining MHC diversity in
this population via rare allele advantage and/or fluctuating selection.
Further work is required to determine whether sexual selection also plays
a role in maintaining MHC diversity in agamid lizards.