Widespread introgression of MHC genes in Iberian Podarcis lizards

Major Histocompatibility Complex (MHC) genes are crucial for the adaptive immune response of jawed vertebrates. Their variation, reaching extreme levels, is driven mainly by an arms race between hosts and pathogens. One hypothesized mechanism contributing to MHC polymorphism is adaptive introgression, the exchange of genetic variants between hybridizing species favoured by selection, yet its effect on MHC variation is poorly understood. Detection of adaptive MHC introgression, though challenging, may be facilitated by the analysis of species complexes forming multiple hybrid zones. Here, we investigated MHC introgression in six hybrid zones formed by seven species of Podarcis lizards inhabiting the Iberian Peninsula. To differentiate adaptive introgression from neutral introgression, we compared the patterns of gene exchange in MHC and genome-wide markers. We found elevated sharing of MHC alleles in the proximity of contact beyond the areas of detectable genome-wide admixture in most hy..., Details can be found in Gaczorek et al. (2023) \"Widespread introgression of MHC genes in Iberian Podarcis lizards.\", R software is needed to reproduce the attached R script.,