Allele Diversity of the Major Histocompatibility Complex in the Common Hamster (Cricetus cricetus) in Urban and Rural Populations

Abstract

Based on the results of targeted sequencing on the Illumina platform we compared the allelic diversity of exon 2 of the DRB gene in urban (city of Simferopol) and rural populations of the common hamster. The urban population significantly differs from the rural one in terms of the composition and diversity of gene alleles. For individuals living in the city, a larger number of alleles, higher values of haplotype and nucleotide diversity indices, and a smaller proportion of individuals with a homozygous genotype were noted. Both populations are characterized by a significant excess of non-synonymous substitutions over synonymous ones and almost every allele of a gene corresponds to a different amino acid sequence. However, the influence of positive selection on the diversity of variants of antigen-binding sites in the alleles of the DRB gene in urban conditions is much more pronounced. The data suggest that resistance of common hamsters living in specific and varied conditions of the urban environment to various kinds of pathogenic load is higher than in rural populations.