Contrasting patterns of variation in MHC loci in the Alpine newt.

摘要: Major histocompatibility complex (MHC) genes are essential in pathogen recognition and triggering an adaptive immune response. Although they the most polymorphic vertebrates, very little information on MHC variation patterns of evolution available for amphibians, a group known to be declining rapidly worldwide. As infectious diseases invoked declines, should contribute devising appropriate conservation strategies. In this study, we examined 149 Alpine newts (Mesotriton alpestris) from three allopatric population groups Poland at northeastern margin distribution species. The genetic distinctiveness has previously been shown by studies skin graft rejection, allozymes microsatellites. Two putative expressed II loci with contrasting levels clear evidence gene conversion/recombination between them were detected. Meal-DAB locus is highly (37 alleles), shows historical positive selection amino acid replacements substantial geographical differentiation allelic richness. On contrary, Meal-DBB exhibits low polymorphism (three alleles differing up two synonymous substitutions) uniform among regions. frequencies presumptively neutral may explained linkage Meal-DAB. We found differences richness regions, consistent hypothesis that drift prevails increasing distance glacial refugia. Pseudogene appear have evolved neutrally. level DAB correlated microsatellite loci, implying interplayed produce pattern observed marginal populations newt.