Data from: Patterns of selection and allele diversity of class I and class II major histocompatibility loci across the species range of sockeye salmon (Oncorhynchus nerka)

The major histocompatibility complex (MHC), an important component of the
vertebrate immune system, provides an important suite of genes to examine
the role of genetic diversity at non-neutral loci for population
persistence. We contrasted patterns of diversity at the two classical MHC
loci in sockeye salmon (Oncorhynchus nerka), MHC class I (UBA) and MHC
class II (DAB), and neutral microsatellite loci across 70 populations
spanning the species range from Washington State to Japan. There was no
correlation in allelic richness or heterozygosity between MHC loci or
between MHC loci and microsatellites. The two unlinked MHC loci may be
responding to different selective pressures; the distribution of FST
values for the two loci was uncorrelated, and evidence for both balancing
and directional selection on alleles and lineages of DAB and UBA was
observed in populations throughout the species range but rarely on both
loci within a population. These results suggest that fluctuating selection
has resulted in the divergence of MHC loci in contemporary populations.