Data from: Heterozygosity-fitness correlation at the major histocompatibility complex despite low variation in Alpine ibex (Capra ibex)

Crucial for the long-term survival of wild populations is their ability to
fight diseases. Disease outbreaks can lead to severe population size
reductions, which makes endangered and reintroduced species especially
vulnerable. In vertebrates, the major histocompatibility complex (MHC)
plays an important role in determining the immune response. Species which
went through severe bottlenecks, often show very low levels of genetic
diversity at the MHC. Due to the known link between the MHC and immune
response, such species are expected to be at particular risk in case of
disease outbreaks. However, so far, only few studies have shown that low
MHC diversity is correlated with increased disease susceptibility in
species after severe bottlenecks. We investigated genetic variation at the
MHC and its correlations with disease resistance and other fitness related
traits in Alpine ibex (Capra ibex), a wild goat species that underwent a
strong bottleneck in the last century and that is known to have extremely
low genetic variability, both genome-wide and at the MHC. We studied MHC
variation in male ibex of Gran Paradiso National Park, the population used
as source for all post-bottleneck reintroductions. We found that
individual MHC heterozygosity (based on six microsatellites) was not
correlated with genome-wide neutral heterozygosity. MHC heterozygosity,
but not genome-wide heterozygosity, was positively correlated with
resistance to infectious kerato-conjunctivitis and with body mass. Our
results show that genetic variation at the MHC plays an important role in
disease resistance and, hence, should be taken into account for
successfully managing species conservation.