Heterozygosity–fitness correlations in a wild mammal population: accounting for parental and environmental effects

Abstract

HFCs (heterozygosity–fitness correlations) measure the direct relationship between an individual's genetic diversity and fitness. The effects of parental heterozygosity and the environment on HFCs are currently under-researched. We investigated these in a high-density U.K. population of European badgers (Meles meles), using a multimodel capture–mark–recapture framework and 35 microsatellite loci. We detected interannual variation in first-year, but not adult, survival probability. Adult females had higher annual survival probabilities than adult males. Cubs with more heterozygous fathers had higher first-year survival, but only in wetter summers; there was no relationship with individual or maternal heterozygosity. Moist soil conditions enhance badger food supply (earthworms), improving survival. In dryer years, higher indiscriminate mortality rates appear to mask differential heterozygosity-related survival effects. This paternal interaction was significant in the most supported model; however, the model-averaged estimate had a relative importance of 0.50 and overlapped zero slightly. First-year survival probabilities were not correlated with the inbreeding coefficient (f); however, small sample sizes limited the power to detect inbreeding depression. Correlations between individual heterozygosity and inbreeding were weak, in line with published meta-analyses showing that HFCs tend to be weak. We found support for general rather than local heterozygosity effects on first-year survival probability, and g2 indicated that our markers had power to detect inbreeding. We emphasize the importance of assessing how environmental stressors can influence the magnitude and direction of HFCs and of considering how parental genetic diversity can affect fitness-related traits, which could play an important role in the evolution of mate choice.

Heterozygosity at a single locus explains a large proportion of variation in two fitness‐related traits in great tits: a general or a local effect?

“…ID tests indicate that genetic diversity estimated at the 15 typed microsatellite markers may be representative of genome‐wide heterozygosity and individual inbreeding coefficients. To our knowledge, this is one of the few studies reporting a significant g 2 value (Olano‐Marín et al ., ; Agudo et al ., ; Ruiz‐López et al ., ; Annavi et al ., ). Analyses based on the method proposed by Balloux et al .…”

Pathogen burden, co‐infection and major histocompatibility complex variability in the European badger (Meles meles)

“…Salmonella intensity was lower for individuals with higher microsatellite heterozygosity, consistent with heterozygosity–fitness correlations (Hansson & Westerberg ; Annavi et al . ). Individuals with lower microsatellite heterozygosity had lower T. pestanai intensity, however, perhaps due to the disruption of locally adapted genes.…”

“…; Annavi ; Annavi et al . ). We genotyped each individual for a mean of 34.0 loci (95% confidence interval = 33.8–34.1; range = 18–35).…”

“…; Annavi et al . , ) and estimated the standardized multilocus heterozygosity of each individual (Coltman et al . ; Annavi ; Annavi et al .…”

Age‐dependent, negative heterozygosity–fitness correlations and local effects in an endangered Caribbean reptile, Iguana delicatissima

“…Among adult marmots, however, no correlation between MLH and fitness was revealed (Cohas et al., 2009). Recent studies have further emphasized the importance of assessing multiple age classes in the detection and direction of HFCs (Annavi et al., 2014; Brommer et al., 2015; Canal et al., 2014; Monceau, Wattier, Dechaume‐Moncharmont, Dubreuil, & Cezilly, 2013). …”