Quantitative genetics of bioenergetics and growth-related traits in the wild mammal, <i>Phyllotis darwini</i>
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Date
2005
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Abstract
We studied the potential for response to selection in typical physiological-thermoregulatory traits of mammals such as maximum metabolic rate (MMR), nonshivering thermogenesis (NST) and basal metabolic rate (BMR) on cold-acclimated animals. We used an animal model approach to estimate both narrow-sense heritabilities (h(2)) and genetic correlations between physiological and growth-related traits. Univariate analyses showed that MMR presented high, significant heritability (h(2) = 0.69 - 0.35, asymptotic standard error), suggesting the potential for microevolution in this variable. However, NST and BMR presented low, nonsignificant h2, and NST showed large maternal/common environmental/nonadditive effects (c(2) = 0.34 +/- 0.17). Heritabilities were large and significant (h(2) > 0.5) for all growth-related traits (birth mass, growth rate, weaning mass). The only significant genetic correlations we found between a physiological trait and a growth-related trait was between NST and birth mass (r = -0.74; P < 0.05). Overall, these results suggest that additive genetic variance is present in several bioenergetic traits, and that genetic correlations could be present between those different kinds of traits.
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animal model, G-matrix, genetic correlations, narrow-sense heritability, quantitative genetics, REML, rodents