Quantitative genetics of bioenergetics and growth-related traits in the wild mammal, Phyllotis darwini.
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 (h2) and genetic correlations between physiological and growth-related traits. Univariate analyses showed that MMR presented high, significant heritability (h2 = 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 (c2 = 0.34 +/- 0.17). Heritabilities were large and significant (h2 > 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.
Nespolo
Roberto F
RF
Instituto de Ecología y Evolución, Facultad de Ciencias, Universidad Austral de Chile, Valdivia. robertonespolo@uach.cl
Bustamante
Diego M
DM
Bacigalupe
Leonardo D
LD
Bozinovic
Francisco
F
D000064:Acclimatization; D000818:Animals; D001481:Basal Metabolism; D005075:Biological Evolution; D049628:Body Size / Q000502:physiology*; D001833:Body Temperature Regulation / Q000502:physiology*; D001837:Body Weights and Measures; D002677:Chile; D004734:Energy Metabolism / Q000502:physiology*; D040582:Inheritance Patterns / Q000235:genetics; D019655:Quantitative Trait, Heritable; D012641:Selection, Genetic; D016205:Sigmodontinae