Data from: Environmental and genetic influences on body mass and resting metabolic rates (RMR) in a natural population of weasel Mustela nivalis

Body mass (BM) and resting metabolic rates (RMR) are two inexorably linked traits strongly related to mammalian life histories. Yet, there have been no studies attempting to estimate heritable variation and covariation of BM and RMR in natural populations. We used a marker-based approach to construct a pedigree and then the ‘animal model’ to estimate narrow sense heritability (h^2) of these traits in a free-living population of weasels Mustela nivalis – a small carnivore characterised by a wide range of BM and extremely high RMR. The most important factors affecting BM of weasels were sex and habitat type, whereas RMR was significantly affected only by seasonal variation of this trait. All environmental factors had only small effect on estimates of additive genetic variance of both BM and RMR. The amount of additive genetic variance associated with BM and estimates of heritability were high and significant in males (h^2 = 0.61), but low and not significant in females (h^2 = 0.32), probably due to small sample size for the latter sex. The results from the two-trait model revealed significant phenotypic (r_P = 0.62) and genetic correlation (r_A = 0.89) between BM and whole body RMR. The estimate of heritability of whole body RMR (0.54) and body mass corrected RMR (0.45) were lower than estimates of heritability for BM. Both phenotypic and genetic correlations between body mass corrected RMR and BM had negative signals (r_P = -0.42 and r_A = -0.58). Our results indicate that total energy expenditures of individuals can quickly evolve through concerted changes in BM and RMR.

体质量（Body mass, BM）与静止代谢率（Resting Metabolic Rates, RMR）是两种密不可分的性状，与哺乳动物生活史紧密相关。然而，目前尚无研究尝试估算自然种群中BM与RMR的遗传变异及遗传协变关系。本研究采用基于分子标记的方法构建谱系，并借助动物模型（animal model）估算野生伶鼬（Mustela nivalis）种群中这两种性状的狭义遗传力（narrow sense heritability, h²）。伶鼬是一类体型质量跨度范围广、静止代谢率水平极高的小型食肉动物。影响伶鼬体质量的最关键因素为性别与生境类型，而静止代谢率仅受自身季节波动的显著影响。所有环境因素对BM与RMR的加性遗传方差（additive genetic variance）估计值仅产生微弱影响。雄性伶鼬中，与BM相关的加性遗传方差量及遗传力估计值均较高且具有统计学显著性（h²=0.61），而雌性个体中该值则较低且无显著性（h²=0.32），这可能是由于雌性样本量较小所致。双性状模型的分析结果显示，BM与整体躯体RMR之间存在显著的表型相关（r_P=0.62）与遗传相关（r_A=0.89）。整体躯体RMR的遗传力估计值（0.54）与校正体质量后的RMR的遗传力估计值（0.45）均低于BM的遗传力估计值。校正体质量后的RMR与BM之间的表型相关及遗传相关均为负值（r_P=-0.42，r_A=-0.58）。本研究结果表明，个体的总能量消耗可通过BM与RMR的协同变化快速发生进化。