Dohm M R, Hayes J P, Garland T
Department of Zoology, University of Wisconsin, Madison, Wisconsin 53706, USA.
Genetics. 2001 Sep;159(1):267-77. doi: 10.1093/genetics/159.1.267.
A positive genetic correlation between basal metabolic rate (BMR) and maximal (VO(2)max) rate of oxygen consumption is a key assumption of the aerobic capacity model for the evolution of endothermy. We estimated the genetic (V(A), additive, and V(D), dominance), prenatal (V(N)), and postnatal common environmental (V(C)) contributions to individual differences in metabolic rates and body mass for a genetically heterogeneous laboratory strain of house mice (Mus domesticus). Our breeding design did not allow the simultaneous estimation of V(D) and V(N). Regardless of whether V(D) or V(N) was assumed, estimates of V(A) were negative under the full models. Hence, we fitted reduced models (e.g., V(A) + V(N) + V(E) or V(A) + V(E)) and obtained new variance estimates. For reduced models, narrow-sense heritability (h(2)(N)) for BMR was <0.1, but estimates of h(2)(N) for VO(2)max were higher. When estimated with the V(A) + V(E) model, the additive genetic covariance between VO(2)max and BMR was positive and statistically different from zero. This result offers tentative support for the aerobic capacity model for the evolution of vertebrate energetics. However, constraints imposed on the genetic model may cause our estimates of additive variance and covariance to be biased, so our results should be interpreted with caution and tested via selection experiments.
基础代谢率（BMR）与最大耗氧率（VO₂max）之间存在正向遗传相关性，这是恒温动物进化的有氧能力模型的一个关键假设。我们估计了家鼠（小家鼠）一个遗传异质实验室品系中，遗传因素（加性遗传方差V(A)和显性遗传方差V(D)）、产前因素（V(N)）和产后共同环境因素（V(C)）对代谢率和体重个体差异的贡献。我们的育种设计不允许同时估计V(D)和V(N)。无论假设V(D)还是V(N)，在完整模型下V(A)的估计值均为负。因此，我们拟合了简化模型（例如，V(A) + V(N) + V(E)或V(A) + V(E)）并获得了新的方差估计值。对于简化模型，BMR的狭义遗传力（h²(N)）<0.1，但VO₂max的h²(N)估计值更高。当用V(A) + V(E)模型估计时，VO₂max和BMR之间的加性遗传协方差为正且在统计上与零有差异。这一结果为脊椎动物能量学进化的有氧能力模型提供了初步支持。然而，对遗传模型施加的限制可能导致我们对加性方差和协方差的估计产生偏差，因此我们的结果应谨慎解释并通过选择实验进行检验。
