Data from: Speeding up growth: selection for mass-independent maximal metabolic rate alters growth rates

Investigations into relationships between life-history traits, such as growth rate and energy metabolism, typically focus on basal metabolic rate (BMR). In contrast, investigators rarely examine maximal metabolic rate (MMR) as a relevant metric of energy metabolism, even though it indicates the maximal capacity to metabolize energy aerobically, and hence it might also be important in trade-offs. We studied the relationship between energy metabolism and growth in mice (Mus musculus domesticus Linnaeus) selected for high mass-independent metabolic rates. Selection for high mass-independent MMR increased maximal growth rate, increased body mass at 20 weeks of age, and generally altered growth patterns in both male and female mice. In contrast, there was little evidence that the correlated response in mass-adjusted BMR altered growth patterns. The relationship between mass-adjusted MMR and growth rate indicates that MMR is an important mediator of life histories. Studies investigating associations between energy metabolism and life histories should consider MMR, as it is potentially as important in understanding life history as basal metabolic rate.

有关生长速率、能量代谢等生活史性状间关联的研究，通常以基础代谢率（basal metabolic rate, BMR）为核心关注对象。与之相对，研究者极少将最大代谢率（maximal metabolic rate, MMR）作为能量代谢的相关指标开展考察，尽管该指标可反映机体有氧代谢能量的最大能力，因此其在生活史权衡关系中或许也具有重要意义。本研究以经选育的高体重独立代谢率小鼠（Mus musculus domesticus Linnaeus）为实验对象，探究其能量代谢与生长之间的关联。对高体重独立最大代谢率的选育，提升了小鼠的最大生长速率，增加了其20周龄时的体质量，且总体上改变了雌雄小鼠的生长模式。与之相对，几乎没有证据表明经体重校正的基础代谢率的相关响应会改变小鼠的生长模式。经体重校正的最大代谢率与生长速率之间的关联表明，最大代谢率是生活史的重要介导因子。探究能量代谢与生活史之间关联的研究应将最大代谢率纳入考量，因其在解析生活史方面的潜在重要性与基础代谢率不相上下。