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 as...

有关生长速率、能量代谢等生活史性状间关联的研究，通常聚焦于基础代谢率（basal metabolic rate, BMR）。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的最大能力，因此其在生理权衡中或同样具有重要意义。本研究针对经高质量独立代谢率（mass-independent metabolic rates）选育的小家鼠（Mus musculus domesticus Linnaeus），探究了能量代谢与生长间的关联。针对高质量独立MMR的选育，提升了小鼠的最大生长速率，增加了20周龄时的体重，并总体上改变了雌雄小鼠的生长模式。与之形成对比的是，几乎没有证据表明经体重校正的基础代谢率（mass-adjusted BMR）的相关响应会改变生长模式。经体重校正的MMR与生长速率间的关联表明，MMR是生活史的重要调控因子。有关……的研究