Nespolo Roberto F, Bacigalupe Leonardo D, Bozinovic Francisco
Instituto de Ecología y Evolución, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile.
Evolution. 2003 Jul;57(7):1679-88. doi: 10.1111/j.0014-3820.2003.tb00373.x.
As a first examination of the additive genetic variance of thermoregulatory traits in a natural population of endotherms, we studied the quantitative genetics of key physiological ecology traits in the leaf-eared mouse, Phyllotis darwini. We measured basal metabolic rate (BMR), nonshivering thermogenesis (NST), maximum metabolic rate for thermoregulation (MMR), thermal conductance (CT), body temperature (Tb), and factorial aerobic scope (FAS) in individuals acclimated to cold and warm conditions. For comparability with previous studies, we included the following morphological traits: foot length (FL), total length (TL), body mass (mb, at birth, sexual maturity, 6 months, and 8 months). Variance components were obtained from two different procedures: the expected variance component in an ANOVA Type III sum of squares and an animal model approach using restricted maximum likelihood. Results suggest the presence of additive genetic variance in FL (h2 = 0.47, P = 0.045), CT of cold-acclimated animals (h2 = 0.66, P = 0.041), and night body temperature, measured in cold-acclimated animals (h2 = 0.68, P = 0.080). Heritabilities of mb were near zero at all ages, but maternal effects and common environment effects were high and significant. We found no evidence of additive genetic variance in BMR, NST, MMR, or FAS (i.e., estimates were not significantly different from zero for all tests). Our results are in general agreement with previous studies of mammals that reported low heritability for: (1) BMR and MMR; (2) daytime body temperature; and (3) body mass for wild, but not laboratory or domestic, populations.
作为对恒温动物自然种群体温调节性状加性遗传方差的首次研究，我们对叶耳鼠（Phyllotis darwini）关键生理生态学性状的数量遗传学进行了研究。我们测量了适应寒冷和温暖条件的个体的基础代谢率（BMR）、非颤抖性产热（NST）、体温调节的最大代谢率（MMR）、热导率（CT）、体温（Tb）和有氧代谢范围系数（FAS）。为了与先前的研究进行比较，我们纳入了以下形态学性状：足长（FL）、全长（TL）、体重（出生时、性成熟时、6个月和8个月时的体重，分别记为mb）。方差成分通过两种不同的方法获得：III型方差分析中预期的方差成分以及使用限制最大似然法的动物模型方法。结果表明，FL存在加性遗传方差（h2 = 0.47，P = 0.045），冷适应动物的CT存在加性遗传方差（h2 = 0.66，P = 0.041），以及冷适应动物夜间体温存在加性遗传方差（h2 = 0.68，P = 0.080）。各年龄段mb的遗传力均接近零，但母体效应和共同环境效应较高且显著。我们没有发现BMR、NST、MMR或FAS存在加性遗传方差的证据（即所有测试的估计值与零无显著差异）。我们的结果总体上与先前对哺乳动物的研究一致，这些研究报告了以下性状的低遗传力：（1）BMR和MMR；（2）白天体温；（3）野生种群（而非实验室或家养种群）的体重。
