White Jordan T, DeSanto Cori L, Gibbons Connie, Lardner Casey K, Panakos Andrew, Rais Salehin, Sharp Kathy, Sullivan Shannon D, Tidhar Wendy, Wright Leanne, Berrigan David, Heideman Paul D
Department of Biology, College of William and Mary, Williamsburg, VA, USA; Department of Biology, Johns Hopkins University, Baltimore, MD, USA.
Department of Biology, College of William and Mary, Williamsburg, VA, USA.
Horm Behav. 2014 Jun;66(1):169-79. doi: 10.1016/j.yhbeh.2014.02.006. Epub 2014 Feb 26.
This article is part of a Special Issue "Energy Balance". Natural populations display a variety of reproductive responses to environmental cues, but the underlying physiology that causes these responses is largely unknown. This study tested the hypothesis that heritable variation in reproductive traits can be described by heritable variation in concentrations of hormones critical to both energy balance and reproduction. To test this hypothesis, we used mouse lines derived from a wild population and selectively bred for response to short day photoperiod. Reproductive and metabolic traits of Peromyscus leucopus display heritable variation when held in short photoperiods typical of winter. Our two lines of mice have phenotypes spanning the full range of variation observed in nature in winter. We tested male and female mice for heritable variation in fasted serum concentrations of three hormones involved in energetic regulation: leptin, insulin-like growth factor 1 (IGF-1) and insulin, as well as the effects of exogenous leptin and a high energy diet on reproductive maturation. Exogenous leptin decreased food intake, but protected males from the reduction in testis mass caused by equivalent food restriction in pair-fed, saline-infused controls. A high energy diet resulted in calorie adjustment by the mice, and failed to alter reproductive phenotype. Concentrations of the three hormones did not differ significantly between selection lines but had correlations with measures of food intake, fertility, blood glucose, and/or body mass. There was evidence of interactions between reproductive traits and hormones related to energy balance and reproduction, but this study did not find evidence that variation in these hormones caused variation in reproductive phenotype.
本文是《能量平衡》特刊的一部分。自然种群对环境线索表现出多种繁殖反应，但其背后导致这些反应的生理机制在很大程度上尚不清楚。本研究检验了这样一个假设，即繁殖性状的遗传变异可以通过对能量平衡和繁殖都至关重要的激素浓度的遗传变异来描述。为了验证这一假设，我们使用了源自野生种群并针对短日照光周期反应进行选择性培育的小鼠品系。当置于典型冬季的短日照条件下时，白足鼠的繁殖和代谢性状表现出遗传变异。我们的两个小鼠品系的表型涵盖了冬季自然界中观察到的全部变异范围。我们测试了雄性和雌性小鼠在禁食血清中参与能量调节的三种激素（瘦素、胰岛素样生长因子1 (IGF-1) 和胰岛素）浓度的遗传变异，以及外源性瘦素和高能量饮食对生殖成熟的影响。外源性瘦素减少了食物摄入量，但保护雄性小鼠免受配对喂食、注入生理盐水的对照组中同等食物限制所导致的睾丸质量下降的影响。高能量饮食导致小鼠进行热量调整，但未能改变生殖表型。这三种激素的浓度在选择品系之间没有显著差异，但与食物摄入量、生育能力、血糖和/或体重的测量值存在相关性。有证据表明繁殖性状与能量平衡和繁殖相关激素之间存在相互作用，但本研究未发现这些激素的变异导致生殖表型变异的证据。
