Data from: Early life experience drives short-term acclimation of metabolic and osmoregulatory traits in the leaf-eared mouse

We studied the putative effect of early experience on the physiological flexibility of metabolic and osmoregulatory traits in the leaf-eared mouse Phyllotis darwini, an altricial rodent inhabiting seasonal mediterranean environments. Adult individuals were collected in central Chile and maintained in breeding pairs. Pups were isolated after weaning and acclimated to different temperature (cold or warm) and water availability (unrestricted and restricted) until adulthood. Subsequently, individuals were re-acclimated to the opposite treatment. Rodents reared in warm and subjected to water restriction had lower basal metabolic rate (BMR), lower total evaporative water loss (TEWL), and body mass (Mb) compared to those developing in the cold treatment; nevertheless, individuals subjected to warm temperatures had greater relative medullary thickness (RMT) and urine concentrating ability (UCA). Cold-reared rodents re-acclimated to warm conditions exhibited physiological flexibility of metabolic traits; however, their osmoregulatory attributes did not vary. Conversely, warm-reared rodents re-acclimated to cold had reduced RMT and UCA, but the metabolic traits of these individuals did not change; these results suggest a trade-off between metabolic performance and renal capabilities that might hinder physiological acclimation. Our results support the hypothesis of ontogenetic dependence of short-term acclimation in osmoregulatory and metabolic traits in Phyllotis darwini.

本研究探讨了早期经历对叶耳鼠（Phyllotis darwini）代谢与渗透调节性状生理可塑性的潜在影响。叶耳鼠是一种栖息于季节性地中海生境的晚成啮齿动物。研究人员于智利中部捕获成年个体，以配对方式进行饲养繁殖。幼崽于断奶后被分离，分别置于不同温度（低温或常温）与供水条件（自由供水与限水）的环境中进行适应性驯化，直至个体发育至成年；随后将所有个体转接至相反的处理条件，开展二次适应性驯化。相较于低温饲养组，经常温饲养且限水的个体，其基础代谢率（basal metabolic rate, BMR）、总蒸发失水量（total evaporative water loss, TEWL）与体质量（body mass, Mb）均更低；但常温饲养的个体拥有更高的肾髓质相对厚度（relative medullary thickness, RMT）与尿液浓缩能力（urine concentrating ability, UCA）。低温饲养后转接至常温环境的个体，其代谢性状呈现出生理可塑性，但渗透调节性状未发生显著变化。反之，常温饲养后转接至低温环境的个体，其RMT与UCA均出现下降，但代谢性状未发生改变；该结果提示代谢性能与肾脏功能之间存在权衡关系，这可能会阻碍生理驯化过程。本研究结果支持“叶耳鼠的渗透调节与代谢性状的短期驯化存在发育依赖性”这一假说。