Phenotypic flexibility of energetics in acclimated Siberian hamsters has a narrower scope in winter than in summer
详细信息 查看全文
- 作者：Jan S. Boratyński ; Małgorzata Jefimow…
- 关键词：Phenotypic flexibility ; Acclimation ; Acclimatization ; Thermoregulation ; Energetics ; Season
- 刊名：Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
- 出版年：2016
- 出版时间：April 2016
- 年：2016
- 卷：186
- 期：3
- 页码：387-402
- 全文大小：767 KB
- 刊物类别：Biomedical and Life Sciences
- 刊物主题：Life Sciences
Biochemistry
Biomedicine
Human Physiology
Zoology
Animal Physiology - 出版者：Springer Berlin / Heidelberg
- ISSN：1432-136X
文摘
As photoperiod shortens with the approach of winter, small mammals should reduce their energy expenditure to survive periods of food limitation. However, within seasons, animals should balance their energy budgets as abiotic conditions change, sometimes unpredictably; cold spells should increase heat production, while warm spells should do the opposite. Therefore, we addressed specific questions about the possible interactions between seasonal acclimatization and the intra-seasonal phenotypic flexibility of metabolic rate. We hypothesized that phenotypic flexibility in small mammals differs seasonally and is greater in summer than in winter, and predicted that seasonal adjustments in energetics, which are driven by photoperiod, overwhelm the influence of variations in the thermal environment. We measured body mass, basal metabolic rate (BMR), facultative non-shivering thermogenesis (fNST), body temperature, and calculated minimum thermal conductance in Siberian hamsters Phodopus sungorus. Animals were acclimated to winter-like, and then to summer-like conditions and, within each season, were exposed twice, for 3 weeks to 10, 20 or 28 °C. We used differences between values measured after these short acclimation periods as a measure of the scope of phenotypic flexibility. After winter acclimation, hamsters were lighter, had lower whole animal BMR, higher fNST than in summer, and developed heterothermy. After these short acclimations to the above-mentioned temperatures, hamsters showed reversible changes in BMR and fNST; however, these traits were less flexible in winter than in summer. We conclude that seasonal acclimation affects hamster responses to intra-seasonal variations in the thermal environment. We argue that understanding seasonal changes in phenotypic flexibility is crucial for predicting the biological consequences of global climate changes.