Temperature and photoperiod as environmental cues affect body mass and thermoregulation in Chinese bulbuls, Pycnonotus sinensis
Temperature and photoperiod as environmental cues affect body mass and thermoregulation in Chinese bulbuls, Pycnonotus sinensis
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温度和光周期作为环境因素影响白鹎的体重和体温调节
DOI：
10.1242/jeb.143842
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发表时间：
2017-03-01
影响因子：
2.8
通讯作者：
Liu, Jin-Song
中科院分区：
文献类型：
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作者：
Hu, Shi-Nan;Zhu, Ying-Yang;Liu, Jin-Song
摘要：温度和光周期的季节性变化是小鸟调节体重和产热的重要环境信号。然而，这些线索在Mb和产热的季节调整方面的相对重要性很难区分。特别是，在许多雀形目植物中，温度和光周期对能量代谢和体温调节的影响尚不清楚。为了解决这一问题，我们测量了温度和光周期对中华球茎（Pycnonotus sinensis） Mb、能量摄入、静息代谢率（RMR）、器官质量和代谢活性生理生化指标的影响。将球茎组在实验室中进行以下条件的驯化：(1)温暖长光周期，(2)温暖短光周期，(3)寒冷长光周期，(4)寒冷短光周期，为期4周。结果表明，球茎在不同温度和光周期下表现出适应性生理调节。冷驯化球茎的Mb、RMR、总能摄入量和可消化能摄入量均高于热驯化球茎，短光期球茎高于长光期球茎。由此产生的能量摄入和RMR的灵活性允许中国灯泡暴露在不同的温度和光周期中，以相应地调整其能量平衡和产热。与适应温暖环境的鸟类相比，适应寒冷环境的鸟类在肝脏和肌肉组织中具有更高的状态4呼吸和细胞色素c氧化酶活性，这表明它们的适应性产热的细胞机制。温度似乎是调节球茎能量收支和产热能力的主要线索；光周期似乎加强了温度诱导的能量代谢和体温调节的变化。摘要：球茎对较冷的温度和较短的光周期的响应增加了基础产热；线粒体状态4呼吸能力和细胞色素c氧化酶活性的增加可能在这种表型灵活性中起作用。
ABSTRACT Seasonal changes in temperature and photoperiod are important environmental cues used by small birds to adjust their body mass (Mb) and thermogenesis. However, the relative importance of these cues with respect to seasonal adjustments in Mb and thermogenesis is difficult to distinguish. In particular, the effects of temperature and photoperiod on energy metabolism and thermoregulation are not well known in many passerines. To address this problem, we measured the effects of temperature and photoperiod on Mb, energy intake, resting metabolic rate (RMR), organ mass and physiological and biochemical markers of metabolic activity in the Chinese bulbul (Pycnonotus sinensis). Groups of Chinese bulbuls were acclimated in a laboratory to the following conditions: (1) warm and long photoperiod, (2) warm and short photoperiod, (3) cold and long photoperiod, and (4) cold and short photoperiod, for 4 weeks. The results indicate that Chinese bulbuls exhibit adaptive physiological regulation when exposed to different temperatures and photoperiods. Mb, RMR, gross energy intake and digestible energy intake were higher in cold-acclimated than in warm-acclimated bulbuls, and in the short photoperiod than in the long photoperiod. The resultant flexibility in energy intake and RMR allows Chinese bulbuls exposed to different temperatures and photoperiods to adjust their energy balance and thermogenesis accordingly. Cold-acclimated birds had heightened state-4 respiration and cytochrome c oxidase activity in their liver and muscle tissue compared with warm-acclimated birds indicating the cellular mechanisms underlying their adaptive thermogenesis. Temperature appears to be a primary cue for adjusting energy budget and thermogenic ability in Chinese bulbuls; photoperiod appears to intensify temperature-induced changes in energy metabolism and thermoregulation. Summary: Chinese bulbuls increase basal thermogenesis in response to colder temperature and shorter photoperiod; increases in mitochondrial state-4 respiration capacity and cytochrome c oxidase activity may play a role in this phenotypic flexibility.