【作者】 汪晓琳；

【导师】 鲍毅新； 柳劲松；

【作者基本信息】 浙江师范大学 ， 生态学， 2008， 硕士

【摘要】 动物对环境的适应策略是生理生态学研究中的一个重要内容。光周期是自然界中重要的环境因子,非冬眠小型哺乳动物在体重、能量代谢和产热能力等方面的调节是其适应季节性环境变化的重要生理策略。本文以黑腹绒鼠(Eothenomys melanogaster)为研究对象,从整体、组织器官到细胞水平等不同层次,研究了黑腹绒鼠在不同光周期下的生理调节反应。主要结果和结论如下:1.不同光周期对黑腹绒鼠的体重无明显影响,与长光照组相比,短光照下的黑腹绒鼠具有较高的能量摄入、体脂重量和体脂含量。单独短光照增加了能量摄入、体脂重量和体脂含量,表明光周期是诱导能量平衡、体脂的季节性变化的因素之一。2.驯化3周后,光周期对黑腹绒鼠心脏和肺湿重有显著影响外,对其他器官的湿重和干重均无显著影响。短光照显著增加了黑腹绒鼠的基础代谢率(BMR)和非颤抖性产热(NST),表明光周期的变化对黑腹绒鼠的器官重量无显著影响,短光照诱导了黑腹绒鼠产热能力的增强,光周期的规律性变化可能是诱导黑腹绒鼠产热能力季节性变化的重要信号之一。3.BMR的残差与肝脏湿重、肝脏干重、心脏湿重和肺湿重的残差呈正相关,表明黑腹绒鼠体内存在着代谢活性器官,BMR能够反映体内代谢机器的大小。4.短光照组黑腹绒鼠的肝脏与褐色脂肪组织(BAT)的细胞色素C氧化酶活力均明显高于长光照组,表明短光照能够激活黑腹绒鼠产热增加。肝脏的细胞色素C氧化酶活性低于BAT细胞色素C氧化酶活性,由此看出BAT是黑腹绒鼠接受短光照刺激增加产热的主要器官,在光周期的季节性变化诱导的体温调节中起主要作用。5.短光照下黑腹绒鼠增加能量摄入,以满足用于产热(BMR和NST)的能量支出的增加。短光照组的BMR、NST、肝脏与BAT的细胞色素C氧化酶活性均明显高于长光照组,从个体水平到细胞水平两组间有显著差异。单独光周期变化是诱导黑腹绒鼠能量代谢和产热变化的重要信号。黑腹绒鼠为了适应光周期的变化,在生理上表现出了适应性调节。黑腹绒鼠适应不同光周期所表现出的可随性变化,对于能量平衡和产热的调节具有重要的适应意义。BAT和肝脏的细胞色素C氧化酶活性的变化是动物适应性产热变化的细胞基础。有关变量间的因果关系等,需要进一步的深入研究。更多还原

【Abstract】 Seasonal changes in photoperiod is an important environmental factor for small mammals to adjust some physiological processes, such as body mass, energy metabolism and thermogenesis, for their survival. In order to further understand the adaptive physiological strategies in Melano-bellied oriental vole (Eothenomys melanogaster), integrated the changes from organism to cellular levels, we studied the responses of this specie to different photoperiods. The main results and conclusions are as follows:1. No effect was detected in body mass by 3-week photoperiod acclimation in Melano-bellied oriental vole. Compared to long photoperiod, Melano-bellied oriental vole exposed to short photoperiod showed increases in energy intake, body fat mass and percentage of body fat. Photoperiod is one of important cues to induce seasonal variations in energy balance and body fat in Melano-bellied oriental vole.2. After 3-week photoperiod acclimation, Significant effect was detected in heart wet mass and lung wet mass. No significant effects were found in other organ’s wet mass and dry mass. However, short photoperiod caused increases in basal metabolic rate(BMR) and nonshivering thermogenesis(NST). Photoperiod had no effect on organ mass. Short photoperiod alone could increase thermogenic capacity in Melano-bellied oriental vole. Photoperiod is an important cue to induce seasonal variations in thermogenic capacity in Melano-bellied oriental vole.3. Residual BMR was positively related to the residual of liver wet mass, liver dry mass, heart wet mass and lung wet mass. These results indicate that there is a relationship between the sizes of internal organs and their contribution to BMR.4. Melano-bellied oriental vole exposed to short photoperiod showed increases in cytochrome c oxidase(COX) activity in liver and brown adipose tissue(BAT). Short photoperiod alone could increase thermogenic capacity. Cytochrome c oxidase(COX) activity in BAT was higher than cytochrome c oxidase(COX) activity in liver. BAT was the main thermogenic organ and took important part in thermoregulation.5. Under short photoperiod, Melano-bellied oriental vole increased the energy intake to meet the requirements of increased energy expenditure for thermogenesis. Melano-bellied oriental vole exposed to short photoperiod showed increases in BMR, NST, cytochrome c oxidase(COX) activity in liver and BAT. There were significant differences from the level of individual and the level of cell between short photoperiod row and long photoperiod row. Short photoperiod alone acted as an important signal to induce energy metabolism and thermogenesis in Melano-bellied oriental vole.In short, experiment data indicated that Melano-bellied oriental vole exhibited adaptive physiological regulations when exposed to different photoperiod. The plasticity in energy intake, BMR and NST was very important for the regulations in energy balance and thermogenesis in Melano-bellied oriental vole exposed to different photoperiod. Change in BAT COX activity and liver COX activity was cellular basis of adaptive thermogenesis. The cause and effect relationship among parameters etal needs further investigation.更多还原