| In order to understand the physiological strategy of this specie for season and ambient temperature deeply, energy metabolism and thermogenesis were studied in Melano-bellied Oriental Vole (Eothenomys melanogaster) which is a familiar species in SouthChina, involve the energy intake, organ mass, basal metabolic rate (BMR), non-shivering thermogenesis (NST), thermogenic property of brown adipose tissue (BAT) and liver under different temperature (25±1℃,15±1℃,5±1℃) 0d,7d,14d, 21d,28d. At the same time, the seasonal changes of these parameters were measured in E. melanogaster. The main results and conclusions are as follows:1. The seasonal variation effected the body mass and body fat mass chang significantly in E. melanogaster. The body mass, body fat mass, the percentage of body fat, wet carcass mass and dry carcass mass showed higher in fall than in winter, lowest is summer except fat-free carcass mass which had no seasonal variation. These dynamic change may be influened not only by environment temperature but also propagate, feeding habit and climate in the habitat of E. melanogaster.2. E. melanogaster in winter showed higher energy intake, digested energy and metabolizable energy than in other seasons as well as digestive track mass increased significantly in winter involved wet mass of big intestine and small intestine, wet and dry mass of stomach and ceacum, which indicates that shape of digestive track may help E. melanogaster have more digestive area for food or more time for food to stay in tract thus kept its high digestibility. Heart mass which is the most important power organ also showed highest level in winter, which could indicate that the metabolic rate in Melano-bellied Oriental Vole improved under pressure of winter.3. Significant difference of metabolic rate was found among different seasons in E. melanogaster. The BMR and NST were all highest in winter, and lowest in summer which showed that heat produce is one of important countermeasure for adapting environmental variation. The relative mass, content of mitochondrial protein (MP) and cytochrome C oxidase (COX) activity of mitochondria in brown adipose tissue (BAT) are on higher level in winter. Though the relative mass of liver increased in summer, the COX activity and MP content of liver all increased to highest in winter. The seasonl change of BAT and liver keeped consistent with metabolic rate in E. melanogaster, which indicates BAT and liver participate in adjusting of thermogenesis.4. Increasing, increasing and decreasing trend were found in body mass respectively under 25±1℃,15±1℃and 5±1℃. Energy intake under 25±1℃,15±1℃and 5±1℃shows decreas, increase and increase respectively. Digestibility and efficiency of metabolizable energy intake didn't show any change under 25±1℃and 15±1℃, but improved significantly after cold acclimation (5±1℃). From this, it can be seen that E. melanogaster could save enough energy for organism construction and functional recovery when under warm temperature, store up more energy to prepeare for coming winter when under lower temperature, reduce body mass and increase energy intake also digestibility to keep balance between energy in and out when under low temperature.5. E. melanogaster under the acclimation of 25±1℃showed stable level in BMR, relative mass and MP content of liver, however reduced in mitochondrial COX activity. Under 15±1℃, BMR increased when the MP content as well as mitochondrial COX activity. Low temperature (5±1℃) induced Melano-bellied Oriental Vole increase BMR and thermogenic capability of liver according to the time of acclimation. Compared with speices in other area, it will be found that the increasing rate of BMR have big relationship with the improving degree of COX activity in liver. What is said above confirmed that change of liver property is one of important cellular mechanism for BMR.6. BAT is the main heat-producing organ for NST, that was also proved in this study. Decreasing trend was found in NST as well as relative mass and mitochondrial COX activity of BAT but all without significant difference under 25±1℃acclimation. Incresing trend was detected in NST by 15±1℃acclimation when every property of BAT showed marked increase. Cold acclimation (5±1℃) induced either NST or BAT activity increase largely. It was also found that the changing range of NST in cold acclimation in E. melanogaster was smaller than their BMR and also smaller than NST in species of NorthChina. It reflected the character of geography and climate in the habitat of Melano-bellied oriental vole.7. The experiment showed that every parameter had rule in the acclimated-time. The parameters increased or decreased while the time of acclimation delayed involve body mass, BMR relative mass, MP content, mitochondrial COX activity of liver and BAT in E. melanogaster,then all of them went to maxi-value when 21 days, or went slower after 21 days. It means that Melano-bellied oriental vole need about 21 days to form new physiological steady state.8. There is a great relationship between seasonal variation and change in different temperature in E. melanogaster. For example, body mass in E. melanogaster decrease in cold winter versus fall, when it also showed decrease under cold acclimation (5±1℃). The energy intake in E. melanogaster showed winter>fall> spring> summer which means it increase with temperatre decrease. Accordingly, the energy intake and digestibility showed decrease in warm temperature (25±1℃), increase in lower temperature (15±1℃) and increase largely in cold acclimation (5±1℃). It indicated to a certain degree that temperature may play an indispensable and crucial role in seasonal acclimation.In short, in order to retain body temperature and normal physiological function in different season and temperature, E. melanogaster exhibited adaptive physiological regulations from organism to cellular levels, which is of great significance for animal to survive, reproduce and evolve in natural environment. There was a special mode of metabolic and thermogenic mode in E. melanogaster, which close connect with its life style and habitat environment. Temperature is an important inducement for seasonal variation in animal's physiological ecology, however, it needs further investigation to study mechanism of concerted reaction between temperature and other ecological factor like food, photoperiod and so on.
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