干旱区生态环境知识资源中心

As a member of the order of Rodentia, jerboa (Jaculus orientalis) is a natural deep hibernator and lives in sub-desert highland in many parts of the world, including Morocco. Its small size (adult body weight similar to 100 g), availability in the wild, tolerance to laboratory conditions, and some unique peroxisomal properties make it a suitable research subject for exploring peroxisome biogenesis under prehibernating and hibernating states. During 3 wk, animals referred to as the prehibernator group were exposed to cold temperature (5 to 7 degrees C) with food ad libitum. Part of the prehibernator group entered deep hibernation 24 to 48 h after starvation. Animals were sacrificed 4 and 6 d after starting hibernation. As a control, a third group, consisting of active animals, was maintained at 22 degrees C. Concerning hibernation, results from plasma analysis showed an increased level for both ketonemia and ureamia, while triglyceredemia was decreased. Liver acyl-CoA oxidase activity, a peroxisomal beta-oxidation enzyme, increased during hibernation. Liver peroxisomal urate oxidase was induced only during the prehibernating state and remained at an increased level until the fourth day of hibernation. The variations were concomitant to a decrease in peroxisomal protein yield and a differential change in peroxisomal protein pattern in sodium dodecyl sulfate-polyacrylamide gel electrophoresis during prehibernating or hibernating states. These preliminary results showed that cold exposure and hibernation affect biogenesis of liver peroxisomes in jerboa.