Mammalian hibernation is a strategy to survive during harsh winter with severe hypothermia and immobility state. It has attracted many researchers for a long time but still remains to be elucidated. Studies in obligate hibernators such as ground squirrels, chipmunk, and bears have revealed that they undergo systemic body remodeling in a season-dependent manner prior to hibernation. By contrast, a facultative hibernator, Syrian hamster, can hibernate in an environment-dependent manner; when they are exposed cold and short photoperiod condition for several months, they begin to hibernate. This inducible hibernation allows researchers to study mechanisms and significance of hibernation under a laboratory condition, whereas exact nature of systemic body remodeling for hibernation in Syrian hamsters remain unclear yet. Using histology and exhaustive gene expression analyses, we compared summer-like hamsters and winter-like hamsters and found that Syrian hamsters extensively remodel white adipose tissues during a pre-hibernation period. Particularly, simultaneous up-regulation of gene expression in both lipid catabolisms and lipid anabolisms takes place in winter-like hamsters, which is a unique property of Syrian hamsters, a“food-storing” hibernator who ingests food stored in the nest during hibernation season.
