Fig. 7From: The bear circadian clock doesn’t ‘sleep’ during winter dormancy a Luminescence tracings of individual bear fibroblast cultured under different serum conditions. Fibroblasts were infected with a lentivirus construct containing the mouse Bmal1 promoter linked to the luciferase gene (see Methods for more details). Cultures are rhythmic but peaks occur at different times depending on the serum condition used. Inset represents the mean traces under each serum condition. b, c Summary data for in vitro rhythm period (B) and amplitude (C) of traces shown in A. ***P < 0.0001 vs FBSBack to article page