Figure 3.

Per1-luc expression in primary granulosa cell cultures. A, Per1-luc expression rhythm recorded by photomultiplier tube from a granulosa cell culture. Although rhythmicity gradually damped, it was restored by a medium change. B, Bioluminescence image of cultured granulosa cells recorded with an ICCD camera. A set of three cells are shown at the times of low (upper panel) and high (12 h later, lower panel) Per1-luc expression. C, Superimposed plots of Per1-luc rhythms from five individual granulosa cells in a culture recorded with an ICCD camera. Individual cells showed different peak phases. Cells were imaged after 5 d in vitro immediately after a medium change.