Fig. 1

Profiling of expression of 15 circadian genes in hearts from intact C57BL/6J and C57.Y^A/J male mice. Expression levels were measured at 4-h intervals between ZT0 and ZT20. Values at each time-point correspond to mean ± SEM (n = 4). The arrows point to ZT8, which is a time when several circadian genes show some disparity in expression levels. Post-hoc Tukey multiple comparison tests were performed for the three genes where the significance of the strain × time interaction had a P value <0.05 (*P < 0.05; **P < 0.01)