The effect of CK1δ inhibition on rhythmic pineal aanat2 mRNA expression is reversible.

Reversibility was determined after two (A) or three (B) LD cycles for re-entrainment. Top panels: Experimental design. The horizontal bars represent the light conditions before and during sampling; white boxes represent light, grey boxes represent subjective day and black boxes represent dark. Middle panels: Whole-mount ISH signals (dorsal views of the heads) of representative specimens treated with DMSO (control, a) or with PF-670462 (b). ZT 2-10b refers to the second 24 h cycle of the sampling. Bottom panels: Signal intensities in the pineal gland. Values represent the mean ± SE optical density of the pineal signals. Statistical analysis was performed using one-way ANOVA followed by Tukey's post-hoc test for each treatment. Following removal of the inhibitor and re-entrainment, for two (A) or three (B) LD cycles, the rhythm of aanat2 mRNA re-appeared but seemed to be shifted.