Figure 5. Expression profile of Aanat messenger RNA over a single 24 h period under distinct lighting conditions. A: In a 12 h light: 12h dark cycle (LD) there was a strongly rhythmic pattern with maximal expression at ZT20, and a nadir 12 h later (n=3-6 per time point). B: In constant dark (DD) the profile was attenuated, with a peak at CT16 (n=5-6 per time point). C: In constant light (LL) there was only a small phase shift, such that peak values were at CT22 (n=4 per time point). Illumination conditions are depicted as solid white (day) and solid grey (night) areas in LD, right hatched (subjective day) and solid grey (subjective night) areas in constant dark (DD) and solid white (subjective day) and left hatched (subjective night) areas in constant light (LL). Animals were killed every 3 or 4 h across the 24 h period, and RNA extracted from retinal tissue. RNA expression levels were quantified by real time PCR. One-way analysis of variance (ANOVA) and cosinor levels of significance (P_A and P_c respectively) are given in the upper right corner of each panel.