Fig. 5
Temporal changes of mRNA levels of target genes in the pineal gland. a, arylalkylamine N-acetyltransferase (AANAT); b, brain and muscle ARNT-like-1 (BMAL1); c, circadian locomotor output cycles kaput (CLOCK); d, cryptochrome-1 (CRY1). The horizontal white bar of the X-axis represents light condition, and the black bar represents dark condition in 12L:12D group, while 0L:24D group is in constant darkness throughout the whole day and it is not shown in the figure. The data are presented as mean ± SEM (n = 3 per group). The curve shows the best fit to the points by cosinor analysis. The solid line represents rhythmical gene expression, and no solid line represents arrhythmical gene expression. R2 values represent the fitting degree. P values indicate the significance of cosinor regression analysis. Significance of difference was set at P < 0.05. ZT, zeitgeber time