Asymmetric expression level of clock genes in left vs. right nasal mucosa in humans with and without allergies and in rats: Circadian characteristics and possible contribution to nasal cycle
Daily profiles of PER1 (A), PER2 (B), CLOCK (C), BMAL1 (D), MUC5AC (E), and aquporin5 (F) mRNA levels in nasal mucosa derived from the right and the left nasal cavity of rat under light/dark conditions.
Zeitgeber Time (ZT) is used to assess endogenous time in constant darkness. ZT0 and ZT24 is assigned to the original time of lights on and ZT12 and ZT 36 to light off. Values of PER1, PER2, CLOCK, BMAL1, MUC5AC, and aquaporin mRNA were normalized to GAPDH mRNA. The signal levels at ZT0 were defined as 1. Each value represents the means ± SD (n = 6 mice per time-point). The difference of expression levels were assessed by Mann-Whitney U test. * means P < .05. All time interval calculations are based at the indicated Zeitgeber time (ZT), and 9:00 a.m. was considered ZT0.