Figure 9.

Reentrainment of mouse pancreas does not reliably occur by day 10 and instead was found to cross over on day 3−4 postnormalization. A single time point (ZT8) was chosen to evaluate daily for 10 days following normalization of the LD cycle to determine if reentrainment occurred (A). The graphs (B) demonstrate the male and female mouse pancreatic relative mRNA expression of Arntl, Per2, and Per3, measured by quantitative real-time PCR, in both the normal circadian (solid black) and chronic jetlag (dashed gray) conditions. Lines represent the mean ΔCT with associated individual animals shown as points (n = 3 M/F at each time point). The ΔCT values are relative to the Hprt housekeeping gene. Individual points indicate the average of technical triplicates. Pairwise comparisons were made with independent Student’s t test. Reentrainment was considered to occur if both conditions were consistently nonsignificant by day 10 of normalization. Graphs demonstrate the core clock genes Arntl, Per2, and Per3 do not reliably reentrain by day 10 postnormalization. ns, Not significant, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. LD, light-dark.