FIGURE 7.

Tissue-specific regulatory roles of Per2 in zebrafish peripheral tissues/organs. Wild-type and per2 mutant fish were sacrificed at 120 days postfertilization, and the organs/tissues of the brain, muscle, heart, and liver were dissected out and collected for RNA extraction at 4-h intervals under LD for a total of consecutive 24 h. Each sample contains tissues/organs from at least two female fish and two male fish. Shown is qRT-PCR analysis of expression levels of four circadian clock genes (per1b, per2, cry1ba, and bmal1b) in the brain (A), muscle (B), heart (C), and liver (D) of wild-type and per2 mutant adult fish. Data represent mean ± S.E. (error bars) (n = 2–3).