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. 2005 Feb 7;102(7):2608–2613. doi: 10.1073/pnas.0409763102

Fig. 5.

Fig. 5.

Effects of Clock and Bmal1 mutations on circadian expression of luciferase in mPer2-E2::Luc transgenic mice. (A) Bioluminescence recorded from SCN explants from mPer2-E2::Luc transgenic mice on the Clock mutant genetic background (E2–1-Clock). Robust circadian oscillations are evident in both Clock WT (+/+) and heterozygous (m/+) SCN. However, E2–1-Clock heterozygotes displayed a longer period and a delayed phase (refer to Fig. 5 B and C) than WT tissue. Circadian oscillations of bioluminescence were abolished in E2–1-Clock homozygotes (m/m). (B) Bioluminescence recorded from SCN explants from mPer2-E2::Luc transgenic mice on the Bmal1 knockout genetic background (E2–1-Bmal1). Robust circadian oscillations in bioluminescence are evident in both Bmal1 WT (+/+) and heterozygous (-/+) SCN and did not differ significantly. Circadian oscillations of bioluminescence were abolished in E2–1-Bmal1 homozygotes (-/-). (C) Period analysis of E2–1-Clock and E2–1-Bmal1. The circadian rhythms in bioluminescence were significantly different between E2–1-Clock WT (+/+) and heterozygous (m/+) animals (period, 23.56 and 24.48 h, respectively; P = 0.015), whereas E2–1-Bmal1 WT (+/+) and heterozygous (-/+) mice were not significantly different from each other (period, 24.00 and 23.94 h, respectively; NS). (D) Phase data for E2–1-Clock and E2–1-Bmal1. The peak of the circadian oscillation was determined during the interval between 12 and 36 h in culture. The average times ± SEM of peaks were plotted against the time of last lights-on. The LD cycle to which the animals were exposed before tissue removal is shown above the plot (white and black bar). The peak phases were significantly different between E2–1-Clock WT (Upper, blue circle) and heterozygous (Upper, red circle) animals (peak at 37.38 and 39.44, respectively; P = 0.031). The peaks of the circadian oscillation in E2–1-Bmal1 WT (Lower, blue circle) and heterozygous (Lower, red circle) mice were not significantly different from each other (peak, 34.84 and 35.02, respectively; NS).