FIG. 1.
Circadian oscillations in PER2 levels in precision cut lung slices from PER2::Luc mice. A, Sample bioluminescence recorded from a lung slice. B, Lung slices showed a typical phase response curve in response to timed application of DEX (200 nm); values are mean ± sem plotted according to the time of DEX application in relation to the peak of PER2 expression (n = 3 repeats). After at least 5 d in the PMT system, lung slices maintain their morphology and still stain positive for Clara cells (CCSP; VIP, purple staining) in the bronchioles (C) and type II pneumocytes (SP-C; DAB, brown staining) in the alveoli (D). Cell nuclei are stained blue with hematoxylin. Scale bars represent 50 μm. cpm, Counts per minute.