Figure 2.

The Clock^PER Reporter Is Not Expressed in All Intestinal Epithelial Cells

(A) Graphs of Clock^PER GFP signal normalized to DAPI under LD photoperiod followed by 24 hr in DD for anterior (left) and posterior (right). Both regions display similar circadian rhythms and the cyc⁰ mutant shows no circadian transactivation. Data presented as mean of n ≥ 10 intestines. Error bars show ±SEM. Control versus cyc⁰: anterior (two-way ANOVA F = 5.842, p < 0.0001), posterior (two-way ANOVA F = 10.7, p < 0.0001).

(B) Schematic of the differentiation of Delta (Dl) positive ISCs, which self-renew and produce differentiated Dl-negative EBs, progenitor cells that differentiate into absorptive ECs or prospero (pros)-positive EE.

(C) Representative confocal z stack showing Clock^PER GFP signal in the epithelium. Cells of interest are outlined: Dl+ marks ISCs, and pros+ marks EEs; ECs are the large polyploid cells. Scale bar represents 10 μm.

(D) Quantification of GFP intensity from confocal sections shows clock activity is absent in EEs, but present in the other three epithelial cell types (one-way ANOVA F = 42.49, p < 0.0001). Data show n > 25 cells from each cell type, error bars show ±SEM.

(E) Confocal section showing nuclear PER antibody staining in ECs but not EEs. Cells of interest are outlined: pros+ marks EEs, ECs are the large polyploid cells. Scale bar represents 10 μm.

See also Figure S3.