Figure 1.

Constant Light Suppresses and Constant Darkness Enhances BDBT Foci after LD Entrainment

(A) Wild-type Canton S flies were harvested at the indicated times in LD (ZT, lights on from 0-12), during the second day of constant darkness (CT times indicate the previous time in LD), or during the first day of constant light (LL times indicate the previous time in LD). Heads were sectioned and probed with anti-BDBT antibody. The rectangle in the ZT19 image shows an area where foci are still visible above the general signal; foci are seen throughout the area in single optical sections (Figure S1A). In the LL samples, foci were often concentrated in fingers on the outside of the retina (a red rectangle surrounds a finger in the LL19 sample). These are produced in R7 cells, some of which coexpress Rh3 adjacent to the BDBT fingers (Figures S1B and S1C).

(B) The location of BDBT (broadly throughout the eye or in fingers on the outside; e.g., LL19) or its lack of expression (none) were tabulated for multiple sections after detection by confocal microscopy. A Kruskal-Wallis nonparametric analysis (H (4, N = 63) = 40.5) followed by multiple comparisons of mean ranks for all groups showed that sections of flies from darkness (a) differed significantly from those of flies from light (p ≤ 0.05), while there were no statistically significant differences within the a or b groups. Scale bar represents 50 microns, and the number of sections analyzed for each bar on the plot is indicated inside the bar.