Figure 6.

Intracellular Ca²⁺ levels in PPM3 neurons lower during day than night but remain similar during day and night in the absence of PDFR. A, TH GAL4 expressing CaLexA in WT and pdfr ⁵³⁰⁴ backgrounds costained with antibodies against TH to mark dopaminergic neurons and GFP to quantify intracellular Ca²⁺ levels at two time points: ZT4 and ZT14. CaLexA-driven GFP⁺ signal was detected at a low level at ZT4 whereas higher intensity at ZT14 (left panels) in WT background. A.U. = arbitrary units. CaLexA-driven GFP⁺ signal was detected at similar high level at ZT4 and ZT14 (right panels) in pdfr ⁵³⁰⁴ background. Asterisks indicate PPM3 neurons which are zoomed in inset. B, Quantification of results in A shows significantly lower GFP fluorescence in TH GAL4 > CaLexA flies at ZT4 as compared to GFP fluorescence in TH GAL4 > CaLexA flies at ZT14, pdfr ⁵³⁰⁴; TH GAL4 > CaLexA flies at ZT4 and ZT14. All other details are as in Figure 1. See also Extended Data Figures 6-1, 6-2.