PDFR is expressed in l-LNvs of young flies.

(A, B) Sleep is elevated in young male flies following eclosion and reaches stable adult values in 3-day-old flies (n = 35–93 flies/age; one-way ANOVA F_[5,472] = 81.34, for age, p = 3.7^E-63). (C–E) FRET ratio measurements in Pdf-GAL4>UAS-Epac1 flies in response to DA (3e-3M), Oa (3e-3M), and PDF (1e-6M) (n = 5–15 ROI. Each ROI represents 2 to 4 l-LNvs). (F) The amplitude of l-LNv responses to PDF decreases with age (PDF amplitude); (n = 13–24 ROI/age; one-way ANOVA for age F_[5,93] = 19.86, p = 3.3^E-13). (G) GFP expression in LNv neurons (Pdf-GAL4; UAS-gfp). (H) Immunohistochemistry reveals coexpression of PDF (red) and myc (green) in 0-day-old P[acman] Pdfr-myc70 flies, which is not observed on day 5. *p < 0.05, modified Bonferroni test. Data underlying this figure can be found in S1 Data. DA, dopamine; FRET, Förster Resonance Energy Transfer; GFP, green fluorescent protein; l-LNv, large ventral lateral neuron; Oa, octopamine; PDF, pigment dispersing factor; PDFR, pigment dispersing factor receptor; ROI, region of interest.