Fig. 1: The Drosophila proventriculus contains a ring of nutrition-sensitive EdU+ cells located in Zone 4.

A Schematic of the Drosophila proventriculus. Zone 4 is indicated in green. B Left: Chs2-Gal4 is expressed in Zone 4 cells. Representative image is shown from N = 2 independent experiments. Middle: HPA lectin stains the peritrophic membrane (PM). Representative images are shown from >10 independent experiments. Right: Wg protein is enriched in Zone 4 cells. Confocal z-slices are shown. Representative images are shown from >5 independent experiments. C Left: EdU labeling is enriched in a ring of cells at the posterior of Zone 4. A maximum intensity projection of EdU staining is overlaid on a single z-slice of DAPI staining. Representative image is shown from >20 independent stainings. Right: EdU+ cells are immediately anterior to cells expressing 10XSTAT:GFP reporter. Single z-slice is shown. Representative image of a single experiment is shown. D The number of EdU+ cells increases with duration of EdU feeding. Maximum intensity projections are shown. E Quantification of EdU+ cell numbers at 1, 3, and 5 days of feeding, for two different fly strains, OregonR and w¹¹¹⁸. N = number of independent proventriculi [1, 3, 5 days]: OreR: 11, 9, 10; w¹¹¹⁸: 9, 11, 8. Differences between genotypes at each time point are not significantly different from each other, tested using the unpaired two-sided t-test with Welch correction. Data are presented as mean ± SD. F The number of EdU+ cells increases as more yeast is added to the food source. Maximum intensity projections are shown. G Quantification of the experiment shown in (F). N = number of independent proventriculi [0, 1, 2, 10%]: 14, 15, 15, 16. Black dots represent mean values, error bars indicate SD. F The data were fitted using a one-phase association model, yielding a rate constant K = 0.5689 (95% CI = 0.1639–1.463). Anterior is up, scale bar is 50 µm in all images. Source data are provided as a Source Data file.