Fig. 1: Restricted JAK-STAT signaling activity to 20 PFCs during oogenesis defines PGC number in the future embryo.
Posterior is to the right. A,A’ Stage 9 embryos arising from control follicles and follicles expressing hopTUM in PFCs under the control of E4-Gal4. Max z-projection showing Vasa (black) to identify PGCs. B Quantification of PGC number in stage 5 to 12 embryos. Numbers within bars indicate the percentage of embryos in each category. C Schematic drawing of an ovariole. The different germ and somatic cell types are indicated. oskar mRNA localization appears in pink. D, F, H, K Posterior-most follicle regions are magnified to focus on oskar mRNA anchoring zone (pink dotted rectangles). Yellow, orange, green, red and white stars indicate PCs, PC + 1, +2, +3 and +4 rows respectively. Arrowheads indicate the anchoring zone boundary on oocyte (pink) and FC (white) sides. D Control follicle (fruitless-Gal4/+) stained for F-Actin (gray, phalloidin), DNA (cyan, DAPI) and Staufen (fire filter). E Measure of the number of FCs around PCs facing Staufen signal. F Follicle expressing hopTUM under the control of E4-Gal4. G Anchoring zone size quantified as the number of FCs around PCs facing Staufen signal, and in diameter. H, K, K’ Sum z-projection of 5 consecutive 1 μm confocal sections of follicles expressing 10XSTAT92E-GFP, stained for DNA (gray, DAPI), GFP (royal filter) and, for (K,K’), Staufen (fire filter). JAK-STAT activity is presented in section view of the posterior pole, outlined in blue (H), and in 3D projections of GFP and DNA staining (H’,H”), showing the first FC row around PCs in orange (PC + 1) and the second in green (PC + 2). Quantifications of the number of GFP-positive (GFP + ) PFCs on section views (I, L) and of FCs around PCs on 3D projections of DNA staining (pole view, J). #: number. St stage, nc nurse cells, oo oocyte, fc follicle cells, bc border cells, sc stretch cells, cc centripetal cells. Scale: 30 µm except magnifications of (D–K’) 15 µm. Statistical tests: two-sided Fisher’s exact test for (B); two-sided Mann–Whitney for (E, G) # of FCs around PCs; two-sided unpaired t test for (G) Diameter and (I, L). Information about statistics and reproducibility is provided in Supplementary Tables 1–6. Source data are provided as a Source Data file.
