Fig. 2. Mutations in fng cause defects of Pros expression in LG. All panels except C and F show three segments of stage 15-16 VNC stained with anti-HRP (green) and co-stained for either Pros or ß-galactosidase, as indicated (magenta). (A) fng^L73 heterozygotes, like wild type, have six Pros-positive LG per hemisegment. (B) The reporter loco-lacZ reveals the number and position of LG in fng heterozygotes. (C) Overlay of D and E without anti-HRP, and with Pros converted to green. (D) fng mutants have fewer Prospositive LG, and the level of Pros expression is often reduced. (E) The number and position of LG in fng mutants appears normal. (F) Overlay of D and E. (G) fng^Df/+ hemizygotes also have six Pros-positive LG per hemisegment as normal. (H) Reduced Pros expression in an fng^13/Df embryo (D). (I) Pros expression is rescued in fng^13/Df mutants using repo-Gal4 to express UAS-fng. (J) Quantification of Pros-positive LG per hemisegment. Every Pros-expressing cell in the vicinity of the neuropil was counted as positive, regardless of staining intensity. The number of abdominal hemisegments counted for each genotype is indicated (N). Because one of the six Pros-expressing LG per hemisegment is often obscured in the compiled images, the results were binned as five or six Prosexpressing LG, versus four or fewer.