Fig. 3. Experiment showing partial rescue from the overgrowth phenotype by expression of N::EYFP. (A,B) Dorsal front views of embryos of 21-22 hours AEL in which a large subset of da neuron expressed GFP. Broken lines represent dorsal midlines. (A) In the wild-type embryo, dendritic terminals of ddaD and ddaE (D and E) did not reach the dorsal midline, and dendrite-free zones were observed (bracket). (B) In contrast, branch terminals in the fmi null mutant reached the midline before hatching. (C) N::EYFP expression partially prevented the dorsal overgrowth (bracket). Bar, 20 µm. (D) Distribution of the distance between the most dorsal tips of dendritic terminals of ddaD and ddaE and the dorsal midline in each hemi-segment. The label <0 on x-axis indicates that branch terminals extended beyond the midline and invaded contralateral hemi-segments. Relevant genotypes were Gal109(2)80 UAS-GFP[S65T]/IH1 UAS-GFP[S65T] (A, and Wild type in D), Gal109(2)80 UAS-GFP[S65T] fmi⁷²/IH1 UAS-GFP[S65T] fmi^E59 (B, and fmi mutant in D), Gal109(2)80 UAS-GFP[S65T] fmi⁷²/IH1 UAS-GFP[S65T] fmi^E59; UAS-fmi::EYFP/UAS-fmi::EYFP (Fmi::EYFP rescue in D), and Gal109(2)80 GFP[S65T] fmi⁷²/IH1 GFP fmi^E59; UAS-N::EYFP/UAS-N::EYFP (C, and N::EYFP rescue in D). Numbers of abdominal segments examined for individual genotypes are indicated.