Figure 2

Ato IPC enhancer characterization. (A) A region upstream of the promoter of ato between the positions -5046 and -4209 drives expression in the IPC. (B-I) Immunostaining of L3 optic lobes using the indicated antibodies. (B,C) IPC-GFP direct fusion (B) co-localizes with almost all Ato⁺ cells and persists in the progeny (C). (D-E) Ato⁺ cells (D, blue) co-localize completely with the ato-LacZ reporter (E, red). LacZ persists in the immediate progeny. IPC-Gal4, UAS-CD8-GFP are delayed. GFP co-localizes with very few Ato⁺ cells (G) but it is present in the immediate LacZ⁺ progeny as well as at later stages (green). (H,I) GFP⁺ cells are Elav⁺ neurons. Scale bars: B-I = 20 μm, IPC, inner proliferation center.