Fig. 4. A subset of coeloconic sense organs which form in weak hypomorphic mutants are sufficient to pattern the antennal lobe. (A-C) Region of the adult antenna showing coeloconic sensilla (arrowheads). Numbers given below are based on counts from at least 10 antenna. Similar numbers were obtained from the canton-S wild-type strain (A) as well as ato¹/+ and Df(3R)p¹³/+ heterozygotes. (B) ato¹/Df(3R)p¹³. (C) ato¹/ato². (D,E) GFP expression in the sensory neurons using SG18.1 in ato¹/ato² background. (D) Adult antennal lobe showing almost normal looking lobe with identifiable glomeruli and presence of commissure (arrow) (compare with Fig. 1A). (E) A single lobe enlarged to show the presence of distinct glomeruli (*). Arrowhead marks entry of antennal nerve to the lobe. Scale bars: in A, 10 µm in A-C; in D, 20 µm in D,E.