Fig. 3. Expression of Bowl is regulated by Notch activity. (A-C) Bowl expression (magenta, anti-Bowl) correlates with expression of Delta (green, anti-Delta). (A,A') 80-84 hour third-instar; Delta expression (green) is found adjacent to Bowl-expressing cells (magenta; presumptive femur fe). (B,B') 90 hours, a further domain of Delta (green) is intercalated within the presumptive tibia (ti) and strong expression is seen adjacent to the t5/pretarsal ring of Bowl (pretarsus, pt). (C,C') 120 hours, further rings of Delta expression are present within the tarsal region (e.g. arrows C,C'). Bowl is detected at tibia/t1 and t5/pretarsus boundaries, not at intervening sites (arrows, C). (D,D') 78-80 hours odd-lacZ expression (green, anti-ß-galactosidase) occurs adjacent to sites of Serrate (magenta, anti-Serrate). Expression of Serrate within presumptive femur is indicated (fe). (E,E') Bowl expression (magenta) at t5/pretarsus boundary is absent in N^81K mutant clones (arrow, marked by absence of GFP). (F,F') Ectopic Notch activity (green; act>Gal4/UAS-N^icd) induces ectopic Bowl expression (magenta). Arrows indicate sites with ectopic Bowl (overlap between Nicd and Bowl appears white in F).