Fig. 8. Ectopic expression of Rst attracts myoblasts to ectopic sites. Embryos are stained in green for muscle-specific markers ((A-C,J-L) ß-3-tubulin (D-I) muscle myosin) and for Rst in red. (C,F,I,L) Merged images. (A) Df(1)w^67k30, Nfa-g embryo: only very few myoblasts can be found close to the epidermis. (B,C) Df(1)w^67k30, Nfa-g; dll-Gal4/+, UAS-rst/+ embryo: attraction of myoblasts towards the epidermis around legdiscs (arrowheads). (D-I) Embryos from the same cross, which are either heterozygous or homozygous for the balancer. (D,G) Embryo not misexpressing Rst. (E,F,H,I) dll-Gal4/+, UAS-rst/+ embryos: ectopic myoblasts cluster in ventral regions of the thoracal segments up to stage 16 (E,F, arrowheads) and in the head region (H,I, arrowheads). (J) wg-Gal4/wg-Gal4 control embryo. (K,L) wg-Gal4/UAS-rst embryo: attraction of myoblasts to epidermal sites distal to the ventral acute muscles. (M,N) Two single focal planes through the epidermis: (M) apical position; (N) 2,5 µm below. Rst labels basal membranes of epidermal cells only at sites of ectopic expression (ectopic) and only very weakly in apodemes (apo). Scale bars: 20 µm.