Fig. 5. Expression of duf-lacZ during abdominal myogenesis. Preparations of duflacZ pupae double labeled with anti-ß-galactosidase (green) and anti-Twist (red). Panels A and B are of the same preparations shown separately in the red and green channels. (C-F) Merged images. (A) Twist-expressing nerve-associated myoblasts in the dorsal hemisegment of A3 in a late third instar larva. (B) duf-lacZ expression in the same cells as in A. (C) A 13-hour APF pupa, again showing co-localization of duf-lacZ with Twist in almost all nerve-associated myoblasts. (D) By 20 hours APF, lacZ expression has faded from many of the myoblasts, and only a subset of myoblasts shows co-localization. (E) At 24 hours APF, the number of Twist and duf-lacZ co-localizing myoblasts is further reduced. By this stage, individual myoblasts expressing high levels of duf-lacZ are seen. (F) Twenty-eight hours APF. Single duf-lacZ-expressing myoblasts are observed at positions corresponding to future fibre forming sites. In all figures anterior is to the top, dorsal to the right. Scale bar: 20 µm.