Expression of Dl in IFMs of 24 h APF pupae.

Expression of Dl was detected with a anti-Dl antibody in wild-type B, B′–C,C') and 1151-Gal4, UAS-RNAiMef2 (E, E′–F,F') 21 h APF pupae. A'–F' show magnified areas indicated by the dotted squares in A–F respectively. Muscles are visualized with DAPI staining by the specific arrangement of their nuclei (asterisks in A, D, A′, D′; muscles are located between the two dotted lines in A′ and D′). Large nucleus (n in A′) is a larval template nucleus. Myoblasts are located between muscles (m in A′, D′). In wild type pupae, Dl is detected in myoblasts and developing fibers (B, B′; overlay in C, C′). Expression levels in myoblasts and fibers are close (B′). Overexpression of a RNAi-Mef2 construct in myoblasts and fibers using the 1151-Gal4 driver (D–F, D′–F′) lowers Dl expression in developing fibers compared to myoblasts (E′, compare m to asterisks) and in 1151-Gal4, UAS-RNAiMef2 muscles compared to wild type muscles (compare E′, asterisks to B′, asterisk).