Fig. 5. The fusion-competent myoblasts of the somatic mesoderm do not differentiate in jeb^weli and mili^Alk mutants. (A-C) sns in situ hybridisation of stage 11 embryos marks fcms in the visceral and somatic mesoderm. In wild-type embryos, sns is expressed in two bands along the entire length of the embryo (A). These bands are connected in a ladder-like pattern, where the ventral band represents the fcms of the somatic mesoderm (arrow in A), and the dorsal band consists of the fcms of the visceral mesoderm (arrowhead in A). In jeb^weli (B) and mili^Alk (C) mutant embryos, the fcms of the visceral mesoderm and some cells that connect the two bands are present (arrowheads); however, the ventral band of fcms of the somatic mesoderm shows no sns expression. (D-F) Alk (green) and Fas3 expression (red) in stage 11 wild-type embryos. In addition to expression in the visceral mesoderm, Alk is also transiently expressed in some cells in the neuroectoderm and in patches in the somatic mesoderm (arrows in D,F). (G-I) Lmd expression of stage 12 embryos. In the wild type, Lmd is expressed in two bands in the fcms of the somatic and visceral mesoderm (G). In jeb^weli (H) and mili^Alk (I) mutants, expression in both mesodermal cell types can be observed.