sv15/sv15im9 showed the wild-type appearance with a very mild Dpy phenotype, and the appearance of sv15im9/sv15im9 homozygotes almost matched of the wild-type.
"Muscle cells are found in a wild-type number (Table 2) and are functional, as contractions are evident in double mutants, but they are scattered and are not organised into rows as they are in wild type (compare Fig. 7C to 1E)."