bin91Fa mutants show a salivary gland phenotype. At stage 14, mutant salivary glands remain associated with the inner circular muscle layer, while in wild type, these structures become separate. After stage 15, cells from the distal tips of the bin91Fa salivary glands spread into the region of the undifferentiated midgut that forms the gastric caecae in the wild-type embryos. The mutant glands become mispositioned and/or elongated and maintain contact with the area of the midgut immediately adjacent to the proventriculus.