Homozygous mutant embryos have irregularly shaped salivary glands with bulges in their epithelia of variable sizes, leading to greater distances between neighbouring nuclei. Salivary glands are also small and/or misshapen in a small percentage of homozygotes. Homozygous mutant salivary glands at stage 15 and beyond have bulges in the lumen of the secretory tube of a variable size. These glands have a reduced lumenal content correlated with a decrease in number of secretory vesicles found near the surface. Otherwise mutant and wild-type salivary glands are indistinguishable at the ultrastructural level.