The salivary gland primordia of fogS4 homozygous stage 11 embryos frequently exhibit an abnormal ingression furrow along their edge, as compared to controls.
fogS4 hemizygous late embryos display severe cuticle defects, and a severe posterior-ventral cuticle hole phenotype, as compared to controls.
fogS4/Y embryos exhibit defects in internalization of mesodermal and posterior midgut cells, which results in changes to the morphology of the ventral midline.
The posterior midgut is not internalised in mutant embryos, and instead develops on the exterior of the embryo. Stage 13 mutant male embryos have a normal number of somatic gonadal precursor cells. Mutant male first instar larvae show a 70% reduction in the number of hub cells in the gonad compared to controls.
Despite blocked gastrulation movements, all tissues except the posterior midgut epithelium develop normally. Cells of the mesoderm and the anterior endoderm are eventually internalized. Two normally sized bands of visceral mesoderm are formed. The anterior endoderm usually reaches its normal position, becomes attached to the visceral mesoderm, and forms a normal epithelium. The posterior endoderm remains on the surface of the embryo. Not contacting the visceral mesoderm, posterior endoderm cells remain mesenchymal.
Suppression of tor13D embryos: increase in proportion of embryos that formed cuticle with denticles and decrease in proportion of embryos that formed empty sacs.