Scer\GAL4^da.G32-mediated expression of Ssk^{dsRNA.Scer\UAS} does not impair gross midgut morphogenesis during embryonic development.

Only a small number of Scer\GAL4^da.G32, Ssk^{dsRNA.Scer\UAS} embryos hatch to first instar larvae, and those that do are sluggish in their movements and do not survive to the second instar stage.

In contrast to wild type, the midgut of late stage 17 Scer\GAL4^da.G32, Ssk^{dsRNA.Scer\UAS} embryos contain dark material, indicating a difference in their contents.

The anterior midgut epithelial cells of late stage 17 Scer\GAL4^da.G32, Ssk^{dsRNA.Scer\UAS} embryos are more elongated in the apical-basal direction than those of wild type. While the wild type cells are cuboidal with a slightly rounded apical surface composed of microvilli, Scer\GAL4^da.G32, Ssk^{dsRNA.Scer\UAS} anterior midgut cells have apical membranes with microvilli often protruding into the lumen, though these cells do retain their apicobasal polarity.

In the midgut of late stage 17 Scer\GAL4^da.G32, Ssk^{dsRNA.Scer\UAS} embryos, parallel plasma membranes between cells are markedly reduced and intercellular spaces of irregular width are often observed. The intercellular space lacks electron-dense material and septa are observed at a much lower frequency than in wild type.

The morphology of pleated septate junctions in the hindgut of late stage 17 Scer\GAL4^da.G32, Ssk^{dsRNA.Scer\UAS} embryos is normal, with parallel plasma membranes containing clear septa.

In contrast to wild type, first instar larvae expressing Ssk^{dsRNA.Scer\UAS} under the control of Scer\GAL4^da.G32 (delayed until 28 hours after egg deposition using Scer\GAL80^ts.αTub84B technique) and fed with TRITC-labeled dextran exhibit the tracer in various parts of the body cavity, consistent with leakage of the tracer from the lumen of the midgut.