Embryos expressing nullo^Scer\UAS.cHa under the control of Scer\GAL4^{mat.αTub67C.T:Hsim\VP16} have defects in ventral furrow formation; ventral cells of the embryo do appear to initiate cell-shape changes and occasionally produce a wide, shallow furrow on the ventral surface but they fail to complete ventral furrow formation. The cephalic furrow appears normal. These embryos eventually form disorganised zonula adherens, but late embryos are highly disrupted, with cuticular holes and severe morphological defects. Embryos expressing nullo^Scer\UAS.cHa under the control of Scer\GAL4^{arm.T:Hsim\VP16} do not show any defects in adherens junctions, morphology or cuticle formation.