Expression of Deaf1^Scer\UAS.cVa under the control of Scer\GAL4^arm.PS or Scer\GAL4^69B does not result in significant cuticle defects at room temperature or 25^oC. Many of the embryos hatch but stop development at larval or pupal stages. Expression of Deaf1^Scer\UAS.cVa under the control of Scer\GAL4^arm.PS at 29^oC, and with Scer\GAL4^arm.PS expressed maternally, results in an abnormal phenotype; most axial cuticle elements are normal but there is a failure of dorsal closure and incomplete germband retraction. Expression of Deaf1^Scer\UAS.cVa under the control of Scer\GAL4^dpp.blk1 results in few survivors, which have curly wings with wider third veins than normal and loss of dorsal thoracic and scutellar macrochaetae. Expression of Deaf1^Scer\UAS.cVa under the control of Scer\GAL4^GMR.PF results in loss of ommatidia and a rough eye phenotype. Expression of Deaf1^Scer\UAS.cVa under the control of Scer\GAL4^Bx-MS1096 results in few survivors, with rudimentary wings and defective macrochaetae. Expression of Deaf1^Scer\UAS.cVa under the control of Scer\GAL4^hs.2sev results in a weak rough eye phenotype, with a smooth and lightly coloured anterior-central region of the eye.