Expression of Tak1D159A.Scer\UAS when driven by Scer\GAL4en-e16E, Scer\GAL4pnr-MD237, or Scer\GAL4arm.PS, does not significantly affect development of the embryos. Expression of Tak1D159A.Scer\UAS when driven by Scer\GAL4pnr-MD237 or Scer\GAL4ap-md544, produces adults that display incomplete closure of the thorax, giving rise to a mild thoracic cleft at the dorsal midline of the notum, and also a lack of bristles in the area. This phenotype has a high penetrance (about 91%).