Embryos expressing HGTXScer\UAS.cCa under the control of Scer\GAL4sca.PU show duplication of the RP2 neurons in 75% of hemisegments, while the number of U motoneurons and EL interneurons per hemisegment is reduced compared to controls. Neurons RP1, RP3, RP4 and RP5 appear normal in these embryos, while the number of EW interneurons is reduced. The number of medial lateral motoneurons per hemisegment is normal in these embryos, but the number of lateral cluster motoneurons per hemisegment is increased compared to controls.