In wild-type, neuroblast NB7-1 generates five U motoneurons. Overexpression of hbΔD.Scer\UAS.T:Hsim\VP16 in NB7-1 under the control of Scer\GAL4en-e16E produces five to six U neurons per hemisegment. The supernumerary neuron is typically U3. The overexpression of Scer\GAL4en-e16E>hbΔD.Scer\UAS.T:Hsim\VP16 frequently generates a supernumerary U5 neuron.
Overexpression of hbΔD.Scer\UAS.T:Hsim\VP16 in hb15/hbP1only mutant NB7-1 under the control of Scer\GAL4en-e16E results in the loss of hb-dependent early born U1/U2 neurons, while still generating a supernumerary U3 neuron.