Expression of Mmus\NumbNPF.Scer\UAS in the SOP lineage, under the control of Scer\GAL4sca-537.4 or Scer\GAL4sca-109-68 causes balding of the notum due to transformation of IIA daughter into a second IIB and subsequent transformation of IIIb's sheath daughter into another neuron, resulting in mutant external sensory organs with as many as four neurons.