Clonal analysis using ScerGAL4ort.C1a shows expression in transmedullary neurons Tm5a and Tm5b. These extend dendrites along photoreceptor axons arborizing in medulla layers M3, M6 and M8 while their axons branch out in lobula layer 5. Expression in transmedullary neuron Tm5c shows dendrites extending to medulla layers M1, M3 and M6, the axon bifurcates in lobula layer 4 and terminates in lobula layers 5 and 6.
ScerGAL4ort.C1a drives expression in toy positive transmedullary neuron Tm20.