N-terminal deletion removing sequences encoding the first 61 amino acids of comm.
Pan-neural expression of one copy of commΔ1.Scer\UAS.T:Avic\GFP-m6 under the control of Scer\GAL4unspecified results in a robo phenocopy in which a subset of longitudinal axons are misdirected across the midline. Pan-neural expression of two copies of commΔ1.Scer\UAS.T:Avic\GFP-m6 under the control of Scer\GAL4unspecified results in a sli phenocopy.