Deletion of unc-5 amino acids 385-446 + TS, i.e. the TSP domain 2.
When expression is driven by Scer\GAL4elav.PLu commissures are completely normal in the embryonic CNS. When expression is driven by Scer\GAL4ap-md544, the axon in which unc-5Scer\UAS.T:Ivir\HA1,T:wg is expressed projects as it does in wild type - i.e. towards the midline.