P{PZ} insertion in the transcription unit, 438bp upstream of the translation start site.
Defasciculation of the normally tightly associated ocellar pioneer axons is seen in 50% of homozygous pupae before head eversion. Occasionally, ocellar pioneer axons associate with the epidermis and remain attached to it. Fas2 expressing axons appear normal in homozygous embryos.
Nrgl4, NrtrP668 has axon | embryonic stage phenotype