R-cell axons appear to project normally in the optic lobes of nvyScer\UAS.cTa; Scer\GAL4GMR.PF late third instar larvae.
When expression is driven by Scer\GAL4elav-C155, ISNb axons fail to defasciculate from the ISN and fail to innervate muscles 6/7 and 12/13. SNa axons also fail to defasciculate and stall on their trajectory. The outermost Fas2-1D4-antibody-detected longitudinal fascicle often fuses with the middle longitudinal fascicle. The majority of defects are manifest as a decrease in repulsion.