The connectives are farther apart than normal in the central nervous system of double mutant NetA^unspecified NetB^unspecified 14 hour embryos and the commissures are often missing, very thin or project towards the periphery. Commissural defects are seen in every segment. The longitudinal connectives are farther away from the midline than normal; the medial tracts are positioned about 20μm apart in 14 hour double mutant NetA^unspecified NetB^unspecified embryos, compared to about 9 μm apart in wild-type embryos. Earlier in development, at approximately 10 hours, the tracts from pCC neurons are projected farther away from the midline than normal in double mutant NetA^unspecified NetB^unspecified embryos. The longitudinal tract phenotype of double mutant NetA^unspecified NetB^unspecified embryos is not altered by expression of fra::robo^{Scer\UAS.RF.T:Hsap\MYC} under the control of Scer\GAL4^elav.PLu. The positioning of the longitudinal tracts in sli^unspecified ; NetA^unspecified NetB^unspecified double mutant embryos is as seen in NetA^unspecified NetB^unspecified mutant embryos. The positioning of the longitudinal tracts in robo^unspecified ; NetA^unspecified NetB^unspecified double mutant embryos is as seen in NetA^unspecified NetB^unspecified single mutant embryos.

NetA^unspecified, NetB^unspecified double mutants show trajectory defects of the ISN; this fascicle stalls, show excessive branching, crosses segment boundaries and projects beyond the dorsal target muscles. The ventral ISNb innervation of muscles 6 and 7 is disrupted. Additionally, the SNa sometimes stalls or is missing one or two of the major branches. The ventral-ISNb branch projection phenotype is suppressed when unc-5^{Scer\UAS.T:Ivir\HA1,T:wg} is expressed, under the control of Scer\GAL4^elav.PLu, in a NetA, NetB double mutant background.