Values in parentheses indicate the number of affected segments/total number of segments examined. For single mutants, segments A1-A7 were examined at stage 17 for defects in AMG migration using sim-Gal4 UAS-tau-GFP and anti-GFP to visualize all midline cells. AMG were identified based on morphology and position and the presence of Runt or Wrapper immunostaining. At stage 17, three phenotypes were observed: (1) Dissociated - dissociation of AMG from MP1 neurons and the failure of AMG to ensheath the PC; (2) Incomplete- dissociation coupled with a failure of AMG to ensheath the AC or PC (more severe than Dissociated alone); (3) Absent - complete absence of AMG. For double mutants, AMG were identified based on morphology, position and the presence of staining for the glial markers argos or Ect3. Homozygous Nrx-IV mutants were identified by the absence of Nrx-IV staining from the epidermis.