FlyBase curator comment: this entry is used to capture phenotypic information when the particular allele (or allele combination) used by the author could not be determined but the context of the experiment suggests that the phenotype being described is some kind of loss of function.
Mutant embryos show a clear fusion of commissures and frequent disruption of longitudinal connectives. Midline glial cells are either reduce in number or fail to properly migrate in between anterior and posterior commissures. General embryonic morphology is relatively normal, though the PNS shows a slight reduction in sensory neurons and defects in the trajectories of motoneurons.