-expressing axons are seen crossing back and forth across the midline in mutant embryos, in contrast to wild type.
In mutant embryos, the motor axons that project through the SNb peripheral nerve fail to form connections to their cognate muscles. Most commonly, SNb axons appear to "stall" somewhere between the point at which they would normally separate from the ISN and the muscle 6/13 junction. In other hemisegments, SNb axons project through the muscles field but fail to branch into the intermuscle clefts where synapses should be formed. The phenotype is slightly weaker than seen in lola5D2
. In mutant embryos neuronal and muscle cell identities are normal. The overall pattern of muscle morphologies and attachments are for the most part normal, though with low penetrance ventral longitudinal muscles can be missing.