Syp^e00286/Syp^e00286 and Syp^e00286/Df(3R)BSC124 mutants exhibit a significant decrease in excitatory junction potential amplitude, and a significant increase in paired pulse ratio, but no difference in miniature excitatory junction potential, measured in neuromuscular junctions of muscle 6 of third instar body walls, as compared to wild type. Both Syp^e00286/Syp^e00286 and Syp^e00286/Df(3R)BSC124 mutants exhibit a number of defects in synaptic vesicle organization, with a heterogenous population of vesicles with a larger average size relative to wild type, and fewer vesicles are found at or in close proximity to the active zone; these mutants also show enlargement of the post-synaptic density and an increase in lesions across the synaptic membrane; and show defects in endocytosis, as assayed by uptake of the styryl dye FM1-43 upon neuromuscular junction stimulation.

Syp^e00286/Syp^e00286 or Syp^e00286/Df(3R)BSC124 third instar larvae show a synaptic overgrowth phenotype at the neuromuscular junction (NMJ), with significant increases in branch number and type Ib bouton numbers (bouton size and shape is not significantly changed), and significant increases in total bouton number and the ratio of 1b bouton numbers to total bouton numbers, compared to wild type. Syp^e00286/Syp^e00286 or Syp^e00286/Df(3R)BSC124 third instar larvae have myonuclear distribution defects, with significant increases in the number of nuclei clusters (but not nuclei number) per muscle hemisegment.

Eggs laid by females containing homozygous germline clones show a range of dorso-ventral patterning defects, including ectopic, fused or missing dorsal appendages, or defects in the spacing and position of the dorsal appendages. Morphological defects are also seen in these eggs, including short, round eggs, and a "moose antler" dorsal appendage phenotype. Many of the embryos that develop from the eggs have a reduced number of pole cells.