Synj^RQ homozygotes are viable but adults exhibit a significant decrease in lifespan under starvation conditions; mutant adults also exhibit significant decreases in the numbers of PPL1 and PPM3, but not PPM1 and PPM2, neurons at day 30 post eclosion, but do not show significant changes in retinal synaptic transmission at days 3-5 post eclosion, as compared to controls; Synj^RQ homozygous third instar larval neuromuscular junctions exhibit concomitant decrease in synaptic vesicles density and increase in cisternae density at boutons under starvation conditions, but do not exhibit significant defects in the number of satellite boutons, in the levels of presynaptic endocytosis or in sustained neurotransmission under high stimulation conditions (assessed by the amplitude of spontaneous excitatory junctional currents), as compared to controls.