In the ventral ganglion, stain is observed in a dotted pattern along nerves that run on the surface of the ganglion and extend to the peripheral tissues. The hikaru genki locus was identified as a P element insertion, isolated using an enhancer trap screen. Homozygous mutant adults have reduced activity levels for locomotion as well as lower fertility and reduced longevity. Mutant flies remain motionless most of the time, moving only occasionally and then only slowly. Although adults die within 1-4 days after eclosion , more than half of the mutant embryos develop and survive to the adult stage.
Females lay no eggs.
Mutants rarely fly and never jump, but they do show grooming behavior. When placed under a strong light or in the presence of a chemical odorant, they quickly respond and move vigorously. Upon hatching, wild-type larvae elongate a significant amount during the process of escaping from the egg shell, but mutant larvae do not elongate. Mutant larvae have uncoordinated locomotion. Mutant larvae rarely move in a straight line and frequently move backward in response to stimuli that normally causes forward locomotion.