para^Shu hemizygous male adults only survive for a few days and exhibit severe defects in locomotion, precluding behavioral assays, and courtship behavior, leading to rare copulation, as compared to controls; para^Shu homozygous females exhibit near lethality before adulthood and para^Shu heterozygous female adults exhibit a significantly decrease in lifespan, as compared to controls.

Both para^Shu hemizygous male adults and para^Shu heterozygous females adults, reared at 25[o]C temperature, exhibit highly penetrant wing posture defects (downturned wings) and highly penetrant thorax indentations, as compared to controls.

para^Shu heterozygous female adults exhibit locomotor defects, as compared to controls: uncoordinated movement, significant increase in the movement time spent in the centre of a circular space (instead of movement mostly along the edges), frequent spontaneous jerking, significant and progressive increase in severe shuddering episodes, significant and progressive decrease in the climbing capacity in negative geotaxis assays, and significant increases in the velocities of head and hind-leg movements under ether anesthesia (the leg movements are sporadic and stop after severance from the body), as compared to controls; these females also exhibit a fully penetrant heat-induced seizure phenotype within 20sec of exposure to a 40[o]C of temperature, which is not observed in controls.

Both para^Shu hemizygous male adults and para^Shu heterozygous female adults exhibit a significant increase in spontaneous neurotransmission to dorsal longitudinal muscles, as compared to controls; the dorsal longitudinal muscles of para^Shu hemizygous male adults also exhibit a significant increase in the latency period, but no significant alteration in the frequency of stimuli that elicits response failure (FF50), as compared to controls; the dorsal longitudinal muscles of para^Shu heterozygous female adults exhibit significant increases in both the duration of discharges and number of spikes per discharge upon high-frequency, high-voltage (>60V) electroconvulsive stimulation, and a small but significant increase in the frequency of stimuli that elicits response failure (FF50), but no significant alteration in the latency period, as compared to controls.

Sudden leg jerks are frequent and enough to topple the fly; negative geotaxis is sluggish and seemingly not a consequence of shuddering bouts during climbing toward top of glass vials; neither of these behavioral abnormalities is pronounced in young adults, but they become maximal after about a week of adult life; lithium or ammonium ions placed in medium on which the mutant is grown reduce the severities of the eventual adult phenotypes. Homozygous females are not observed.