Vmat^SH0459 homozygote adults display loss of dopaminergic neurons in the PAL and PPL1 clusters compared to age-matched controls and this decrease in the number of neurons is restored upon precise excision of the P-element insertion from this line.

Under standard culture conditions, less than 1% of homozygotes survive to adulthood, but if the density of the cultures is reduced, up to 40% of homozygotes eclose and survive to adulthood in bottles and up to 100% survive to adulthood in vials.

Homozygous males and both homozygous and heterozygous females show a decrease in lifespan of approximately 30% and begin dying 1 week before controls.

Homozygous females are essentially infertile and do not appear to lay any eggs as virgins or after mating. Only 21% of homozygous males produce adult progeny when mated with wild-type females.

The ovaries of 3 day old, mated homozygous females contain 3.5 fold more mature oocytes than control ovaries. The mutant ovaries are similar in length and only slightly larger than control ovaries despite the dramatic increase in oocyte content.

The ovaries of 3 day old, virgin homozygous females contain fewer mature oocytes than control ovaries from wild-type virgin females (which retain mature oocytes in their ovaries) and the mutant virgins show a modest decrease in ovary size compared to controls.

Similar to wild-type females, mutant mated females show a two-fold increase in the number of mature oocytes and an increase in ovary size (although less than that of controls) when fed yeast paste for 24 hours.

Homozygous larvae show reduced movement compared to wild-type controls, while heterozygous larvae show increased locomotion compared to wild-type controls.

Heterozygous larvae show a normal response to touch, while homozygous larvae show a slight deficit in this response compared to wild-type controls.

The amplitude of the evoked junctional potential (EJP) at the larval neuromuscular junction is doubled in homozygotes compared to wild type. The input resistance of the mutant muscle is higher than that of controls, suggesting that muscle size may be smaller in the mutant larvae. The quantal content at the neuromuscular junction is increased in the homozygous larvae compared to wild type. Spontaneous EJP (mEJP) frequency is increased in homozygous larvae compared to wild type.

Homozygous larvae show very few spontaneous action potentials in the segmental nerves or contractions of the corresponding muscles, in contrast to wild-type larvae. These defects in initiating spontaneous action potentials and contractions can be partially overcome by mechanically stimulating the larvae or by recording in saline with a lower Mg[2+] concentration. The action potentials seen in mutant larvae during a burst episode are indistinguishable from those of wild type (both in duration and spike frequency).

Homozygous flies show a modest reduction in performance in a negative geotaxis assay in response to a mechanical stimulus, when given 15 seconds to climb.

Given 5 seconds to climb in a negative geotaxis assay in response to a mechanical stimulus, heterozygous flies perform better than wild-type flies.

Heterozygous flies perform better than wild-type flies in a dark reactivity assay in which flies are mechanically agitated and allowed to "escape" using a horizontally oriented apparatus. Homozygous flies perform less well than control flies in this assay.

Homozygous and heterozygous adults locomote faster than controls in an open field assay, crossing 60% more grid lines per minute than controls.

Mutant flies show a blunted response to cocaine; heterozygous flies show a 20% increase in locomotion relative to untreated flies (wild-type flies show a 56% increase in locomotion when fed cocaine), while homozygous flies show no significant change in locomotion when fed cocaine.

The performance index of heterozygous flies in a fast phototaxis assay measuring attraction to light is not significantly different from that of wild-type flies, while the performance index of homozygous flies is significantly increased compared to wild type.