Ultrastructural analysis shows considerable alterations in endoplasmic reticulum (ER) morphology in homozygous atl¹ mutant neurons. ER profiles are shortened in the mutants compared to wild-type.

Oocytes are much smaller than normal in homozygous females.

Homozygous pupae and adults are smaller in body size than wild type.

Homozygous clones are recovered in imaginal discs, but are smaller than their control twin spots.

The mean life span of male and female mutant flies is 55% and 58% shorter, respectively, than wild-type controls. The mutant flies die suddenly around 25 days after eclosion.

Mutants are "bang sensitive", being paralysed by mechanical shock; 44% of 10 day old mutant flies and 83% of 15 day old mutant flies are paralysed after vortexing for 5 seconds (wild-type flies move quickly and climb upwards after vortexing at both ages). Less than 73% of 2 day old mutant flies climb over 8cm in 10 seconds after being vortexed for 5 seconds (nearly all wild-type controls are able to complete this climb in 10 seconds). Less than 2% of 15 day old mutant flies are able to climb over 8cm in 10 seconds after being vortexed for 5 seconds.

Mutant flies show reduced locomotor activity compared to control flies. The level of locomotor activity of the mutant flies does not decrease with age.

1 day old mutant flies do not show any visible abnormalities in the dopaminergic neurons in the brain, but as the mutant flies age, less dopaminergic neurons are detected (the dopaminergic neurons in PPL2 and PPM1/2 clusters of 15 day old mutant flies are reduced to almost half the number seen in control flies).