Ube3a15B/Ube3a15B third instar larvae have similar numbers of total boutons (and satellite boutons) at the neuromuscular junction compared to wild type; Ube3a35/Ube3a15B or Ube3a15B/Df(3L)ED4470 third instar larvae have a significant increase in total boutons (and satellite boutons) at the neuromuscular junction (compared to Ube3a15B/Ube3a15B).
Ube3a15B/Ube3a15B larvae show a decrease (significantly more than wild type) in EJP amplitude during rapid stimulation (30 stimulations at 15Hz) and have significantly more negative muscle resting membrane potential compared to wild type. There is no significant difference in amplitude of the first EJP between Ube3a15B/Ube3a15B and wild type, though short-term facilitation is seen significantly more in wild type larvae. There is no significant difference in active zone density, bouton numbers or synaptic vesicle number or size at the neuromuscular junction of Ube3a15B/Ube3a15B third instar larvae compared to wild type.
Mutant flies do not show taste adaptation in response to a camphor diet, in contrast to wild-type flies, which show reduced camphor avoidance and reduced camphor-induced action potentials in the S6 taste sensilla after being maintained on a camphor diet.
Ube3a15B flies, which exhibit a reduction in dopamine, also exhibit a concurrent reduction in locomotor activity.
Both young and old Ube3a15B mutant flies perform significantly more poorly than age-matched wild-type flies in climbing assays. Mutant flies show no obvious defects in their ability to initiate flight.
Ube3a15B mutant flies show defective 1-day memory compared to wild-type after a period of spaced-training sessions in olfactory learning and memory assays. Levels of memory are similar compared to wild-type animals after a period of massed-training sessions, or after a single training session. Mutant and wild-type flies perform similarly in direct tests of shock reactivity and olfaction.
Young Ube3a15B mutant males and old mutant flies of each sex, entrained to a 12h light/dark cycle for 3 days, all display arrhythmic rest/activity behaviour cycles.
Ube3a15B mutant flies exposed to mechanical or thermal stress do not show any sign of paralysis.