Expression of Hsap\HD128Q.FL.Scer\UAS using the strong Scer\GAL4GMR.PF driver results in depigmentation and disorganization of ommatidia.
Expression of Hsap\HD128Q.FL.Scer\UAS using a weaker Scer\GAL4GMR.PF driver does not disrupt rhabdomere organization in 1 day old flies. However, significantly fewer rhabdomeres per ommatidium are found in flies aged for 20 days, showing that this eye phenotype is progressive.
Flies expressing Hsap\HD128Q.FL.Scer\UAS using Scer\GAL4C164 show reduced survival in adult life compared to controls.
Flies expressing Hsap\HD128Q.FL.Scer\UAS using Scer\GAL4C164 show impaired motor performance as a function of age compared to controls, as measured by climbing and flying assays.
Aged flies expressing Hsap\HD128Q.FL.Scer\UAS using Scer\GAL4C164 show a neurodegenerative phenotype: motor neurons innervating the indirect flight muscles and neuromuscular junctions are lost.
Abnormalities in bouton number, branching or morphology are not observed in Hsap\HD128Q.FL.Scer\UAS, Scer\GAL4elav-C155 larvae.
Excitatory junction potentials (EJPs) at neuromuscular junctions of third instar larvae expressing Hsap\HD128Q.FL.Scer\UAS using Scer\GAL4elav-C155 are similar to controls at 1.2 mM extracellular Ca[2+], but are increased about 5-fold at 0.25 mM Ca[2+], and by ~30% at 0.6 mM Ca[2+].
Spontaneous fusion events at neuromuscular junctions in the absence of stimulation (mEJPs) in Hsap\HD128Q.FL.Scer\UAS, Scer\GAL4elav-C155 animals are similar in frequency and amplitude to controls.
The number of failures (non-events) when motor nerves are stimulated 2-3 times above threshold in 0.25 mM Ca[2+] in Hsap\HD128Q.FL.Scer\UAS, Scer\GAL4elav-C155 animals are very low - neurotransmitter is reliably released upon stimulation. This contrasts with controls which fail to release 20-25% of the time.
Resting synaptic Ca[2+] levels at presynaptic terminals are elevated by ~2-fold in Hsap\HD128Q.FL.Scer\UAS, Scer\GAL4elav-C155 larvae. In addition, Ca[2+] levels are more variable in these larvae compared to controls, with a bimodal distribution indicative of bouton populations with both normal and aberrant Ca[2+] levels.