The co-expression of Hsap\BACE1^UAS.Exel and Hsap\APP^695.UAS.Exel under the control of Scer\GAL4^elav-C155 leads to significant decreases in adult climbing ability and in the number of rhabdomere per ommatidium, as compared to controls.

Co-expression of Hsap\APP^{695.Scer\UAS.Exel} and Hsap\BACE1^{Scer\UAS.Exel} under the control of Scer\GAL4^GMR.PF results in age-progressive neurodegeneration (retinal collapse) and adult eye morphological defects. Co-expression under the Scer\GAL4^elav.PLu driver does not affect pupariation rate but significantly decreases the eclosion rate of adult flies, leads to age-progressive deterioration of their climbing abilities and reduces the adult survival rate and median lifespan.

Co-expression of Hsap\APP^{695.Scer\UAS.Exel} and Hsap\BACE1^{Scer\UAS.Exel} driven by Scer\GAL4^{elav.Switch.PO} (with 200um RU486) results in significant hyperactivity (including nocturnal hyperactivity followed by a rapid decline, the effect is more prominent in male flies, and the effect disappears as flies age); this effect is more striking on a diet with a high carbohydrate to protein ratio (compared to low carbohydrate to protein ratio).

Co-expression of Hsap\APP^{695.Scer\UAS.Exel} and Hsap\BACE1^{Scer\UAS.Exel} driven by Scer\GAL4^elav-C155 results in significant hypoactivity compared to controls, though total activity at night is not significantly altered (it is significantly decreased during the day).

Larvae co-expressing Hsap\APP^{695.Scer\UAS.T:Hsap\MYC} and Hsap\BACE1^{Scer\UAS.Exel} under the control of Scer\GAL4^elav-C155 show a significant decrease in third instar larval body wall contractions.

The crawling defects seen when Hsap\BACE1^{Scer\UAS.Exel} is expressed under the control of Scer\GAL4^elav-C155 are enhanced upon co-expression of Hsap\APP^{695.Scer\UAS.T:Hsap\MYC}.

The body wall contraction and crawling phenotypes seen in flies co-expressing Hsap\APP^{695.Scer\UAS.T:Hsap\MYC} and Hsap\BACE1^{Scer\UAS.Exel} under the control of Scer\GAL4^elav-C155 on standard food are partially rescued when the flies are raised on food containing the γ-secretase inhibitor L-685,458.

Co-expression of Hsap\APP^{695.Scer\UAS.T:Hsap\MYC} and Hsap\BACE1^{Scer\UAS.Exel} under the control of Scer\GAL4^elav-C155 results in structural changes in the synapse of the muscle 6 and 7 NMJ. These structural changes are rescued when the flies are raised on the γ-secretase inhibitor L-685,458. The overall number of boutons is reduced compared to controls, with reductions in the numbers of both 1b and 1s boutons. The 1s bouton phenotype is significantly rescued by L-685,458, and the 1b phenotype is partially rescued. The total area of motor neuron innervation in flies expressing Hsap\APP^{695.Scer\UAS.T:Hsap\MYC} and Hsap\BACE1^{Scer\UAS.Exel} is similar to controls, but a significant reduction is seen in the amount of motor neuron branching, as well as the size of muscles 6 and 7 at the NMJ. Feeding the larvae L-685,458 suppresses the branching defect, but has no effect on the reduction in muscle size. The density of presynaptic release sites (brp-positive active zones) is normal, both on standard food or L-685,458. Mitochondrial localisation defects are seen in motor neurons and this is also rescued by L-685,458.

Co-expression of Hsap\BACE1^{Scer\UAS.Exel} and Hsap\APP^{695.Scer\UAS.Exel} under the control of Scer\GAL4^GMR.PF results in a rough eye phenotype with disorganization of the retina, atrophy of ommatidia, and presence of abnormal amyloid deposits, as compared to controls.

Co-expression of Hsap\BACE1^{Scer\UAS.Exel} and Hsap\APP^{695.Scer\UAS.Exel} under the control of Scer\GAL4^elav.PLu leads to a significant decrease in lifespan and significant deterioration of climbing ability with age, as compared to controls.