Flies (1 or 10 days old) with expression of Atpα^HMS00047 driven by Scer\GAL4^GMR.long or Scer\GAL4^GMR.PF do not respond to light pulses (ERG recording on the eye surface - ERG amplitude is significantly decreased at both ages compared to controls). Rhabdomere integrity in the ommatidia is intact (7 rhabdomeres present) in 1 day old Scer\GAL4^GMR.long>Atpα^HMS00047 flies, but integrity significantly decreases by day 10 (age-dependent degeneration). Giant fiber system recordings from Scer\GAL4^GMR.long>Atpα^HMS00047 flies (1 or 10 days old) do not show any electrical response of thoracic muscles at the end of light stimulation, unlike control flies. Both phototaxis and optomotor responses are severely impaired in Scer\GAL4^GMR.long>Atpα^HMS00047 flies (both 1 and 10 days old) compared to controls.

Control of the timing of expression of Scer\GAL4^GMR.long>Atpα^HMS00047 is achieved using P{tubP-GAL80^ts} : inducing RNAi expression (at the restrictive 31[o]C temperature) during larval to 'light' pupal stages (P9-11) does not significantly affect ERG amplitude in response to light in the eye and rhabdomeres remain intact even at 2 weeks old; inducing RNAi starting during 'dark' pupal stages (after P12) for 2 weeks significantly decreases ERG amplitude and no rhabdomeres are intact at 2 weeks old.

Scer\GAL4^GMR.long>Atpα^HMS00047 flies reared in complete darkness from embryonic stages lack ERG responses to light and show rhabdomere loss at 10 days old (light-independent degeneration).

Rhabdomeres of photoreceptors are slightly smaller than controls in 1 day old Scer\GAL4^GMR.long>Atpα^HMS00047 flies and show signs of apoptosis and necrosis at 10 days old (condensed nuclei, dark chromatin clumps, necrotic changes including cytoplasmic vacuolization).

Recordings from photoreceptors of 1 day old Scer\GAL4^GMR.long>Atpα^HMS00047 flies show no response to light (already depolarized in the dark).