Mosaic flies with homozygous Pis1 eyes in otherwise heterozygous flies show rough eyes of reduced size. These eyes have no detectable photoreceptors within the ommatidia.
Expression of Pishs.T:Hsap\MYC between the embryonic and the late pupal stages by daily heat-shock treatments allows Pis1 flies to survive to adult stages. When newly-eclosed Pis1; Pishs.T:Hsap\MYC flies are dark adapted for 2 minutes and then exposed to three pulses of orange light, the ERG amplitudes produced are similar to wild-type flies. However, when the same flies are exposed to this light regimen after 3 days without heat shock, the ERG amplitude resulting from the second light pulse is decreased compared with the first. When flies are tested after 7 days without heat shock, amplitudes are further decreased and a very small photoresponse is observed during exposure to the third light pulse.
The ERG recordings of newly-eclosed Pis1; Pishs.T:Hsap\MYC flies exposed to 2 minutes of orange light, followed by a 3 s dark adaptation are not significantly different to those produced by wild-type flies. 3-day-old Pis1; Pishs.T:Hsap\MYC flies (which have no further heat shock after eclosion) show a much smaller ERG amplitude after the 2 min light adaptation, which is restored after 1.5-2 minutes of dark adaptation. 7-day-old Pis1; Pishs.T:Hsap\MYC flies require a minimum of 2 min of dark adaptation to recover the light response.
When newly-eclosed Pis1; Pishs.T:Hsap\MYC flies are reared in the dark without additional heat shocks for 7 days and subsequently exposed to a 12 h light/dark cycle the eyes undergo a gradual loss of rhabdomeres. By 14 days, the rhabdomeres are either missing or dramatically smaller than in wild type and are distorted in appearance. This rhabdomere degeneration phenotype is not seen when newly eclosed Pis1; Pishs.T:Hsap\MYC flies are maintained in the dark. Induction of daily heat-shock treatments after day 7 in Pis1; Pishs.T:Hsap\MYC flies reared in a light/dark cycle prevents rhabdomere loss.
Pis1 has lethal | embryonic stage phenotype, suppressible by Hsap\CDIPTPis.PW
Pis1 has eye | somatic clone phenotype, suppressible by Hsap\CDIPTPis.PW
Pis1 has eye photoreceptor cell | somatic clone phenotype, suppressible by Hsap\CDIPTPis.PW
Expression of Hsap\CDIPTPis.PW rescues both the embryonic lethality and the eye phenotype of Pis1 flies. Rescue of eyes is complete as the ERG response of rescued flies is indistinguishable from wild type.