The aberrant long-period circadian locomotor rhythm under free-running constant dark conditions characteristic for Lsm12Δ6 mutant adults is partially rescued by Scer\GAL4cry.PE-driven expression of perScer\UAS.cBa.
The length of the circadian cycle is increased when perScer\UAS.cBa is expressed in homozygous cwoPB9 flies with one copy of per01 under the control of either a Scer\GAL4tim.PE or a Scer\GAL4cry.PE driver.
per01 mutant files co-expressing perScer\UAS.cBa and Ctet\TeTxLCTNT.Scer\UAS under the control of Scer\GAL4Mai179 display morning anticipation in their locomotor activity, but they completely lose evening anticipation, compared with controls with Ctet\TeTxLCIMPTNT-V.Scer\UAS expression.
Anticipatory activity is absent in the morning and almost completely lost in the evening in per01 mutants co-expressing perScer\UAS.cBa and Ctet\TeTxLCTNT.Scer\UAS under the control of both Scer\GAL4Mai179 and Scer\GAL80Pdf.PS.
Expression of perScer\UAS.cBa under the control of Scer\GAL4Clk.1.5 partially rescues the circadian locomotor activity defects seen in per01 flies under light-dark conditions; the rescued flies show a robust anticipation of the lights-on transition (morning peak), but evening anticipation is extremely weak and difficult to distinguish from an increase in locomotor activity also observed in control per01 flies at the end of the day.
Expression of perScer\UAS.cBa under the control of Scer\GAL4tim.PE (per expression in all clock neurons) in per01 flies results in animals that show a similar locomotor activity to wild-type flies, except that the rescued flies have a later evening peak under 12:12 hour light-dark conditions and a longer period under constant darkness conditions.
per01 flies that are expressing perScer\UAS.cBa under the control of Scer\GAL4Mai179 (per expression in the majority of the lateral neurons) show bimodal locomotor activity patterns under 12:12 hour light-dark conditions. The flies show an advanced morning peak of activity. These flies show morning and evening peaks of locomotor activity that shift into night under 12:12 hour light moonlight conditions (under these conditions, a dim light of quarter-moonlight intensity, 0.03 lux, is switched on during the dark phase), although the morning peak is strongly reduced and is not present in all flies. When it is present, it occurs 1.4 hours earlier than in controls. Under constant moonlight conditions, the morning peak is further reduced and is only visible in 50% of the rescued flies. Most of the rescued flies remain rhythmic under constant moonlight or constant darkness conditions.
per01 flies that are expressing perScer\UAS.cBa under the control of Scer\GAL4Mai179 in the presence of Scer\GAL80Pdf.PS (this restricts expression of per to the 5th s-LNv and the 3 cry-positive LNd lateral neurons) have a prominent lights-on peak of locomotor activity. The morning peak occurs before lights-on and appears suppressed in most flies, and the average activity increase that occurs before lights-on is not different from non-rescued per01 flies (although it is possible to determine the phase of the morning peak in individual rescued flies). Under 12:12 hour light moonlight conditions (under these conditions, a dim light of quarter-moonlight intensity, 0.03 lux, is switched on during the dark phase) the rescued flies show morning and evening peaks of locomotor activity that are shifted into the night. Under constant moonlight conditions approximately 50% of the rescued flies remain rhythmic with a wide phase relationship between morning and evening peaks. Under constant darkness conditions, all of the rescued flies become arrhythmic.
Similarly to wild-type animals, per01 mutants expressing Scer\GAL80Pdf.PS and Scer\GAL4Mai179 or Scer\GAL4cry.PE driven perScer\UAS.cBa do not display locomotor acivity rhythms under constant darkness.