Pdf01 mutant adults have advanced evening peak circadian locomotor activity under light-dark (LD) conditions, compared to controls.
Pdf01 mutants show a relatively normal temperature preference during daytime, as compare to controls.
Pdf01 mutant adults have significantly reduced strength of circadian locomotor rhythms under constant darkness, compared to heterozygous controls.
Pdf null mutants still display residual rhythmicity in emergence for the first two days after transfer to constant darkness, similar to controls; this is lost at later timepoints.
Pdf01 homozygous mutant adults, reared under 12:12 light:dark zeitgeber cycle, present an advanced temperature preference rhythm phenotype and a significantly decreased night-time preferred temperature (zeitgeber times 16-24), but still display a similar day-time preferred temperature increase (between zeitgeber times 1-3 and 10-12) and a similar night-onset preferred temperature decrease (between zeitgeber times 10-12 and 13-15), as compared to controls.
Pdf01 mutants exhibit light-dependent temperature preference similar to that of wild-type.
In contrast to controls, which adjust their morning and evening activity peaks to align with seasonal dawn and dusk, Pdf01 mutant flies show defective morning behavior when exposed to either a winter light:dark cycle (10 hours day:14 hours night) or a summer cycle (14 hours day:10 hours night).
Unlike wild-type, vast majority of Pdf01 mutant adults show a distinct ultradian rhythmicity in walking activity under constant dark conditions, with a mean ultradian period of about 50-60min. The period of this ultradian rhythmicity is highly temperature-dependent, with Q coefficient of 2.68 for temperatures between 20-27.5oC.
Mutant males show a dramatic reduction in the amount of (z)-7-Tricosene, (z)-5-Tricosene and (z)-7-Pentacosene at all circadian time points and a loss of the subjective day/night difference compared to wild type (measured on the sixth day of constant darkness).
Pdf01 males mate more frequently than Canton-S males, regardless of the genotype of the females, but less often with Pdf01 females than with Canton-S females.
Pdf01 mutants exhibit daytime temperature preference rhythms similar to those of wild-type flies during LD.
Pdf01 flies under LD conditions show no increased morning activity before lights-on, with evening anticipatory activity becoming advanced and reduced in amplitude. Furthermore, they show decreased rhythmicity and a shortened circadian period under DD.
Pdf01 mutants exhibit wild-type triglyceride levels.
Mutant flies lack the normal morning peak of circadian locomotor activity under 12 hour light:12 hour dark conditions.
Pdf01 mutant adult flies do not display any morning and evening anticipation behavior (and a corresponding peak in locomotor activity) when kept in constant darkness.
Approximately 67% of mutant flies show arrhythmic or weakly rhythmic locomotor activity under constant darkness conditions.
Pdf01 flies exhibit severe deficits in free-running locomotor rhythms, with ~50% arrythmicity in flies in constant darkness.
Under light:dark (LD) conditions, mutant flies show increases in sleep during the late night. At the time when wild-type flies are waking up in advance of lights-on, the mutant flies fail to wake up.
During the first day of constant darkness (DD) conditions, mutant flies show a significant increase in total sleep during the subjective day compared to control flies.
Pdf01 mutants display reduced morning anticipation and an advanced evening peak under light/dark cycles, and high levels of arhythmicity and a shortened free-running period under constant darkness.
Compared to controls, Pdf01 mutant flies show significantly more daytime sleep in light/dark or dark/dark conditions. The increase in daytime sleep is primarily due to a decrease in wake duration/consolidation during the day. Sleep latency is decreased in the light period of light/dark experiments, and in the subjective night period of dark/dark experiments compared to controls.
Pdf01 mutants under 12h:12h light:dark cycles show a significantly advanced evening activity peak, which becomes more pronounced if in combination with synchronous 25[o] C:20 [o]C (or 20[o] C:10 [o]C) temperature cycles, as compared to controls; when the temperature cycle is advanced by 6h, the evening activity peak occurs even earlier and the activity gradually decreases toward lights-off.
Under constant light conditions, about 55% of Pdf01 mutants display locomotor activity rhythms. Under the same conditions, only 10% of the wild-type controls show activity rhythms.
Under constant darkness, 50% of Pdf01 mutants display rhythms of locomotor activity with a period of about 22.5h.
Pdf01 mutant larvae show no significant differences from wild-type larvae in larval light avoidance assays. Pdf01 mutants, like wild-type larvae, display circadian modulation of photophobic behaviour.
Pdf01 flies display an absence of lights-on anticipation and a phase advancement in the evening peak (lights-off anticipation).
Approximately 44% of homozygous Pdf01 mutants display rhythmic locomotion.
Approximately 83% of heterozygous Pdf01 mutants display rhythmic locomotion.
Pdf01 homozygous flies display a strong negative geotaxis phenotype.
Mutant flies are arrhythmic for locomotor activity under constant light conditions at a constant temperature of 25[o]C, but become rhythmic after being exposed to a temperature cycle of 12 hours at 25[o]C and 12 hours at 30[o]C. The flies show two clear peaks at temperature transitions and an anticipatory activity before the temperature step-down. However, the anticipatory activity is not so sharp but rather dispersed in comparison with that of the wild-type flies. Some transient cycles are observed until establishment of a stable phase-angle relationship with the temperature cycle.
Pdf01 flies kept in constant darkness show weak short-period rhythmicity.
Loss of locomotor behavior is observed in 70% of Pdf01 flies and manifests gradually with residual rhythms being present for 2-3 days after release into constant dark conditions. In the brains of these flies, the phasing of ventral LN neurons disperses over time and the dorsal LN neurons phase advance when kept in constant darkness compared to control flies.
Homozygous or hemizygous mutant animals exhibit a normal response to cocaine exposure.
Pdf01 homozygous adults gradually lose circadian locomotor activity rhythms when kept in constant darkness. However, a significant fraction of are still weakly rhythmic after 4 days in constant darkness, but most of these accumulate an approximately 4-hour phase advance by this time relative to wild-type flies kept under the same conditions.
Pdf01 flies display only two peaks of locomotor activity under cycling conditions. The morning peak lacks anticipation and is very narrow; the evening peak shows anticipation is sustained and is phase-advanced relative that of wild-type. Pdf01 flies remain rhythmic under constant conditions (DD) for days 1-2, but only 16% remain rhythmic over DD days 3-9.
The number and morphology of LNv neurons, and tritocerebral and abdominal neurons that normally express Pdf is normal in hemizygous Pdf01/Df(3R)Tl-X flies. The locomotor activity of hemizygous Pdf01 flies is not entirely normal. The flies are well entrained during 12 hour light:12 hour dark (LD) cycles, but the evening activity peak is advanced by approximately 1 hour compared to wild-type flies and there is a lack of lights-on anticipation. Free-running locomotor activity in constant darkness is severely abnormal. Homozygous and hemizygous flies are much less rhythmic than wild-type controls. 50-98% of mutant flies show no detectable rhythmicity for the duration of 9 days in constant darkness. Most flies are rhythmic for 2 or 3 days in constant darkness but later lose rhythmicity. Homozygous and hemizygous flies that do maintain rhythmicity have free-running periods approximately 1 hour shorter than wild-type or heterozygous flies.