pers mutant adults have their longest daytime sleep bout significantly earlier than controls.
pers mutant adults a distinct ultradian rhythmicity in walking activity under constant light conditions, which however is not significantly different from that exhibited by wild-type flies. pers flies do not show ultradian rhythmicity in walking under constant dark conditions.
The phase of the evening peak of locomotor activity is advanced compared to wild type under 12 hour light/12 hour dark conditions.
Mutant flies have locomotor activity rhythms with 19.7 hour periods (shorter than wild type) when the free running period is determined in constant darkness conditions at 25[o]C after 4 days of 12 hour light: 12 hour dark conditions.
Mutant flies have a shorter circadian locomotor activity period than control flies.
Under constant darkness conditions at 25[o]C, flies show rhythmic locomotor activity, but the period is shorter than the wild-type period length (19.2 +/- 0.1 hours compared to 24.0 +/- 0.1 hours respectively).
The evening peak of activity occurs earlier than normal in mutant flies under 12 hour light: 12 hour dark conditions.
Unlike wild-type males, pers homozygous males that have undergone courtship conditioning (kept in the presence of a female for 7 hours) do not spend significantly less time engaged in courtship behaviour when placed with a female 5 days after conditioning than non-conditioned males of the same genotype.
Mutant flies have a circadian locomotor activity period of 18.9 +/- 0.1 hours (compared to 23.6 +/- 0.1 hours for wild-type flies).
Light pulse phase response curves for pers are similar to those of dcoS and substantially different from the wild-type phase response curves.
pers flies entrain normally at 28oC under an light-dark (LD) 10:10 regime.
pers; cryb flies show a 19.2 +/- 0.6 hour period in intense constant light.
For wild-type, approximately 80% of the flies tested appear strongly rhythmic in light-pulse experiments, compared to approximately 50% of the pers mutants. The most frequently observed period values (the plurality categories) are 24 to 24.5 h for wild-type and 18.5 to 19 h for pers.
The effect of light pulse is different in wild-type and pers. An average phase delay of 5.9 h (with reference to the free running periods) is observed in wild-type, whereas the opposite kind of behavioural shift - a phase advance of approximately 4 h - is detected for pers mutants ( a 3.1 h advance in real time). These values are significantly different for those of non-pulsed controls for both wild-type and pers mutant flies.
pers mutants show increased responsiveness to initial cocaine 75μg exposure, and weak sensitization (as compared to wild-type) to a second exposure when tested for behavioural responses. These flies do not show sensitization to other cocaine doses.
The period of the interpulse interval (IPI) of the male courtship song is 45.9 seconds (wild-type value is 67.9 seconds).
Mean courtship bout duration in pers males is not significantly different from that of wild-type males.
The period of locomotor activity under constant darkness conditions is 19.3 +/- 0.1 hours (shorter than wild-type flies).
At 25oC, homozygous flies show clear bimodal locomotor activity rhythms peaking around lights-on and before lights-off, with the activity being concentrated in the light phase, under 12 hour light:12 hour dark conditions. At 30oC, daytime activity tends to decrease and night time activity increases. These patterns of activity are similar to wild-type flies. Flies show clear freerunning locomotor activity rhythms under constant darkness. The freerunning period increases significantly with decreased temperature, in contrast to wild-type flies which show little change in freerunning period with increased temperature. Locomotor rhythms can be entrained to temperature cycles under constant lighting conditions, but the entrainability is reduced compared to wild-type flies.
Endogenous period is 19 hours instead of the wild type 24 hours. Flies are very light sensitive, could be the reason why flies can entrain well to 24 hour LD cycles.
Circadian period is 19 hours, timSL can lengthen the period by an hour.
Shorted circadian rhythms.
Free running periods of 19 hours.
Mutation has no effect on larval heartbeat.
Exposing flies reared in constant darkness (DD) to light as embryos or larvae has no effect on circadian rhythm. Exposing adults fully restores normal circadian rhythms.
Mutants have a shortened active phase (α). Phase response curves (PRCs) change from a low amplitude, Type 1 to a high amplitude, Type 0 with increased duration of the light pulse. Mutants have increase light 'sensitivity'. The shortening of circadian period is a consequence of changes in the time course of the oscillation in the late subjective day.
No larvae exhibit appreciable diel rhythms under cycling conditions of light or temperature. Larvae are also not rhythmic under free-running conditions.
Mutants display short circadian rhythm and males produce short song rhythms. This genetic coupling found in males does not extend to females, females have a preference for wild type courtship song over the mutant short song rhythm.
Short cycle duration, the evening peak of activity is shifted to an earlier time than wild type.
Evening activity peak is shifted to an earlier time in light-dark regimes.
Measures of acquisition at intermediate and maximum levels and of 30 min memory retention are normal. Mean Courtship Index (CI) for males exposed to fertilised females for 30 mins shows a significant decrease in response to virgin females, but does not differ significantly when flies are exposed to other fertilised females. After 30 mins exposure of an immature male to another immature male a significantly suppressed response to another immature male is observed.
The activity rhythm period of pers/Y flies is lengthened by CkIIβAnd, by 1.0 hours.
Pupal and larval stages are less pronounced. Circadian rhythm runs 5 hours faster than wild type. In conditions of cycling light (12h light and 12h darkness) the pacemaker can be reset to exhibit 24h rhythmicity, but the 'evening peaks' of locomotor activity are in the daytime, not in the evening.
Spectral analysis of tone pulse production demonstrated that pers male courtship song is strongly rhythmic.
pers eggs hatch significantly faster than wild-type. Larvae develop faster than wild-type larvae under constant very bright light or under 12 hour light:12 hour dark conditions. pers flies eclose significantly faster than wild-type flies.
Flies can be entrained to a 24 hour cycle of light and dark (Konopka, Ph.D. Thesis, Pasadena). The effect on circadian behaviour is matched by the effect on the song cycle, a short 40 sec lovesong cycle (Kyriacou and Hall, Anim. Behav. 37: 850). Flies develop faster than wild type under a variety of environmental conditions when the circadian behaviour is arrhythmic (Kyriacou, Heredity, in press). Males do not show defective courtship conditioning (Jackson, J. Comp. Phys. A 151: 545). Transplantation of donor pers brains into per01 abdomens causes some per01 hosts to take on the donors locomotor activity characteristics (Handler, Nature 279: 236). A possible neurohumoral mediation of circadian rhythms may be involved in switching on pers rhythm in the host, certain neurosecretory cells in the brain are abnormal (Konopka, J. Neurobiol 11: 411).
The average period of locomotor activity rhythm increases slightly with decreasing temperature. The period increases by about 0.6 hours when pers flies are transferred to constant infrared light after 10 days of constant light. The light intensity threshold for maximum lengthening of the period and production of arrhythmia is decreased compared to wild-type.
Normal song pulses and hums.
Mutants show reduced activity of Tdc gene product.
circadian rhythms; short period Adults stain normally with anti-PER antibody (Siwicki, Eastman, Petersen, Rosbasch and Hall, 1988)