cry02 mutants exhibit rhythmic behavior in constant dim white light, in contrast to control flies which largely show arrhythmic behavior in these conditions. The l-LNv neurons in these flies do not exhibit significant changes in resting membrane potential or spontaneous firing rate, as compared to wild type; but fail to respond to blue light stimulus, in contrast to wild type.
cry02 mutants exhibit normal light-dependent temperature preference. Similarly to wild-type, they prefer higher temperature in the light than in the dark.
Homozygous cry02 flies do not show a naive response to a magnetic field under full-spectrum light conditions. cry02/+ and w1118 controls do respond significantly in the same conditions.
Homozygous flies show robust periodic locomotion in two free-running conditions; constant darkness (DD) and constant light (LL) (a condition that causes genetically normal flies to go arrhythmic). In DD, most cry02 flies show solidly rhythmic locomotion at 25o or 29oC. Period values are generally in the normal range, except that approximately 20% of the mutant flies tested at 25oC give shorter than normal values. At 18oC, cry02 flies show weak rhythmicity, although the rhythmic individuals have normal period values. In LL, most cry02 flies behave rhythmically at 25oC. Most of the rhythmic individuals have two rhythmic components within a given behavioural record in LL, the average for the relatively short free-running period is 21-22 hours and that of the longer is 25-26 hours. At 29oC and at 18oC in LL, cry02 flies show a relatively high degree of arrhythmicity. At 25oC in LL, when periodic components can be reliably analysed, approximately 60% of the flies show two periodicities whose average values are 20 and 24 hours. At 18oC in LL, the rhythmic mutant flies show only one periodic component, of approximately 24 hours.
Most cry02/Df(3R)Dl-BX12 flies behave rhythmically under constant light conditions at 25oC, approximately one-third of the mutant flies have one periodic component (approximately 24 hours) and the remainder have two periodic components per individual (approximately 22 and 25 hours).
cry02 flies entrained to 12 hour light: 12 hour dark cycles and then exposed to 8 hour delayed light-dark (LD) cycles are able to resynchronise to the new light regime.
cry02 flies that are entrained to 12 hour light: 12 hour dark cycles ( 12:12 LD) and are then shifted to 9:9 , 13:13 or 14:14 LD cycles routinely re-entrain to behave in synchrony with the novel non-24 hour cycles.
After entrainment by LD cycles, cry02 flies emerge rhythmically under constant darkness conditions with periodicity similar to controls. Under constant light conditions (which cause wild-type animals to eclose arrhythmically) the mutant flies eclose rhythmically and the period is similar to that seen in animals emerging in constant darkness.