Unlike controls, cry01 individuals maintain circadian rhythmicity under constant light.
I-LNv neurons in cry01 individuals show a severely impaired electrophysiological response to light stimulus, as compared to controls (i.e. Scer\GAL4cry.PZ>cryUAS.EGFP, cry01 rescued individuals): UV and blue light stimulation induces membrane potential hyperpolarization during/after stimulation instead of the expected depolarization, and induces a much lower firing frequency after stimulation, although the response duration is unaffected; red light stimulus fails to induce the expected membrane potential depolarization during/after stimulation, but does not change the firing frequency after stimulation.
When cry01 individuals are rescued by Scer\GAL4cry.PZ>cryW420Y.UAS.EGFP, I-LNv neurons show membrane potential depolarization to UV, blue and red light stimulation, but of much lower amplitude than controls; there is a much lower firing frequency after UV and blue light stimulation, dispute of a similar response duration, as compared to controls. These individuals predominantly arrhythmic under moderate-low constant light, as controls, but not under very low light.
When cry01 individuals are rescued by Scer\GAL4cry.PZ>cryW397Y.UAS.EGFP, I-LNv neurons show lower membrane potential depolarization to UV light stimulation than controls (i.e. Scer\GAL4cry.PZ>cryUAS.EGFP, cry01 rescued individuals), and unaffected lower attenuated duration of response, despite of unaffected firing frequency, as compared to controls; the electrophysiological responses to blue and red light are unaffected as compared to controls. These individuals predominantly arhythmic under moderate-low or very low constant light, as controls.
cry01 homozygous adults reared under 12h:12h white light:dark cycles exhibit a significantly earlier morning activity onset and significantly later evening activity onset, as compared to controls. These mutants show an apparently normal resynchronization to a 6h delay in 12h:12h white light:dark cycle, as well as no obvious rhythmicity defects after a few days of either constant light or darkness, as compared to controls.
cry01 homozygous adults previously trained under 12h:12h light:dark cycles present a subtle decrease in circadian rhythmicity under constant darkness conditions, fail to become arrhythmic under constant light conditions, present a severe decrease in circadian phase shifting in response to light pulses during the night period, present a significant delay in circadian phase shifting in response to a 8h delay in the light:dark transition, and present defective arousal - i.e. a significant decrease in the frequency of arousal and a significant delay in arousal - in response to a light pulse during the night period, as compared to controls; the large ventrolateral neurons (l-LNv) of the adult brain in these mutants exhibit a severe decrease in the frequency of firing in response to white light, which is less severe in response to blue light (405nm) than to orange light (550-1000nm), as compared to controls.
cry01 mutants exhibit normal light-dependent temperature preference. Similarly to wild-type, they prefer higher temperature in the light than in the dark.
cry01 mutant class IV dendritic arborization neurons do not exhibit any defects in light response.
Homozygous cry01 flies do not show a naive preference to a magnetic field, or an enhanced preference to a magnetic field after training, under full-spectrum light conditions. cry01/Canton-S flies do show a significant response under the same conditions.
Transheterozygous cryb/cry01 flies do not show significant naive or trained responses to a magnetic field.
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 cry01 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, cry01 flies show weak rhythmicity, although the rhythmic individuals have normal period values. In LL, most cry01 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, cry01 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 cry01/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).
cry01 flies entrained to 12 hours 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.
cry01 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.