Exquisite Light Sensitivity of Drosophila melanogaster Cryptochrome
Figure 2
Phase shift magnitude as a function of intensity and duration of blue light pulses.
LD-entrained flies were given light pulses of either: A) 10 min, or B) 120 min, at different intensities at times centered at ZT20. n = 10 per condition. For both duration light pulses, there are graded phase shift responses as a function of increasing light intensity. 10 min: 7,000 vs 50 nw/cm2, P = 0.02; 120 min: 50 vs 4 nw/cm2: P = 0.04; 4 vs 0.3 nw/cm2: P = 0.03 (ANOVA). Asterisks indicate significantly different values from the no pulse control. 10 min: 600 nw/cm2 vs no pulse: P = 0.02; 7,000 nw/cm2 vs no pulse: P = 0.007. 120 min: 0.3, 4 nw/cm2 vs no pulse: not significant; 50 nw/cm2 vs no pulse: P = 0.0.006. Error bars = SEM. The dashed line indicates two light pulses with equal numbers of photons: not significantly different.