Action Spectra for Phase Shifts of a Circadiain Rhythm in Drosophila

Science  14 Feb 1969:
Vol. 163, Issue 3868, pp. 688-689
DOI: 10.1126/science.163.3868.688


Action spectra were determined for lightinduced phase shifts of the circadian rhythm of adult emergence in Drosophila pseudoobscura. The action spectra for advance and delay phase shifts are similar; the most effective wavelengths are in the blue region, with a sharp cutoff above 500 nanometers. This similarity suggests that the same photoreceptive pigment mediates both advance and delay phase shifts.