CRY, a Drosophila clock and light-regulated cryptochrome, is a major contributor to circadian rhythm resetting and photosensitivity

Cell. 1998 Nov 25;95(5):669-79. doi: 10.1016/s0092-8674(00)81637-2.


Light is a major environmental signal for circadian rhythms. We have identified and analyzed cry, a novel Drosophila cryptochrome gene. All characterized family members are directly photosensitive and include plant blue light photoreceptors. We show that cry transcription is under circadian regulation, influenced by the Drosophila clock genes period, timeless, Clock, and cycle. We also show that cry protein levels are dramatically affected by light exposure. Importantly, circadian photosensitivity is increased in a cry-overexpressing strain. These physiological and genetic data therefore link a specific photoreceptor molecule to circadian rhythmicity. Taken together with the data in the accompanying paper, we propose that CRY is a major Drosophila photoreceptor dedicated to the resetting of circadian rhythms.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • ARNTL Transcription Factors
  • Animals
  • Animals, Genetically Modified
  • Basic Helix-Loop-Helix Transcription Factors
  • CLOCK Proteins
  • Circadian Rhythm*
  • Cryptochromes
  • Drosophila
  • Drosophila Proteins*
  • Eye Proteins*
  • Female
  • Flavoproteins / genetics
  • Flavoproteins / physiology*
  • Insect Proteins / physiology
  • Light
  • Male
  • Molecular Sequence Data
  • Nuclear Proteins / physiology
  • Period Circadian Proteins
  • Photoreceptor Cells, Invertebrate*
  • Receptors, G-Protein-Coupled
  • Trans-Activators / physiology
  • Transcription, Genetic


  • ARNTL Transcription Factors
  • Basic Helix-Loop-Helix Transcription Factors
  • Cryptochromes
  • Drosophila Proteins
  • Eye Proteins
  • Flavoproteins
  • Insect Proteins
  • Nuclear Proteins
  • PER protein, Drosophila
  • Period Circadian Proteins
  • Receptors, G-Protein-Coupled
  • Trans-Activators
  • cry protein, Drosophila
  • cyc protein, Drosophila
  • tim protein, Drosophila
  • CLOCK Proteins

Associated data

  • GENBANK/AF099734