The cryb mutation identifies cryptochrome as a circadian photoreceptor in Drosophila

Cell. 1998 Nov 25;95(5):681-92. doi: 10.1016/s0092-8674(00)81638-4.


A new rhythm mutation was isolated based on its elimination of per-controlled luciferase cycling. Levels of period or timeless clock gene products in the mutant are flat in daily light-dark cycles or constant darkness (although PER and TIM oscillate normally in temperature cycles). Consistent with the fact that light normally suppresses TIM, cryb is an apparent null mutation in a gene encoding Drosophila's version of the blue light receptor cryptochrome. Behaviorally, cryb exhibits poor synchronization to light-dark cycles in genetic backgrounds that cause external blindness or demand several hours of daily rhythm resets, and it shows no response to brief light pulses. cryb flies are rhythmic in constant darkness, correlating with robust PER and TIM cycling in certain pacemaker neurons.

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

  • Animals
  • Behavior, Animal
  • Circadian Rhythm*
  • Cryptochromes
  • Darkness
  • Drosophila Proteins*
  • Drosophila melanogaster
  • Eye Proteins*
  • Flavoproteins / genetics*
  • Flavoproteins / physiology
  • Insect Proteins / biosynthesis
  • Light
  • Mutation, Missense
  • Neurons / metabolism
  • Nuclear Proteins / biosynthesis
  • Open Reading Frames
  • Period Circadian Proteins
  • Photoreceptor Cells, Invertebrate / physiology*
  • Receptors, G-Protein-Coupled


  • Cryptochromes
  • Drosophila Proteins
  • Eye Proteins
  • Flavoproteins
  • Insect Proteins
  • Nuclear Proteins
  • PER protein, Drosophila
  • Period Circadian Proteins
  • Receptors, G-Protein-Coupled
  • cry protein, Drosophila
  • tim protein, Drosophila

Associated data

  • GENBANK/AF099734