title: Role of mouse cryptochrome blue-light photoreceptor in circadian photoresponses.
abstract: Cryptochromes are photoactive pigments in the eye that have been proposed to function as circadian photopigments. Mice lacking the cryptochrome 2 blue-light photoreceptor gene (mCry2) were tested for circadian clock-related functions. The mutant mice had a lower sensitivity to acute light induction of mPer1 in the suprachiasmatic nucleus (SCN) but exhibited normal circadian oscillations of mPer1 and mCry1 messenger RNA in the SCN. Behaviorally, the mutants had an intrinsic circadian period about 1 hour longer than normal and exhibited high-amplitude phase shifts in response to light pulses administered at circadian time 17. These data are consistent with the hypothesis that CRY2 protein modulates circadian responses in mice and suggest that cryptochromes have a role in circadian photoreception in mammals.
authors.affiliation: Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Thresher
authors.forename: M H
authors.initials: MH
authors.lastname: Vitaterna
authors.forename: Y
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: A
authors.initials: A
authors.lastname: Kazantsev
authors.forename: D S
authors.initials: DS
authors.lastname: Hsu
authors.forename: C
authors.initials: C
authors.lastname: Petit
authors.forename: C P
authors.initials: CP
authors.lastname: Selby
authors.forename: L
authors.initials: L
authors.lastname: Dawut
authors.forename: O
authors.initials: O
authors.lastname: Smithies
authors.forename: J S
authors.initials: JS
authors.lastname: Takahashi
authors.forename: A
authors.initials: A
authors.lastname: Sancar
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins; D002940:Circadian Rhythm / Q000502:physiology*; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005260:Female; D005420:Flavoproteins / Q000235:genetics / Q000502:physiology*; D005786:Gene Expression Regulation; D018390:Gene Targeting; D017403:In Situ Hybridization; D008027:Light; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009043:Motor Activity; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics; D056950:Period Circadian Proteins; D017956:Photoreceptor Cells, Invertebrate; D020419:Photoreceptor Cells, Vertebrate / Q000502:physiology*; D043562:Receptors, G-Protein-Coupled; D013493:Suprachiasmatic Nucleus / Q000378:metabolism
chemical_list: D018797:Cell Cycle Proteins; C538967:Cry2 protein, mouse; D056931:Cryptochromes; D029721:Drosophila Proteins; D005136:Eye Proteins; D005420:Flavoproteins; D009687:Nuclear Proteins; C539023:Per1 protein, mouse; D056950:Period Circadian Proteins; D043562:Receptors, G-Protein-Coupled; C119828:cry protein, Drosophila