RIGUI, a putative mammalian ortholog of the Drosophila period gene

Cell. 1997 Sep 19;90(6):1003-11. doi: 10.1016/s0092-8674(00)80366-9.


The molecular components of mammalian circadian clocks are elusive. We have isolated a human gene termed RIGUI that encodes a bHLH/PAS protein 44% homologous to Drosophila period. The highly conserved mouse homolog (m-rigui) is expressed in a circadian pattern in the suprachiasmatic nucleus (SCN), the master regulator of circadian clocks in mammals. Circadian expression in the SCN continues in constant darkness, and a shift in the light/dark cycle evokes a proportional shift of m-rigui expression in the SCN. m-rigui transcripts also appear in a periodic pattern in Purkinje neurons, pars tuberalis, and retina, but with a timing of oscillation different from that seen in the SCN. Sequence homology and circadian patterns of expression suggest that RIGUI is a mammalian ortholog of the Drosophila period gene, raising the possibility that a regulator of circadian clocks is conserved.

Publication types

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

MeSH terms

  • Adaptation, Ocular / physiology
  • Animals
  • Cell Cycle Proteins
  • Circadian Rhythm / genetics*
  • DNA, Complementary / analysis
  • Drosophila
  • Drosophila Proteins
  • Gene Expression / physiology
  • Humans
  • In Situ Hybridization, Fluorescence
  • Mammals
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Nuclear Proteins / genetics*
  • Period Circadian Proteins
  • Periodicity
  • Purkinje Cells / physiology
  • RNA, Messenger / analysis
  • RNA, Messenger / isolation & purification
  • Retina / physiology
  • Sequence Homology, Amino Acid
  • Suprachiasmatic Nucleus / physiology
  • Transcription, Genetic / physiology


  • Cell Cycle Proteins
  • DNA, Complementary
  • Drosophila Proteins
  • Nuclear Proteins
  • PER protein, Drosophila
  • PER1 protein, human
  • Per1 protein, mouse
  • Period Circadian Proteins
  • RNA, Messenger

Associated data

  • GENBANK/AF022991
  • GENBANK/AF022992