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The mPer2 gene encodes a functional component of the mammalian circadian clock

B Zheng1, D W Larkin, U Albrecht

  • 1Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030, USA.

Nature
|July 17, 1999
PubMed

Insights

Mice with a mutated mPer2 gene showed shorter circadian rhythms and lost rhythmicity in darkness. This suggests mPer2 is crucial for mammalian circadian clocks and influences mPer1 expression.

Area of Science:

  • Chronobiology
  • Molecular Biology
  • Genetics

Background:

  • Circadian rhythms are regulated by endogenous biological clocks.
  • Mammalian circadian clocks involve the suprachiasmatic nucleus and mPer genes.
  • mPer1, mPer2, and mPer3 are mammalian homologues of the Drosophila period gene.

Purpose of the Study:

  • To investigate the in vivo function of the mouse mPer2 gene.
  • To characterize the effects of a deletion mutation in the mPer2 PAS domain.

Main Methods:

  • Generated a deletion mutation in the PAS domain of the mouse mPer2 gene.
  • Analyzed circadian rhythmicity in homozygous mutant mice under constant darkness.
  • Assessed the expression patterns of mPer1 and mPer2 in the suprachiasmatic nucleus.

Main Results:

  • Mice homozygous for the mPer2 mutation exhibited a shorter circadian period.
  • Mutant mice lost circadian rhythmicity in constant darkness.
  • The mutation diminished the oscillating expression of mPer1 and mPer2 in the suprachiasmatic nucleus.

Conclusions:

  • mPer2 plays a significant role in the mammalian circadian clock.
  • mPer2 may regulate mPer1 expression in vivo.
  • mPer2 is a key component of the mammalian circadian oscillator.

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