Expression profiles of 10 circadian clock genes in human peripheral blood mononuclear cells

Neurosci Res. 2008 Jun;61(2):136-42. doi: 10.1016/j.neures.2008.01.012. Epub 2008 Feb 6.


The circadian clock system regulates daily rhythms of physiology and behavior. The mammalian master clock in the suprachiasmatic nuclei orchestrates these biological rhythms in peripheral tissues. Since blood is the most accessible tissue source, we sought to dissect the human circadian clock system by characterizing clock gene expression in human peripheral blood mononuclear cells (PBMCs) isolated from eight young, healthy subjects. By evaluating the temporal expression profiles of 10 circadian clock genes, we found that Period 1 (Per1), Per2, and Per3 are rhythmically expressed in human blood samples. Our results suggest that evaluating the rhythmic expression of human Per genes could reveal an individual's circadian phenotype.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Circadian Rhythm / genetics*
  • Gene Expression
  • Gene Expression Profiling*
  • Humans
  • Leukocytes, Mononuclear / physiology*
  • Male
  • RNA, Messenger / analysis
  • Reverse Transcriptase Polymerase Chain Reaction


  • RNA, Messenger