Antiphase circadian expression between BMAL1 and period homologue mRNA in the suprachiasmatic nucleus and peripheral tissues of rats

Biochem Biophys Res Commun. 1998 Dec 18;253(2):199-203. doi: 10.1006/bbrc.1998.9779.


BMAL1 is a putative transcription factor which is involved in circadian rhythm generation in Drosophila. Northern blot analysis was performed to investigate the expression of rat BMAL1 mRNA in the suprachiasmatic nucleus (SCN) and peripheral tissues. In the SCN, circadian expression of BMAL1 mRNA which reaches its peak level at the time of dark-light transition was observed, and the expression pattern was antiphase to those of two period (per) homologues, rPer1 and rPer2. However, no circadian oscillation for rat Clock mRNA was detected. The circadian expression of BMAL1 mRNA was also observed in peripheral tissues such as brain (excluding the SCN), eye, heart, kidney, and lung. The amplitudes of BMAL1 and rPer2 mRNA expression levels were correlated between the different tissues, suggesting that the circadian expression of BMAL1 mRNA plays an important role in generating the circadian expression of per homologue genes in mammals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ARNTL Transcription Factors
  • Animals
  • Basic Helix-Loop-Helix Transcription Factors
  • Blotting, Northern
  • CLOCK Proteins
  • Cell Cycle Proteins
  • Circadian Rhythm / genetics*
  • Darkness
  • Male
  • Nuclear Proteins / biosynthesis
  • Nuclear Proteins / genetics*
  • Organ Specificity / genetics
  • Period Circadian Proteins
  • RNA, Messenger / biosynthesis*
  • Rats
  • Rats, Wistar
  • Sequence Homology, Nucleic Acid
  • Suprachiasmatic Nucleus / metabolism*
  • Trans-Activators / genetics
  • Transcription Factors / biosynthesis
  • Transcription Factors / genetics*


  • ARNTL Transcription Factors
  • ARNTL protein, human
  • Basic Helix-Loop-Helix Transcription Factors
  • Cell Cycle Proteins
  • Nuclear Proteins
  • Per2 protein, rat
  • Period Circadian Proteins
  • RNA, Messenger
  • Trans-Activators
  • Transcription Factors
  • CLOCK Proteins
  • CLOCK protein, human
  • Clock protein, rat