Experimental validation of a predicted feedback loop in the multi-oscillator clock of Arabidopsis thaliana

James C.W. Locke, László Kozma-Bognár, Peter D. Gould, Balázs Fehér, Éva Kevei, Ferenc Nagy, Matthew S. Turner, Anthony Hall, Andrew J. Millar

Research output: Contribution to journalArticle

319 Citations (Scopus)


Our computational model of the circadian clock comprised the feedback loop between LATE ELONGATED HYPOCOTYL (LHY), CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) and TIMING OF CAB EXPRESSION 1 (TOC1), and a predicted, interlocking feedback loop involving TOC1 and a hypothetical component Y. Experiments based on model predictions suggested GIGANTEA (GI) as a candidate for Y. We now extend the model to include a recently demonstrated feedback loop between the TOC1 homologues PSEUDO-RESPONSE REGULATOR 7 (PRR7), PRR9 and LHY and CCA1. This three-loop network explains the rhythmic phenotype of toc1 mutant alleles. Model predictions fit closely to new data on the gi;lhy;cca1 mutant, which confirm that GI is a major contributor to Y function. Analysis of the three-loop network suggests that the plant clock consists of morning and evening oscillators, coupled intracellularly, which may be analogous to coupled, morning and evening clock cells in Drosophila and the mouse.

Original languageEnglish
Article number59
JournalMolecular systems biology
Publication statusPublished - May 16 2006


  • Circadian rhythm
  • Genetic network
  • Mathematical model
  • Photoperiod
  • Systems biology

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)
  • Agricultural and Biological Sciences(all)
  • Applied Mathematics

Fingerprint Dive into the research topics of 'Experimental validation of a predicted feedback loop in the multi-oscillator clock of Arabidopsis thaliana'. Together they form a unique fingerprint.

  • Cite this