Open AccessExperimental validation of a predicted feedback loop in the multi‐oscillator clock of Arabidopsis thaliana
Author(s) -
Locke James C W,
KozmaBognár László,
Gould Peter D,
Fehér Balázs,
Kevei Éva,
Nagy Ferenc,
Turner Matthew S,
Hall Anthony,
Millar Andrew J
Publication year - 2006
Publication title -
molecular systems biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 8.523
H-Index - 148
ISSN - 1744-4292
DOI - 10.1038/msb4100102
Subject(s) - biology , circadian clock , arabidopsis thaliana , regulator , feedback loop , gigantea , mutant , negative feedback , loop (graph theory) , microbiology and biotechnology , arabidopsis , circadian rhythm , genetics , botany , physics , neuroscience , computer science , gene , computer security , mathematics , quantum mechanics , voltage , combinatorics
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.