Edinburgh Research Explorer

Quantitative analysis of regulatory flexibility under changing environmental conditions

Research output: Contribution to journalArticlepeer-review

Related Edinburgh Organisations

Open Access permissions



  • Download as Adobe PDF

    Rights statement: This is an open-access article distributed under the terms of the Creative Commons Attribution Noncommercial Share Alike 3.0 Unported License, which allows readers to alter, transform, or build upon the article and thendistribute the resultingwork under the same or similar license to this one.Theworkmust be attributed back to the original author and commercial use is not permitted without specific permission.

    Final published version, 443 KB, PDF document

Original languageEnglish
Article number424
Number of pages11
JournalMolecular Systems Biology
Publication statusPublished - 2 Nov 2010


The circadian clock controls 24-h rhythms in many biological processes, allowing appropriate timing of biological rhythms relative to dawn and dusk. Known clock circuits include multiple, interlocked feedback loops. Theory suggested that multiple loops contribute the flexibility for molecular rhythms to track multiple phases of the external cycle. Clear dawn- and dusk-tracking rhythms illustrate the flexibility of timing in Ipomoea nil. Molecular clock components in Arabidopsis thaliana showed complex, photoperiod-dependent regulation, which was analysed by comparison with three contrasting models. A simple, quantitative measure, Dusk Sensitivity, was introduced to compare the behaviour of clock models with varying loop complexity. Evening-expressed clock genes showed photoperiod-dependent dusk sensitivity, as predicted by the three-loop model, whereas the one- and two-loop models tracked dawn and dusk, respectively. Output genes for starch degradation achieved dusk-tracking expression through light regulation, rather than a dusk-tracking rhythm. Model analysis predicted which biochemical processes could be manipulated to extend dusk tracking. Our results reveal how an operating principle of biological regulators applies specifically to the plant circadian clock.

    Research areas

  • Arabidopsis thaliana, biological clocks, dynamical systems, gene regulatory networks, mathematical models, photoperiodism

Download statistics

No data available

ID: 1852670