Projects per year
Circadian clocks are biological timekeepers that allow living cells to time their activity in anticipation of predictable environmental changes. Detailed understanding of the circadian network of higher plants, such as Arabidopsis thaliana, is hampered by the high number of partially redundant genes. However, the picoeukaryotic alga Ostreococcus tauri, which was recently shown to possess a small number of non-redundant clock genes, presents an attractive alternative target for detailed modelling of circadian clocks in the green lineage. Based on extensive time-series data from in vivo reporter gene assays, we developed a model of the Ostreococcus clock as a feedback loop between the genes TOC1 and CCA1. The model reproduces the dynamics of the transcriptional and translational reporters over a range of photoperiods. Surprisingly, the model is also able to predict the transient behaviour of the clock when the light conditions are altered. Despite the apparent simplicity of the clock circuit, it displays considerable complexity in its response to changing light conditions. Systematic screening of the effects of altered day length revealed a complex relationship between phase and photoperiod, which is also captured by the model. The complex light response is shown to stem from circadian gating of light-dependent mechanisms. This study provides insights into the contributions of light inputs to the Ostreococcus clock. The model suggests that a high number of light-dependent reactions are important for flexible timing in a circadian clock with only one feedback loop.
|Number of pages||11|
|Journal||The Plant Journal|
|Publication status||Published - 2011|
- CLOCK Proteins
- Circadian Clocks
- Gene Expression Regulation, Plant
- Models, Biological
- Plant Proteins
- Transcription Factors
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- 2 Finished
Miinimal models of the circadian clock in a novael biological system
1/12/07 → 31/05/11
SynthSys; formerly CSBE: Centre for Systems Biology at Edinburgh
Millar, A., Beggs, J., Ghazal, P., Goryanin, I., Hillston, J., Plotkin, G., Tollervey, D., Walton, A. & Robertson, K.
8/01/07 → 31/12/12
- 1 Other contribution
Mathematical model of the clock gene circuit in the alga Ostreococcus tauriMillar, A., 2011
Research output: Other contribution