http://www.nutshell-videos.ed.ac.uk/andrew-millar-biological-clocks/In this video Andrew describes how Systems Biology uses glowing plants to study the 24-hour clock, which drives daily and seasonal rhythms. Surprisingly, cells from humans to algae may have two biological clocks.
Background:
Professor Andrew Millar, Chair of Systems Biology in the School of Biological Sciences and associate director of SynthSys, combines molecular, physiological, and mathematical approaches in his research on the circadian clock in Arabidopsis thaliana.
Research:
The biological clock generates 24-hour rhythms that synchronise many biological processes with the environmental day/night cycles, from the human sleep-wake cycle to photosynthetic potential in plants. The circuit of interconnected genes in the clock mechanism governs both autonomous rhythms and responses to the environment: it has become one of the paradigms for understanding biological regulation in eukaryotes. Andrew’s laboratory uses experimental and theoretical approaches to understand the operating principles of biological networks, the mechanisms of the plant circadian clock and the physiological importance of daily and seasonal clocks for plant growth and crop yield.
The model plant Arabidopsis thaliana is the group’s main experimental system. Its biological clock is illustrated by the transgenic leaf, rhythmically glowing under our microscope (Wenden et al. Proc.Natl.Acad.Sci. USA, 2012). The plant carries a firefly luciferase gene that is controlled by its biological clock, so the glow from luciferase ‘reports’ the rhythmic activity of the related clock gene.
On the ROBuST project led by Karen Halliday, we are studying how the signalling network including the plant clock copes with changes in ambient temperature, and how this affects plant growth. The TiMet project aims to understand the bidirectional regulation between primary and secondary metabolism and the clock. The group is also developing data infrastructure to link experimental results to mathematical models. New modelling approaches are explored with several SynthSys collaborators, including stochastic models with Ramon Grima and Jane Hillston, Boolean models with Ozgur Akman and Peter Ghazal, and rule-based models with Vincent Danos. Current interests include a framework model to study particular biological regulation, such as the clock, in the context of a whole, growing plant: a prototype Digital Organism.
Work on the unicellular, marine alga Ostreococcus tauri (in the green images) was initiated with Francois-Yves Bouget and has grown to a major focus, with the discovery of a non-transcriptional clock (O’Neill et al. Nature, 2011) that might be shared from humans to archaea (Edgar et al. Nature, 2012). With John O’Neill and Akhilesh Reddy, we work on the unknown mechanisms of this oscillator. Thierry Le Bihan in the KPF has developed modern proteomics methods for the alga, and with Sinead Collins we are working on experimental evolution.
