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Light and circadian regulation of clock components aids flexible responses to environmental signals

Dixon, Laura E.; Hodge, Sarah K.; van Ooijen, Gerben; Troein, Carl LU ; Akman, Ozgur E. and Millar, Andrew J. (2014) In New Phytologist 203(2). p.568-577
Abstract
The circadian clock measures time across a 24h period, increasing fitness by phasing biological processes to the most appropriate time of day. The interlocking feedback loop mechanism of the clock is conserved across species; however, the number of loops varies. Mathematical and computational analyses have suggested that loop complexity affects the overall flexibility of the oscillator, including its responses to entrainment signals. We used a discriminating experimental assay, at the transition between different photoperiods, in order to test this proposal in a minimal circadian network (in Ostreococcus tauri) and a more complex network (in Arabidopsis thaliana). Transcriptional and translational reporters in O.tauri primarily tracked... (More)
The circadian clock measures time across a 24h period, increasing fitness by phasing biological processes to the most appropriate time of day. The interlocking feedback loop mechanism of the clock is conserved across species; however, the number of loops varies. Mathematical and computational analyses have suggested that loop complexity affects the overall flexibility of the oscillator, including its responses to entrainment signals. We used a discriminating experimental assay, at the transition between different photoperiods, in order to test this proposal in a minimal circadian network (in Ostreococcus tauri) and a more complex network (in Arabidopsis thaliana). Transcriptional and translational reporters in O.tauri primarily tracked dawn or dusk, whereas in A.thaliana, a wider range of responses were observed, consistent with its more flexible clock. Model analysis supported the requirement for this diversity of responses among the components of the more complex network. However, these and earlier data showed that the O.tauri network retains surprising flexibility, despite its simple circuit. We found that models constructed from experimental data can show flexibility either from multiple loops and/or from multiple light inputs. Our results suggest that O.tauri has adopted the latter strategy, possibly as a consequence of genomic reduction. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
biological clocks, flexibility, marine algae, mathematical analysis, nonlinear dynamics, photoperiod, systems biology
in
New Phytologist
volume
203
issue
2
pages
568 - 577
publisher
Wiley-Blackwell
external identifiers
  • wos:000337639800021
  • scopus:84902550909
ISSN
1469-8137
DOI
10.1111/nph.12853
language
English
LU publication?
yes
id
2502b60b-cf7f-415e-aa93-53c42c3061c7 (old id 4609495)
date added to LUP
2014-08-26 11:06:39
date last changed
2017-04-09 03:14:10
@article{2502b60b-cf7f-415e-aa93-53c42c3061c7,
  abstract     = {The circadian clock measures time across a 24h period, increasing fitness by phasing biological processes to the most appropriate time of day. The interlocking feedback loop mechanism of the clock is conserved across species; however, the number of loops varies. Mathematical and computational analyses have suggested that loop complexity affects the overall flexibility of the oscillator, including its responses to entrainment signals. We used a discriminating experimental assay, at the transition between different photoperiods, in order to test this proposal in a minimal circadian network (in Ostreococcus tauri) and a more complex network (in Arabidopsis thaliana). Transcriptional and translational reporters in O.tauri primarily tracked dawn or dusk, whereas in A.thaliana, a wider range of responses were observed, consistent with its more flexible clock. Model analysis supported the requirement for this diversity of responses among the components of the more complex network. However, these and earlier data showed that the O.tauri network retains surprising flexibility, despite its simple circuit. We found that models constructed from experimental data can show flexibility either from multiple loops and/or from multiple light inputs. Our results suggest that O.tauri has adopted the latter strategy, possibly as a consequence of genomic reduction.},
  author       = {Dixon, Laura E. and Hodge, Sarah K. and van Ooijen, Gerben and Troein, Carl and Akman, Ozgur E. and Millar, Andrew J.},
  issn         = {1469-8137},
  keyword      = {biological clocks,flexibility,marine algae,mathematical analysis,nonlinear dynamics,photoperiod,systems biology},
  language     = {eng},
  number       = {2},
  pages        = {568--577},
  publisher    = {Wiley-Blackwell},
  series       = {New Phytologist},
  title        = {Light and circadian regulation of clock components aids flexible responses to environmental signals},
  url          = {http://dx.doi.org/10.1111/nph.12853},
  volume       = {203},
  year         = {2014},
}