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Clocks, criteria and critical genes

Nature Genetics volume 22, pages 217–219 (1999)Cite this article

Perhaps we need to break away from the compartmentalized view of the circadian system to further our understanding of how clock genes work. For example, in some mathematical models, an arrhythmic phenotype can result from under- or overexpression of a gene that is either a rhythmically expressed component of the input pathway or a part of the central oscillator3. The conceptual limitations inherent in the traditional representation of the circadian system have been recently confronted in the pages of Nature by Martha Merrow and colleagues, through their study of the frequency gene ( frq) of N. crassa (Fig. 1; ref. 4).

Circadian rhythms in N. crassa can be monitored through the rhythmic pattern of asexual spore production (conidiation) of cultures growing in glass tubes—as originally demonstrated by the pioneering experiments of Jerry Feldman5. The subsequent development of this species into a molecular model was accompanied by the demonstration that frq fulfilled all the original criteria of a clock component: null mutants of frq show random (arrhythmic) conidiation under constant lighting conditions; frq is self-regulated by negative feedback; and experimental induction of frq expression re-sets the circadian phase of conidiation. Thus, frq has been represented as the dominant component of the circadian oscillator of N. crassa2.

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Figure 1: Circadian organization has long been conceptualized as comprising three distinct tasks, represented by 'black boxes' corresponding to the transduction of environmental inputs, a rhythm-generating circadian oscillator and output pathways to effector systems (a).
Figure 2: A simple conceptualization of the circadian light entrainment pathway, in which the first stage is the absorption of a photon by a light-sensitive pigment.

References

  1. Eskin, A. Fed. Proc. Am. Soc. Exp. Biol. 38, 2573– 2579 (1979).

    CAS  Google Scholar 

  2. Dunlap, J.C. Cell 96, 271–290 ( 1999).

    Article  CAS  Google Scholar 

  3. Roenneberg, T. & Merrow, M. J. Biol. Rhythms 13, 167–179 (1998).

    Article  CAS  Google Scholar 

  4. Merrow, M., Brunner, M. & Roenneberg, T. Nature 399, 584– 586 (1999).

    Article  CAS  Google Scholar 

  5. Feldman, J.F. & Hoyle, M.N. Genetics 75, 605–613 (1973).

    CAS  PubMed  PubMed Central  Google Scholar 

  6. Loros, J.J. & Feldman, J.F. J. Biol. Rhythms 1 , 187–198 (1986).

    Article  CAS  Google Scholar 

  7. Aschoff, J. in Handbook of Behavioral Neurobiology: Biological Rhythms (ed. Aschoff, J.) 81–94 (Plenum Press, New York, 1981).

    Google Scholar 

  8. Miyamoto, Y. & Sancar, A. Proc. Natl Acad. Sci. USA 95, 6097–6102 (1998).

    Article  CAS  Google Scholar 

  9. van der Horst, G.T.J. et al. Nature 398, 627– 630 (1999).

    Article  CAS  Google Scholar 

  10. Lucas, R.J. & Foster, R.G. J. Biol. Rhythms 14 , 4–9 (1999).

    Article  Google Scholar 

Download references

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  1. Department of Biology, Imperial College of Science Technology and Medicine, Sir Alexander Fleming Building, London, SW7 2AZ, UK

    Russell G Foster & Robert J Lucas

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  1. Russell G Foster
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  2. Robert J Lucas
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Foster, R., Lucas, R. Clocks, criteria and critical genes. Nat Genet 22, 217–219 (1999). https://doi.org/10.1038/10270

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