Abstract
Circadian rhythms are based on endogenous clocks that allow organisms to adjust their physiology and behavior by entrainment to the solar day and, in turn, to select the optimal times for most biological variables. Diverse model systems - including mice, flies, fungi, plants, and bacteria - have provided important insights into the mechanisms of circadian rhythmicity. However, the general principles that govern the circadian clock of Caenorhabditis elegans have remained largely elusive. Here we report robust molecular circadian rhythms in C. elegans recorded with a bioluminescence assay in vivo and demonstrate the main features of the circadian system of the nematode. By constructing a luciferase-based reporter coupled to the promoter of the suppressor of activated let-60 Ras (sur-5) gene, we show in both population and single-nematode assays that C. elegans expresses ∼24-h rhythms that can be entrained by light/dark and temperature cycles. We provide evidence that these rhythms are temperature-compensated and can be re-entrained after phase changes of the synchronizing agents. In addition, we demonstrate that light and temperature sensing requires the photoreceptors LITE and GUR-3, and the cyclic nucleotide-gated channel subunit TAX-2. Our results shed light on C. elegans circadian biology and demonstrate evolutionarily conserved features in the circadian system of the nematode.
| Original language | English |
|---|---|
| Pages (from-to) | E7837-E7845 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 113 |
| Issue number | 48 |
| DOIs | |
| Publication status | Published - 29 Nov 2016 |
| Externally published | Yes |
Bibliographical note
Funding Information:We thank S. Simonetta for initial discussions; P. Schwarzbaum and C. Alvarez for protocols and reagents; H. de la Iglesia for critical discussions and reading of the manuscript; M. Yanovsky for advice, reading of the manuscript, and technical support; L. Larrondo for discussions about the project and suggestions of experiments; A. Thackeray, W. Joyce, and M. Lamberti for critical technical assistance; S. Xu for the Ptax-2:: tax-2::YFP plasmid; D. Banerjee for advice with kin-20 mutants; and the Caenorhabditis Genetics Center funded by NIH Office of Research Infrastructure Programs Grant P40 OD010440 for strains. This work was supported by grants from the Agencia Nacional de Promoci?n Cient?fica y Tecnol?gica, Consejo Nacional de Investigaciones Cient?ficas y T?cnicas de Argentina (CONICET) and Universidad Nacional de Quilmes (Argentina) (to D.A.G.), and by NIH Grant R01-AG041870-01 (to C.Y.B.). M.E.G. and C.S.C. are PhD CONICET Fellows, and A.R. is a Bunge y Born Foundation Fellow.
Publisher Copyright:
© 2016, National Academy of Sciences. All rights reserved.
Funding
We thank S. Simonetta for initial discussions; P. Schwarzbaum and C. Alvarez for protocols and reagents; H. de la Iglesia for critical discussions and reading of the manuscript; M. Yanovsky for advice, reading of the manuscript, and technical support; L. Larrondo for discussions about the project and suggestions of experiments; A. Thackeray, W. Joyce, and M. Lamberti for critical technical assistance; S. Xu for the Ptax-2:: tax-2::YFP plasmid; D. Banerjee for advice with kin-20 mutants; and the Caenorhabditis Genetics Center funded by NIH Office of Research Infrastructure Programs Grant P40 OD010440 for strains. This work was supported by grants from the Agencia Nacional de Promoci?n Cient?fica y Tecnol?gica, Consejo Nacional de Investigaciones Cient?ficas y T?cnicas de Argentina (CONICET) and Universidad Nacional de Quilmes (Argentina) (to D.A.G.), and by NIH Grant R01-AG041870-01 (to C.Y.B.). M.E.G. and C.S.C. are PhD CONICET Fellows, and A.R. is a Bunge y Born Foundation Fellow.
Keywords
- C. elegans
- Circadian rhythms
- Light
- Luminescence
- Temperature