Information Transfer in the Mammalian Circadian Clock
Most species evolved a circadian clock to adapt to the 24 h period of the solar day. In mammals, these clocks generate endogenous rhythms by regulatory gene networks in almost every cell. A pacemaker, the suprachiasmatic nucleus (SCN) as the master clock, receives environmental input and orchestrates peripheral organs via sympathetic enervation, temperature and humoral factors. However, the mechanisms by which this synchronization is achieved are largely unknown. In order to elucidate paradigms of environmental information transfer within the circadian network, we address the following questions: How is environmental information perceived by different circadian networks? Do different circadian networks vary in their responses to a given signal, and, if so, do the differences depend on inherent circadian properties? Which part of the signal (onset, offset, duration, strength) is relevant for the responses? To address these questions, we combine experimental data from cultured single cells and organotypic slices with mathematical models of circadian oscillators and find that temperature signals have a strong impact on circadian rhythms, depending on the specific circadian properties of the clock cells.
We would like to thank Márton Danóczy for his help with the data processing algorithms and Maike Mette-Thaben for expert technical assistance.
- Abraham U et al (2010) Coupling governs entrainment range of circadian clocks. Mol Syst Biol 6(1):438. http://www.ncbi.nlm.nih.gov/pubmed/21119632, http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC3010105
- Albrecht U (2012) Timing to perfection: the biology of central and peripheral circadian clocks. Neuron 74(2):246–260. https://www.example.edu/paper.pdf
- Bordyugov G et al (2015) Tuning the phase of circadian entrainment. J R Soc Interface/R Soc 12(108):20150282. http://www.ncbi.nlm.nih.gov/pubmed/26136227, http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC4528595
- Brown SA et al (2008) Molecular insights into human daily behavior. Proc National Acad Sci 105(5):1602–1607. http://www.pnas.org/cgi/doi/10.1073/pnas.0707772105
- Buhr ED, Yoo S-H, Takahashi JS (2010) Temperature as a universal resetting cue for mammalian circadian oscillators. Science (New York, N.Y.) 330(6002):379–385. http://www.ncbi.nlm.nih.gov/pubmed/20947768, http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC3625727
- Granada AE et al (2013) Human chronotypes from a theoretical perspective. PloS One 8(3):e59464. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3609763&tool=pmcentrez&rendertype=abstract
- Maier B et al (2009) A large-scale functional RNAi screen reveals a role for CK2 in the mammalian circadian clock. Genes Dev 23(6):708–718. http://genesdev.cshlp.org/cgi/doi/10.1101/gad.512209
- Ouyang Y et al (1998) Resonating circadian clocks enhance fitness in cyanobacteria. Proc National Acad Sci USA 95(15):8660–8664. http://www.ncbi.nlm.nih.gov/pubmed/9671734, http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC21132
- Saleh M et al (2015) Genome-wide screen reveals rhythmic regulation of genes involved in odor processing in the olfactory epithelium. J Biol Rhythm 30(6):506–518. http://jbr.sagepub.com/cgi/doi/10.1177/0748730415610197
- Vollmers C, Panda S, DiTacchio L (2008) A high-throughput assay for siRNA-based circadian screens in human U2OS cells. PLoS One 3(10):e3457. http://dx.plos.org/10.1371/journal.pone.0003457 (Ed. by Nitabach MN)
- Yoo S-H et al (2004) PERIOD2::LUCIFERASE real-time reporting of circadian dynamics reveals persistent circadian oscillations in mouse peripheral tissues. Proc National Acad Sci USA 101(15):5339–5346. http://www.ncbi.nlm.nih.gov/pubmed/14963227, http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=PMC397382