Gen Kurosawa |
Even in an environment without the information of time such as sun light, organisms show its sustained rhythms in behavior level whose period is around 24hrs (curiously it is not exactly 24hrs!!).
This autonomous rhythm is called circadian rhythm or biological clock. This can be observed not only in prokaryote but also in eucaryote.
Because of the recent development of molecular biology, important genes of this system have been identified for various species,
and molecular mechanism is going to be revealed.
Clock genes are transcribed and from mRNA of it proteins are produced.
These proteins enter the nucleus through some modifications and inhibit the transcription of own gene.
This negative feedback loop with time delay is thought to generate the circadian rhythm for various organisms.
Modelling the molecular mechanism, the condition for the generation of rhythm and the stability of rhythms can be analysed theoretically.
My research themes have been " what kinds of reaction mechanism could affect the generation of circadian rhythm?",
" how temperature compensation of circadian rhythm is organised? ", and " why circadian period is different from 24h?"
For theme , we discussed in (1)-(3), below and whilst we are currently studying theme  and .
Takeuchi T, T. Hinohara, G. Kurosawa, K. Uchida, in press. A temparature compensated model for circadian rhythms that can be entrained by temperature cycles. Journal of Theoretical Biology
Kurosawa G, K. Aihara, Y. Iwasa, 2006. A model for the circadian rhythm of cyanobacteria that maintains oscillation without gene expression. Biophysical Journal, 91(6):2015-23.
Kurosawa G, and A. Goldbeter, 2006. Amplitude of circadian oscillations entrained by 24-h light-dark cycles. Journal of Theoretical Biology, 242(2):478-88.
Kurosawa, G., and Y. Iwasa, 2005. Temperature compensation in circadian clock models. Journal of Theoretical Biology, 233(4):453-6.
Kurosawa, G., and Y. Iwasa, 2002. Saturation of enzyme kinetics in circadian clock models. Journal of Biological Rhythms, 17: 568-577.
Kurosawa, G., A. Mochizuki, and Y. Iwasa, 2002. Processes promoting oscillations -- comparative study of circadian clock models. Journal of Theoretical Biology, 216: 193-208.
|[Reviews, Books, and Proceedings]|
Kurosawa G., K. Tsumoto, K. Aihara, 2006. Entrainment of Circadian Oscillations under 24h Light-Dark Cycles. International Symposium on Nonlinear Theory and its Applications (NOLTA 2006). pp.759-62.
Kurosawa G., K. Aihara, Y. Iwasa, 2006. Bifurcation analyses in cyanobacterial circadian clock model. IEEE/National Library of Medicine, Life Science System and Applications Workshop. pp.44-5.
Kurosawa G., 2005. Gene-protein dynamics generates circaidian clocks. Tanpakushitsu Kakusan Koso. 50(15) : 1934-1939. pubmed
Kurosawa, G., A. Mochizuki and Y. Iwasa, 2000. Theoretical study for circadian rhythm in Drosophila: Condition for generating a limit cycle. Proceeding of the first international
conference on systems biology (ICSB 2000). pp.179-184. JST.
Aihara Complexity Modelling Project,
ERATO, Japan Science and Technology Agency,
Komaba Open Laboratory, The University of Tokyo,
4-6-1 Komaba, Meguro-ku,
Tokyo 153-8505, JAPAN
The Biophysical Society of Japan
Japanese Association for Mathematical Biology
Japanese Society for Chronobiology
The Molecular Biology Society of Japan
The Society for Mathematical Biology
The Society for Research on Biological Rhythms
[back to Laboratory of Mathematical Biology]
Last updated December, 2006