MERCREDI 17 JUIN 2009
15 heures 15 (Attention: horaire inhabituel!)
Séminaire d'Intérêt Général
Salle Séminaire 5
Centre de Physique Théorique
Marseille-Luminy

Lev Tsimring
Institute for Nonlinear Science, UCSD, San Diego, Californie

Title: Oscillatory dynamics of small gene circuits

Abstract: One of the defining characteristics of life is the ability to
keep time, which organisms often achieve by using internal genetic
"clocks" to govern fundamental cellular behavior. While the gene
networks that produce oscillatory expression signals are typically quite
elaborate, certain recurring network motifs are often found at the core
of these biological clocks. In this talk, I will describe our recent
experimental and theoretical work on small genetic networks exhibiting
oscillatory behavior. One common motif which may lead to oscillations
is delayed auto-repression. We constructed synthetic oscillators based
on this design principle, and observed robust and tunable oscillations
both in bacteria and yeast. Since genetic systems typically involve
small number of reacting components, intrinsic fluctuations play an
important role in the dynamics. I will introduce theoretical and
computational tools which can be used for modeling dynamics of small
genetic networks.