Title: General principles for timing and oscillations in stochastic reaction systems

Speaker: Prof. Johan Paulsson, Department of Systems Biology, Harvard University

Time: 8:40-9:30, September 29, 2019

Location: Deng Youcai Hall, Jinguang Life Science Building

Abstract:

Precise timing can be advantageous in many biological processes but is difficult to achieve because chemical reactions often produce exponentially distributed waiting times for individual events. I will discuss hard bounds on timing and the phase-drift of oscillators in reaction networks with finite numbers of molecules, based on analytical theory for classes of stochastic processes. Based on this theory, I then show how we designed and built a series of ultra-precise synthetic gene oscillators, some of which can oscillate for 500 cell generations without entrainment before drifting out of phase with even half a period. Finally, I will show how some natural systems use the same simple but counterintuitive principles to achieve timing in cell fate decisions, and how these are easily missed in deterministic modeling frameworks.