| Abstract: |
| Bistable switches are a common in many areas of physics and biology. In developing biological tissues, they are often controlled by gradients of secreted signalling molecules - morphogens -, providing a mechanism to convert a signalling gradient into stripes of gene expression that determine the arrangement of distinct cell types. In this talk I will present our work focusing on the role of intrinsic fluctuations in bistable switches that result from the stochastic nature of gene expression. To tackle this problem we make use of different techniques, using Gillespie simulations, Langevin equations and Minimum Action Path theory. The results reveal that noise induces a switching wave that propels the stripe boundary away from the morphogen source, eventually settling at a steady state different from the deterministic description. Additionally, the same formalism can be extended to understand transitions from oscillatory to steady state behaviour tackling situations such as neuronal activation spike trains. |
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