From: Laboratory of Artificial & Natural Evolution (LANE), Dept. of Genetics & Evolution, University of Geneva, Geneva, Switzerland & SIB Swiss Institute of Bioinformatics, Geneva, Switzerland

Will give a seminar entitled:

The unreasonable effectiveness of computational models in biological patterning and morphogenesis

I will discuss how vertebrate skin colours and skin appendages (scales, feathers, hairs, …) are spatially patterned through Turing and mechanical instabilities. First, I will show that Reaction-diffusion (RD) models are particularly effective for understanding skin colour patterning at the macroscopic scale, without the need to parametrise the profusion of variables at the microscopic scales. I suggest that the efficiency of RD is due to its intrinsic ability to exploit continuous colour states and the relations among growth, skin-scale geometries, and the (Turing) pattern intrinsic length scale. Second, I will show how drug treatments can permanently trigger transitions between scale appendage types or even between chemical and mechanical self-organisation. Third, I will show that a three-dimensional mechanical model, integrating growth and material properties of embryonic skin layers, captures most of the dynamics and steady-state pattern of head scales in crocodiles and tortoises. Fourth, I will show that the spectacular morphogenesis of the strongly overlapping snake scales can be recapitulated with a mechanical model integrating tissue plasticity and active material properties. These studies indicate that Biology, despite its ‘messy’ nature (with its unmanageable profusion of cellular & molecular variables) can be efficiently and quantitatively investigated mathematically, including with simple phenomenological models.

Speaker website