Living matter is organized across scales, and is so dynamically, unlike human artefacts.
Understanding how biological forms emerge from molecular and cellular constituents is
answering one of life’s deepest secrets. How are biological forms encoded ? The stupendous diversity of shapes at the cellular, tissue and organismal scales begs the question of whether general principles underlie their emergence. What is the nature of the information driving cell and
tissue morphogenesis.

It is well appreciated that genes encode shape though how they do so remains largely not
understood. We argue that, beyond genetics, morphogenetic information comprises three
modules: genetics/biochemical activity, but also mechanics and geometry which conspire to encode space and time. Mechanics characterize forces and material properties. Geometry defines boundary conditions, namely the size and structure of the space in which mechanochemistry operates. We contrast two general modalities of information flow: information executing a deterministic program and information resulting from self-organised, stochastic interactions.

We decipher the “language of morphogenesis” using the fruitfly Drosophila as a model organism. We study cells, tissues, embryos and organs as they change shape and grow. To this end we experimentally characterize their organization and dynamics using live fluorescent microscopy; we quantitatively assess imaging data; we test mechanistic hypothesis using genetic, optogenetic, chemical and mechanical perturbations; we use mathematical models to make testable, quantitative predictions. Our lab is interdisciplinary and rests on the conviction that physics offers the necessary foundation for a quantitative understanding of biological processes.

Thomas Lecuit is Professor at the Collège de France, chair Dynamics of living systems, and prepares a series of lectures on a new topic every year. The videos and pdf of these lectures are all available online.