Developmental biology studies the multi-scale process by which a single fertilized cell becomes a complex organism. Recent developments in imaging technologies have triggered new quantitative approaches at the single cell resolution.

The complete digital reconstruction of a small cohort of developing sea urchin embryos enabled us to characterize and quantify intra- and inter-individual variability in cellular dynamics. A multi-level data-driven probabilistic model was derived from the phenomenological reconstruction. It serves as a basis for the construction of a prototypical embryo. This prototype is defined with Bregman centroids that aggregate individual cell features distributions.

Images of epithelium provide access to one of the simplest cellular structures. The combinatorial structure of the network of cellular contacts is the result of a historical process involving cell displacements, cell proliferation and cell extrusion. To characterize patterns at various scales in a tissue we developed a methodology based on persistent homology leading to a multi-scale topological signature of various networks.