How cell-cell interactions lead to emergent behaviours, such as pattern formation at the tissue scale, collective synchronisation, tissue deformations, and regeneration of a lost body part, is poorly understood. The research work presented in this thesis, combining theory and collaboration with experimentalists, focuses on elucidating how local interactions between individual cells produce robust large-scale organisation. We address this question in three different biological processes: vein refinement in Drosophila pupal wings (collaboration with Jean-Paul Vincent’s group), development of the Drosophila abdominal epidermis (collaboration with Nicolas Tapon’s group), and regeneration of zebrafish scales (collaboration with Alessandro De Simone’s group).

In the context of vein refinement in Drosophila wing, we demonstrate that a minimal model based on known short-range signals, such as Dpp, EGFR, and Delta/Notch, is sufficient to reproduce stereotypically thin and straight veins irrespective of global tissue deformations.

In the context of the development of the Drosophila abdominal epidermis, cell cycle synchronisation may be important for growth control and the development of a functional tissue. We show that synchronous cell divisions and the sharp transition to growth termination originate from local cell-cell communication, mediated by gap-junctions.

In the context of the regeneration of zebrafish scales, the spatiotemporal regulation of cell proliferation is crucial for successful regeneration. We suggest that the observed moving front of proliferation arrest and Erk inactivation may arise from the interplay between local bone deposition and a positive feedback between excitable Erk activity and cell proliferation.

Overall, our findings highlight the role of local cellular dynamics in generating reproducible large-scale patterns in various biological contexts.