Cells in a tissue mutually coordinate their behaviors to maintain tissue homeostasis and control morphogenetic dynamics. As well as chemical signals, mechanical entities such as force and strain can be possible mediators of the signalling cues for this mutual coordination, but how such mechanical cues can propagate has not been fully understood. Here, we propose a mechanism of long-range force propagation through the extracellular matrix. We experimentally found a novel concentric wave of deformation in the elastic substrate underlying an epithelial monolayer around an extruding cell, under weakly-adhesive conditions which we define in our work. The deformation wave propagates over two cell sizes in ten minutes. The force transmission is revealed by the emergence of a pronounced peak in the deformation field of substrate. We derive a theoretical model based on linear elasticity theory, to analyse the substrate dynamics and to quantitatively validate this model. Through model analysis, we show that this propagation appears as a consequence of the stress exerted by the tissue on a soft substrate sliding on a stiff one. These results infer that the tissue can interact with embedding substrate with weakly adhesive structures to precisely transmit long-range forces for the regulation of a variety of cellular behaviors.
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