Break It To Make It: How Fracturing Sculpts Tissues and Organs

Jean-Léon Maître There’s a moment, just before the tight mass of cells that is a developing mouse embryo implants itself in the womb, that it all comes apart. Hundreds of tiny fluid-filled bubbles expand between each of the orb’s few dozen cells. The bubbles grow and press outward on cell membranes — and then, in a moment of fracture, pry them apart. Thin protein strands tether the cells together as the dissociated embryo floats. Over the course of a few hours, the smaller bubbles empty into...