Author (s): Arroyo, M.; Trepat, X.
Pages: 442 – 443
From a broken bone to a major earthquake, the fracture of a material usually means trouble. However, in some practical applications engineers have learned how to harness the mechanisms of fracture. This is illustrated by the well-known process of hydraulic fracturing, or “fracking,” in which injection of pressurized fluid in shale rocks opens cracks to extract oil or gas (1). On page 465 of this issue, Dumortier et al. (2) show that the developing mouse embryo uses this same principle to transiently disrupt its shape and sculpt a more complex one. Fracking is the key mechanism that enables the early embryo to develop its first symmetry axis, a key stage in fetal morphogenesis.