Gastruloids Gain Muscle: Somite Formation in Embryo-Like Structures

Gastruloids are embryo-like structures that display key features of post-implantation embryonic development, yet whether they fully recapitulate in vivo embryogenesis remains unsolved. Recently in Nature, van den Brink et al. (2020) performed high-resolution gene expression analysis to identify significant similarities between mouse gastruloids and embryos in positional lineage segregation and somite formation.