Mapping cell migrations and fates from a gastruloid model to the human primitive streak

Abstract

Although fate maps of early gastrula embryos exist for nearly all model organisms, a fate map of the gastrulating human embryo remains elusive. Here we use human gastruloids to piece together part of a rudimentary fate map of the human primitive streak (PS). This is possible because stimulation with differing levels of BMP, WNT, and NODAL leads to self-organization of gastruloids into large and homogenous different subpopulations of endoderm and mesoderm, and comparative parallel analysis of these gastruloids, together with the fate map of the mouse embryo, allows the organization of these subpopulations along an anterior-posterior axis. We also developed a novel cell tracking technique that allowed the detection of robust fate-dependent cell migrations in our gastruloids comparable to those found in the mouse embryo. Taken together, our gastruloid derived fate map and recording of cell migrations provides a first coarse view of the embryonic human PS.