­­Highly Conducive Ex utero Mouse Embryogenesis from Pre-Gastrulation to Late Organogenesis

Abstract In mammals, morphogenesis and organogenesis take place after the embryo implants into the uterus, which makes it relatively inaccessible for observation and manipulation. While methods for in vitro culture of pre- and peri-implantation mouse embryos are routinely used, approaches for efficient and stable culture of post-implantation embryos from egg cylinder stages until advanced organogenesis remain to be established. We recently developed highly robust ex utero post-implantation mouse embryo culture platforms, that enable appropriate and faithful development of embryos before gastrulation (E5.5) until the hind limb formation stage (E11). In these protocols, late gastrulating embryos (E7.5) are grown in 3D rotating bottles settings, while extended culture from pre-gastrulation stages (E5.5 or E6.5) requires a combination of static and rotating bottle culture protocols. These systems support stable growth of normal mouse embryos ex utero from pre-gastrulation to advanced organogenesis.