LAUSR

Synthetic embryology offers a fresh vantage point for studying the role played by boundaries during development. Here we review recent progress from this emerging field that reveals the diverse roles played by embryonic boundaries during development, and summarize the current state-of-the-art tools for creating and shaping boundaries in vitro. A central point we hope to illuminate is that outcome of selforganization in vitro is strongly influenced by the boundary imposed, and new insight into the complex functions of embryonic boundaries has direct and immediate relevance to creating better self-organizing tissues for basic science, drug development, and regenerative medicine. Finally, we consider challenges to recreating boundaries in vitro and imagine what sort of boundaries we will need in the future if we are to create fully synthetic embryos and organs.