To better understand how an entire embryo develops from a single cell, Dr. Philipp Keller and colleagues developed a technique to image and quantitatively reconstruct mouse embryogenesis from gastrulation through early organogenesis at the single-cell level. Keller’s lab developed an adaptive light-sheet microscope to follow the mouse embryo for 48 hours while it’s developing its germ layers (mesoderm, endoderm, and ectoderm), early tissues, and organs. By combining long-term high-resolution imaging, computational, and statistical analyses, they generated a dynamic fate map of the embryo. These open-access resources aid in the understanding of the dynamic cell behaviors that allow for proper growth and development of the embryo.