Novel Approaches to Study and Visualize Human Embryonic Development

Introduction

Developmental biologists have extensively studied the developmental stages of the embryo via mouse models and scarce human embryo data. While there is a detailed understanding of the pre-implementation stages, much less is understood between the peri-implantation to gastrulation stages due in large part because the implantation of the embryo makes it extremely challenging to visualize and study^{(reviewed in 1)}. Gaining a better understanding of how embryos develop could help researchers understand why nearly 60% of pregnancies fail between fertilization and implantation stages; furthermore, a greater understanding of the development during this period could also provide insight for treating early-stage developmental-related diseases and provide embryo-like models for testing the safety of drugs during pregnancy. There are several technical and ethical barriers that have impeded scientific progress toward understanding this “black box” in embryonic development; for example, novel approaches to growing embryos outside of the uterus have been a limiting factor.  Recent advances in the tools, processes, and models have drastically enhanced scientists’ ability to elucidate a more complete picture of human embryonic development, and below we discuss some of the fundamental discoveries.