Figure 3.

Functions of Hippo pathway in embryogenesis and development. This diagram shows the YAP/TAZ subcellular distributions and their functions at different embryonic stages. In zygotes, YAP/TAZ is critical in preventing the premature expression of SOX2 and abnormal ICM differentiation. In morula and blastocyst, cells are specialized depending on Hippo pathway activity in response to their position and polarity. The exterior cells with high YAP/TAZ activity develop into trophoblasts while the inner cells with low YAP/TAZ activity develop into ICM. YAP/TAZ is required for organogenesis in all three germ layers. The color of cell outlines and text boxes represent certain germ layers (gray, blue, green, and red for trophectoderm, ectoderm, mesoderm, and endoderm, respectively). The text in colored background denotes phenotypes of altered Hippo signaling at each indicated embryonic “E” stage.