Cardiovascular system (CVS) is firstly developed during embryogenesis to deliver oxygen/nutrition to tissues/organs and to remove the wastes from them. To understand the mechanism underlying organogenesis in vivo, cell responses including proliferation, differentiation, and migration as well as signal transduction should be simultaneously visualized during development.

We have used transparent zebrafish embryo to understand cardiogenesis and angiogenesis that are required for cardiovascular development. Both activity of signal transduction and responces of CVS-constituting cells are imaged during embryogenesis. Using this technique, we have demonstrated the mechanisms that control the formation of vascular niche for early hematopoiesis, coronary vessel formation, and left-right asymmetry.

In this talk, I will introduce our bio-imaging data by showing video images that might convince you of the advantage of imaging biology to scrutinize the fundamental process of development. In addition, I will briefly introduce new see-through fish that are 100% transparent even in the adult stage that might accelerate the understanding the physiology and pathophysiology of living animals.