Vascular cell biology in vivo: a new piscine paradigm?

Understanding how blood vessels form has become increasingly important in recent years yet remains difficult to study. The architecture and context of blood vessels are difficult to reproduce in vitro, and most developing blood vessels in vivo are relatively inaccessible to observation and experimental manipulation. Zebrafish, however, provide several advantages. They have small, accessible, transparent embryos and larvae, facilitating high-resolution imaging in vivo. In addition, genetic and experimental tools and methods are available for functional manipulation of the entire organism, vascular tissues or even single vascular- or non-vascular cells. Together, these features make the fish amenable to 'in vivo vascular cell biology'.