During development of the cardiovascular system, blood flow and the forces induced by this flow are known to impact the morphogenesis of vessels. It is therefore likely that flow abnormalities during development, and resultant defects in vascular growth and remodelling, might result in clinically relevant cardiovascular phenotypes. However, in order to understand how abnormal flow might contribute to aberrations in morphology, we first need an in-depth picture of the normal patterns and the degree to which they might vary between individuals. Stephanie Lindsey, Jonathan Butcher and Irene Vignon-Clementel tackle this problem, focusing on the pharyngeal arch arteries of the chick embryo, by developing an experimental pipeline to integrate high-resolution maps of vessel morphology with haemodynamic parameters. Taking measurements from multiple embryos at multiple developmental stages, they are able to characterise both the changes across time and the inter-individual variability with high spatial resolution. The correlations between flow patterns and morphogenetic changes also allow the authors to assess the likely contribution of different types of flow-dependent force (shear wall stress and transmural pressure) to growth and remodelling. These quantitative data provide a framework for establishing relationships between vascular morphogenesis and flow, as well as a valuable dataset against which analyses of defects in development can be benchmarked.
