Abstract
The development of the vascular system is essential for embryonic development, including processes such as angiogenesis. Angiogenesis plays a critical role in many normal physiological and pathological processes. It is driven by a set of angiogenic proteins, including angiogenic growth factors, chemokines, and extracellular matrix proteins. Among various animal model systems, the chorioallantoic membrane (CAM), a specialized and highly vascularized tissue of the avian embryo, has proven to be a valuable tool for analyzing the angiogenic potential of candidate cells or factors. In this protocol, we provide detailed procedures for establishing the CAM model to evaluate the function and mechanism of migrasomes in embryonic angiogenesis. This includes the CAM nylon mesh assay and CAM ex vivo sprouting assay to assess CAM angiogenesis, as well as the observation, purification, and delivery of migrasomes. Additionally, we describe the generation of T4-KO-mCherry-KI embryos using the CRISPR system within the CAM tissue to investigate the role of migrasomes in angiogenesis.