Fig. 3. (A,B) Adjacent sections from a stage 19 segmental plate recipient embryo stained with QCPN (A), to reveal the locations of all quail cells, and QH1 (B), to identify quail endothelial cells. These show that most of the cells that migrated from transplanted trunk mesoderm are angioblasts. (C) A QH1-stained section from a stage 28 lateral somite recipient, showing the substantial contributions of trunk-derived angioblasts to endothelial cells within and surrounding the brain.