File:Embryogenesis-of-the-First-Circulating-Endothelial-Cells-pone.0060841.s007.ogv

English: A recording of an epiblastic stage embryo (HH4-) electroporated with a DNA plasmid encoding a mitochrondrial-directed yellow fluorescent protein (Mito-YFP). The Mito-YFP plasmid was electroporated such that only intra-embryonic mesoderm of the embryo proper was fluorescently tagged (see Movie S4, Fig. 4 and Fig. S1). The ROI delineated by the white box shows a number of Mito-YFP cells engaged in vasculogenesis (Fig. 6). The live specimen was also microinjected with QH1 antibody to confirm the endothelial identity of selected cells shown in the ROI (see the arrows in Fig. 6). Note that most of the cells in the ROI (white box) are abruptly lost from view as time progresses, suggesting the cells engaged in rapid displacement behavior and entered circulation. Figure 6 shows 16 key individual frames extracted from this Movie. Thus, this, and similar recordings include simultaneous positional fate (YFP) and lineage fate (QH1) data. This embryo, the specimens shown in Movies S3, S4, and other time-lapse recordings not shown demonstrate that plasmid tagged intra-embryonic tissue gives rise to circulating cells (n = 11). Further, in all cases examined such electroporated cells are reactive with the endothelial specific QH1 antibody. The recording rate is 7.5fph or 8 min between frames. The compression algorithms used in creating this movie result in a loss of resolution compared to the native image files (see Methods). Mag bar  = 100 µm.