File:Embryogenesis-of-the-First-Circulating-Endothelial-Cells-pone.0060841.s005.ogv

English: A recording of an embryo electroporated with a plasmid encoding a H2B-GFP construct and the corresponding DIC data. The H2B-GFP plasmid was electroporated such that only intra-embryonic mesoderm expresses the GFP. The wide-field optics confirm that plasmid-derived nuclear fluorescence is restricted to intra-embryonic, and only intra-embryonic mesoderm; i.e., compare the fluorescently labelled areas with the corresponding areas in the brightfield (BF) image. Nuclear-directed green fluorescence is detectable from HH Stage 5 until the end of the recording at 22.6 h. Cells derived from the primitive epiblast (HH4-) are observed to gastrulate and form the splanchnic mesoderm of the head and trunk (also see Fig. 4 and Fig. S1 for details). Some of the H2B-GFP labelled mesodermal cells are specified to the endothelial lineage and engage in vasculogenesis. A few labelled endothelial cells eventually enter circulation (circle at 21.41-21.51 h). These data confirm that cells derived from electroporated intra-embryonic mesoderm give rise to circulating cells – thus confirming the cell's positional fate. The data do not, however, establish an endothelial lineage fate for the circulating cell (i.e., the fluorescent marker is not endothelial lineage specific). The compression algorithms used in creating this movie result in a loss of resolution compared to the native image files (see Methods). Mag bar  = 200 µm.