English: Movie 2 : qmc551: GFP+haemogenic endothelial cells undergo basal epithelial to mesenchymal transition. This movie is related to Figure 1. It shows image series and still frames of confocal timelapse microscopy experiments performed on qmc551: eGFP;flk1/kdrl: tdTom-double transgenic embryos. The embryo was immobilized in 1% low melting point agarose. The embryo faces to the left with dorsal up. The timelapse experiment started at 31 hpf. In (A) only GFP expression is shown, highlighting that qmc551: GFP marks HECs before, during and after epithelial to mesenchymal transition. In (B), both GFP and tdTom fluorescence are shown. tdTom expression confirms that spindle-shaped GFP+ cells undergoing EMT are vDA ECs. tdTom also highlights the outline of the vein. Please note that green horizontal lines in the DA and the PCV are caused by GFP+ prRBCs in circulation. The still frame shows the final image of the timelapse series shown in (B). It highlights the HEC-derived mesenchymal cell (yellow arrow) and the endothelium (white arrow) that has closed up above it. All images show single 2.1 µm optical sections. Images were processed in Imaris and annotated in iMovie.