Differentiation dynamics of ES cells by BMP4+RA.

<p>(<b>A</b>) Schematic of the differentiation protocol. (<b>B</b>) Cells were recorded by time-lapse microscopy and cultured as indicated. Phase contrast images of the same field are shown. Arrowhead shows colony of ES cells that differentiated into cells of mesenchymal appearance. (<b>C</b>) Phase-contrast images of ES cell-derived mesodermal progenitors cultured for 7 days in NSC medium (left panel, scale bar 100 µm) or at the 3^rd passage in NSC medium (right panel, scale bar 50 µm).