Figure 1.
ES cell differentiation into endothelial cells. ES cells gave rise to colonies on the OP9 feeder cell layer in the absence of LIF. Expression of Flk1 and PECAM-1 was detected in R1 ES cells by immunostaining or in Flk1+/lacZ ES cells by X-gal staining. The expression pattern of PECAM-1 and Flk1 were similar at day 5. Scale bar, 100 μm.