Increased BL-CFC number and altered expression of hemangioblast-related genes within day 3.5 Smad5^−/− EBs.

(A) Day 3.5 EBs were dissociated and then plated in BL-CFC assay culture containing VEGF and KL. After 5 days of growth, 3 types of colonies, secondary EBs, transitional colonies, and blast colonies were observed. These colonies could be readily detected and distinguished according to established morphology criteria. Original magnification for panel A, × 100. (B) The number of blast colonies shown represents the means ± SEMs from 3 independent experiments. *represents data found to be significantly different from the wild-type control values (P < .05). (C) Expression of Smad5 and hemangioblast-related genes were defined by RT-PCR analysis of day 3.5 EBs. The arrows on the top of the photo in panel C represent the 10-fold dilution of samples.