Status of the Wnt pathway and effect of exogenous addition of sFRP-1 during mESC adipogenesis. (a) Stationary view of the KEGG canonical Wnt signaling pathway at day 6 of mESC differentiation in cells treated with CD2314 compared to untreated cells. Genes in the pathway are represented as colored rectangles, each stripe within a rectangle representing one gene member of the same family. Fold changes in RNA levels in the CD2314 condition compared to untreated control determine the colors on a red-to-green scale, with red meaning induction, green meaning repression, and grey meaning no significant variation. (b) Wnt pathway activity in differentiating mESCs stably transfected with the TOP-FLASH reporter construct. EBs were left untreated (control, solid line) or incubated with 100 ng/ml of recombinant sFRP-1 (secreted frizzled-related protein-1; dashed line) from days 3 to 6. (c-f) Effect of exogenous addition of sFRP-1 on adipocyte development. EBs were incubated with CD2314 and sFRP-1, alone or in combination, from days 3 to 6, and adipocyte development was assessed as in Figure 1.