Fig. 2.

Expression pattern of genes involved in mesoderm and cardiac development during in vitro EB differentiation. Suppressive effects of Cdx induction on cardiac genes. (A) Markers of early cardiac development such as Mesp1, Isl1, Gata4 and Nkx2.5 are upregulated during EB differentiation shortly after establishment of the mesodermal marker Brachyury. Mesp1 shows a sharp peak of expression and extinguishes rapidly upon activation of other cardiac genes such as Nkx2.5. iCdx1 ES cells were differentiated in basic differentiation medium in the absence of doxycycline and samples collected at several time-points. Gene expression analysis was performed by real-time PCR analysis and results are shown as fold gene expression relative to expression levels in undifferentiated ES cells. Shown are data from one representative experiment for each marker. (B, C) Continuous suppression of Isl1, Gata4 and Nkx2.5 following early induction of Cdx1 by addition of doxycycline between day 2.25 to 6 (B, C) or as a brief pulse between day 2.25 to 4 only (C). A,B: Shown are data from one representative experiment; C: shown are summarized data from at least two independent experiments for each analyzed condition.