Fig. 5

Fig. 5

Increased Fgf signaling causes a posterior expansion of cardiac progenitor markers. Heat-shocked control sibling embryos and Tg(hsp70:ca-fgfr1)^pd3 embryos with increased Fgf signaling at the TB stages probed for nkx2.5 and ntla (A,C) and gata4 and ntla (B,D) at 8s. (A,B) There is minimal overlap between the posterior limit of nkx2.5 and gata4 and the anterior limit of ntla expression. (C,D) Increased Fgf signaling extends the posterior limit of nkx2.5 and gata4 expression and the overlap with the anterior limit of ntla expression. Bars in A–D indicate the amount of overlap between the posterior limits of nkx2.5 and gata4 and anterior limit of ntla. All images are dorsal views with anterior left. (E) Measurements of the length of overlap in heat-shocked control sibling and Tg(hsp70:ca-fgfr1)^pd3 embryos in arbitrary units. Asterisks indicate statistically significant difference using Student′s t-test.