Fig. 7

pdgfaa is expressed in the anterior endoderm, medially adjacent to the ALPM.

(A–G) Fluorescent in situ hybridization and immunofluorescence compare the expression of pdgfaa (magenta) and Tg(sox17:egfp) (green) in wt embryos at 13 s. (A–C) Dorsal views, anterior to the top, of a three-dimensional reconstruction show that pdgfaa is expressed in bilateral domains of the anterior endoderm, near the lateral edges of the endodermal sheet. Expression of pdgfaa is also evident in cranial rhombomeres. (D–F) A coronal (XY) slice of the same embryo demonstrates the overlap between pdgfaa and Tg(sox17:egfp) expression. (G) A sagittal (ZY) slice of the same embryo provides a lateral view. (H–J) Transverse cryosections compare the expression of pdgfaa (blue) and the expression of Tg(sox17:egfp) (green) in wt embryos at 13 s, showing that pdgfaa is expressed in lateral domains of the endodermal sheet. (K–P) Comparison of hand2 (green) and pdgfaa (red) expression patterns demonstrates that pdgfaa is expressed medially adjacent to the domains of hand2 expression in the ALPM. (K–M) Three-dimensional confocal reconstructions of dorsal views, anterior to the top. (N–P) Single transverse (XZ) slices from (K–M), respectively. (Q–S) Dorsal views, anterior to the top, display the expression of myl7 at 22 s in nontransgenic (Q) or Tg(hsp70l:pdgfaa-2A-mCherry) (R,S) embryos, following heat shock at the tailbud stage. Ectopic expression of pdgfaa causes cardiac fusion defects. See Figure 2—figure supplement 2 and Figure 5—figure supplement 2 for additional information regarding this phenotype. Scale bars: 60 μm.