Fig. 3

Fig. 3 laf mutants exhibit lateral plate mesoderm deficiencies. (A) Schematic representation of gene expression patterns in the ALPM in an embryo at the 10-somite stage (Schoenebeck et al., 2007); dorsal view, anterior to the top. gata5 is expressed throughout the two bilateral strips of ALPM. hand2 overlaps with gata5 in the posterior regions of the ALPM, which correspond to the heart fields. nkx2.5 overlaps with hand2 in the medial portions of the heart fields. (B–G) In situ hybridization depicts expression of nkx2.5, hand2 and gata5 at the 10-somite stage; dorsal views, anterior to the top. Scale bar represents 50 μm. (B–D) are wild-type embryos and (E–G) are laf mutant siblings. (B, E) nkx2.5 expression is indistinguishable in wild-type and laf mutant embryos (n = 15/15). (C, D, F, G) laf mutants display narrowed domains of hand2 (n = 18/20) and gata5 (n = 17/20) expression, revealing a defect in the width of the cardiac ALPM. hand2 and gata5 expression levels vary from normal to reduced in laf mutants, which also exhibit reduced expression of other cardiac progenitor markers, including gata4, nkx2.7, and tbx5 (SRM and DY, unpublished data).