Fig. 4.

Fig. 4.

Genetic interactions between gata4 and gata5 impact progenitor migration and heart tube formation. ISH was performed using offspring from a gata4^+/−, gata5^+/− in-cross and probes targeting either myocardial marker myl7 or cardiac progenitor marker nkx2.5. (A) Progressive loss of gata4 and gata5 alleles results in a range of heart tube defects due to abnormal heart tube morphogenesis. Loss of a gata5 allele in gata4 mutants generates a thin heart tube, while loss of gata4 alleles partially rescues the gata5^−/− bifid phenotype. Representative scale bars in WT panels: 0.1 mm. (B) Quantification of nkx2.5 staining shown in A shows that loss of gata4 does not significantly affect cardiac specification. Error bars shown are s.e.m. *P<0.05, **P<0.01. (C) Schematic showing combinatorial loss of gata4 and gata5 disrupts proper fusion of the heart tube.