Fig. 5.

Whole mount in situ hybridization analysis of tbx5a expression in wildtype, cdx4 and cdx1a/4-deficient embryos shows expansion of cardiogenic anterior-lateral plate mesoderm. The intermediate mesoderm field, marked by pax2a expression, shows a posterior shift and reduction in cell number, as reported previously. The effect was more pronounced in cdx1/4 double deficient embryos than in cdx4−/− embryos. Shown are zebrafish embryos at 15-somite stage. Purple staining was used for tbx5 and pax2a and red staining for krox20 and myoD as landmarks of other tissues.