Fig. 7. Expression of Mlc2v and Tbx5 in embryos with compound mutations in Hand1 and Hand2. Expression of (A) Mlc2v and (B) Tbx5 was examined by in situ hybridization to transverse or sagittal sections of E9.0 embryos of the indicated genotypes. Silver grains are pseudocolored in red. a, atrium; lv, left ventricle; v, ventricular chamber.