(A-J) Immunofluorescence with MF20 (green, denoted by arrow). Genotypes are shown. (K) Myocardial thickness at E10.5. (L,M) Bar graph for QRTPCR assay. (N-S) Immunofluorescence with Isl1 antibody (green, arrows) at E9.75. (T-W) Whole mount in situ hybridization at E9.5. ba, branchial arch; e, eye. Nuclei stained with TO-PRO-3 iodide (TP3) (red) in all Immunofluorescence. *, (P < 0.05; error bars represent SEM).