Extended Data Figure 3. Absence of obvious morphological abnormalities in limb enhancer knockouts.

Side-by-side comparison of enhancer KO limb skeletons with wild-type littermate controls at E18.5. Neither forelimbs (this figure) nor hindlimbs (data not shown) of the enhancer KO lines revealed any obvious morphological differences in comparison to wild-type littermates. Cartilage is stained blue and bone dark red. The number of embryos with normal limb phenotypes over the total number of homozygous-null embryos examined is shown in the bottom left. “n”, number of independent biological replicates with similar results. Scale bar, 1 mm.