Whole mount in situ hybridization of E10.5 mouse embryos was performed with riboprobes corresponding to the indicated genes (left). The right limb buds are shown with the anterior at the top and posterior at the bottom. Compared to that in wt limb buds (A1–G1), the expression of the Gli1, Ptch1, Fgf4, Grem, Hand2, Hoxd11, and Hoxd13 genes is reduced in Gli3+/Δ701 limb buds (A2–G2) or not detected in both Gli3Δ701/Δ701 (A3–G3) and Shh mutants (A4–G4). However, Shh remains expressed in both Gli3+/Δ701 and Gli3Δ701/Δ701 limbs (H2, H3). The reduced Hoxd11 and Hoxd13 expression is detected in Gli3Δ699/Δ699 limbs (F5, G5). Arrowheads indicate the edge of Fgf4 expression.