Figure 3.

Anterior-posterior polarity is partially maintained at the limb bud stage in the hmm^−/− embryo. In situ hybridization of Hand2 (A–D), Gli3 (E–H), Alx4 (I–L′), Lhx9 (M–P′), Hoxd13 (Q–T′,Y–b) and Hoxa13 (U–X,c–f). All images are oriented with the anterior side up and the posterior side down. (O,P,P′) Red arrowheads indicate the expanded expression domain of Lhx9 on the posterior side. (S′,T′) Yellow arrowheads indicate the region where Hoxd13 is not expressed in the autopod. (Y,Z) Yellow arrowheads indicate the region where Hoxd13 is not expressed on the anterior side of the digit 1 primordium. FLB, forelimb bud; HLB, hindlimb bud.