Fig. 5. Loss of most LR asymmetric expression domains of Pitx2 in Pitx2^ASE/ASE embryos. Expression of Pitx2 was examined in wild-type (A,D,G,J,M,P), Pitx2^ASE/ASE (B,E,H,K,N,Q) or cryptic^-/- (C,F,I,L,O,R) embryos at E8.2 (A-C), E9.0 (D-F) or E9.5 (G-R) by whole-mount in-situ hybridization. The whole-mount embryos shown in G-I were sectioned transversely at the indicated planes and the sections are shown in J-R. Expression of Pitx2 in left LPM at E8.2 was lost in Pitx2^ASE/ASE and cryptic^-/- embryos. Asymmetric Pitx2 expression was lost in Pitx2^ASE/ASE embryos at E9.0, with the exception of a reduced level of expression remaining in the common cardinal vein and vitelline vein (green arrow in E). Asymmetric Pitx2 expression was completely absent from cryptic^-/- embryos at E9.0. Asymmetric Pitx2 expression remained apparent at a reduced level in the common cardinal vein and vitelline vein of Pitx2^ASE/ASE embryos at E9.5 (green arrows in H, N and Q) but was absent from cryptic^-/- embryos at this time. Scale bars: 200 µm. cac, common atrial chamber; ccv, common cardinal vein; dm, gut dorsal mesentery; lb, lung bud; st, septum transversum; vv, vitelline vein.