Fig. 8. Effect of misexpression of Wnt5a (A,C,E,G,I) or Wnt11 (B,D,F,H,J) in vivo. Chick embryonic fibroblasts (CEFs) infected with retroviruses expressing either Wnt5a or Wnt11 were grafted into the stage 18/19 wing bud. Limbs were fixed after a further 7 days (i.e. at embryonic day 10) and processed for in situ hybridisation. Comparison of light field (A,B) and dark field (C-J) micrographs showing the endogenous and misexpressed Wnt5a (C) or Wnt11 (D). The effects on chondrogenic differentiation were assessed by analysis of Wnt5b (E,F), Ihh (G,H), and type X collagen (I,J), which are expressed at different stages of chondrocyte differentiation. The insets in A and B show high power views of the chondrocytes from the diaphyseal region in the infected elements. In the Wnt5a-infected elements, the majority of cells are rounded with few prehypertrophic chondrocytes in contrast to the control where the chondrocytes are hypertrophic. In the Wnt11-infected element, the chondrocytes are undergoing hypertrophic differentiation. Bars, 500 µm (A,B); 200 µm (insets).