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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).
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