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Figure 4. Sfrp5 interacts with Wnt5 and Wnt11. (A) In situ hybridization with the indicated probes to bisected neurula embryos showed that wnt11 and fz7 are expressed in the foregut endoderm (red arrow) underlying the sfrp5 expressing cells. (lpm) Lateral plate mesoderm. (B) Coinjection of wnt5b or wnt11 plasmids into the endoderm rescued the enlarged foregut (white arrow) caused by sfrp5 RNA overexpression, while wnt8 did not. Enlarged hindgut (yellow arrow). (C) Summary of the rescue experiments. Embryos were injected with or without sfrp5 RNA and the indicated wnt plasmid. The histogram shows the percentage of embryos with expanded foreguts. Wnt5a, Wnt5b, Wnt11, and a constitutively active JNK, rescued the Sfrp5 overexpression phenotype, whereas Wnt2b, Wnt4, Wnt7b, Wnt8 and a stabilized β-catenin did not. n > 15 embryos for in each condition. (D) Western blotting of a coimmunoprecipitation showing that V5-tagged Sfrp5 preferentially bound to HA-tagged Wnt5a and Wnt11 from transfected COS-1 cell extracts. |
