Fig. 6.

Expression of known Wnt signaling target genes at the tail bud of E10.5 embryos (′37 somite pairs). (A-B′) Wholemount in situ hybridization reveals that, after neural tube closure is completed in the control embryo (A,A′), T mRNA signals were dramatically diminished at the tail bud (tb), but relatively unchanged in the primitive streak (ps), of the E10.5 β-catenin cKO embryo (B,B′). (C-D′) Tbx6 signals were almost absent in the mutant tail bud. (E-F′) Fgf8 signals were specifically diminished in the mutant tail bud. (G-H′) Somite marker gene Uncx4.1 signals showed conserved numbers but apparently disrupted organization of mutant somites in the caudal body axis. Arrowheads, the regions of dorsally bent caudal body axis in the mutant embryos. Asterisks, the anterior-most opening sites of the caudal neural folds in the mutants.