FIG 2.
Zfp703 is a direct target gene of Wnt/β-catenin signaling. (A) Whole-mount in situ hybridization (WISH) detection of Zfp703 transcripts (top panels) and comparison to BATlacZ (Wnt/β-catenin/Tcf1-Lef1 reporter) β-galactosidase-stained mouse embryos (bottom panels) (stages E7.75 to E9.5). Sections (second panels from left) are through the PS region with the ingressed PS region marked with black arrows. (B) WISH analysis of Zfp703 expression in E8.0 control (left) and mutant (right) embryos lacking β-catenin function in the PS (T-Cretg/+; Ctnnb1Δ/flox). Posterior views (bottom panels) show that Zfp703 expression was reduced in posterior progenitors in the PS. (C) qPCR of Zfp703 expression in untreated and Wnt3a-treated mouse embryoid bodies, compared to Wnt target genes Lef1 and Sp5. (D) qPCR of Zfp703 expression in untreated and Wnt agonist CHIR99021-treated mouse embryoid bodies, compared to Wnt target genes Lef1 and Sp5. (E) Genomic map of β-catenin binding to the mouse Zfp703 locus with center of peak indicated as bp −839 from the transcriptional start site. (F) Luciferase assay of 854 bp upstream from ATG (includes 836-bp upstream putative regulatory region from transcription start site) of Zfp703 under untreated and β-catenin-stimulating conditions (Wnt3a and/or CHIR99021) relative to vector control. Abbreviations: Al, allantois; PS, primitive streak; PP, posterior progenitors; EB, embryoid bodies.