Fig. S4

Wnt activity in gpx4b MZ ^allele2 mutants and morphants. (A) The expression of boz, chd, and sqt mRNA in each indicated group of embryos at 4.3 hpf as analyzed by qRT-PCR. (B) Expression of direct zygotic Wnt markers cdx4, sp5l, and tbx6 in MZ^allele2 mutants compared to WT embryos at 9 hpf as revealed by WISH. (C) Effects of gpx4b knockdown on the expression of cdx4 and sp5l at 9 hpf as revealed by WISH. The frequency of embryos with the indicated patterns is shown in the bottom right corner of each panel. Asterisks indicate the edges of the indicated mRNA expression domains. l, lateral views with dorsal to the right and animal pole up. (D) The mRNA expression levels of indicated zygotic Wnt direct target genes in WT and MZ^allele2 mutant embryos at 8 hpf analyzed by qRT-PCR. (E) Knockdown of gpx4b increased Wnt/β-catenin reporter activity. One-cell stage embryos were injected with TOPFlash reporter DNA together with cMO (6 ng), MO (6 ng), or 50 pg wnt3a mRNA. Values are means ±s.e.m. (n = 3). *P < 0.05; **P < 0.01; ***P < 0.001. Unpaired t test, Two-tailed. Scale bar = 200 μm.