Fig. 4

Wnt regulator mutants have differential effects on Wnt target genes. qRT-PCR was performed at 30% (A and C) and 50% (B, D, and E) epiboly for the Wnt target genes axin2, nkd1, and sp5a. Target gene expression was normalized to actin and made relative to WT uninjected expression levels. Injections were performed with 100 pg of wnt8 at the one cell stage. Expression of axin2, nkd1, and sp5a tended to increase in axin2gh1/gh1 mutants at both 30 and 50% epiboly but only axin2 expression increased significantly at 30% epiboly. However, in the nkd1gh2/gh2 and axin2gh1/gh1;nkd1gh2/gh2 mutants, axin2 and nkd1 expression did not increase substantially compared with wild type. In contrast, sp5a expression showed a significant increase at 30 and 50% epiboly in the nkd1gh2/gh2 mutants and at 50% in the axin2gh1/gh1;nkd1gh2/gh2 (A–E, error bars represent SEM, * = p value < 0.05, ** = p value < 0.01, one-way ANOVA). Injection of Wnt8 into wild type (column 3) is often significant to uninjected wild type (column 1), but this is not shown for clarity.