Fig. S2

Effects of ppp4cb or its mutant overexpression, related to Figure 2. (A) 50 pg of ppp4cb mRNA (p4cb) or ppp4cb-RL mRNA (p4cb-RL) encoding the phosphatase-dead mutant form of Ppp4cb was injected at the one-cell stage and injected embryos were observed at 24 hpf. Boxed areas were enlarged to see the notochord that was indicated by arrows. p4cb overexpression interrupted the notochord development, but p4cb-RL overexpression did not cause any detectable morphological defects, which suggests that the phosphatase activity of Ppp4c is required for Ppp4c function in zebrafish embryos. (B) The embryos were injected at the one-cell stage with indicated mRNAs and examined for gsc expression at the shield stage. The statistical data were shown in the right. Notably, higher doses of ppp4cb mRNA resulted in an expansion of gsc, which was inhibited by co-injection of dnsmad3b mRNA encoding the dominant negative form of Smad2/3 (Jia et al. 2008), suggesting that too much Ppp4cb enhances Smad2/3 activity.