Figure 3

Xmab21l2 rescues dorsal structures in BMP4 injected embryos. (A) As previously described, injection of 0.6 ng of BMP4 mRNA gave rise to ventralized embryos. The most severely ventralized phenotype of BMP4 injection, called bauchstück, was scored with a dorso-anterior index (DAI) of 0 (top), whereas normally dorsalized embryos were assigned a DAI of 5 (bottom). (B) Embryos were injected with 0.6 ng BMP4 (n = 111), with 0.6 ng BMP4 plus 0.8 ng Mab21l2 (n = 83), or with 0.6 ng BMP4 plus 1.6 ng Mab21l2 (n = 101). In each group, we scored the percentage of complete ventralization (DAI = 0, grey bars) and normal dorsal axis formation (DAI = 5, black bars) in embryos that completed development. Intermediate classes are omitted in the plot. Coinjection of embryos with Mab21l2 significantly increased the percentage of correctly dosalized embryos (see text for details). Statistical analysis was conducted using the Chi square algorithm (1 df). *: p = 0.0005; **: p = 0.0087.