Figure 4

Xmab21l2 restores the normal expression of Xvent2 and Chordin in BMP4 -injected embryos. Chordin (A–C) and Xvent2 (D–E) expression were analyzed by whole mount in situ hybridization. Embryos are shown in a vegetal view, dorsal to the top, ventral to the bottom. (A, D) Wild type expression of Chordin (A) and Xvent2 (D) in stage 10.5 gastrulae; (B, E) embryos injected with 1.2 ng of BMP4 mRNA alone showed reduced Chordin expression (B) (22/25) and expanded Xvent2 expression (E) (16/25); (C, F) embryos co-injected with 1.2 ng of BMP4 and 1.6 ng Xmab21l2 mRNA showed a rescue of wild type Chordin (C) (17/36) and Xvent2 expression (F) (24/29). (G) Percentage of embryos exhibiting wild type (black bars) or reduced (grey bars) Chordin gene expression in embryos injected with 1.2 ng BMP4 alone, and in embryos coinjected with 1.6 ng Mab21l2. Coinjection of Mab21l2 significantly increased the number of embryos exhibiting a wild type Chordin expression pattern; *: p = 0.004. (H) Percentage of embryos exhibiting wild type (black bars) or expanded (grey bars) Xvent2 gene expression in embryos injected with 1.2 ng BMP4 and in embryos coinjected with 1.6 ng Mab21l2. Again, Mab21l2 significantly increased the number of embryos exhibiting a wild type Xvent2 expression pattern; **: p = 0.00044. Statistical analysis was conducted using the Chi square algorithm (1 df).