FIGURE 2

Expression patterns of mesendodermal markers and nodal genes in WT and mutant embryos. The expression of the endodermal marker sox32, the mesodermal marker tbxta and the epidermal marker gata2a as well as ndr1 and ndr2 was examined by WISH (A,C) or qRT-PCR (B,D) at indicated stages. Embryos in (A,C) were shown in animal-pole view with dorsal to the right if the dorsal was recognizable. The ratio of embryos with the representative pattern was indicated at the right bottom. Note that the majority of Meomesa;Mhwa embryos completely lacked tbxta expression while the other had some tbxta expression. Scale bars: 100 μm. For RT-PCR analysis, 15 embryos were pooled for each assay, and the expression level was normalized to that of eif4g2a in WT embryos at the same stage. Error bars indicated S.D. based on three biological replicates (indicated by small circles). Color keys for embryo types were shown in (A,C). Statistically significant levels: ns, nonsignificant; **, p < 0.01; ***, p < 0.001.