Fig. 2.

C. owczarzaki Brachyury (CoBra) and Tbox-3 (CoTbx3) mRNAs rescue XBra_En injections in Xenopus assays. (A) All panels show MyoD expression in stage-30 embryos injected with 500 pg of the mRNA or the combinations of mRNAs indicated in the Upper Left. The phenotypes were classified in three categories based on the amount of trunk structures observed in the injected embryos as determined by muscle MyoD expression. Wild-type embryos showed complete trunk and full MyoD expression. Mild affected embryos showed partial reduction of the trunk with reduced MyoD expression domain. Severe affected embryos lacked almost all trunk tissue, and the expression of MyoD was hardly or not detected. Lower Right shows bar plots summarizing the different phenotypes observed in each case. (B) Quantitative RT-PCR experiments showing two muscle (MyoD and Muscle actin) and one notochord (Shh) genes in the different injected embryos. Controls are noninjected embryos. Bar plots represent relative expression, normalized with endogenous Histone 4 expression levels. Error bars represent SD from at least two different biological replicates.