Figure 1.

Dynamic spatial gene expression patterns and territories of the oral ectoderm. A) Expression of pax4l, ets4, sip1 and emx. pax4l transcripts are localized in the oral ectoderm during the blastula stage, similar to nodal. Initially ets4, sip1, and emx transcripts cover both oral and aboral ectoderm. Oral expression of these genes fades at mid-blastula and becomes complementary to the central oral ectoderm (marked by lefty expression in the double WMISH) after18 h. B) Diagrams illustrating ectodermal gene expression domains shown in lateral view. Developmental stages are the early blastula stage (12h), late blastula stage (18h), and mesenchyme blastula stage (24h). For simplicity, endomesodermal domains are not indicated. Ectodermal domains are color-coded and labeled on the left; domain-specific genes are shown in Table S1. Apical—apical plate; Ec—ectoderm. lv—lateral view; vv—vegetal view; av—apical view. All embryos in lateral or vegetal views were shown with the oral ectoderm facing left. C) Expression matrix for ectodermal genes during the blastula stage. Three time points were included representing the early blastula stage (12h), late blastula stage (18h), and mesenchyme blastula stage (24h). A graphic presentation of the expression patterns is shown in Table S1.