Fig. 2. Spatial GFP expression driven by the R-module and intron GFP reporters. (A) Diagram of the five regulatory elements from sea urchin nodal used for the spatial expression analysis. (B) Expression data summary for GFP constructs containing the various regulatory elements. Embryos with expression clones just in the oral ectoderm were scored as oral only; clones in either aboral ectoderm or endoderm were scored as ectopic only; and embryos that contained clones in both oral and ectopic territories were scored as oral+ectopic. (C-E) Examples of embryos that fit into these categories: (C) oral only, (D) oral+ectopic, (E) ectopic only.