Fig. S4.

The expression of the 123-gene early dorsal β-catenin signature examined via principal component analysis (PCA) to analyze dimensionality in six experimental conditions: Cerberus/control (Cer/con), β-catenin morpholino/control (β-CatMO/con), Siamois/control (Sia/con), lithium chloride/control (LiCl/con), dorsal/ventral regenerating halves (Dor/Ven), and Wnt8/control (Wnt/con). Each axis represents a principal component (PC), with the first one having the most variation. PCA analysis confirmed the reproducibility of the early β-catenin signature by clustering replicate conditions together and distinguishing ventralizing (β-catenin depletion) and dorsalizing treatments. The Cerberus mRNA-injected condition was located between the β-CatMO and the rest of the sequenced conditions due to its ability to inhibit both Nodal and BMP target genes.