Figure 2. Transcriptional variation among non-BaCl₂-exposed isolated worms (Control) and non-BaCl₂-exposed worms that recently developed from tail pieces (Tail regenerate).

a. PCA plot based on normalized gene expression data from planarian samples. Each point represents a biological replicate, colored by experimental condition. Control (blue): non-BaCl₂-exposed isolated worms. Tail regenerate (green): non-BaCl₂-exposed worms that recently developed from tail pieces.

b. 1,853 genes are differentially expressed in non-BaCl₂-exposed isolated worms (Control) versus non-BaCl₂-exposed worms that recently developed from tail pieces (Tail regenerate). The volcano plot shows that more genes are upregulated (left) than downregulated (right) in non-BaCl₂-exposed isolated worms (Control) versus non-BaCl₂-exposed worms that recently developed from tail pieces (Tail regenerate). More genes are downregulated (left) than upregulated (right) in non-BaCl₂-exposed worms that recently developed from tail pieces (Tail regenerate) versus non-BaCl₂-exposed isolated worms (Control). The x-axis represents the shrunken log₂ fold change, and the y-axis shows the −log₁₀ of the s-value. Orange dots denote genes passing both statistical significance and fold change thresholds; blue dots indicate statistically significant fold change without statistical significance in s-value; gray dots indicate no statistically significant fold change.

c. Gene ontology (GO) groups of example upregulated (left) and downregulated (right) genes in the non-BaCl₂-exposed worms that recently developed from tail pieces (Tail regenerate) versus non-BaCl₂-exposed isolated worms (Control). Dot size refers to the number of associated genes, and the x-axis shows the −log₁₀(p-value) of each GO term.