Differentially regulated genes involved in calcium signaling pathways. A) Genes along the calcium signaling pathway that may be differentially regulated in the epithelium and mesenchyme. Only differentially expressed genes and co-regulated genes identified by cosine similarity analysis are shown. B-E) Expression comparisons of calcium signaling pathway-associated, differentially expressed genes and coregulated genes between feather and scale skins of similar plasticity: B) E7fe vs. E9se; C) E7fm vs. E9sm; D) E9fe vs. E11se; and E) E9fm vs. E11sm. *represents p-values < 0.05 for the bracketed comparisons; biological repeats ≥ 3.