Ure S2. Multiple species utility of microarray. (A) When all species are normalized together, principal components analysis (PCA) indicates the largest variance between genus Salmo (PC1+) and Oncorhynchus (PC1-), and the second largest variance between species O. keta (PC2-) and O. gorbuscha (PC2+). The basal expression differences captured by the PCA are due to both true biological differences an