Gene expression response to different long-term acclimations (A, B, C) analyzed by Principal Component Analysis (PCA) in <i>Drosophila melanogaster</i> larvae of two strains, Oregon (blue symbols) and Hsp70^- (red symbols).

<p>Log2-transformed values of the fold-differences in relative mRNA levels (shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0128976#pone.0128976.s004" target="_blank">S4 Fig</a>) were fitted into the PCA model and a plot of principal components PC1 and PC2 is presented. The ellipsoids in lower part of Fig 5 delimit the areas of clustering of three biological replications of each treatment. The eigenvectors in the upper part of Fig 5 represent individual mRNAs.