<p>Selected genes belonging to nine functional categories are listed below the figure and represented as symbols in front of each gene name. <b>A</b>) Hierarchical clustering of the relative expression levels of 42 immune related genes in non-stimulated oysters of H and L line (three groups of ten oysters per line). Each cell in the matrix corresponds to the expression level of one gene in one sample. The intensity of the color from green to red indicates the magnitude of differential expression (see color scale at the bottom of the image). Relative expressions were calculated according the 2<sup>−ΔΔCq</sup> method [21]. The dendrogram at the top of the figure indicate relationship among samples; while the dendrogram at the right of the figure indicate relationship among the relative expression levels of selected genes. Hierarchical clustering was constructed with Multiple ArrayViewer software using average linkage clustering with Spearman Rank Correlation as the default distance metric. Significant differences of relative expressions between oyster lines were determined by the Mann-Whitney U test and genes with significant variation are underlined (<i>p</i><0.05). (<b>B</b>) Hierarchical clustering of the melting temperatures of qPCR amplicons of 42 selected genes in non-stimulated oysters of H and L line (three groups of ten oysters per line). Melting temperature of each sample is represented as the deviation from the mean of melting temperatures of all samples for each gene. Each cell in the matrix corresponds to the deviation from the mean of melting temperature of one gene in one sample. The intensity of the color from green to red indicates the magnitude of the deviation of melting temperature from the mean of each gene (see color scale at the bottom of the image). The dendrogram at the top of the figure indicate relationship among samples; while the dendrogram at the right of the figure indicate relationship among variation of melting temperatures of selected genes. Hierarchical clustering was constructed with Multiple Array Viewer software using average linkage clustering with Pearson Correlation as the default distance metric. Genes who present variation equal or superior to 0.5°C between samples and/or a significant differences of melting temperature between oyster lines (Mann-Whitney U test, <i>p</i><0.05) are underlined. Asterisks (*) indicate genes who present a significant differential of expression together with a variation of melting temperature.</p
