Hierarchical cluster of differentially expressed genes between B6 and D2 mice. All the relevant genes are grouped by hierarchical clustering based on expression values (log2ratios) across all the samples. Ratios were calculated between 0 week and the rest of time points in each mouse strains. Samples (Four time-points in C57BL/6J and DBA/2J, respectively) are displayed in columns and genes in rows. Gene expression is represented as a color, normalized across each row, with brighter red for higher values and brighter green for lower values. A. Heatmap of all the differentially expressed genes, most of which have different expression patterns between B6 and D2; B. Heatmap of genes involved in some major pathways, gene symbols listed to the right.