Figure 1

Heat maps displaying patterns of expression for 5,715 regulated genes clustered by gene and sample. Genes are depicted based on their expression ratios across the seven microarray experiments. Colors range from bright red (up regulation, log2 ratio ≥ 3) to bright green (down regulation, log2 ratio ≤ -3). Hierarchical clustering was performed based on Pearson's correlation of log2 ratios. The dendograms at the top identify arrays showing the greatest similarity in their patterns of expression. M3, male liver at 3 wk; M4, male liver at 4 wk; M8, male liver at 8 wk; F3, female liver at 3 wk; F4, female liver at 4 wk; and F8, female liver at 8 wk. A. Heat map showing expression ratios for 4,503 adult sex-independent genes in the four microarray comparisons indicated at the top. Qualitative differences between sexes were seen in the developmental changes for the gene groups marked A-C at the right: group A genes showed greater up regulation in male liver than in female liver, group B genes showed greater up regulation in female liver than in male liver, and group C genes showed greater down regulation in male liver than in female liver. Group D genes showed strong down regulation in both sexes from 3 or 4 wk to 8 wk and includes genes associated with cell cycle and mitosis. B. Heat map showing expression ratios for 1,212 adult sex-specific genes across the seven microarray comparisons indicated at the top. Marked at the right are genes in group E, which show developmental up regulation from 3 or 4 wk to 8 wk in male liver but not in female liver, and genes in group F, which show developmental up regulation in female liver and down regulation in male liver.