Figure 3

Correlation of orthologous gene expression in human and mouse. (a) Pearson correlation of normalized tissue-specific expression levels of orthologous imprinted genes in human and mouse. The figure shows Pearson correlation coefficients as 2 dimensional heatmaps of orthologous imprinted genes in human (vertical) and mouse (horizontal). The color coded scale is shown as a bar on top of the figure. Pearson correlation coefficients of orthologous gene pairs are marked on the dashed red diagonal line, and the respective values are given in the table aside. The correlations were calculated on normalized and averaged expression data of annotated genes (Figure 1 and Materials and Methods). (b) Pearson correlation of orthologous gene expression in human and mouse tissues. A set of 19 orthologous genes that were present on the human expression array as well as the mouse expression array was sampled 1000 times. Pearson correlation coefficients for each set in all tissues were calculated. The boxplot displays the resulting Pearson correlation coefficients as follows. The x-axis displays the different tissues, the y-axis lists the Pearson correlation coefficients. The horizontal bar in each box gives the median PCC of the sampled orthologous genes, while the upper and lower boundaries of the box mark the first and third quartiles. Whiskers show 1.5 times the box range. Red squares mark the PCC of imprinted orthologous genes.