Figure 4. Population-average estimates of allelic expression at 416 SNPs from the first panel.

Each blue cross stands for one SNP and is displayed on the left y-axis based on the average allelic ratio observed using all heterozygous individuals for this SNP. The SNPs are ranked on the x-axis from 1 (SNP with the highest average allelic imbalance) to 416 (lowest average allelic imbalance). Green dots stand for SNPs in imprinted genes, pink dots for SNPs in X-linked genes. The red line represents our significance threshold based on the estimation of experimental variability and corresponds to an average allelic ratio of 40∶60. The red crosses are the 25 SNPs also analyzed using quantitative sequencing of RT-PCR products and are displayed on the right y-axis according to the strength of the correlation (Pearson's r²) between the estimates of both methods (i.e., 1 indicates complete correlation between both estimations, 0 no correlation). Non significant correlations (p>0.05) are indicated with r² = 0.