Figure 6

Chromosomal distribution of predicted target genes is influenced by length and GC content of 3' UTRs. The line chart of the z-scores of human chromosomal 3' UTR GC and length distribution (A) and the line chart of the combination of these z-scores compared to the human "Vari" target density z-scores of at least three Dlk1/Gtl2 microRNAs (B). The scattered area in (A) corresponds to a p-value higher than 0.05. The values in (B) are normalized by their standard deviation to focus on the relationship and not the values. Additionally, the Pearson correlation coefficient r is given. The plots show that the observed non-uniform distribution of the targets is probably caused by the non-uniform distribution of 3' UTR GC content and length over the chromosomes. For predicted murine targets a similar effect is observed, the corresponding Pearson correlation coefficient is 0.950. If we restrict the chromosomes included in the calculation to the chromosomes with target densities significantly different to a random distribution (p-value smaller than 0.01), we obtain even higher values (0.982 and 0.968 respectively).