Figure 2

Classification of miRNA target genes. The total set of genes is grouped in different subclasses, defined by the presence of alternative UTRs and the location of target sites. Constitutive targets encompass predicted target genes with constitutive UTRs, as well as genes with alternative UTRs, in which all sites are located within the constitutive UTR regions. Alternatively targeted genes have at least one target site located in an alternative 3'UTR segment. On/off targets are alternative targets in which all target sites fall exclusively into alternative UTR regions; modulated targets contain alternative targets with sites in both constitutive and alternative UTR regions. Shown are the total number of genes in each class, as well as the relative size of the subclasses.