Hierarchical clustering of miRNA target sites in the 3′ UTRs of differentially expressed isoforms.

Heat map representing Z-scores derived from MRE frequency. Red indicates a frequent appearance of the MRE (suggesting low miRNA activity in the corresponding cell type) and green a low frequency (suggesting possible high miRNA activity in the corresponding cell type). Cluster II contains miRNAs with responsive elements appearing in 3′UTRs of transcripts overexpressed in DRGs. Cluster I miRNAs are present in most of the transcripts regardless of comparison indicating these miRNAs may not be active in neurons. Clusters VI-VIII represent miRNAs that could be potentially active in DRG enriched transcripts due to their low appearance in DRG 3′UTRs, while Cluster II and III represent miRNAs potentially active in CGNs. Cluster IV and V represent miRNAs with a low abundance of target sites regardless of cell type suggesting these miRNAs may be active in both neuronal types.