miRStart, a novel resource of human microRNA TSSs (transcription start sites), systematically incorporates significant datasets derived from TSS-relevant experiments to identify transcription start sites of microRNAs. The distribution patterns of these experimental features within 50 k upstream region of microRNA precursors provides an insight into determining reliable microRNA TSSs. In general, a high-confidence TSS is recommended for each microRNA based on a SVM training model. However, users can customize their preferable microRNA TSSs according to the straightforward display of experimental TSS signals.
Published experimental evidences used in miRStart are described as follows:
(1) CAGE (Cap Analysis of Gene Expression) tags: Recognize 5’-end of a gene
(2) TSS Seq tags: More than 300 million 5’-end sequences of human and mouse cDNAs by combining oligo-capping method and Solexa sequencing technology
(3) H3K4me3 enrichment (histone H3 is trimethylated at its lysine 4 residue): Enriched surrounding TSSs
Moreover, ESTs and comparative genomics around putative miRNA TSSs are used to provide strong supports for reconfirmation.
The following figure demonstrates the concept of miRStart.