Production of miRNAs starts with the transcription of?genomic DNA into long primary transcripts called primiRNAs. The pri-miRNAs are subsequently cleaved by?RNase III Drosha?into shorter precursor transcriptswith hairpin structure calledpre-miRNAs. The pre-miRNAs are?transported into the cytoplasm where they are processed?by RNase III Dicer into ～22 nt double-stranded miRNA?molecules. Both strands of this duplex may become functional mature miRNAs.
Sequences of the miRNA oligonucleotides were obtained?from the miRBase Release 21 (www.mirbase.org 我在這個網站中不能進行搜索，什么原因我也不清楚，推薦大家直接在Download中下載mature. fa，文件用記事本打開，輸入miRNA名就可以直接搜索到成熟miRNA序列，各個物種都有).?
