Short, interfering RNAs (siRNAs) arise from the processing of long double-stranded RNA (dsRNA) by Dicer enzymes. Dicers generate siRNA duplexes by successive hydrolysis of both strands of the dsRNA phosphodiester backbone at positions determined by measuring 21-24 nucleotides from an exposed dsRNA terminus. Therefore, a population of dsRNAs with precisely identical termini will produce siRNA spaced in regular, 21-24-nucleotide intervals. This chapter presents an easily customized and generally applicable strategy for identifying loci which produce the "phased" siRNAs diagnostic of such processing. Given the input of a large set of expressed small RNAs and of the corresponding genome or transcriptome from which the small RNAs are derived, the methodology produces a ranking of user-defined loci with respect to their likely production of phased siRNAs. Top ranked loci are candidates for further computational and biological analyses.
All Science Journal Classification (ASJC) codes
- Molecular Biology