Project description:Cis-natural antisense transcripts (cis-NATs) have been speculated to be substrates for endogenous RNA interference (RNAi), but little experimental evidence for such a pathway in animals has been reported. Analysis of massive Drosophila melanogaster small RNA data sets now reveals that endogenous small interfering RNAs (siRNAs) are produced via bidirectional transcription. >100 cis-NATs with overlapping 3' exons generate 21-nt, Dicer-2 (Dcr-2)dependent, 3'-end modified siRNAs. To determine whether any co-expressed cisNATs are denied entry into the RNAi pathway, we analyzed the gene expression profile of S2 cells. The analysis suggested that the processing of cis-NATs by RNAi are actively restricted, and the selected loci are enriched for nucleic acidbased functions and include Argonaute-2 (AGO2) itself. Keywords: Gene expression
