PIWI-associated piRNA in Drosophila melanogaster ovary

Heterochromatin, representing the silenced state of transcription, largely consists of transposon-enriched and highly repetitive sequences. Implicated in heterochromatin formation and transcriptional silencing in Drosophila are PIWI and repeat-associated small interfering RNAs (rasiRNAs). Despite this, the role of PIWI in rasiRNA expression and heterochromatic silencing remains unknown. Here we report the identification and characterization of 12,903 PIWI-interacting RNAs (piRNAs) in Drosophila, demonstrating that rasiRNAs represent a subset of piRNAs. Keywords: PIWI, piRNA, epigenetic regulation, heterochromatin PIWI-associated small RNA cDNA library was sequenced for one time by high-throughput 454 pyrosequencing. Putative small RNA sequences were extracted and BLAST against the Drosophila melanogaster genome release 5. Presented here is a list of non-redundant PIWI-associated small RNAs, which have at least one genome match determined by BLASTn.