Identification of Virus Encoding MicroRNAs Using 454 FLX Sequencing Platform

MicroRNAs are a class of small noncoding RNA molecules that play a pivotal role in the regulation of gene expression at the posttranscriptional level. Most large double-stranded DNA viruses, mainly the herpesvirus family, are known to express miRNAs. Viral miRNAs can regulate both viral- and cellular transcripts. By eliminating cloning steps for large number of Sanger sequencing reactions, recent development of massively parallel next-generation sequencing methods has accelerated identification of small RNA species expressed from viruses, prokaryotes, and eukaryotes. The miRNAs expressed from infectious laryngotracheitis virus (ILTV), which is an alphaherpesvirus belonging to the herpesviridae family and which causes an acute respiratory disorder in chicken, were identified by small RNA enrichment and the 454 FLX sequencing method.