Identification of host encoded microRNAs interacting with novel swine-origin influenza A (H1N1) virus and swine influenza virus

The discovery of microRNAs (miRNAs) is a remarkable breakthrough in the field of life science, and they are important actors whichregulate gene expression in diverse cellular processes. Recently, several reports indicated that miRNAs can also target viruses and regulatevirus replication. Here we discovered 36 pig-encoded miRNAs and 22 human-encoded miRNAs which have putative targets in swineinfluenza virus (SIV) and Swine-Origin 2009 A/H1N1 influenza virus (S-OIV) genes respectively. Interestingly, the putative interactions ofssc-miR-124a, ssc-miR-136 and ssc-miR-145 with their SIV target genes had been found to be maintained almost throughout all of the virusevolution. Enrichment analysis of previously reported miRNA gene expression profiles revealed that three miRNAs are expressed at higherlevels in human lung or trachea tissue. The hsa-miR-145 and hsa-miR-92a putatively target the HA gene and hsa-miR-150 putatively targetsthe PB2 gene. Analysis results based on the location distribution from which virus was isolated and sequence conservation imply that someputative miRNA-mediated host-virus interactions may characterize the location-specificity.