MicroRNA profiling of Atlantic salmon challenged with Infectious Pancreatic Necrosis virus: Comparison between resistant and susceptible fish

Abstract Text: Resistance to Infectious Pancreatic Necrosis Virus (IPNV) is a heritable trait largely under the control of a single genomic region, yet the underlying functional mechanisms remains unclear. We recently developed a microRNA (miRNA) resource for Atlantic salmon using high-throughput sequencing. In this study, the aim was to characterize the miRNA profile in IPNV-challenged and control Atlantic salmon, and to compare resistant and susceptible fish. 36 Atlantic salmon fry were sequenced on the Illumina platform resulting in the discovery of ~900 putative miRNAs. One miRNA was identified which showed highly significant differential expression between fry homozygous for the resistant allele at the major IPN resistance QTL and those homozygous for the susceptible allele. miR-4792 was overexpressed 3.6 fold in resistant homozygotes (P < 0.0006) and its predicted target genes may play a role in the differential host response to IPN infection underlying the major QTL.

Keywords: Atlantic salmon, miRNA, IPN