Molecular characterization and expression analysis of the duck viperin gene

- Duck viperin gene was successfully cloned and was highly similar to other species' Viperin gene.
- Secondary and 3D structures of the duck viperin protein were predicted.
- Duck viperin expression was widely distributed in various organs and up-regulated by Newcastle disease virus.

Viperin is well known as one of the interferon-stimulated genes involved in innate immunity. Recent studies showed that this gene is mainly responsible for antiviral response to a large variety of viral infections. In this study, we successfully cloned and characterized the complete coding sequence of duck viperin gene. The duck viperin gene encodes 363 amino acids (aa) and is highly similar to viperins from other species. Moreover, secondary and 3D structures were predicted, and these structures showed two main domains, one signal peptide, and one radical S-adenosyl methionine (SAM) domain. Additionally, the duck viperin expression was analyzed in vitro and in vivo, and analysis results indicated that the duck viperin can be strongly up-regulated by poly(I:C) and Newcastle disease virus in primary duck embryo fibroblast cells. Results also demonstrated that Newcastle disease virus significantly induced duck viperin expression in the spleen, kidneys, liver, brain, and blood. Our findings will contribute to future studies on the detailed functions and potential underlying mechanisms of this novel protein in innate immunity.