Genomics of antiviral defenses in the duck, a natural host of influenza and hepatitis B viruses

Abstract

We review our progress using genomics approaches to examine key antiviral defenses of the White Pekin mallard duck, Anas platyrhynchos. Our interest stems from the fact that ducks are the natural host of avian influenza, and are an important animal model for hepatitis B research. First, we have conducted an expressed sequence tag (EST) project and identified more than 200 immune relevant genes in the duck. Our analysis of these genes allows us to evaluate the homology between ducks and their closest genetic model organism, the chicken. We have also constructed genomic and cDNA libraries from the same individual duck, allowing us to directly compare expressed sequences with those present in the genome. These resources allow us to determine the organization and expression of regions of the genome important in antiviral defenses. Here we examine the organization of the immunoglobulin heavy chain locus, the Major Histocompatibility Complex class I region, the lectin immunoreceptors and Toll-like receptor 7. We discuss our research-in-progress in the context of the immune defense against viruses, particularly influenza.