2008 Annual Report 1a.Objectives (from AD-416) 1) Pathogenesis of avian inluenza virus isolates in swine;. 2)Role of avian polymerases in adaptation of swine influenza viruses to swine;. 3)Genetic characterization of swine and avian influenza viruses to swine; and. 4)Preparation of reagents. 1b.Approach (from AD-416) 1) Pathogenesis of avian influenza virus isolates in swine will be evaluated after inoculation into a group of four week old pigs. Microscopic and macroscopic lung lesions and viral replication in lungs and nasal cavities will be determined.. 2)Various reassortant viruses containing avian and/or swine polymerase genes will be established using reverse genetics approaches. These reassortant viruses will be tested for their pathogenic potential in swine.. 3)Swine and avian influenza isolates will be genetically characterized using conventional sequencing approaches.. 4)Hyperimmune sera and various viruses will be made available as reagents. 3.Progress Report This is the first year of a 7 year project that is part of a multi-institutional grant. The National Animal Disease Center's role in this grant is to study molecular mechanisms by which influenza viruses acquire increased pathogenicity for humans and animals, and determination of the molecular mechanisms responsible for the transmission of influenza viruses between animals, between humans, and from animals to humans. Initial studies have focused on in vitro analysis of the swine influenza virus polymerase complex. This research addresses NP103 – Animal Health Action Plan Components: 3. Zoonotic diseases and 4. Respiratory diseases. Methods for monitoring this project include email and site visitation.