2012 Annual Report 1a.Objectives (from AD-416): Thorough investigation of the immunogenetic responses involved in host-pathogen interactions in Avian Influenza will lead to better understanding of genetic countrol of host response to AI and the identification of immunogenetic mechanisms which will facilitate the development of novel vaccination strategies against AI. 1b.Approach (from AD-416): APDL plans to apply avian cDNA intestinal IEL microarray (AVIELA) chips which were developed in the laboratory at BARC to characterize the differential immune response patterns of different genetic breeds of broiler chickens with different disease phenotypes. 3.Progress Report: During this period, the key role of chicken common cytokine receptor gamma chain family in the regulation of innate and adaptive immune responses was investigated. Unlike mammals, chickens possess two different gamma-chain transcripts. To determine if this difference is present in other avian species, gamma-chain cDNA and genomic clones from ducks and quails were investigated. Two different gamma-chain transcripts were identified in both species and designated as duck gamma-chain-a (du-a), du-b, quail gamma-chain-a (qu-a), and qu-b. Comparisons between the duck and quail gamma-chain cDNA and genomic sequences indicated that the two transcripts were produced by alternative splicing. Unexpectedly, the du-b contained the fifth intron, a frame-switching 88-bp insertion, resulting in a receptor molecule lacking a transmembrane region. These findings indicate a possibility that avian species, unlike mammals, express two different gamma-chain transcripts due to alternative splicing. This study is the first demonstration of an alternatively-spliced gamma-chain isoform that lacks a transmembrane domain.