My research interests fall within the areas of molecular immunology and immunogenetics with a focus on diversity in the genes and proteins controlling pathogen recognition and the response to infection and vaccination in livestock populations. Current research is directed towards the genes at the major histocompatibility complex (MHC). The MHC includes the most polymorphic protein-encoding loci in vertebrates with allelic diversity associated with the binding of peptide antigen and immune recognition. In order to eliminate much of the natural variation at the MHC, a resource flock with well defined MHC haplotypes has been developed. This has a wide range of applications in defining the mechanisms of natural immunity to infection and the identification of pathogen proteins which stimulate protective responses. These may then be fed into the vaccine development pathway. Additional interests are in the genetics of livestock disease resistance focusing on sheep diseases such as Johne's disease, ovine pulmonary adenocarcinoma and mastitis. I currently chair the International Society for Animal Genetics/International Union of Immunological Societies, Comparative MHC nomenclature committee. The aim of this committee and the IPD databases (http://www.ebi.ac.uk/ipd/mhc/ovar/index.html) are to provide a single nomenclature for alleles at polymorphic MHC loci in sheep. Using these databases we can now focus on quantifying current levels of genetic diversity in common and rare sheep breeds in the UK and worldwide with a view to analyzing the links between MHC diversity and resistance and susceptibility to infectious disease and for the development of rational approaches to conservation of genetic diversity in livestock.