This is a new project to apply molecular biological techniques to the characterisation of the disease process in food-borne viruses. The project aims to use heterologous expression of viral coat proteins to generate material with which to study interaction with target human cells. <P> The viral family Caliciviridae infects a wide range of host organisms. One of the four genera in this family, Norovirus, is a major cause of foodborne gastroenteritis in humans. Calicivirus genome evolution was examined and its phylogeny compared to that of its hosts. It was concluded that Caliciviruses have a recent evolutionary origin with frequent cross-species transfers being responsible for the observed co-phylogeny. The demographic growth of the Noroviruses was also examined and compared to human demography. It was concluded that Norovirus population growth occurred concomitant with large-scale human population movement.<P> Recombination is known to be a prevailing drive in shaping viral genome evolution but searching for evidence of recombination in Norovirus sequences required new computational tools. A novel software application was introduced for high-throughput analysis of recombination events (Etherington et al 2005 Bioinformatics 21(3):278-81. Epub 2004 Aug 27). Application to Norovirus sequences revealed evidence of hitherto unidentified recombinants implicated in the worldwide transmission of these viruses.