The Whelan laboratory studies the biology of negative-strand (NS) RNA viruses. These viruses have genomes that are complementary to message sense RNA and must therefore carry into the cell the necessary machinery to copy their genomic RNA into mRNA. The genomes of the viruses can be non-segmented (ns) or segmented (s). We use vesicular stomatitis virus (VSV) as a model for the nsNS RNA viruses. The nsNS RNA viruses include some of the most significant human pathogens, as well as a number of highly lethal emerging infections. The work of the laboratory is divided between two major areas of focus: studies of viral gene expression and studies on viral-host cell interactions.