Viruses encounter several environments and niches as they travel within and between hosts. For example, enteric viruses are exposed to the external environment, digestive enzymes, and intestinal microbes before they initiate replication in the gut. Some enteric viruses can disseminate to the central nervous system through blood or neural routes. How do these different environments influence viral replication, evolution, pathogenesis, and transmission? What barriers limit viral dissemination? Our lab uses tractable model viruses to learn about niche-specific factors that influence viral infection and evolution.