Foot-and-mouth disease (FMD) virus is still the most feared in animal farming. The re-emergence of old viruses and emergence of new sero- and genotypes of the virus is a constant threat to agriculture, resulting in dramatic losses either due to direct harm to the infected host, to trade restrictions or to the necessity of slaughtering animals on a large scale to contain disease outbreaks. Molecular analyses of FMD virus (the type member of the genus Apthovirus within the Picornaviridae) has yielded important insight into the role that different viral proteins play for replication in cell culture and in the infected animal. Viral factors relevant for FMD pathogenesis have been identified, and new diagnostic assays have been developed that allow the differentiation between vaccinated and infected animals. Moreover, work on FMD virus has also contributed to the revolutionary concept of the quasispecies of RNA viruses, which stands at the basis of their impressive evolutionary potential. The concept of quasispecies, which results from the error-prone genome replication by RNA-dependent RNA polymerase, leads straight to the new finding that, besides increasing the fitness, i.e. the extent of virus adaptation to the environment, it can also lead to extinction.

from Martinez-Salas, Saiz and Sobrino in Chapter 1: Foot-and-Mouth Disease Virus from Animal Viruses: Molecular Biology

Further reading: Animal Viruses: Molecular Biology

Labels: virology, virus