The Evolutionary Genetics of Viral Emergence
Despite the wealth of data describing the ecological factors that underpin viral emergence, little is known about the evolutionary processes that allow viruses to jump species barriers and establish productive infections in new hosts. Understanding the evolutionary basis to virus emergence is therefore a key research goal and many of the debates in this area can be considered within the rigorous theoretical framework established by evolutionary genetics. In particular, the respective roles played by natural selection and genetic drift in shaping genetic diversity are also of fundamental importance for understanding the nature of viral emergence. Herein, we discuss whether there are evolutionary rules to viral emergence, and especially whether certain types of virus, or those that infect a particular type of host species, are more likely to emerge than others. We stress the complex interplay between rates of viral evolution and the ability to recognize cell receptors from phylogenetically divergent host species. We also emphasize the current lack of convincing data as to whether viral emergence requires adaptation to the new host species during the early stages of infection, or whether it is largely a chance process involving the transmission of a viral strain with the necessary genetic characteristics.
Unable to display preview. Download preview PDF.
- Breman JG, Johnson KM, van der Groen G, Robbins CB, Szczeniowski MV, Ruti K, Webb PA, Meier F, Heymann DL (1999) A search for Ebola virus in animals in the Democratic Republic of the Congo and Cameroon: ecologic, virologic, and serologic surveys, 1979–1980. J Infect Dis 179:S139–S147.CrossRefPubMedGoogle Scholar
- DeFilippis VR, Villarreal LP (2000) An introduction to the evolutionary ecology of viruses. In: Hurst CJ (ed) Viral ecology. Academic Press, New York, pp 126–208.Google Scholar
- Gillespie JH (1998) Population genetics: a concise course. Johns Hopkins University Press, Baltimore.Google Scholar
- Matrosovich MN, Gambaryan AS, Teneberg S, Piskarev VE, Yamnikova SS, Lvov DK, Robertson JS, Karlsson KA (1997) Avian influenza A viruses differ from human viruses by recognition of sialyloligosaccharides and gangliosides and by a higher conservation of the HA receptor-binding site. Virology 233:224–234.CrossRefPubMedGoogle Scholar
- Yeh S-H, Wang H-Y, Tsai C-Y, Kao C-L, Yang J-Y, Liu H-W, Su I-J, Tsai S-F, Chen D-S, Chen P-J, and the National Taiwan University SARS Research Team (2004) Characterization of severe acute respiratory syndrome coronavirus genomes in Taiwan: Molecular epidemiology and genome evolution. Proc Natl Acad Sci U S A 101:2542–2547.CrossRefPubMedGoogle Scholar