Mechanisms of viral emergence
Centro de Biología Molecular Severo Ochoa (CSIC-UAM), C/Nicolas Cabrera, 1, Cantoblanco, Madrid 28049, Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Barcelona, Spain
* Corresponding author: email@example.com
Accepted: 4 February 2010
A number of virologic and environmental factors are involved in the emergence and re-emergence of viral disease. Viruses do not conservatively occupy a single and permanent ecological niche. Rather, due to their intrinsic capacity for genetic change, and to the evolvability of fitness levels, viruses display a potential to parasitize alternative host species. Mutation, recombination and genome segment reassortment, and combination of these molecular events, produce complex and phenotypically diverse populations of viruses, which constitute the raw material on which selection acts. The majority of emerging viral diseases of humans have a zoonotic origin. Sociologic and ecologic factors produce diverse and changing environments in which viral subpopulations have ample opportunities to be selected from intrinsically heterogeneous viral populations, particularly in the case of RNA viruses. In this manner, new human, animal and plant viruses have emerged periodically and, from all evidence, will continue to emerge. This article reviews some of the mechanisms that have been identified in viral emergence, with a focus on the importance of genetic variation of viruses, and on the general concept of biological complexity.
Key words: mutation / recombination / reassortment / quasispecies / virus adaptation
© INRA, EDP Sciences, 2010
This is an Open Access article distributed under the terms of the Creative Commons Attribution-Noncommercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted use, distribution, and reproduction in any noncommercial medium, provided the original work is properly cited.