Open AccessIntraclonal variation in RNA viruses: generation, maintenance and consequences
Author(s) -
ELENA SANTIAGO F.,
CODOÑER FRANCISCO M.,
SANJUÁN RAFAEL
Publication year - 2003
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1046/j.1095-8312.2003.00173.x
Subject(s) - biology , natural selection , genetic drift , evolutionary biology , genetic variation , mutation rate , genetic fitness , genetic variability , viral evolution , fixation (population genetics) , experimental evolution , genetics , selection (genetic algorithm) , neutral theory of molecular evolution , balancing selection , adaptation (eye) , rna , genotype , biological evolution , gene , artificial intelligence , neuroscience , computer science
This paper explores the evolutionary implications of the enormous variability that characterizes populations of RNA viruses and retroviruses. It begins by examining the magnitude of genetic variation in both natural and experimental populations. In natural populations, differences arise even within individual infected patients, with the per‐site nucleotide diversity at this level ranging from < 1% to 6%. In laboratory populations, two viruses sampled from the same clone differed by ∼0.7% in their fitness. Three different mechanisms that may be important in maintaining viral genetic variability were tested: (1) Fisher's fundamental theorem, to compare the observed rate of fitness change with the extent of fitness‐related variation within the same experimental populations; (2) magnitude of genomic mutation rate, to assess whether it correlated with fitness‐related variation, as predicted by the mutation‐selection balance hypothesis; (3) frequency‐dependent selection, which affords rare genotypes an advantage. The paper concludes with a discussion of two evolutionary consequences of variability: the fixation of deleterious mutations by drift in small populations and the role of clonal interference in large ones. © 2003 The Linnean Society of London. Biological Journal of the Linnean Society , 2003, 79 , 17–26.