Historical variations in mutation rate in an epidemic pathogen, Yersinia pestis.
Proc Natl Acad Sci U S A
; 110(2): 577-82, 2013 Jan 08.
Article
em En
| MEDLINE
| ID: mdl-23271803
ABSTRACT
The genetic diversity of Yersinia pestis, the etiologic agent of plague, is extremely limited because of its recent origin coupled with a slow clock rate. Here we identified 2,326 SNPs from 133 genomes of Y. pestis strains that were isolated in China and elsewhere. These SNPs define the genealogy of Y. pestis since its most recent common ancestor. All but 28 of these SNPs represented mutations that happened only once within the genealogy, and they were distributed essentially at random among individual genes. Only seven genes contained a significant excess of nonsynonymous SNP, suggesting that the fixation of SNPs mainly arises via neutral processes, such as genetic drift, rather than Darwinian selection. However, the rate of fixation varies dramatically over the genealogy the number of SNPs accumulated by different lineages was highly variable and the genealogy contains multiple polytomies, one of which resulted in four branches near the time of the Black Death. We suggest that demographic changes can affect the speed of evolution in epidemic pathogens even in the absence of natural selection, and hypothesize that neutral SNPs are fixed rapidly during intermittent epidemics and outbreaks.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Variação Genética
/
Yersinia pestis
/
Evolução Molecular
/
Deriva Genética
/
Taxa de Mutação
Tipo de estudo:
Prognostic_studies
País/Região como assunto:
Asia
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article