Genetic lesions associated with Muller's ratchet in an RNA virus.
J Mol Biol
; 264(2): 255-67, 1996 Nov 29.
Article
en En
| MEDLINE
| ID: mdl-8951375
The molecular basis of Muller's ratchet has been investigated using the important animal pathogen foot-and-mouth disease virus (FMDV). Clones from two FMDV populations were subjected to serial plaque transfers (repeated bottleneck events) on host BHK-21 cells. Relative fitness losses were documented in 11 out of 19 clones tested. Small fitness gains were observed in three clones. One viral clone attained an extremely low plating efficiency, suggesting that accumulation of deleterious mutations had driven the virus near extinction. Nucleotide sequence analysis revealed unique genetic lesions in multiply transferred clones that had never been seen in FMDVs isolated in nature or subjected to massive infections in cell culture. In particular, a frequent internal polyadenylate extension has identified a mutational hot spot on the FMDV genome. Furthermore, amino acid residue substitutions in internal capsid sites which are severely restricted during FMDV evolution, amounted to half of capsid replacements in the transferred clones. In addition, a striking dominance of non-synonymous replacements fixed upon large population infections of FMDV was not observed upon serial plaque transfers. The nucleotide sequence of the entire genome of a severely debilitated clone suggests that very few mutations may be sufficient to drive FMDV near extinction. The results provide an account of the molecular basis of Muller's ratchet for an RNA virus, and insight into the types of genetic variants which populate the mutant spectra of FMDV quasispecies.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
ARN Viral
/
Aphthovirus
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
J Mol Biol
Año:
1996
Tipo del documento:
Article
País de afiliación:
España
Pais de publicación:
Países Bajos