Expression of a peroral infection factor determines pathogenicity and population structure in an insect virus
Fecha
2013Autor
Versión
Acceso abierto / Sarbide irekia
Tipo
Artículo / Artikulua
Versión
Versión publicada / Argitaratu den bertsioa
Impacto
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10.1371/journal.pone.0078834
Resumen
A Nicaraguan isolate of Spodoptera frugiperda multiple nucleopolyhedrovirus is being studied as a possible biological
insecticide. This virus exists as a mixture of complete and deletion genotypes; the latter depend on the former for the
production of an essential per os transmission factor (pif1) in coinfected cells. We hypothesized that the virus population
was structured to account for the ...
[++]
A Nicaraguan isolate of Spodoptera frugiperda multiple nucleopolyhedrovirus is being studied as a possible biological
insecticide. This virus exists as a mixture of complete and deletion genotypes; the latter depend on the former for the
production of an essential per os transmission factor (pif1) in coinfected cells. We hypothesized that the virus population
was structured to account for the prevalence of pif1 defector genotypes, so that increasing the abundance of pif1 produced
by a cooperator genotype in infected cells would favor an increased prevalence of the defector genotype. We tested this
hypothesis using recombinant viruses with pif1 expression reprogrammed at its native locus using two exogenous
promoters (egt, p10) in the pif2/pif1 intergenic region. Reprogrammed viruses killed their hosts markedly faster than the
wild-type and rescue viruses, possibly due to an earlier onset of systemic infection. Group success (transmission) depended
on expression of pif1, but overexpression was prejudicial to group-specific transmissibility, both in terms of reduced
pathogenicity and reduced production of virus progeny from each infected insect. The presence of pif1-overproducing
genotypes in the population was predicted to favor a shift in the prevalence of defector genotypes lacking pif1-expressing
capabilities, to compensate for the modification in pif1 availability at the population level. As a result, defectors increased
the overall pathogenicity of the virus population by diluting pif1 produced by overexpressing genotypes. These results offer
a new and unexpected perspective on cooperative behavior between viral genomes in response to the abundance of an
essential public good that is detrimental in excess. [--]
Materias
PIF factors,
Spodoptera frugiperda multiple nucleopolyhedrovirus,
Biological insecticides
Editor
Public Library of Science
Publicado en
Plos One, 8(11): e78834
Departamento
Universidad Pública de Navarra. Departamento de Producción Agraria /
Nafarroako Unibertsitate Publikoa. Nekazaritza Ekoizpena Saila /
Universidad Pública de Navarra/Nafarroako Unibertsitate Publikoa. IdAB. Instituto de Agrobiotecnología / Agrobioteknologiako Institutua
Versión del editor
Entidades Financiadoras
This study received financial support from the Spanish Ministry for Science and Technology projects AGL2005-07909-CO3-01 and AGL2008-05456-CO3-
01/AGR. O.S. received a Jose´ Castillejo grant for postdoctoral mobility.