Evolution of a polydnavirus gene in relation to parasitoid-host species immune resistance.
CrV1, a polydisperse DNA virus (polydnavirus or PDV) gene contributes to the suppression of host immunity in Cotesia genus parasitoids. Its molecular evolution was analyzed in relation to levels of resistance in the sympatric host species. Natural selection for nonsynonymous substitutions (positive Darwinian selection) was observed at specific amino acid sites among CrV1 variants; particularly, between parasitoid strains immune suppressive and nonimmune suppressive to the main resistant stem borer host, Busseola fusca. In Cotesia sesamiae, geographic distribution of CrV1 alleles in Kenya was correlated to the relative abundance of B. fusca. These results suggest that PDV genes evolve through natural selection and are genetically linked to factors of suppression of local host resistance. We discuss the forces driving the evolution of CrV1 and its use as a marker to understand parasitoid adaptation to host resistance in biological control.
IRD, UR R072 c/o CNRS, Lab. L.EG.S., BP1, 1 avenue de la Terrasse, 91198 Gif-sur-Yvette, France. dupas@legs.cnrs-gif.fr
Stéphane
S
Dupas
Catherine Wanjiru
CW
Gitau
Antoine
A
Branca
Bruno Pierre
BP
Le Rü
Jean-François
JF
Silvain
D000595:Amino Acid Sequence; D000818:Animals; D005075:Biological Evolution; D005260:Female; D005814:Genes, Viral; D005819:Genetic Markers; D005838:Genotype; D006790:Host-Parasite Interactions / Q000235:genetics; D007630:Kenya; D007814:Larva / Q000469:parasitology / Q000821:virology; D008297:Male; D008969:Molecular Sequence Data; D009036:Moths / Q000276:immunology* / Q000469:parasitology* / Q000821:virology; D010572:Pest Control, Biological; D010802:Phylogeny; D018071:Polydnaviridae / Q000235:genetics*; D012641:Selection, Genetic; D045868:Sorghum; D014863:Wasps / Q000145:classification / Q000502:physiology / Q000821:virology*; D003313:Zea mays
D005819:Genetic Markers