title: The dynamics of cooperative bacterial virulence in the field.
abstract: Laboratory experiments have shown that the fitness of microorganisms can depend on cooperation between cells. Although this insight has revolutionized our understanding of microbial life, results from artificial microcosms have not been validated in complex natural populations. We investigated the sociality of essential virulence factors (crystal toxins) in the pathogen Bacillus thuringiensis using diamondback moth larvae (Plutella xylostella) as hosts. We show that toxin production is cooperative, and in a manipulative field experiment, we observed persistent high relatedness and frequency- and density-dependent selection, which favor stable cooperation. Conditions favoring social virulence can therefore persist in the face of natural population processes, and social interactions (rapid cheat invasion) may account for the rarity of natural disease outbreaks caused by B. thuringiensis.
authors: School of Biological Sciences, Royal Holloway University of London, Egham, UK. ben.raymond@rhul.ac.uk
authors: Ben
authors: B
authors: Raymond
authors: Stuart A
authors: SA
authors: West
authors: Ashleigh S
authors: AS
authors: Griffin
authors: Michael B
authors: MB
authors: Bonsall
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis / Q000254:growth & development / Q000472:pathogenicity* / Q000502:physiology; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D001937:Brassica / Q000382:microbiology; D004731:Endotoxins / Q000096:biosynthesis* / Q000235:genetics; D006458:Hemolymph / Q000382:microbiology; D006460:Hemolysin Proteins / Q000096:biosynthesis* / Q000235:genetics; D007814:Larva / Q000472:pathogenicity / Q000502:physiology; D056265:Microbial Interactions; D009036:Moths / Q000382:microbiology*; D018515:Plant Leaves / Q000382:microbiology*; D014774:Virulence; D037521:Virulence Factors / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D004731:Endotoxins; D006460:Hemolysin Proteins; D037521:Virulence Factors; C030956:insecticidal crystal protein, Bacillus Thuringiensis