title: Evolutionary trade-offs of insect resistance to Bacillus thuringiensis crops: fitness cost affecting paternity.
abstract: Evolution of resistance to insecticides provides a useful model for examining fitness trade-offs associated with adaptation to stress. Here, we examined male reproductive costs in pink bollworm (Pectinophora gossypiella) resistant to an insecticidal protein of Bacillus thuringiensis (Bt) produced by transgenic cotton, using contrasts between two pairs of related susceptible and resistant strains. Without competition for access to females, no costs affecting reproductive success of resistant males were observed. Resistant and susceptible males had similar mating frequency and fertility. Additionally, fecundity of females mated to resistant and susceptible males was comparable. In competition for matings with virgin females, resistant and susceptible males had comparable success in one strain, whereas susceptible males tended to mate more often than resistant males in the other. However, irrespective of strain origin, resistant males that mated first sired significantly less offspring than susceptible males that mated first. The reduced first-male paternity in resistant males may involve reduced sperm precedence caused by mutations in a cadherin gene linked with resistance to Bt cotton.
authors.affiliation: Department of Entomology, University of Arizona, Tucson, Arizona 85721, USA.
authors.forename: Dawn M
authors.initials: DM
authors.lastname: Higginson
authors.forename: Shai
authors.initials: S
authors.lastname: Morin
authors.forename: Megan E
authors.initials: ME
authors.lastname: Nyboer
authors.forename: Robert W
authors.initials: RW
authors.lastname: Biggs
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Tabashnik
authors.forename: Yves
authors.initials: Y
authors.lastname: Carrière
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000633:toxicity*; D001427:Bacterial Toxins / Q000633:toxicity*; D005075:Biological Evolution; D015820:Cadherins / Q000235:genetics; D004731:Endotoxins / Q000633:toxicity*; D005260:Female; D003368:Gossypium / Q000378:metabolism* / Q000382:microbiology; D006460:Hemolysin Proteins; D007305:Insecticide Resistance / Q000235:genetics; D008297:Male; D009036:Moths / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D009154:Mutation / Q000235:genetics; D030821:Plants, Genetically Modified; D016133:Polymerase Chain Reaction; D012098:Reproduction / Q000502:physiology; D012726:Sexual Behavior, Animal / Q000502:physiology*; D013045:Species Specificity
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D015820:Cadherins; D004731:Endotoxins; D006460:Hemolysin Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis