Higginson Dawn M, Morin Shai, Nyboer Megan E, Biggs Robert W, Tabashnik Bruce E, Carrière Yves
Department of Entomology, University of Arizona, Tucson, Arizona 85721, USA.
Evolution. 2005 Apr;59(4):915-20.
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.
杀虫剂抗性的进化为研究与适应压力相关的适合度权衡提供了一个有用的模型。在此，我们利用两对相关的敏感和抗性品系之间的对比，研究了对转基因棉花产生的苏云金芽孢杆菌（Bt）杀虫蛋白具有抗性的棉铃虫（Pectinophora gossypiella）雄性的生殖成本。在没有争夺雌性的情况下，未观察到影响抗性雄性生殖成功的成本。抗性和敏感雄性具有相似的交配频率和生育能力。此外，与抗性和敏感雄性交配的雌性的繁殖力相当。在与未交配过的雌性竞争交配时，抗性和敏感雄性在一个品系中的成功几率相当，而在另一个品系中，敏感雄性往往比抗性雄性交配更频繁。然而，无论品系来源如何，首先交配的抗性雄性产生的后代明显少于首先交配的敏感雄性。抗性雄性中首次交配雄性的父权降低可能涉及与对Bt棉花抗性相关的钙黏蛋白基因突变导致的精子优先性降低。
