Initial frequency of alleles for resistance to Bacillus thuringiensis toxins in field populations of Heliothis virescens
Initial frequency of alleles for resistance to Bacillus thuringiensis toxins in field populations of Heliothis virescens
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DOI：
10.1073/pnas.94.8.3519
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发表时间：
1997-04-15
影响因子：
11.1
通讯作者：
Laster, M
中科院分区：
文献类型：
--
作者：
Gould, F;Anderson, A;Laster, M
害虫对杀虫剂快速适应的风险高度依赖于田间种群中抗性等位基因的初始频率。由于我们缺乏对这些频率的经验估计，抗性进化的群体遗传模型依赖于广泛的理论估计。最近的商业化的基因工程棉花，组成性地产生一种杀虫蛋白质来源于生物控制剂，苏云金芽孢杆菌（Bt）引起了人们的关注，我们缺乏所需的数据来量化昆虫害虫的风险，如Heliothis virescens迅速适应这类具有生态价值的毒素。通过单独交配超过2,000只雄性H.通过对4个州的绿翅蛾进行Bt毒蛋白抗性实验室品系雌蛾的抗性筛选，并对F-1和F-2后代进行毒蛋白抗性筛选，我们能够直接估计抗性等位基因的田间频率为1.5 × 10 ~（-3）。这种高初始频率强调了在部署转基因棉花以控制害虫时需要谨慎。我们的单对交配技术大大提高了检测隐性抗性等位基因的效率。由于降低靶标位点对Bt毒素和其他杀虫剂敏感性的等位基因通常是隐性的，因此该技术可用于估计暴露于转基因杀虫作物或常规杀虫剂的其他昆虫中的抗性等位基因频率。
The risk of rapid pest adaptation to an insecticide is highly dependent on the initial frequency of resistance alleles in field populations. Because we have lacked empirical estimates of these frequencies, population-genetic models of resistance evolution have relied on a wide range of theoretical estimates. The recent commercialization of genetically engineered cotton that constitutively produces an insecticidal protein derived from the biocontrol agent, Bacillus thuringiensis (Bt) has raised concern that we lack data needed to quantify the risk of insect pests such as Heliothis virescens rapidly adapting to this ecologically valuable class of toxins. By individually mating over 2,000 male H. virescens moths collected in four states to females of Bt toxin-resistant laboratory strain, and screening F-1 and F-2 offspring for tolerance of the toxic protein, we were able to directly estimate the field frequency of alleles for resistance as 1.5 x 10(-3). This high initial frequency underscores the need for caution in deploying transgenic cotton to control insect pests. Our single-pair mating technique greatly increases the efficiency of detecting recessive resistance alleles. Because alleles that decrease target site sensitivity to Bt toxins and other insecticides are often recessive, this technique could be useful in estimating resistance allele frequencies in other insects exposed to transgenic insecticidal crops or conventional insecticides.