Three cadherin alleles associated with resistance to Bacillus thuringiensis in pink bollworm
Three cadherin alleles associated with resistance to Bacillus thuringiensis in pink bollworm
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DOI：
10.1073/pnas.0831036100
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发表时间：
2003-04-29
影响因子：
11.1
通讯作者：
Tabashnik, BE
中科院分区：
文献类型：
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作者：
Morin, S;Biggs, RW;Tabashnik, BE
害虫抗性的进化是通过产生苏云金芽孢杆菌（Bt）毒素的转基因作物长期控制昆虫的主要威胁。由于转基因作物对Bt毒素的抗性遗传通常是隐性的，因此基于DNA的杂合子抗性等位基因筛选可能比用生物测定检测抗性纯合子更有效。然而，这种筛选需要了解田间害虫种群中与Bt作物生存相关的抗性等位基因。在这里，我们报告，粉红色的棉铃虫（Pectinophora gossypiella），一个主要的棉花害虫，田间种群，窝藏三个突变等位基因的钙粘蛋白编码基因与抗Bt毒素Cry1Ac和生存转基因Bt棉。三个抗性等位基因中的每一个都具有预期消除钙粘蛋白的推定毒素结合区上游的至少八个氨基酸的缺失。在任何组合中，具有两个抗性等位基因的幼虫都是抗性的，而具有一个或没有抗性等位基因的幼虫对Cry1Ac是敏感的。与以前的证据一起，这里报道的结果将钙粘蛋白基因确定为基于DNA的鳞翅目害虫对Bt作物的抗性筛选的主要目标。
Evolution of resistance by pests is the main threat to long-term insect control by transgenic crops that produce Bacillus thuringiensis (Bt) toxins. Because inheritance of resistance to the Bt toxins in transgenic crops is typically recessive, DNA-based screening for resistance alleles in heterozygotes is potentially much more efficient than detection of resistant homozygotes with bioassays. Such screening, however, requires knowledge of the resistance alleles in field populations of pests that are associated with survival on Bt crops. Here we report that field populations of pink bollworm (Pectinophora gossypiella), a major cotton pest, harbored three mutant alleles of a cadherin-encoding gene linked with resistance to Bt toxin Cry1Ac and survival on transgenic Bt cotton. Each of the three resistance alleles has a deletion expected to eliminate at least eight amino acids upstream of the putative toxin-binding region of the cadherin protein. Larvae with two resistance alleles in-any combination were resistant, whereas those with one or none were susceptible to Cry1Ac. Together with previous evidence, the results reported here identify the cadherin genie as a leading target for DNA-based screening of resistance to Bt crops in lepidopteran pests.