McKenzie J A, Batterham P
Department of Genetics, University of Melbourne, Parkville, Victoria, Australia.
Philos Trans R Soc Lond B Biol Sci. 1998 Oct 29;353(1376):1729-34. doi: 10.1098/rstb.1998.0325.
Strategies to manage resistance to a particular insecticide have usually been devised after resistance has evolved. If it were possible to predict likely resistance mechanisms to novel insecticides before they evolved in the field, it might be feasible to have programmes that manage susceptibility. With this approach in mind, single-gene variants of the Australian sheep blowfly, Lucilia cuprina, resistant to dieldrin, diazinon and malathion, were selected in the laboratory after mutagenesis of susceptible strains. The genetic and molecular bases of resistance in these variants were identical to those that had previously evolved in natural populations. Given this predictive capacity for known resistances, the approach was extended to anticipate possible mechanisms of resistance to cyromazine, an insecticide to which L. cuprina populations remain susceptible after almost 20 years of exposure. Analysis of the laboratory-generated resistant variants provides an explanation for this observation. The variants show low levels of resistance and a selective advantage over susceptibles for only a limited concentration range. These results are discussed in the context of the choice of insecticides for control purposes and of delivery strategies to minimize the evolution of resistance.
管理对特定杀虫剂抗性的策略通常是在抗性出现后才制定的。如果能够在新型杀虫剂在田间产生抗性之前预测其可能的抗性机制，那么实施保持易感性的方案或许是可行的。基于这一想法，在对澳大利亚绵羊绿蝇（Lucilia cuprina）的敏感品系进行诱变后，在实验室中筛选出了对狄氏剂、二嗪农和马拉硫磷具有抗性的单基因变异体。这些变异体抗性的遗传和分子基础与先前在自然种群中进化出的抗性相同。鉴于这种对已知抗性的预测能力，该方法被扩展到预测对环丙氨嗪可能的抗性机制，环丙氨嗪是一种杀虫剂，在近20年的使用后，绿蝇种群对其仍保持敏感。对实验室产生的抗性变异体的分析为这一观察结果提供了解释。这些变异体表现出低水平的抗性，并且仅在有限的浓度范围内相对于敏感个体具有选择优势。将在选择用于防治目的的杀虫剂以及尽量减少抗性进化的施药策略的背景下讨论这些结果。
