The use of a site-specific homing-based gene drive for insect pest control has long been discussed, but the easy design of such systems has become possible only with the recent establishment of CRISPR/Cas9 technology. In this respect, novel targets for insect pest management are provided by new discoveries regarding sex determination. Here, we present a model for a suppression gene drive designed to cause an all-male population collapse in an agricultural pest insect. To evaluate the molecular details of such a sex conversion-based suppression gene drive experimentally, we implemented this strategy in Drosophila melanogaster to serve as a safe model organism. We generated a Cas9-based homing gene-drive element targeting the transformer gene and showed its high efficiency for sex conversion from females to males. However, nonhomologous end joining increased the rate of mutagenesis at the target site, which resulted in the emergence of drive-resistant alleles and therefore curbed the gene drive. This confirms previous studies that simple homing CRISPR/Cas9 gene-drive designs will be ineffective. Nevertheless, by performing population dynamics simulations using the parameters we obtained in D. melanogaster and by adjusting the model for the agricultural pest Ceratitis capitata, we were able to identify adequate modifications that could be successfully applied for the management of wild Mediterranean fruit fly populations using our proposed sex conversion-based suppression gene-drive strategy.

使用基于位点特异性归巢的基因驱动来控制害虫早已被讨论，但只有随着最近 CRISPR/Cas9 技术的建立，此类系统的简单设计才成为可能。在这方面，性别决定的新发现为害虫管理提供了新的目标。在这里，我们提出了一个抑制基因驱动模型，旨在导致农业害虫的全雄性种群崩溃。为了通过实验评估这种基于性别转换的抑制基因驱动的分子细节，我们在果蝇中实施了这种策略，作为安全的模型生物。我们生成了一个基于 Cas9 的针对Transformer基因的归巢基因驱动元件，并展示了其从女性到男性性别转换的高效性。然而，非同源末端连接增加了靶位点的诱变率，导致驱动抗性等位基因的出现，从而抑制了基因驱动。这证实了之前的研究，即简单的归巢 CRISPR/Cas9 基因驱动设计将是无效的。尽管如此，通过使用我们在黑腹果蝇中获得的参数进行种群动态模拟，并通过调整农业害虫Ceratitis headata的模型，我们能够确定适当的修改，可以成功地应用于野生地中海果蝇种群的管理我们提出的基于性别转换的抑制基因驱动策略。