Data61, CSIRO, 3 Castray Esplanade, Battery Point TAS, Australia.
Mineral Resources, CSIRO, 1 Technology Court, Pullenvale QLD, Australia.
PLoS Comput Biol. 2022 Jun 1;18(6):e1009526. doi: 10.1371/journal.pcbi.1009526. eCollection 2022 Jun.
Malaria is one of the deadliest vector-borne diseases in the world. Researchers are developing new genetic and conventional vector control strategies to attempt to limit its burden. Novel control strategies require detailed safety assessment to ensure responsible and successful deployments. Anopheles gambiae sensu stricto (s.s.) and Anopheles coluzzii, two closely related subspecies within the species complex Anopheles gambiae sensu lato (s.l.), are among the dominant malaria vectors in sub-Saharan Africa. These two subspecies readily hybridise and compete in the wild and are also known to have distinct niches, each with spatially and temporally varying carrying capacities driven by precipitation and land use factors. We model the spread and persistence of a population-modifying gene drive system in these subspecies across sub-Saharan Africa by simulating introductions of genetically modified mosquitoes across the African mainland and its offshore islands. We explore transmission of the gene drive between the two subspecies that arise from different hybridisation mechanisms, the effects of both local dispersal and potential wind-aided migration to the spread, and the development of resistance to the gene drive. Given the best current available knowledge on the subspecies' life histories, we find that an introduced gene drive system with typical characteristics can plausibly spread from even distant offshore islands to the African mainland with the aid of wind-driven migration, with resistance beginning to take over within a decade. Our model accounts for regional to continental scale mechanisms, and demonstrates a range of realistic dynamics including the effect of prevailing wind on spread and spatio-temporally varying carrying capacities for subspecies. As a result, it is well-placed to answer future questions relating to mosquito gene drives as important life history parameters become better understood.
疟疾是世界上最致命的虫媒传染病之一。研究人员正在开发新的遗传和传统的病媒控制策略，以试图减轻其负担。新的控制策略需要进行详细的安全评估，以确保负责任和成功的部署。冈比亚按蚊亚种（s.s.）和冈比亚按蚊库蚊亚种（Anopheles coluzzii）是冈比亚按蚊复合体（s.l.）中两种密切相关的亚种，是撒哈拉以南非洲地区主要的疟疾媒介。这两个亚种在野外很容易杂交和竞争，也被认为有不同的生态位，每个生态位都有由降水和土地利用因素驱动的空间和时间变化的承载能力。我们通过模拟在非洲大陆及其近海岛屿上引入经过基因改良的蚊子，来模拟这些亚种中一种改变种群的基因驱动系统的传播和持久性。我们探讨了来自不同杂交机制的两个亚种之间基因驱动的传播，局部扩散和潜在的风辅助迁移对传播的影响，以及对基因驱动的抗性的发展。鉴于目前对亚种生活史的最佳了解，我们发现，即使在遥远的近海岛屿上，具有典型特征的引入基因驱动系统也可以在风驱动迁移的帮助下传播到非洲大陆，而抗性在十年内开始占据主导地位。我们的模型考虑了区域到大陆范围的机制，并展示了一系列现实的动态，包括盛行风对传播的影响和亚种时空变化的承载能力。因此，它可以很好地回答与蚊子基因驱动有关的未来问题，因为重要的生活史参数得到了更好的理解。
