The creation and selection of mutations resistant to a gene drive over multiple generations in the malaria mosquito
The creation and selection of mutations resistant to a gene drive over multiple generations in the malaria mosquito
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DOI：
10.1371/journal.pgen.1007039
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发表时间：
2017-10-01
期刊：
影响因子：
4.5
通讯作者：
Nolan, Tony
中科院分区：
文献类型：
--
作者：
Hammond, Andrew M.;Kyrou, Kyros;Nolan, Tony
基因驱动在控制与医学和农业相关的昆虫种群方面具有巨大的潜力。通过优先偏向自己的遗传，基因驱动可以迅速引入遗传性状，即使这些性状对种群具有负面的适应性影响。我们最近开发了基于CRISPR核酸酶结构的基因驱动，旨在破坏疟疾蚊子雌性生殖能力所必需的关键基因。在配子形成过程中，该结构将自身和相关的遗传破坏从一条同源染色体复制到另一条染色体上，这一过程被称为归巢，确保大多数后代继承了这种驱动。这种驱力有可能造成长期、可持续的种群抑制，尽管它们也有望对蚊子的抗性施加很大的选择压力。其中一个种群抑制基因驱动在4代以上的时间里显示出对笼子种群的快速入侵，为该技术建立了原理证明。为了评估基因驱动在这个群体中出现抗药性的可能性，我们让它运行了25代，并随着时间的推移监测基因驱动的频率。随着基因驱动的初始增加，我们观察到其频率逐渐降低，同时伴随着小的核酸酶诱导突变在靶基因上的传播，这些突变可以抵抗进一步的切割并恢复其功能。这样的突变在面对基因驱动时显示出与正选择一致的增长率。我们的研究结果代表了对合成基因驱动的抗性选择的第一个记录示例，并导致了重要的设计建议和考虑，以减轻未来基因驱动应用中的抗性。
Gene drives have enormous potential for the control of insect populations of medical and agricultural relevance. By preferentially biasing their own inheritance, gene drives can rapidly introduce genetic traits even if these confer a negative fitness effect on the population. We have recently developed gene drives based on CRISPR nuclease constructs that are designed to disrupt key genes essential for female fertility in the malaria mosquito. The construct copies itself and the associated genetic disruption from one homologous chromosome to another during gamete formation, a process called homing that ensures the majority of offspring inherit the drive. Such drives have the potential to cause long-lasting, sustainable population suppression, though they are also expected to impose a large selection pressure for resistance in the mosquito. One of these population suppression gene drives showed rapid invasion of a caged population over 4 generations, establishing proof of principle for this technology. In order to assess the potential for the emergence of resistance to the gene drive in this population we allowed it to run for 25 generations and monitored the frequency of the gene drive over time. Following the initial increase of the gene drive we observed a gradual decrease in its frequency that was accompanied by the spread of small, nucleaseinduced mutations at the target gene that are resistant to further cleavage and restore its functionality. Such mutations showed rates of increase consistent with positive selection in the face of the gene drive. Our findings represent the first documented example of selection for resistance to a synthetic gene drive and lead to important design recommendations and considerations in order to mitigate for resistance in future gene drive applications.