Wilke André Barretto Bruno, Marrelli Mauro Toledo
Departamento de Epidemiologia, Faculdade de Saúde Pública, Universidade de São Paulo, Av. Dr. Arnaldo 715, São Paulo, SP, CEP-01246-904, Brazil.
Parasit Vectors. 2015 Jun 24;8:342. doi: 10.1186/s13071-015-0959-2.
The three main mosquito genera, Anopheles, Aedes and Culex, transmit respectively malaria, dengue and lymphatic filariasis. Current mosquito control strategies have proved unsuccessful, and there still is a substantial number of morbidity and mortality from these diseases. Genetic control methods have now arisen as promising alternative strategies, based on two approaches: the replacement of a vector population by disease-refractory mosquitoes and the release of mosquitoes carrying a lethal gene to suppress target populations. However, substantial hurdles and limitations need to be overcome if these methods are to be used successfully, the most significant being that a transgenic mosquito strain is required for every target species, making genetically modified mosquito strategies inviable when there are multiple vector mosquitoes in the same area. Genetically modified bacteria capable of colonizing a wide range of mosquito species may be a solution to this problem and another option for the control of these diseases. In the paratransgenic approach, symbiotic bacteria are genetically modified and reintroduced in mosquitoes, where they express effector molecules. For this approach to be used in practice, however, requires a better understanding of mosquito microbiota and that symbiotic bacteria and effector molecules be identified. Paratransgenesis could prove very useful in mosquito species that are inherently difficult to transform or in sibling species complexes. In this approach, a genetic modified bacteria can act by: (a) causing pathogenic effects in the host; (b) interfering with the host's reproduction; (c) reducing the vector's competence; and (d) interfering with oogenesis and embryogenesis. It is a much more flexible and adaptable approach than the use of genetically modified mosquitoes because effector molecules and symbiotic bacteria can be replaced if they do not achieve the desired result. Paratransgenesis may therefore become an important integrated pest management tool for mosquito control.
按蚊、伊蚊和库蚊这三大主要蚊属分别传播疟疾、登革热和淋巴丝虫病。目前的蚊虫控制策略已被证明并不成功，这些疾病仍导致大量发病和死亡。基于两种方法，遗传控制方法现已成为有前景的替代策略：用对疾病有抗性的蚊子取代病媒种群，以及释放携带致死基因的蚊子以抑制目标种群。然而，如果要成功使用这些方法，还需要克服诸多障碍和限制，其中最显著的是每个目标物种都需要一种转基因蚊株，当同一区域存在多种病媒蚊子时，转基因蚊子策略就不可行。能够在多种蚊子物种中定殖的转基因细菌可能是解决这一问题的办法，也是控制这些疾病的另一种选择。在昆虫共生菌转基因方法中，共生细菌经过基因改造后重新引入蚊子体内，在那里它们表达效应分子。然而，要在实际中使用这种方法，需要更好地了解蚊子的微生物群，并确定共生细菌和效应分子。昆虫共生菌转基因方法在本质上难以转化的蚊子物种或近缘物种复合体中可能非常有用。在这种方法中，转基因细菌可以通过以下方式发挥作用：(a) 对宿主产生致病作用；(b) 干扰宿主的繁殖；(c) 降低病媒的传播能力；(d) 干扰卵子发生和胚胎发生。与使用转基因蚊子相比，这是一种更灵活、适应性更强的方法，因为如果效应分子和共生细菌没有达到预期效果，可以进行替换。因此，昆虫共生菌转基因方法可能会成为蚊虫控制的一种重要的综合害虫管理工具。
