Novel genetic and biological control methods for an invasive insect pest.

白纹伊蚊是一种入侵性蚊子，在许多国家传播人类（如登革热和基孔肯雅）和牲畜病毒。在过去的十年中，它一直在欧洲稳步传播，导致人们担心它与气温上升相结合可能是主要病毒流行病的原因。此外，蚊子造成严重的白天叮咬滋扰。它在美国南部和东部的传播，现在是叮咬投诉的头号原因，已经导致人类行为改变，因为人们花更多的时间在室内以避免它。因此，希望（i）减少人们被蚊子叮咬的频率，例如通过抑制蚊子种群和（ii）减少蚊子种群的媒介能力。有了这些工具，可以酌情采用其中一种或两种。压制：大规模释放不育雄性可以对目标种群进行有效的、物种特异性的、环境友好的抑制，并且已经在针对一些主要农业害虫的大规模计划中做到了这一点。遗传学的进步使基于遗传的不育释放成为一种潜在的有吸引力的蚊子控制新策略（释放携带显性致死基因的昆虫，RIDL）1-2。继在埃及伊蚊2身上取得成功之后，我们正试图将这项技术转移到白纹伊蚊身上。到目前为止，我们已经成功地实现了转化，并且有初步数据表明我们可以实现必要的遗传学。学生将继续这项工作。减少向量能力：Ae。自然界中的白纹伊蚊自然感染了两种遗传性细胞内细菌沃尔巴克氏体。沃尔巴克氏体可以利用细胞质不相容性（CI）操纵宿主繁殖，从而提供在种群中快速传播的能力。最近发现，某些沃尔巴克氏体菌株（包括果蝇中的wMel）能够阻断或减少果蝇和埃及伊蚊中各种病毒和丝虫线虫寄生虫的发展或传播3，4。这些数据对控制各种具有医学和农业重要性的虫媒病原体具有影响。Wolbachia的wMel菌株将从D. melanogaster转化为四环素固化的Ae系。使用已建立的细胞质转移技术对白纹伊蚊进行了研究，选择了一个高孕产妇传播率的品系，并在该品系中测试了对登革热和基孔肯雅病毒传播的影响。将通过交叉和qRT-PCR表达分析来分析CI和免疫状态。这些方法的一个统一特征是，它们都通过改造蚊子在野外交配野生蚊子来产生影响。因此，影响这一点的菌株性能的定量测量（例如交配竞争力，寿命，飞行能力，繁殖力等）将成为学生工作的重要组成部分;这些实验的数据将用于参数化蚊子种群的数学模型，以及更有前途的菌株和策略的成本效益分析。RIDL和沃尔巴克氏体的方法相结合，以开发创新的不应期加抑制策略的可能性也将被审查。1.托马斯，D. D、Donnelly，C.一、伍德河，巴西-地J. & Alphey，L. S.利用显性的、可抑制的、致死的遗传系统控制昆虫种群。Science 287，2474-2476（2000）. 2 ℃，H. K.迟效显性致死遗传系统和蚊子控制。BMC Biology 5，11，doi：doi：10.1186/1741-7007-5-11（2007）. 3 Kambris，Z.，库克体育Alzheimer，H. K. & Sinkins，S. P.缩短寿命的沃尔巴克氏体的免疫激活和蚊子中丝虫能力的降低。Science 326，134-136（2009）.赫奇斯湖4号M.，布朗利，J.C.，奥尼尔，S. L. &约翰逊，K. N.沃尔巴克氏体与昆虫的病毒保护。Science 322，702（2008）。

Aedes albopictus is an invasive mosquito species that transmits human (e.g. Dengue and Chikungunya) and livestock viruses in many countries. It has been spreading steadily through Europe over the course of the last decade, leading to fears that in combination with rising temperatures it may be responsible for major viral epidemics. Furthermore, the mosquito causes severe daytime biting nuisance. Its spread through the south and east USA, where it is now the number one cause of biting complaints, has led to human behavioural change as people spend more time indoors to avoid it. It would therefore be desirable to (i) reduce the frequency with which people are bitten by the mosquito, e.g. by suppressing the mosquito population and (ii) reduce the vectorial capacity of the mosquito population. With such tools, either or both could be applied, as appropriate. Suppression: Mass-release of sterile males can give effective, species-specific, environmentally friendly suppression of target populations, and has done so in large-scale programs against some major agricultural pests. Advances in genetics make genetics-based sterile-release a potentially attractive new strategy for mosquito control (Release of Insects carrying a Dominant Lethal gene, RIDL)1-2. Following success in Aedes aegypti2, we are attempting to transfer this technology to Aedes albopictus. So far we have successfully achieved transformation and also have preliminary data indicating that we can achieve the necessary genetics. The student will develop this work. Reduced vectorial competence: Ae. albopictus in nature are naturally infected with two strains of the inherited intracellular bacterium Wolbachia. Wolbachia can manipulate host reproduction to their own ends using cytoplasmic incompatibility (CI), providing an ability to spread rapidly through populations. It has recently been found that certain strains of Wolbachia (including wMel in Drosophila) are able to block or reduce the development or dissemination of various viruses and filarial nematode parasites in Drosophila and in Aedes aegypti mosquitoes3,4. These data have implications for the control of a variety of insect-borne pathogens of medical and agricultural importance. The wMel strain of Wolbachia will be transferred from D. melanogaster into a tetracycline-cured line of Ae. albopictus using established techniques of cytoplasm transfer, a line selected for high rates of maternal transmission, and effects on Dengue and Chikungunya transmission tested in this line. The CI and immune status will be analysed by crossing and qRT-PCR expression analyses. A unifying feature of these approaches is that they all have their impact via modified mosquitoes mating wild mosquitoes in the field. Quantitative measures of strain performance that would impact this (e.g. mating competitiveness, longevity, flight ability, fecundity, etc as appropriate) will therefore form a significant part of the student's work; data from these experiments will be used to parameterise mathematical models of mosquito populations and also cost-benefit analyses for the more promising strains and strategies. The possibility of combining RIDL and Wolbachia approaches to develop innovative refractory-plus-suppression strategies will also be examined. 1 Thomas, D. D., Donnelly, C. A., Wood, R. J. & Alphey, L. S. Insect population control using a dominant, repressible, lethal genetic system. Science 287, 2474-2476 (2000). 2 Phuc, H. K. et al. Late-acting dominant lethal genetic systems and mosquito control. BMC Biology 5, 11, doi:doi: 10.1186/1741-7007-5-11 (2007). 3 Kambris, Z., Cook, P. E., Phuc, H. K. & Sinkins, S. P. Immune activation by life-shortening Wolbachia and reduced filarial competence in mosquitoes. Science 326, 134-136 (2009). 4 Hedges, L. M., Brownlie, J. C., O'Neill, S. L. & Johnson, K. N. Wolbachia and virus protection in insects. Science 322, 702 (2008).