PROPERTIES OF AMPLIFIED GENES FOR RESISTANCE IN CULEX

抗药性是有效控制害虫的一个严重障碍。 疾病的昆虫媒介。我的研究项目是针对 了解影响人类遗传和种群的过程， 病媒种群对杀虫剂抗药性的演变。长期 我的工作目标是提供必要的信息，设计矢量 最小化阻力演变速率的控制策略。 致倦库蚊对有机磷的抗药性 杀虫剂与高活性酯酶等位酶有关， EST-B1。高酯酶活性的分子基础 耐药个体是扩增（拷贝数增加） EST-B1基因。 为了了解EST-B1基因扩增的动态， 我们需要了解基因过程如何与 杀虫选择以产生具有高酯酶活性的个体， 这些高活性表型的稳定性，以及如何 酯酶活性表型影响生殖适合度， 没有杀虫剂。 本研究的具体目标是：1）染色体 携带和EST-B1基因扩增， 酯酶活性明显高于敏感品系 水平将从致倦库蚊的S-Y菌株中分离， 表现出广泛的酯酶活性表型。株携带 该染色体将进行杀虫选择以评估 酯酶活性表型频率和分布的变化 随着时间这个实验将提供一个粗略的频率估计 酯酶活性变体的产生，以及高酯酶活性变体的产生 活性表型通过选择产生。2)高稳定性 通过选择产生的酯酶活性表型将通过以下测定： 检测酯酶活性频率和分布的变化 表型随着时间的推移从杀虫选择释放的菌株。第三章 酯酶活性表型与其抗氧化能力的关系 将在变量S-Y中确定杀虫剂处理的存活率 通过将个体样本置于不同浓度的 杀虫剂和测量幸存者的酯酶活性。4)的 酯酶活性表型与生殖适合度的关系 将通过测量酯酶在可变S-Y菌株中测定 活动和个体生殖适合度的几个组成部分。

Insecticide resistance is a serious obstacle to the effective control of insect vectors of disease. My research program is directed toward understanding the genetic and population processes influencing the evolution of insecticide resistance in vector populations. The long-term goal of my work is to provide the information necessary to design vector control strategies which minimize the rate of evolution of resistance. In the mosquito Culex quinquefasciatus, resistance to organophosphate insecticides is associated with a highly active esterase allozyme, designated EST-B1. The molecular basis of high esterase activity in resistant individuals is amplification (increase in copy number) of the EST-B1 gene. To understand the dynamics of amplified EST-B1 genes in populations we need information about how genetic processes interact with insecticidal selection to produce individuals with high esterase activity, the stability properties of these high activity phenotypes, and how esterase activity phenotype affects reproductive fitness in the presence of absence of insecticide. The specific objectives of the proposed research are: 1) A chromosome carrying and EST-B1 gene amplification which results in a small bud readily detectable increase in esterase activity over susceptible strain levels will be isolated from the S-Y strain of C quinquefasciatus which exhibits a wide range of esterase activity phenotypes. Strains carrying this chromosome will be subjected to insecticidal selection to assess changes in the frequency and distribution of esterase activity phenotypes over time. This experiment will provide a rough estimate of the frequency with which esterase activity variants arise, and how quickly high esterase activity phenotypes are produced by selection. 2) The stability of high esterase activity phenotypes produced by selection will be determined by examining changes in the frequency and distribution of esterase activity phenotypes over time in strains released from insecticidal selection. 3) The relationship between esterase activity phenotype and the ability to survive insecticide treatment will be determined in the variable S-Y strain by subjecting samples of Individuals to different concentrations of insecticide and measuring the esterase activity of survivors. 4) The relationship between esterase activity phenotype and reproductive fitness will be determined in the variable S-Y strain by measuring esterase activity and several components of reproductive fitness of individuals.