Genomics of mosquito resistance to Plasmodium

说明(由申请人提供)：这是一个四年项目#AI42361的竞争性延续提案，以前的标题是“冈比亚按蚊对疟原虫易感性的遗传学”。自项目开始以来，该项目首次对蚊子免疫机制和自然界对疟原虫的抗药性进行了系统研究。了解这些相互作用的生物学特性可以开发出抑制寄生虫传播的新策略。在最后一个项目期间，我们对主要的人类疟疾媒介冈比亚按蚊进行了现场遗传分析。这项工作首次在一种病毒中发现了基因。冈比亚减少恶性疟原虫的自然传播。我们定位了两个抗寄生虫的基因座，Pfin1和Pfin2。Pfin1基因座的抗性纯合子平均每只蚊子有0.17个卵囊，而敏感纯合子的平均每只蚊子有50.6个卵囊。我们发现了明显的高自然频率的抗性等位基因，这表明疟疾寄生虫(或类似的病原体)对媒介种群施加了显著的选择压力。在这里，我们提出了新的综合目标，直接建立在先前工作的基础上，在自然疟疾传播系统的背景下研究蚊子免疫和寄生虫抗性的遗传学和基因组学。我们将：1)筛选一个自然种群。在西非马里，冈比亚通过在自然传播系统中以10厘米的分辨率进行全基因组扫描，寻找控制恶性疟原虫耐药性的基因座。2)以高遗传分辨率定位Aim 1中确定的自然抗性基因座，分离出数量可观的候选抗病基因。3)通过序列分析、转录图谱分析和生理研究筛选候选抗性基因，并定位克隆至少一个已失去的抗性性状。拟议的延续项目将是对蚊子田间种群进行的第一次基因筛查，以寻找对疟疾寄生虫具有抗药性的基因。我们将在10厘米的遗传分辨率下确定抗寄生虫性状的数量、频率和基因组组织。我们将保持蚊子家族分离选定的特征，我们可能会选择稳定的品系，我们将绘制特征图，描述细胞机制，我们将定位克隆一个或多个潜在基因。

DESCRIPTION (provided by the applicant): This is a competing continuation proposal for the four-year project #AI42361, previously entitled, "Genetics of An. gambiae susceptibility to Plasmodium." Since its inception, this project has comprised the first systematic examination of mechanisms of mosquito immunity and resistance to Plasmodium in nature. Understanding the biology of these interactions could permit development of novel strategies to inhibit parasite transmission. In the last project period, we carried out a field-based genetic analysis of the major human malaria vector, Anopheles gambiae. This work for the first time identified genes in An. gambiae that reduce the natural transmission of P. falciparum. We mapped two loci for parasite resistance, Pfin1 and Pfin2. Resistant homozygotes at the Pfin1 locus had a mean of 0.17 oocysts per mosquito, while susceptible homozygotes had 50.6. We found an apparent high natural frequency of resistance alleles, which suggests that malaria parasites (or a similar pathogen) exert a significant selective pressure on vector populations. Here, we present new integrated Aims that build directly upon the previous work to study the genetics and genomics of mosquito immunity and parasite resistance in the context of the natural malaria transmission system. We will: 1) Screen a natural population of An. gambiae by genome-wide scanning at 10 cM resolution for loci that control resistance to P. falciparum in the natural transmission system in Mali, West Africa. 2) Map natural resistance loci identified in Aim 1 at high genetic resolution to isolate a tractable number of candidate resistance genes. 3) Filter the candidate resistance genes by sequence analysis, transcriptional profiling, and physiological studies, and positionally clone at least one resistance trait gone. The proposed continuation project will be the first genetic screen in a mosquito field population for genes conferring resistance to malaria parasites. We will determine the number, frequencies, and genomic organization of parasite-resistance traits, at 10 cM genetic resolution. We will maintain mosquito families segregating chosen traits and we may select stable lines, we will map the traits, describe the cellular mechanism, and we will positionally clone one or more underlying genes.