Refining Mendelian genetics of malaria parasites

完善疟疾寄生虫的孟德尔遗传学

• 批准号: 10216647
• 负责人: Stefan HI Kappe
• 金额: $ 23.84万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2024-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10216647
• 关键词: Animal Model; Anopheles Genus; Anti-malarial drug resistance; Artemisinins; Back; Backcrossings; Bite; Blood; Candidate Disease Gene; Cessation of life; Chromosome Mapping; Cloning; Complex; Coupled; Culicidae; Data; Development; Drug resistance; Erythrocytes; Ethics; Evolution; Experimental Genetics; Extrachromosomal Inheritance; Female; Generations; Genes; Genetic; Genetic Crosses; Genetic Determinism; Genetic Population Study; Genetic Recombination; Genetic Research; Genetic study; Genome; Genotype; Geographic Locations; Germ Cells; Grant; Growth; Haploidy; Hepatocyte; Human; Individual; Infection; Ingestion; Intervention; Knowledge; Laboratories; Life Cycle Stages; Link; Liver; Malaria; Maps; Measures; Midgut; Mitochondria; Modeling; Mus; Mutation; Pan Genus; Parasite resistance; Parasites; Partner in relationship; Pharmaceutical Preparations; Phenotype; Plasmodium; Plasmodium falciparum; Population; Population Genetics; Process; Publishing; Quantitative Trait Loci; Recombinants; Recovery; Reproductive Biology; Research; Research Project Grants; Resistance; Sampling; Sexual Reproduction; Southeastern Asia; Speed; Sporozoites; Supporting Cell; System; Technology; Testing; Time; United States National Institutes of Health; asexual; experimental study; fitness; fly; forward genetics; genetic approach; genome sequencing; insight; interest; intravenous administration; intravenous injection; mouse model; pathogen; preference; prevent; reproductive; resistance gene; success; tool; trait; vector mosquito

ABSTRACT A well informed experimental genetic cross is a powerful forward genetics tool because it generates recombinant progeny for genetic mapping of observed phenotypes. This approach has been extensively used in many model organisms from flies to mice but crossing different strains of the human malaria parasite Plasmodium falciparum, responsible for the deaths of hundreds of thousands of individuals every year, is a challenge. The parasite's life cycle is complex, alternates between the mosquito vector and human host and includes obligate sexual reproduction. In order to generate and phenotype recombinant parasites, the complete life cycle from asexual blood stage-to-sexual blood stage-to-recombinant formation in the mosquito-to-liver stage and back to asexual blood stage must occur in the laboratory. Previously, the liver stage-to blood stage transition was only possible in splenectomized chimps and due to the ethical and financial roadblocks to chimp research only three genetic crosses were ever performed before the NIH banned chimp research. We have developed a human-liver chimeric mouse model that allows for P. falciparum liver stage development and transition to blood stage infection and have used this model successfully to recover progeny from P. falciparum genetic crosses. The ease of use of this mouse model will now allow us to create numerous well-informed crosses. This Research Project will initially define variables and factors that will allow us to maximize the recovery of unique recombinant parasites. We predict that with >60 unique recombinant progeny, we will be able to fine map traits of interest to genome regions containing just a few candidate genes. Furthermore, we will use recombinant progeny for backcrossing experiments to determine genes involved in the parasite's ability to avoid selfing and promote hybridization as well as cytoplasmic genome incompatibility observed in crossing experiments. Accelerated hybridization could drive recombination between parasite strains and thus could speed the spread of drug resistant genes through a parasite population. Conversely, cytoplasmic genome incompatibility could prevent parasites strains from recombining. The mating mechanisms analyzed within this project are of great importance in the context of the overall P01 grant, which aims to more fully understand artemisinin resistance and resistance to partner drugs, including piperaquine, which currently are a significant concern in malaria elimination efforts. Finally, we will establish bulk segregant analyses coupled with genome sequencing and quantitative trait loci mapping to enable more efficient mapping of genes linked to phenotypes and this will be especially important for analysis of emerging piperaquine resistant parasites that have now been documented in Southeast Asia. The successful completion of this Research Project will greatly enhance P. falciparum genetics research and will further our understanding of parasite drug resistance, with regard to its emergence, evolution and spread.

抽象的 消息灵通的实验遗传杂交是一种强大的正向遗传学工具，因为它产生重组 后代用于观察到的表型的遗传图谱。这种方法在很多模型中得到了广泛的应用 从苍蝇到小鼠​​的生物体，但交叉了人类疟原虫恶性疟原虫的不同菌株， 每年造成数十万人死亡，这是一项挑战。寄生虫的一生 周期很复杂，在蚊子媒介和人类宿主之间交替，并且包括专性性行为 生殖。为了产生重组寄生虫并对其进行表型分析，需要从无性生殖到完整的生命周期 血液阶段到有性阶段 血液阶段到重组形成 蚊子到肝脏阶段并返回无性阶段 血液阶段必须在实验室进行。以前，肝脏阶段到血液阶段的转变是唯一可能的 在脾脏切除的黑猩猩中，由于黑猩猩研究的伦理和财务障碍，只有三种基因 在美国国立卫生研究院禁止黑猩猩研究之前就曾进行过杂交。我们开发了人类肝脏 允许恶性疟原虫肝脏阶段发育并过渡到血液阶段的嵌合小鼠模型 感染，并已成功使用该模型从恶性疟原虫遗传杂交中恢复后代。这 该小鼠模型的易用性现在使我们能够创建许多消息灵通的杂交。这项研究 项目最初将定义变量和因素，使我们能够最大限度地回收独特的重组蛋白 寄生虫。我们预测，通过超过 60 个独特的重组后代，我们将能够精细绘制感兴趣的性状 仅包含一些候选基因的基因组区域。此外，我们将使用重组后代 回交实验以确定与寄生虫避免自交和促进能力相关的基因 杂交以及杂交实验中观察到的细胞质基因组不相容性。加速 杂交可以促进寄生虫菌株之间的重组，从而加速药物的传播 通过寄生虫种群产生抗性基因。相反，细胞质基因组不相容性可以阻止 寄生虫菌株重组。该项目中分析的交配机制非常重要 在总体 P01 拨款的背景下，旨在更全面地了解青蒿素耐药性和耐药性 合作药物，包括哌喹，目前是消除疟疾工作中的一个重大问题。 最后，我们将建立结合基因组测序和数量性状位点的批量分离分析 映射以更有效地映射与表型相关的基因，这对于 对东南亚现已记录的新出现的哌喹抗性寄生虫的分析。这 该研究项目的成功完成将极大地促进恶性疟原虫遗传学研究，并将 进一步加深我们对寄生虫耐药性及其出现、进化和传播的了解。