Determinants of growth and fitness in drug resistant malaria parasites

耐药疟疾寄生虫生长和健康的决定因素

• 批准号: 8005522
• 负责人: Michael T Ferdig
• 金额: $ 35.95万
• 依托单位: UNIVERSITY OF NOTRE DAME
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8005522
• 关键词: Accounting; Address; Africa; Alleles; Antimalarials; Architecture; Automobile Driving; Bioinformatics; Biological; Biological Process; Biology; Candidate Disease Gene; Cell physiology; Chemicals; Chloroquine; Chloroquine resistance; Chromosome Mapping; Code; Complement; Complex; Control Locus; Copy Number Polymorphism; Crystallization; DNA; Data; Databases; Development; Dimensions; Disease; Drug resistance; Drug usage; Erythrocytes; Event; Evolution; Exhibits; Future; Gene Amplification; Gene Chips; Gene Dosage; Gene Expression; Genes; Genetic; Genetic Crosses; Genetic Polymorphism; Genetic Transcription; Genetic Variation; Genome; Genome Mappings; Genomics; Goals; Growth; Health; Human; In Vitro; Inherited; Institutes; Intervention; Knowledge; Laboratories; Lead; Left; Letters; Link; Location; Malaria; Maps; Measures; Methodology; Methods; Molecular; Multi-Drug Resistance; Mutation; Parasite resistance; Parasites; Pathway interactions; Pattern; Pharmaceutical Preparations; Phenotype; Physiological; Physiology; Plasmodium falciparum; Point Mutation; Population; Positioning Attribute; Principal Investigator; Production; Published Comment; Quantitative Trait Loci; Regulation; Regulatory Element; Relative (related person); Research; Resistance; Resolution; Role; Solutions; Structure; Therapeutic; Time; Transcript; Transcriptional Regulation; Trees; Vacuole; Variant; Virulence; comparative; cost; fitness; gene function; genetic linkage; genome sequencing; genome-wide; hemozoin; insertion/deletion mutation; insight; killings; mutant; neglect; novel strategies; parasite genome; pressure; programs; resistance mutation; segregation; tool; trait

DESCRIPTION (provided by applicant): The malaria parasite, Plasmodium falciparum, continues to devastate human health. The emergence and spread of multi-drug resistant (MDR) parasites following decades of over-use of chloroquine (CQ) is of fundamental significance to current malaria control efforts. The near-global selective sweep of the K76T- encoding mutation in the CQ resistance (CQR) gene, pfcrt, left behind an adapted genome impacting parasite growth, fitness, and a propensity for rapid MDR evolution. The long-term goal of this project is to identify the molecular components of this resistance-adapted genome. Our hypothesis is that there is an essential genetic background of CQR parasites, comprising networked gene actions that compensate for altered PfCRT function and stabilize parasite physiology and growth in the absence of drug pressure. To detect the genome-wide presence of these drug resistance adaptations, we focus on basic growth and normal cellular processes in two different parasite solutions to historical drug pressure: 1) progeny of a genetic cross that maintain a common pfcrt allele in a segregating CQR/MDR background; 2) a spectrum of laboratory-selected pfcrt mutant lines in a single controlled genetic background. Our Specific Aims build upon a detailed analysis of growth and physiological traits in the absence of drug to drive a genome-wide search for the gene networks controlling key parameters of fitness. Specific Aim 1. To precisely quantify growth and physiological parameters as indicators of parasite fitness in cultured red blood cells. We will use QTL mapping of these inter- related traits to pinpoint genome regions to facilitate searches for key genes using powerful emerging comparative databases and tools. Specific Aim 2. To identify strain-specific shifts in pfcrt-mutant transcription profiles and to map expression (e)QTL controlling inheritance of expression level traits. Specific Aim 3. To identify genome structural variants associated with CQ-selection. We will determine copy number polymorphisms in genes known to be associated with drug resistance and use high resolution CGH identification of gene copy number variations, small deletions, and some SNPs throughout the genome. Formal integration of these layers of independent but complimentary whole-genome biological data highlights a novel approach to elucidate new avenues for antimalarial intervention. Project Narrative: Malaria kills more than 2 million kids in Africa and infects more than 500 million people worldwide each year. The recently completed /Plasmodium falciparum /comparative genome sequencing project at the Broad Institute provides a vast view of genetic diversity of this species; however, few methods have been developed to use this information. Our proposal uses a combination of classical genetic linkage mapping with new tools to study gene expression variation and chromosomal structural variation around the entire genome. An integration of these tools will facilitate the mapping of the molecular determinants of fitness and virulence in dangerous multi-drug resistant malaria parasites. This knowledge will lead to new avenues of attack against this disease.

描述（由申请人提供）：疟疾寄生虫，恶性疟原虫继续破坏人类健康。数十年过度使用氯喹（CQ）后，多药抗药性（MDR）寄生虫的出现和传播对当前的疟疾控制工作具有至关重要的意义。 CQ抗性（CQR）基因PFCRT中K76T编码突变的近全球选择性扫描留在了适应的基因组后，影响了寄生虫的生长，适应性和快速MDR进化的倾向。该项目的长期目标是确定该抗性适应性基因组的分子成分。我们的假设是，CQR寄生虫有一个必不可少的遗传背景，其中包括网络基因作用，可以补偿PFCRT功能改变并在没有药物压力的情况下稳定寄生虫生理和生长。为了检测这些耐药性适应的全基因组的存在，我们着重于两个不同的寄生虫溶液中的基本生长和正常的细胞过程，用于历史药物压力：1）遗传杂交的后代，该遗传十字在分离的CQR/MDR背景下保持常见的PFCRT等位基因； 2）在单个受控遗传背景中的一系列实验室选择的PFCRT突变线。我们的具体目的基于对没有药物的生长和生理特征的详细分析，以推动全基因组搜索控制关键适应性参数的基因网络的搜索。具体目的1。精确量化生长和生理参数，作为培养的红细胞中寄生虫适应性的指标。我们将使用这些相关性状的QTL映射来查明基因组区域，以促进使用强大的新兴比较数据库和工具来搜索关键基因。具体目的2。确定PFCRT突变转录曲线中的应变特异性变化并映射表达（E）QTL控制表达水平特征的遗传。特定目的3。确定与CQ序列相关的基因组结构变体。我们将确定已知与耐药性相关的基因中的拷贝数多态性，并使用高分辨率CGH鉴定基因拷贝数变化，小缺失和整个基因组中的一些SNP。这些独立但免费的全基因组生物学数据的这些层层的正式整合突出了一种新的方法，用于阐明新的抗性干预途径。 项目叙述：疟疾在非洲造成超过200万儿童，每年在全球感染超过5亿人。广阔研究所的最近完成 /恶性疟原虫 /比较基因组测序项目提供了对该物种的遗传多样性的广阔视野。但是，很少开发使用此信息的方法。我们的建议结合了经典的遗传链接映射与新工具的结合，以研究整个基因组周围的基因表达变异和染色体结构变异。这些工具的整合将促进危险多药抗性疟疾寄生虫中适应性和毒力的分子决定因素的映射。这些知识将导致对这种疾病的攻击新途径。