Plasmodium falciparum gametocytogenesis

恶性疟原虫配子细胞发生

• 批准号: 7615529
• 负责人: Kim C Williamson
• 金额: $ 27.57万
• 依托单位: LOYOLA UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-06-01 至 2012-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7615529
• 关键词: 3' Flanking Region; 5' Flanking Region; Binding; Biological Assay; Blood; Candidate Disease Gene; Chromosome Mapping; Culicidae; DNA; DNA-Binding Proteins; Data; Development; Disease; EMSA; Early Diagnosis; Electrophoretic Mobility Shift Assay; Erythrocytes; Factor Analysis; Future; Gene Deletion; Gene Expression; Gene Targeting; Genes; Genetic; Genome; Genomics; Germ Cells; Harvest; Health; Human; Hybrids; Immune response; Immunoassay; Lead; Life Cycle Stages; Malaria; Maps; Mass Spectrum Analysis; Messenger RNA; Microarray Analysis; Midgut; Molecular; Northern Blotting; Nuclear Extract; Nucleic Acid Regulatory Sequences; Oligonucleotide Microarrays; Parasitemia; Parasites; Pattern; Persons; Pharmaceutical Preparations; Plasmodium; Plasmodium falciparum; Proteins; Proteomics; Regulatory Element; Reporter; Reporter Genes; Reverse Transcriptase Polymerase Chain Reaction; Role; Sporozoites; Staging; System; Testing; Time; Transcript; Translating; World Health; Yeasts; asexual; base; cDNA Library; deletion analysis; design; inhibitor/antagonist; killings; mRNA Expression; prevent; promoter; protein expression; tool; transcription factor; transmission process

DESCRIPTION (provided by applicant): Malaria continues to be a major world health problem, killing1-2 million people annually. The Plasmodium parasites that cause malaria have a multistage life cycle, which contributes to their ability to evade host immune responses. For malaria transmission, the parasite must undergo sexual differentiation into mature gametocytes that, when taken up in a blood meal by a mosquito can fertilize and begin sporogonic development. The molecular basis for the critical switch from asexual replication to sexual differentiation in the parasite's life cycle is unknown. Our hypothesis is that this transition is initiated by the activation of transcription factors that regulate the expression of genes required to effect gametocytogenesis. Once the regulatory factors are identified, inhibitors could be designed to block gametocytogenesis, which would prevent malaria transmission. To identify the genes involved, Plasmodium falciparum gametocyte producing (G+) and non-producing (G-) parasite lines were derived from strain 3D7 parasites. The first Specific Aim will be to use whole genome microarray analysis to compare mRNA harvested from the G+ and G- clones during the asexual to sexual transition. This comparison should identify the earliest differentially expressed genes. Specific Aim 2 will be to analyze the factors involved in regulating the gametocyte-specific expression of these genes. The ability of the 5' and 3' flanking regions of the genes to drive stage-specific reporter gene expression will be tested and the specific regulatory regions required will be identified by promoter mapping supplemented with motif analysis. Specific Aim 3 will be to identify the genes required for the induction of gametocytogenesis by determining the genetic differences between the G+ and G- parasite lines, as well as the genes that interact with the regulatory regions identified in Specific Aim 2. The relationship between gametocytogenesis and the genetic differences found will be further analyzed by complementation of the G- line and targeted gene disruption of wild type G+ parasites. This information should provide new gene candidates that could be used in the future to design new strategies to control malaria transmission.

描述（由申请人提供）：疟疾仍然是一个主要的世界卫生问题，每年使1 -2百万人患病。引起疟疾的疟原虫寄生虫具有多阶段的生命周期，这有助于它们逃避宿主免疫反应的能力。为了传播疟疾，寄生虫必须经历性分化成为成熟的配子母细胞，当被蚊子吸收到血液中时，配子母细胞可以受精并开始孢子生殖发育。在寄生虫的生命周期中，从无性复制到性分化的关键转换的分子基础是未知的。我们的假设是，这种转变是由转录因子的激活，调节所需的基因的表达，以影响配子体发生启动。一旦确定了调节因子，就可以设计抑制剂来阻断配子体发生，这将防止疟疾传播。为了鉴定所涉及的基因，恶性疟原虫配子体产生（G+）和非产生（G-）寄生虫系源自菌株3D 7寄生虫。第一个具体目标将是使用全基因组微阵列分析来比较从G+和G-克隆在无性向有性过渡期间收获的mRNA。这种比较应该确定最早的差异表达基因。具体目标2将是分析参与调控这些基因的配子体特异性表达的因素。将检测基因的5'和3'侧翼区驱动阶段特异性报告基因表达的能力，并通过启动子作图辅以基序分析鉴定所需的特异性调控区。具体目标3是通过确定G+和G-寄生虫系之间的遗传差异，以及与具体目标2中确定的调控区相互作用的基因，鉴定诱导配子体发生所需的基因。配子体发生与发现的遗传差异之间的关系将通过G-系的互补和野生型G+寄生虫的靶向基因破坏来进一步分析。这一信息将提供新的候选基因，可在未来用于设计控制疟疾传播的新战略。