3-D FINE STRUCTURE OF THE APICAL POLAR RING IN TOXOPLASM GONDII

弓形虫顶端极环的 3-D 精细结构

• 批准号: 7354997
• 负责人: NAOMI S MORRISSETTE
• 金额: $ 0.47万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-09-26 至 2007-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7354997
• 关键词: Plasmodium; intracellular; microtubules; mutant; phenotype

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Toxoplasma gondii is an obligate intracellular parasite that is related to Plasmodium, the agent of malaria. Toxoplasma is disseminated by cats, which harbor infectious spores and pass them in their feces. Toxoplasma in pregnant women can cause birth defects or miscarriage; in immunocompromised individuals it can cause life- threatening infection. Toxoplasma, Plasmodium and other Apicomplexan parasites all have morphologically similar microtubule cytoskeletons. We are interested in the structural arrangement of the apical polar ring, a microtubule organizing center that nucleates 22 subpellicular microtubules. This year we have produced tomograms of this cytoplasmic region from wild type cells, using chemically-fixed preparations. To improve the structural preservation of the cells, Morrissette has been using the Balzers high pressure freezer at the Danforth Center in St. Louis and has produced some promising samples. In addition, the Morrissette lab is currently developing molecular genetic techniques to complement cellular and biochemical studies that are going on elsewhere. They are constructing genetic tools for Toxoplasma including a genomic map, vectors for DNA transformation and protein expression, and large-scale sequencing of cDNAs for gene discovery. These approaches are being applied to identify the molecular basis of virulence and to generate mutants with altered phenotypes in adhesion, invasion, and intracellular survival. The 3-D lab will characterize the phenotypes of these mutants, as they become available.

这个子项目是利用由NIH/NCRR资助的中心拨款提供的资源的许多研究子项目之一。子项目和调查员(PI)可能从另一个NIH来源获得了主要资金，因此可能会出现在其他CRISE条目中。列出的机构是针对中心的，而不一定是针对调查员的机构。弓形虫是一种专性胞内寄生虫，与疟疾病原体疟原虫有亲缘关系。弓形虫是由猫传播的，猫携带有感染性的孢子，并通过粪便传播。孕妇的弓形虫可能会导致出生缺陷或流产；在免疫功能受损的人中，它可能会导致危及生命的感染。弓形虫、疟原虫和其他细粒复合体寄生虫都有形态相似的微管细胞骨架。我们感兴趣的是顶端极环的结构安排，它是一个微管组织中心，形成22个膜下微管。今年，我们使用化学固定的方法，从野生型细胞中制作了这一细胞质区域的断层图像。为了改善细胞的结构保存，莫里塞特一直在圣路易斯的丹福斯中心使用Balzers高压冷冻机，并生产了一些有希望的样品。此外，莫里塞特实验室目前正在开发分子遗传学技术，以补充其他地方正在进行的细胞和生化研究。他们正在构建弓形虫的遗传工具，包括基因组图、DNA转化和蛋白质表达的载体，以及用于基因发现的大规模cDNA测序。这些方法正被应用于鉴定毒力的分子基础，并产生在黏附、侵袭和细胞内生存方面表型发生变化的突变株。当这些突变体出现时，3D实验室将对它们的表型进行表征。