CRYO-ELECTRON TOMOGRAPHY OF GIARDIA INTESTINALIS

肠贾第鞭毛虫的冷冻电子断层扫描

• 批准号: 7955058
• 负责人: CINDY L SCHWARTZ
• 金额: $ 2.14万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2010-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7955058
• 关键词: Anterior; Cell membrane; Cellular Structures; Computer Retrieval of Information on Scientific Projects Database; Cyst; Cytoskeleton; Detergents; Dorsal; Duodenum; Electrons; Epithelial; Flagella; Funding; Giardia; Giardia lamblia; Giardiasis; Grant; Infection; Ingestion; Institution; Intestines; Lateral; Mastigophora; Microtubules; Movement; Negative Staining; Nutrient; Parasites; Plastic Embedding; Research; Research Personnel; Resolution; Resources; Sampling; Side; Source; Staging; Structure; Suction; Surface; Techniques; United States National Institutes of Health; electron tomography; intestinal epithelium; kinetosome; light microscopy; programs

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. Giardia intestinalis (also known as Giardia lamblia) is a unicellular, flagellated protist with a two-stage lifecycle. Giardiasis is caused by ingestion of the cyst form of the parasite which then excysts in the duodenum into the trophozoite form. The trophozoite form has a highly specialized microtubule cytoskeleton (eight flagella, the "median body" and the "ventral disc"), which permits the parasite to evade peristaltic movement in the host's intestine. Infection with Giardia is the results of parasite attachment directly to the intestinal epithelium; deriving nutrients from the mucosal secretions of the epithelial layer. The mechanism of attachment is not fully understood, but recent evidence suggests the parasite uses suction created by conformational changes of the ventral disc. The ventral disc consists of a counterclockwise array of microtubules that originate from electron dense bands directly anterior to the caudal and posterior-lateral flagellar basal bodies. The ventral surface of the microtubules is attached to the plasma membrane. On the dorsal side of each microtubule is a microribbon that is connected to neighbor microribbons by cross-linkers. Previous studies of the Giardia cytoskeleton have focused on understanding the basic disc structure using low-resolution techniques such as light microscopy, chemically fixed plastic embedded samples, and negative stain. In our study, we are using cryo-electron tomography of isolated detergent-extracted cytoskeletons to determine the structural-functional relationships between the various components of the ventral disc. We have used our program PEET to average the microtubules of the ventral disc.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目和 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 肠贾第虫（也称为贾第虫兰伯利亚）是一种单细胞、有鞭毛的原生生物，具有两个阶段的生命周期。贾第鞭毛虫病是由摄入寄生虫的包囊形式引起的，然后在十二指肠中包囊成滋养体形式。滋养体形式具有高度特化的微管细胞骨架（八个鞭毛、“中体”和“腹盘”），这使得寄生虫能够逃避宿主肠道中的蠕动运动。贾第鞭毛虫感染是寄生虫直接附着在肠上皮上的结果；从上皮层的粘膜分泌物中获取营养。附着机制尚不完全清楚，但最近的证据表明寄生虫利用腹盘构象变化产生的吸力。腹侧盘由逆时针微管阵列组成，这些微管源自尾部和后外侧鞭毛基体直接前方的电子致密带。微管的腹侧表面附着​​在质膜上。每个微管的背侧都有一条微带，通过交联剂与相邻的微带连接。先前对贾第鞭毛虫细胞骨架的研究主要集中在使用低分辨率技术（例如光学显微镜、化学固定塑料嵌入样品和负染色）了解基本的椎间盘结构。在我们的研究中，我们使用冷冻电子断层扫描来分离去污剂提取的细胞骨架，以确定腹椎间盘各个组成部分之间的结构功能关系。我们使用我们的程序 PEET 来平均腹侧椎间盘的微管。