CRYO-ELECTRON TOMOGRAPHY OF GIARDIA INTESTINALIS

肠贾第鞭毛虫的冷冻电子断层扫描

• 批准号: 8170839
• 负责人: CINDY L SCHWARTZ
• 金额: $ 2.49万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-05-01 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8170839
• 关键词: Anterior; Cell membrane; 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.

该副本是利用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这不一定是调查员的机构。 贾第鞭毛虫（Giardia intestinalis）（也称为贾第鞭毛虫（Giardia lamblia））是一个单细胞的，具有两阶段生命周期的鞭毛量。贾第鞭毛虫病是由寄生虫的囊肿形式摄入，然后在十二指肠中脱颖而出。滋养体形式具有高度专业化的微管细胞骨架（八个鞭毛，“中位体”和“腹盘”），该骨骼允许寄生虫在宿主的肠中逃避蠕动的蠕动运动。贾第鞭毛虫感染是寄生虫附着直接与肠上皮的结果。从上皮层的粘膜分泌物中得出营养。依恋机制尚未完全理解，但是最近的证据表明，寄生虫使用腹盘的构象变化产生的吸力。腹盘由逆时针阵列组成，该微管由直接在尾部和后侧鞭毛基底体的前面的电子密度带中。微管的腹表面附着在质膜上。在每个微管的背侧是一个微孔，该微孔通过交联连接到邻居微管。先前对贾第鞭毛虫细胞骨架的研究重点是使用低分辨率技术，例如光学显微镜，化学固定的塑料嵌入样品和阴性染色来理解基本的盘结构。在我们的研究中，我们使用的是分离的清洁剂提取的细胞骨架的冷冻电子断层扫描术来确定腹盘各个组件之间的结构功能关系。我们已经使用程序PEET平均腹盘的微管。