REGULATION OF ASYMMETRIC FLAGELLAR WAVEFORMS

不对称鞭毛波形的调节

• 批准号: 2189867
• 负责人: PAUL A. LEFEBVRE
• 金额: $ 12.46万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-01 至 1998-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2189867
• 关键词: Chlamydomonas; chemical binding; chemical models; cilium /flagellum motility; epitope mapping; gene complementation; immunoelectron microscopy; immunofluorescence technique; microtubule associated protein; molecular cloning; nucleic acid hybridization; nucleic acid sequence; phase contrast microscopy; phenotype; phosphorylation; polymerase chain reaction; protein sequence; protein structure function; restriction mapping; site directed mutagenesis; southern blotting; transmission electron microscopy

The unicellular green alga Chlamydomonas can swim with two very different flagellar waveforms. Forward swimming is accomplished using an asymmetric beat, resembling the beat of cilia. Reverse swimming is accomplished by a symmetrical waveform, similar to classic flagellar beating. The transition between the two forms is controlled by the contraction of Ca++ around the axoneme. Two different classes of mutants in Chlamydomonas have been isolated which have lost the ability to generate the asymmetric waveform: central pair apparatus defective mutants and move backward only mutants. The recent development of insertional mutagenesis in this organism has made it possible to rapidly generate mutants in many genes regulating flagellar function and to clone the affected genes. This technique will be used in this project to begin a comprehensive molecular, biochemical and ultrastructural analysis of the regulation of flagellar waveforms. The specific aims are: 1) to use insertional mutagenesis to identify and clone genes whose products are required for generation of an asymmetric waveform in Chlamydomonas flagella; 2) to identify the gene products of each cad and mbo gene by sequencing genomic and cDNA clones; 3) to localize each gene product within the flagellum; 4) to address the function of each gene product by detailed characterization of mutant phenotypes. Chlamydomonas is the primary genetic system available for the study of flagellar structure and function. Dozens of mutants affecting flagellar function have been well- characterized, and many of the genes coding for components of the microtubules, radial spoke assembly and dynein arms have been isolated. The central apparatus is perhaps the least understood region of the axoneme. This product will identify and characterize many of the proteins involved in the generation of the asymmetric flagellar waveform. This research will advance our understanding of human biology in several important ways, given the important role of cilia in respiratory function and the role of flagella in male fertility.

单细胞绿色藻类衣原体可以与两个截然不同的游泳 鞭毛波形。 使用一个 不对称的节拍，类似于纤毛的节拍。 反向游泳是 通过对称波形完成，类似于经典的鞭毛 跳动。 两种形式之间的过渡由 轴突周围Ca ++的收缩。 两个不同类别的突变体 在衣原体中，已经孤立了，这已经失去了能力 生成不对称波形：中央对设备有缺陷 突变体和仅向后移动突变体。 最近的发展 该生物中的插入诱变使得能够快速 在调节鞭毛功能和克隆的许多基因中产生突变体 受影响的基因。 该技术将在该项目中使用 全面的分子，生化和超微结构分析 鞭毛波形的调节。 具体目的是：1）使用 插入诱变以识别和克隆的基因 在衣原体中生成不对称波形所需 鞭毛； 2）通过 测序基因组和cDNA克隆； 3）定位每个基因产品 在鞭毛内； 4）通过 突变表型的详细表征。 衣原体是 可用于研究鞭毛结构和 功能。 影响鞭毛功能的数十个突变体已经很好 表征，许多编码组件的基因 微管，径向辐条组件和动力蛋白臂已被分离。 中央设备也许是最了解的地区 Axoneme。 该产品将识别并表征许多 蛋白质涉及不对称鞭毛波形的产生。 这项研究将提高我们对人类生物学的理解 鉴于纤毛在呼吸功能中的重要作用，重要的方式 以及鞭毛在男性生育中的作用。