REGULATION OF ASYMMETRIC FLAGELLAR WAVEFORMS

不对称鞭毛波形的调节

• 批准号: 2459556
• 负责人: PAUL A. LEFEBVRE
• 金额: $ 17.21万
• 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 1998-09-14
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2459556
• 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.

单细胞绿藻衣藻可以与两种截然不同的生物一起游泳 鞭毛波形。 向前游泳是通过使用 不对称的节拍，类似于纤毛的节拍。 逆泳是 通过对称波形完成，类似于经典的鞭毛 殴打。 两种形式之间的转换由 Ca++ 围绕轴丝收缩。 两种不同类别的突变体 衣藻中已被分离出来，它们已经失去了 产生不对称波形：中央对设备有缺陷 突变体和向后移动的突变体。 近期的发展 该生物体中的插入突变使得快速 在许多调节鞭毛功能的基因中产生突变体并克隆 受影响的基因。 该技术将在本项目开始时使用 全面的分子、生化和超微结构分析 鞭毛波形的调节。 具体目标是：1）使用 插入诱变来识别和克隆其产物的基因 衣藻中产生不对称波形所需的 鞭毛; 2) 通过以下方法鉴定每个 cad 和 mbo 基因的基因产物 对基因组和 cDNA 克隆进行测序； 3) 定位每个基因产物 在鞭毛内； 4）通过以下方式解决每个基因产物的功能 突变表型的详细表征。 衣藻属是 可用于研究鞭毛结构和 功能。 数十种影响鞭毛功能的突变体已被充分研究 已被表征，并且许多基因编码 微管、径向辐条组件和动力蛋白臂已被分离出来。 中央装置可能是最不为人所知的区域 轴丝。 该产品将识别和表征许多 参与不对称鞭毛波形生成的蛋白质。 这项研究将在几个方面增进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，这是重要的方式 以及鞭毛在男性生育能力中的作用。