Molecular Analysis of Uniparental Inheritance of Chloroplast DNA in Chlamydomonas Reinhardtii

莱茵衣藻叶绿体DNA单亲遗传的分子分析

• 批准号: 0717179
• 负责人: Ursula Goodenough
• 金额: $ 45万
• 依托单位: Washington University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-15 至 2011-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0717179&HistoricalAwards=false
• 关键词: Molecular; Analysis; Uniparental; Inheritance; Chloroplast

Uniparental (UP) inheritance of organellar (mitochondrial and chloroplast) DNA occurs throughout the eukaryotic kingdom, but there is as yet no complete molecular description of its mechanism in any species. UP inheritance of chloroplast chromosomes in the soil alga Chlamydomonas reinhardtii shares a striking feature with mitochondrial DNA inheritance in most animals: the organellar DNA of one parent (the minus mating type in the alga, the male in animals) is specifically destroyed by nuclease activity, meaning that the organellar DNA of the other parent (plus, female) must be protected from the nuclease. This project will evaluate a candidate protector protein, Otu2, and a candidate destroyer, TatD1, in C. reinhardtii as well as two other proteins, Ezy1 and Ezy2, that apparently facilitate their activities in the zygote. Approaches will include immunolocalization and the effects on UP of knocking down and mis-expressing these proteins in gametes and zygotes. Since Otu2 orthologs feature in deubiquination pathways, and TatD1 nucleases with mitochondrial targeting sequences are posited to play a role in apoptosis, these studies may have an impact beyond an understanding of UP.This project promises to provide long-sought answers to the questions of why organellar (mitochondrial and chloroplast) DNA is only transmitted through one parent, and how this is accomplished. Such understanding is likely to be important to plant and animal breeding programs wherein organellar incompatibilities may contribute to breeding failures. Committed to increasing the public's scientific literacy, the investigator engages extensively in such areas as teacher training and adult education. In addition, she will recruit undergraduate trainees.

细胞器（线粒体和叶绿体）DNA的单亲（UP）遗传发生在整个真核生物界，但在任何物种中还没有完整的分子描述其机制。 土壤中叶绿体染色体的UP遗传莱茵衣藻与大多数动物的线粒体DNA遗传有一个显著的特征：一个亲本（在莱茵衣藻中为负交配型，在动物中为雄性）的细胞器DNA被核酸酶活性特异性地破坏，这意味着另一个亲本（正交配型，雌性）的细胞器DNA必须被保护免受核酸酶的影响。 该项目将评估候选保护蛋白Otu2和候选破坏蛋白TatD1。reinhardtii以及另外两种蛋白质Ezy1和Ezy2，这两种蛋白质显然有助于它们在受精卵中的活性。 方法将包括免疫定位和在配子和合子中敲低和错误表达这些蛋白质对UP的影响。 由于Otu2的直系同源物在去泛素化途径中起作用，并且带有线粒体靶向序列的TatD1核酸酶被认为在细胞凋亡中起作用，这些研究可能会产生超出对UP的理解的影响。该项目有望为为什么细胞器（线粒体和叶绿体）DNA只通过一个亲本传递以及如何实现这一点的问题提供长期寻求的答案。 这种理解可能是重要的植物和动物育种计划，其中细胞器不相容性可能导致育种失败。 致力于提高公众的科学素养，调查员广泛参与教师培训和成人教育等领域。此外，她还将招收本科学员。