En-Gen: Mutation in Genomes of Obligate Symbionts and Impacts on the Ecological Tolerances and Distributions of Hosts: Buchnera and Pea Aphids

En-Gen：专性共生体基因组突变及其对生态耐受性和宿主分布的影响：Buchnera 和豌豆蚜

• 批准号: 0723472
• 负责人: Nancy Moran
• 金额: $ 77.24万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0723472&HistoricalAwards=false
• 关键词: En; Gen; Mutation; Genomes; Obligate

The health and survival of most animals and plants depends on specialized symbiotic microorganisms, mostly bacteria. Symbionts can affect the tolerances of hosts to environmental factors such as heat, parasites or nutritional stress. In many cases, symbionts are transferred from mother to offspring before birth, with maternal transmission especially common in insects. This project focuses on mutations affecting symbiont genomes and on how these mutations impact the functioning and environmental tolerances of hosts. Full genome resequencing will be carried out for Buchnera, the bacterial symbionts of aphids and one of the best studied examples of symbiosis. These data will reveal the overall frequency of mutations in the symbiont genome and the frequency of mutations that affect functions important to hosts, such as production of essential nutrients or tolerance to heat. To quantify the effects of these mutations on hosts, lab experiments with live insects containing different symbiont genotypes will be conducted. Preliminary evidence indicates that even a single change in the symbiont DNA sequence can have a massive effect on the aphid's ability to survive heat exposure. The new results will show the extent of such mutations across the entire symbiont genome. The results will add to understanding of fundamental processes determining the distribution of a major group of crop pests (aphids) and will have implications for similar symbiotic systems found in many other insect pests. The study has direct implications for predicting how organisms respond to climate change. Educational components, from the high school to graduate level, are integrated into the research. Graduate and undergraduate students will conduct significant portions of the primary research. In addition, high school students will participate through a sustained collaboration between the main investigator and a biology teacher at a large urban high school with a majority of students from groups underrepresented in science and in the university.

大多数动物和植物的健康和存活都取决于专门的共生微生物，主要是细菌。共生体可以影响宿主对环境因素（例如热，寄生虫或营养应激）的公差。在许多情况下，共生体是在出生前从母亲转移到后代的，母亲的传播在昆虫中尤其常见。该项目的重点是影响共生基因组的突变以及这些突变如何影响宿主的功能和环境公差。将针对Buchnera，蚜虫的细菌共生体和共生的最佳示例之一进行全基因组重新定价。这些数据将揭示共生基因组突变的总体频率以及影响对宿主重要功能的突变频率，例如产生必需营养物质或对热的耐受性。为了量化这些突变对宿主的影响，将对含有不同共生基因型的活昆虫进行实验室实验。初步证据表明，即使是共生型DNA序列的单一变化也可能对蚜虫的生存能力产生巨大影响。新结果将显示整个共生基因组中此类突变的程度。结果将增加对确定主要的作物害虫（蚜虫）分布的基本过程的理解，并将对许多其他昆虫中发现的类似共生系统产生影响。该研究对预测生物如何应对气候变化有直接的影响。从高中到研究生一级的教育组成部分都融入了研究中。研究生和本科生将进行主要研究的大部分。此外，高中生将通过主要研究者与一位大型城市高中的生物学老师之间的持续合作，其中大多数来自科学和大学的人数不足的学生。