Collaborative Research: Molecular Dissection of an Epibiotic Symbiosis in a Highly Thermotolerant Metazoan

合作研究：高度耐热后生动物中表生共生的分子解剖

• 批准号: 9317734
• 负责人: Jeffrey Stein
• 金额: $ 2.57万
• 依托单位: Agouron Institute
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-11-15 至 1996-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9317734&HistoricalAwards=false
• 关键词: Collaborative; Research; Molecular; Dissection; Epibiotic

9317334 STEIN Closely integrated symbiotic associations between bacteria and eukaryotic hosts abound in nature. This is particularly the case in marine systems where novel associations are being routinely discovered. Whether the bacteria reside externally to the host or endosymbiotically the functional role of the association have remained poorly understood. This research project seeks to understand the structure and function of the diverse epibiotic bacterial populations found associated with the Alvinellid polychaete, Alvinella pompejana, which inhabits the high temperature environment surrounding deep-sea hydrothermal vents. The polychaetes are considered the most thermotolerant eukaryotes known. The primary thesis of the project maintains that within the evolutionary confines of this symbiosis the symbiont and host have evolved unique adaptations to survive this harsh environment. The primary objective of this research project is to metabolically characterize the predominant symbionts within the mixed population in order to determine their functional role in the symbiosis. Specifically the project will: 1) phylogenetically characterize the dominant symbionts in the population, 2) determine the spatial orientation and metabolic state of these symbiont in situ, 3) determine the metabolic capabilities and segregation of activity within the structure of the symbiont population. In order to achieve these goals two powerful molecular techniques which were developed with the philosophy that bacteria from natural ecosystems, like organelles, can be studied without cultivation will be integrated. Past studies have demonstrated the utility of nucleic acid probing technology to identify and localize target sequences in situ with a high degree of specificity. The utility of Bacterial Artificial Chromosome (BAC) vectors to characterize mixed marine microbial communities by preserving their genomic content in the form of "environmental libraries" has recently bee n demonstrated. This project proposes to combine these technologies to genetically dissect the predominant symbionts from the mixed population and to identify and quantify in situ the expression of metabolically important genes implicated in the symbiosis. The descriptive nature of these techniques will provide not only valuable insights into the ecology of this symbiosis but will provide characterization of novel genes that confer adaptation to the extremes of the hydrothermal vent environment. ***

9317334斯坦在自然界中大量存在细菌和真核宿主之间紧密结合的共生关系。在海洋系统中尤其如此，在那里经常发现新的联系。无论细菌是存在于宿主的外部还是内部共生，这种联系的功能作用仍然知之甚少。这项研究项目试图了解与阿尔维内利德多毛类(Alvinellid Pompejana)相关的各种共生细菌的结构和功能，这种多毛类生活在深海热液喷口周围的高温环境中。多毛类被认为是已知的耐热性最强的真核生物。该项目的主要论点认为，在这种共生的进化范围内，共生体和宿主进化出了独特的适应能力，能够在这种恶劣的环境中生存下来。这项研究的主要目标是对混合种群中的主要共生体进行代谢特征，以确定它们在共生中的功能作用。具体来说，该项目将：1)确定种群中主要共生体的系统发育特征；2)在原位确定这些共生体的空间方向和代谢状态；3)确定共生体种群结构中的代谢能力和活动隔离。为了实现这些目标，将整合两种强大的分子技术，这两种技术的发展理念是，无需培养就可以研究来自自然生态系统的细菌，就像细胞器一样。过去的研究已经证明，核酸探测技术在原位识别和定位靶序列方面具有很高的特异性。细菌人工染色体(BAC)载体通过以“环境文库”的形式保存混合海洋微生物群落的基因组内容，最近证明了其在表征海洋混合微生物群落中的作用。该项目建议结合这些技术从混合种群中从遗传上分离出主要的共生体，并在原位识别和量化与共生有关的代谢重要基因的表达。这些技术的描述性性质不仅将提供对这种共生生态的宝贵见解，还将提供对使其适应极端热液喷口环境的新基因的表征。***