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

9314595卡里细菌和真核宿主之间紧密结合的共生关系在自然界中比比皆是。 在海洋系统中，经常发现新的协会，情况尤其如此。 无论是细菌驻留在外部的主机或内共生的功能作用的协会仍然知之甚少。该研究项目旨在了解与Alvinellid多毛类（Alvinella pompejana）有关的各种表生细菌种群的结构和功能，Alvinella pompejana栖息在深海热液喷口周围的高温环境中。 多毛类被认为是已知最耐热的真核生物。 该项目的主要论点认为，在这种共生的进化范围内，共生体和宿主已经进化出独特的适应性，以在这种恶劣的环境中生存。 本研究项目的主要目标是代谢特性的主要共生体内的混合人口，以确定其功能的共生作用。 具体而言，该项目将：1）确定种群中优势共生体的遗传特征; 2）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内的代谢能力和活性分离。 为了实现这些目标，将整合两种强大的分子技术，这两种技术是根据自然生态系统中的细菌（如细胞器）可以在没有培养的情况下进行研究的理念开发的。 过去的研究已经证明了核酸探测技术在原位以高度特异性鉴定和定位靶序列方面的实用性。 最近，细菌人工染色体（BAC）载体通过以“环境文库”的形式保存其基因组内容来表征混合海洋微生物群落的实用性已被广泛应用。 演示。本项目建议将这些技术联合收割机结合起来，从遗传学上剖析混合种群中的主要共生体，并原位鉴定和量化共生体中涉及的代谢重要基因的表达。 这些技术的描述性质不仅将提供对这种共生的生态学的宝贵见解，而且将提供使适应热液喷口极端环境的新基因的特征。 ***

9314595 CARY 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 been 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. ***