EAGER: Evaluation of Dual Symbiosis in Lucinid Bivalves

在过去的三十年里，化学营养细菌和海洋双壳类之间的共生关系已经被确定。大多数是与硫营养（硫氧化）细菌，但甲烷氧化（甲烷氧化）和双共生的硫营养和甲烷营养细菌也有报道，从深水双壳类。 本实验室最近在佛罗里达和巴哈马的浅海草床中的透明双壳类动物中发现了细菌内共生体，这表明在梳状扁裸蛤宿主中存在双重系统。该项目将利用这些双壳类的可用性来（1）解决与P. pectinatus宿主中的硫营养和甲烷营养细菌代谢相关的基因的同源性，以及（2）使用这些基因组信息来开发荧光原位杂交（FISH）技术的组合，显微放射自显影和二次离子质谱，以评估内共生体丰度和硫化物和甲烷利用在相同的动物。多学科的研究结果不仅将提供深入了解这种新的双壳类共生，但将有可能改变共生生物学领域。由于Lucinids大大影响海草床和其他近岸海洋环境的生产力和多样性，丰度高达1500人/平方米，这项研究将提高对气候敏感的近岸海洋系统中甲烷循环的理解，并应在受威胁的沿海环境中对沿海资源管理决策产生广泛影响。该研究将直接为在STEM领域代表性不足的女性和少数民族学生提供丰富的研究和教育机会。研究结果将用于为K-12科学教育社区开发关于“动物-细菌伙伴关系”的在线年级适当的科学教育模块。

Numerous symbiotic associations between chemotrophic bacteria and marine bivalves have been identified over the last three decades. Most are associations with thiotrophic (sulfur-oxidizing) bacteria, but methanotrophic (methane-oxidizing) and dual symbiosis of thiotrophic and methanotrophic bacteria have also been reported from deep-water bivalves. This laboratory has recently found bacterial endosymbionts in lucinid bivalves from shallow seagrass beds of Florida and the Bahamas that indicate a dual system in Phacoides pectinatus hosts. This project will take advantage of the availability of these bivalves to (1) resolve the phylogeny of genes associated with thiotrophic and methanotrophic bacterial metabolism from P. pectinatus hosts, and (2) use this genomic information to develop a combination of fluorescence in situ hybridization (FISH) technologies, microautoradiography and secondary ion mass spectroscopy to assess endosymbiont abundance and sulfide and methane utilization in the same animals. The multidisciplinary findings will not only provide insight into this novel bivalve symbiosis, but will have the potential to transform the field of symbiosis biology. Because lucinids substantially impact the productivity and diversity of seagrass beds and other nearshore marine environments, with abundances of up to 1500 individuals/m2, this research will improve understanding of methane cycling in climatically sensitive, nearshore marine systems, and should have broad implications for coastal resource management decisions in threatened coastal settings. The research will directly contribute to an enriching research and educational opportunity for women and minority students that are underrepresented in STEM areas. The findings will be used to develop online grade-appropriate science-education modules on 'animal-bacterial partnerships' for the K-12 science-education community.