How Mussel Gill Mitochondria Choose Between Sulfide and Endogenous Carbon Substrate as a Source of Electrons for ATP Production

Deoller 9728409硫化氢是几种天然和人造水生生境的共同成分，既是一种强有力的有氧细胞呼吸毒素，也是一种被一些细菌用作能源的富电子分子。在富含硫化物沉积物的海洋贻贝Geukensia demissa的纤毛鳃中，硫化物氧化支持细胞工作，这首次表明在完整的后生动物组织中，线粒体从碳分解代谢转换为硫化物氧化以产生能量。在这个项目中，使用完整的甘草鳃和分离的鳃线粒体，将解决三个关于碳分解代谢到硫化物氧化的转变的中心问题：这种转变的性质是什么；什么因素调节它；以及，由于硫化物暴露历史影响硫化物氧化的能力，什么机制(S)在能力的改变之下？这项工作的结果将有助于严格解决一个长期存在的问题，即生物体如何适应硫化物暴露？这些发现可能表明，如果硫化物氧化可以节省后生动物的碳，那么包含硫化物栖息地的生态系统的能量平衡需要重新考虑。使用创新和最先进的技术评估线粒体功能将进一步加深我们对这种可能广泛适应似乎在宜人环境中的适应的理解。

Deoller 9728409 Hydrogen sulfide, a common constituent of several natural and man-made aquatic habitats, is both a potent toxin of aerobic cellular respiration and an electron-rich molecule used by some bacteria as an energy source. In ciliated gills from Geukensia demissa, a marine mussel from sulfide rich sediments, sulfide oxidation supports cellular work, indicating for the first time that in an intact metazoan tissue, mitochondria switch from carbon catabolism to sulfide oxidation for energy production. In this project, using excised intact G. demissa gills and isolated gill mitochondria, three central questions concerning the transition from carbon catabolism to sulfide oxidation will be addressed: what is the nature of this transition; what factors regulate it; and, since sulfide exposure history influences capacity for sulfide oxidation, what mechanism(s) underlies this alternation in capacity? The results of this work will help rigorously address a long-standing question, namely how do organisms adapt to sulfide exposure? The findings may indicate that energy budgets of ecosystems containing sulfide habitats need reconsideration if sulfide oxidation can result in carbon sparing in metazoans. Assessment of mitochondrial function using innovative and state-of-the-art techniques will further our understanding of this possibly widespread adaptation to seemingly in hospitable environments.