COLLABORATIVE RESEARCH: Physiological Adaptation to Extreme Environments: Genes, Function, and Evolutionary Patterns

合作研究：极端环境的生理适应：基因、功能和进化模式

• 批准号: 1557860
• 负责人: Michael Tobler
• 金额: $ 41.22万
• 依托单位: Kansas State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-01 至 2021-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1557860&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Physiological; Adaptation; Extreme

Extreme environments allow for the investigation of life's capacity and limitations to cope with far-from-average environmental conditions. Springs rich in hydrogen sulfide represent some of the most extreme freshwater environments, because hydrogen sulfide halts energy production in animal cells. Nonetheless, some fish have colonized sulfide springs throughout the Americas, and it remains unknown how they can tolerate conditions so toxic that most other organisms perish. This project will compare closely related populations that live in adjacent sulfidic or nonsulfidic habitats to identify differences in genetic, biochemical, and physiological traits that underlie tolerance to this noxious chemical. It involves the identification of genetic differences between hydrogen sulfide-tolerant and susceptible populations, particularly in genes associated with pathways affected by hydrogen sulfide toxicity or detoxification. In addition, the tolerance and the susceptibility of fish populations will be measured in the presence or absence of hydrogen sulfide. This project will yield new insights into mechanisms underlying physiological tolerance to hydrogen sulfide and the workings of animals in the presence of physiochemical stressors. Given hydrogen sulfide's role in cellular processes and disease formation, this also has implications for biomedical applications. This project provides training opportunities in integrative biology for participants at all levels of higher education. It will also contribute to science education and public outreach through the generation of an exhibit at a local zoo and the involvement of high school teachers that will generate lesson plans implementing next generation science education standards for K-12 education in STEM fields. Leveraging knowledge from toxicological and biomedical studies, this project addresses hypotheses about mechanisms of physiological adaptation to naturally H2S-rich environments and focuses on components of and associated with the oxidative phosphorylation pathway (OXPHOS) in mitochondria. These components include targets of H2S toxicity as well as enzymes involved in H2S detoxification. It is predicted that focal components are modulated or modified in sulfide spring populations, such that individuals have an increased ability to withstand elevated H2S concentrations, an increased ability to detoxify H2S enzymatically, and an ability to maintain or even increase mitochondrial energy production by using H2S a substrate to fuel metabolism. Furthermore, it is anticipated that modification of OXPHOS components has occurred repeatedly across independent lineages that have colonized sulfide springs. To test these predictions, this project focuses on an established model system (Poecilia mexicana) for the investigation of H2S adaptation and has three major empirical components: (1) Characterization of transcriptional and coding variation in candidate genes by use of high-throughput sequencing techniques and subsequent validation of effects on protein concentrations and structure. (2) Quantification of functional consequences of transcriptional and coding variation for H2S detoxification and bioenergetics both in vitro and in vivo. (3) Comparison of gene sequence and expression variation across a dozen independent population pairs from sulfidic and non-sulfidic habitats to test for convergence.

极端环境可以调查生活能力和局限性，以应对远离平均环境条件。富含硫化氢的弹簧代表了一些最极端的淡水环境，因为硫化氢会停止动物细胞中的能量产生。尽管如此，一些鱼类在整个美洲都定殖了硫化物的泉水，但尚不清楚它们如何忍受如此毒性，以至于大多数其他生物都会灭亡。该项目将比较生活在相邻的硫酸或非硫磺栖息地中的密切相关的人群，以确定对这种有害化学物质宽容的遗传，生化和生理特征的差异。它涉及鉴定硫化物耐氢和易感人群之间的遗传差异，特别是在与受硫化氢毒性或排毒影响的途径相关的基因中。另外，在存在或不存在硫化氢的情况下，将测量鱼类种群的耐受性和敏感性。该项目将为对硫化氢的生理耐受性以及在存在生理化学胁迫的情况下的生理耐受性以及动物的作用提供新的见解。鉴于硫化氢在细胞过程和疾病形成中的作用，这也对生物医学应用有影响。该项目为各级高等教育的参与者提供了综合生物学的培训机会。它还将通过在当地动物园的一个展览以及高中教师的参与来为科学教育和公众推广提供贡献，该展览将制定课程计划，以实施STEM领域K-12教育的下一代科学教育标准。从毒理学和生物医学研究中利用知识，该项目介绍了关于生理适应自然富含H2S的环境机制的假设，并着重于线粒体中氧化磷酸化途径（OXPHOS）的组成部分。这些成分包括H2S毒性的靶标以及与H2S解毒有关的酶。据预测，焦点成分在硫化物春季种群中进行调节或修饰，使得个体具有承受H2S浓度升高的能力，可以通过使用H2S A sibstrate燃料代谢的H2S A substrate来维持H2S的H2S酶排毒的能力，并具有维持甚至增加线粒体能量产生甚至增加线粒体能量的能力。此外，预计Oxphos成分的修饰已经在具有硫化物弹簧的独立谱系中反复发生。为了测试这些预测，该项目着重于既定的模型系统（墨西哥Poecilia），以研究H2S适应，并具有三个主要的经验组成部分：（1）通过使用高通量测序技术以及对蛋白质浓度和结构效应的效果的候选基因转录和编码变化的表征。 （2）在体外和体内量化H2S解毒和生物能的转录和编码变化的功能后果。 （3）比较从硫酸和非硫磺栖息地的十几个独立人群对中的基因序列和表达变异，以测试收敛。