Ocean Acidification: Physiological and genetic responses of the deep-water coral, Lophelia pertusa, to ongoing ocean acidification in the Gulf of Mexico

海洋酸化：深水珊瑚 Lophelia pertusa 对墨西哥湾持续海洋酸化的生理和遗传反应

• 批准号: 1220478
• 负责人: Erik Cordes
• 金额: $ 65.9万
• 依托单位: Temple University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1220478&HistoricalAwards=false
• 关键词: Ocean; Acidification; Physiological; genetic; responses

The Gulf of Mexico deep water ecosystems are threatened by the persistent threat of ocean acidification. Deep-water corals will be among the first to feel the effects of this process, in particular the deep-water scleractinians that form their skeleton from aragonite. The continued shoaling of the aragonite saturation horizon (the depth below which aragonite is undersaturated) will place many of the known, and as yet undiscovered, deep-water corals at risk in the very near future. The most common deep-water framework-forming scleractinian in the world's oceans is Lophelia pertusa. This coral is most abundant in the North Atlantic, where aragonite saturation states are relatively high, but it also creates extensive reef structures between 300 and 600 m depth in the Gulf of Mexico where aragonite saturation states were previously unknown. Preliminary data indicate that pH at this depth range is between 7.85 and 8.03, and the aragonite saturation state is typically between 1.28 and 1.69. These are the first measurements of aragonite saturation state for the deep Gulf of Mexico, and are among the lowest Aragonite saturation state yet recorded for framework-forming corals in any body of water, at any depth. This project will examine the effects of ocean acidification on L. pertusa, combining laboratory experiments, rigorous oceanographic measurements, the latest genome and transcriptome sequencing platforms, and quantitative PCR and enzyme assays to examine changes in coral gene expression and enzyme activity related to differences in carbonate chemistry. Short-term and long-term laboratory experiments will be performed at Aragonite saturation state of 1.45 and 0.75 and the organismal (e.g., survivorship and calcification rate) and genetic (e.g., transcript abundance) responses of the coral will be monitored. Genomic DNA and RNA will be extracted, total mRNA purified, and comprehensive and quantitative profiles of the transcriptome generated using a combination of 454 and Illumina sequencing technologies. Key genes in the calcification pathways as well as other differentially expressed genes will be targeted for specific qPCR assays to verify the Illumina sequencing results. On a research cruise, L. pertusa will be sampled (preserved at depth) along a natural gradient in carbonate chemistry, and included in the Illumina sequencing and qPCR assays. Water samples will be obtained by submersible-deployed niskin bottles adjacent to the coral collections as well as CTD casts of the water column overlying the sites. Water samples will be analyzed for pH, alkalinity, nitrates and soluble reactive phosphorus. These will be used in combination with historical data in a model to hindcast Aragonite saturation state.Intellectual Merit: This project will provide new physiological and genetic data on an ecologically-significant and anthropogenically-threatened deepwater coral in the Gulf of Mexico. An experimental system, already developed by the PIs, offers controlled conditions to test the effect of Aragonite saturation state on calcification rates in scleractinians and, subsequently, to identify candidate genes and pathways involved in the response to reduced pH and Aragonite saturation state. Both long-term and population sampling experiments will provide additional transcriptomic data and specifically investigate the expression of the candidate genes. These results will contribute to our understanding of the means by which scleractinians may acclimate and acclimatize to low pH, alkalinity, and Aragonite saturation state. Furthermore, the investigators will continue a time series of oceanographic measurements of the carbonate system in the Gulf of Mexico, which will allow the inclusion of this significant body of water in models of past and future ocean acidification scenarios.Broader Impacts: Results that combine the study of ongoing ocean acidification in the Gulf of Mexico with the physiological and genetic responses of the corals to low saturation state will be presented at conferences, seminars, and published in high-impact and open-access publications. Raw and processed data will be made available in existing databases including NCBI (genetic and genomic data), and through the Biological and Chemical Oceanography Data Management Office (BCO-DMO). All project data will also be made available via a local ftp server linked to each of the PIs websites. The PIs are committed to the inclusion of under-represented minorities in their research, and have a proven record of mentoring undergraduates at Temple University, one of the most diverse institutions in the U.S. A two-day workshop for 20 Gulf Coast high school teachers, and also including students from Temple, will be led by the PIs and coordinated by Dr. Shelia Brown at the Gulf Coast Research Lab in Ocean Springs, MS to provide teachers with the background and materials needed to bring curricula based on these results directly into their classrooms. A high school teacher will also participate in the cruise. Through these efforts, the investigators hope to raise public consciousness of the issue of ocean acidification, increase the level of awareness of the presence of deep-water coral communities in U.S. waters, and to inspire the next generation of scientists.

墨西哥湾深水生态系统受到海洋酸化持续威胁的威胁。深水珊瑚将是最先感受到这一过程影响的生物之一，特别是由文石形成骨架的深水硬珊瑚。文石饱和层（文石不饱和的深度）的持续变浅将使许多已知的、尚未发现的深水珊瑚在不久的将来面临危险。世界海洋中最常见的深水骨架形成石珊瑚是Lophelia pertusa。这种珊瑚在北大西洋最丰富，那里的文石饱和度相对较高，但它也在墨西哥湾300至600米深处形成了广泛的珊瑚礁结构，那里的文石饱和度以前是未知的。初步数据表明，该深度范围的pH值在7.85和8.03之间，文石饱和状态通常在1.28和1.69之间。这是对墨西哥湾深海文石饱和度状态的首次测量，也是迄今为止在任何水体、任何深度形成框架珊瑚的最低文石饱和度状态之一。本项目将研究海洋酸化对L.本研究采用实验室实验、严格的海洋学测量、最新的基因组和转录组测序平台以及定量PCR和酶分析相结合的方法，研究与碳酸盐化学差异有关的珊瑚基因表达和酶活性的变化。短期和长期实验室实验将在文石饱和度为1.45和0.75以及有机体（例如，存活率和钙化率）和遗传（例如，转录本丰度）的反应。将提取基因组DNA和RNA，纯化总mRNA，并使用454和Illumina测序技术的组合生成转录组的全面和定量图谱。钙化途径中的关键基因以及其他差异表达基因将被靶向用于特定qPCR测定，以验证Illumina测序结果。在一次研究巡航中，L。将沿着碳酸盐化学的自然梯度对百日咳菌进行沿着采样（保存在深处），并将其纳入Illumina测序和qPCR测定中。水样将通过邻近珊瑚采集的水下部署的尼斯金瓶以及覆盖现场的水柱的CTD模型获得。将分析水样的pH值、碱度、硝酸盐和可溶性活性磷。这些将与历史数据结合使用，在一个模型中，后推文石饱和度state.Intellectual优点：该项目将提供新的生理和遗传数据的生态重要性和生殖威胁的深水珊瑚在墨西哥湾。一个实验系统，已经开发的PI，提供了控制条件，以测试文石饱和状态对钙化率的影响，在scleractinians，随后，以确定候选基因和参与响应降低pH值和文石饱和状态的途径。长期和群体采样实验将提供额外的转录组学数据，并专门研究候选基因的表达。这些结果将有助于我们理解的手段，其中石珊瑚可能驯化和驯化低pH值，碱度，文石饱和状态。此外，调查人员将继续对墨西哥湾碳酸盐系统进行时间序列海洋学测量，这将使这一重要水体能够纳入过去和未来海洋酸化情景的模型中。将对墨西哥湾正在进行的海洋酸化研究与珊瑚对低饱和状态的生理和遗传反应联合收割机相结合的结果将是在会议、研讨会上提出，并在影响力大的开放式出版物上发表。原始数据和经过处理的数据将在现有数据库中提供，包括NCBI（遗传和基因组数据），并通过生物和化学海洋学数据管理办公室（BCO-DMO）提供。 所有项目数据也将通过与每个PI网站链接的本地FTP服务器提供。PI致力于将代表性不足的少数民族纳入他们的研究，并在美国最多样化的机构之一天普大学指导本科生的记录。MS向教师提供将基于这些结果的课程直接带入课堂所需的背景和材料。一名高中教师也将参加这次巡航。通过这些努力，研究人员希望提高公众对海洋酸化问题的认识，提高对美国沃茨深水珊瑚群落存在的认识水平，并激励下一代科学家。