How do multiple coastal stressors structure the genomic diversity of marine populations?

多个沿海压力源如何构建海洋种群的基因组多样性？

• 批准号: 2049613
• 负责人: Jonathan Puritz
• 金额: $ 68.09万
• 依托单位: University of Rhode Island
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-15 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2049613&HistoricalAwards=false
• 关键词: How; do; multiple; coastal; stressors

Marine species face a complex suite of stressors that span multiple temporal and spatial scales from long-term global ocean change to localized episodes of coastal acidification. The cumulative and concurrent impacts of multiple stressors remain relatively unknown and requires investigating their synergistic impacts across all life stages. Two common stressors in coastal environments are hypoxia, or low dissolved oxygen, and coastal acidification. Hypoxia and coastal acidification are linked to daily cycles of respiration and photosynthesis, even in pristine bays and estuaries. Coastal waters are also affected by pulses of natural and artificial freshwater runoff driven by rainfall and storm events. Pulses of freshwater can cause short-term, low salinity conditions, another stressor, that are expected to worsen with climate change. For many marine species, larval stages are the only means of migration and genetic exchange, and larvae are likely encountering hypoxia, coastal acidification, and low salinity stressors while they are in shallow coastal waters. Additionally, early juveniles may encounter extended periods of all three stressors. The interaction of early life-history stages with repeated and combinations of coastal stressors has the potential to result in an increase of larval/juvenile mortality or the removal of less tolerant larvae. The consequences of this differential mortality are being investigated in the eastern oyster using laboratory multi-stressor exposure experiments and in the field through genomic surveys of natural populations. Patterns of genetic selection are being analyzed by combining genomic and environmental data to elucidate how multiple stressors are shaping marine populations. Broader impacts include training opportunities for a post-doctoral fellow, graduate and undergraduate students and societal impacts. Results from the study are key to predicting how oyster reefs will adapt to long-term climate change and human population growth. A symposium is planned to bring scientists and members of the broader community together to discuss conservation and restoration of oyster reefs and sustainable aquaculture. A better understanding the physiological limits of larvae and juveniles to stressors is contributing to new strategies for oyster hatcheries to optimize selection and screening of brood stock for robust larvae and juveniles.The broad goal is to characterize how hypoxia (DO), coastal acidification (CA), and low salinity events (LS) shape population connectivity and microevolutionary processes of marine invertebrates. As larvae grow and develop, they may be able to tolerate short-term exposures to environmental stressors, but prolonged exposure to diurnal DO/CA cycling and LS events may reduce subsequent survival, especially in juveniles. Larval and juvenile interactions with multiple stressors have the potential to either disrupt gene flow by simply not allowing migrant exchange or to act as a selective force, structuring populations through genotype-environment interactions. This project uses a coupled experimental and seascape genomics approach to investigate how multiple stressors are shaping observed genomic diversity. Phase 1 is determining how larval and juvenile genotypes and phenotypes respond to multiple stressors across different developmental time points. Experiments include two larval short-term exposures to factorial combinations of DO/CA and LS, and a long-term juvenile exposure to factorial combinations of DO/CA diurnal cycling and LS. The coding regions of genes expressed during experimental exposures are being sequenced using a cost-effective exome capture method. Phase 2 is determining the role of natural and anthropogenic forces shaping the evolution of oyster populations by testing if selective regimes differ and interact across life-history stages and if the frequencies of both neutral and resistant genotypes correlate with environmental conditions. Surveys of the genomes of adult populations across multiple localities from several urbanized estuaries are generating a seascape genomic framework based on a panel of genomic markers, including potential loci under selection during early-life history. These data are being integrated with environmental data to elucidate the mix of factors that contribute to population structure and local genetic diversity. Results are linking adult genotype frequencies at both neutral and putatively selective loci to changes in allele frequencies in response to early larval, late larval, and early juvenile exposure to stressors. The research is unraveling the complex interaction of selection, migration, and drift on marine genetic diversity for a mechanistic understanding of the genomic consequences of coastal stressor and their interaction on larvae.This project is jointly funded by Biological Oceanography and Integrative Organismal Systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

海洋物种面临着一系列复杂的压力源，这些压力源跨越从长期全球海洋变化到局部沿海酸化的多个时空尺度。多重压力源的累积和并发影响仍然相对未知，需要调查其在所有生命阶段的协同影响。沿海环境中两个常见的压力源是缺氧或低溶解氧和沿海酸化。缺氧和海岸酸化与呼吸和光合作用的每日循环有关，即使在原始海湾和河口也是如此。沿海沃茨也受到降雨和风暴事件驱动的天然和人工淡水径流脉冲的影响。淡水的脉动会造成短期的低盐度条件，这是另一个压力源，预计会随着气候变化而恶化。对于许多海洋物种来说，幼虫阶段是迁移和遗传交换的唯一手段，幼虫在沿海浅水沃茨中可能会遇到缺氧、沿海酸化和低盐度的压力。此外，早期的青少年可能会遇到所有三个压力源的延长期。早期生活史阶段的相互作用与重复和组合的沿海压力有可能导致增加幼虫/少年死亡率或去除不太宽容的幼虫。这种差异的死亡率的后果正在研究在东部牡蛎使用实验室多应激暴露实验，并在该领域通过自然种群的基因组调查。遗传选择的模式正在通过结合基因组和环境数据进行分析，以阐明多种压力因素如何塑造海洋种群。更广泛的影响包括博士后研究员、研究生和本科生的培训机会以及社会影响。研究结果是预测牡蛎礁如何适应长期气候变化和人口增长的关键。计划举办一次研讨会，将科学家和更广泛的社区成员聚集在一起，讨论牡蛎礁的保护和恢复以及可持续水产养殖。研究低氧、海岸酸化和低盐度事件对海洋无脊椎动物种群连通性和微进化过程的影响，为牡蛎孵化场优化选择和筛选健壮幼贝提供新的策略。随着幼虫的生长和发育，它们可能能够耐受短期暴露于环境压力，但长期暴露于昼夜DO/CA循环和LS事件可能会降低随后的生存，特别是在青少年。幼虫和少年的相互作用与多种压力有可能破坏基因流，简单地不允许移民交流或作为一种选择性的力量，通过基因型与环境的相互作用，结构人口。该项目使用耦合实验和海景基因组学方法来研究多种压力源如何塑造观察到的基因组多样性。第一阶段是确定幼虫和幼虫的基因型和表型如何在不同的发育时间点对多种应激源作出反应。实验包括两个幼虫短期暴露于DO/CA和LS的阶乘组合，和长期的少年暴露于DO/CA昼夜循环和LS的阶乘组合。正在使用具有成本效益的外显子组捕获方法对实验暴露期间表达的基因编码区进行测序。第二阶段是确定自然和人为力量塑造牡蛎种群进化的作用，通过测试选择制度是否不同，并在生活史阶段相互作用，以及中性和抗性基因型的频率是否与环境条件相关。对来自几个城市化河口的多个地点的成年人基因组的调查正在基于一组基因组标记生成海景基因组框架，包括在早期生活史中选择的潜在基因座。这些数据正在与环境数据结合起来，以阐明有助于种群结构和当地遗传多样性的各种因素。结果是连接成人基因型频率在中性和pupelis选择位点的等位基因频率的变化，在早期幼虫，晚期幼虫，和早期少年暴露于压力。这项研究揭示了选择，迁移，和漂移对海洋遗传多样性的影响，以了解沿海压力及其对幼体的相互作用的基因组后果。该项目由生物海洋学和综合有机体系统联合资助。该奖项反映了NSF的法定使命，并通过利用基金会的智力价值和更广泛的评估，被认为值得支持。影响审查标准。