The Role of the Epigenetic Mechanism, DNA Methylation, in the Tolerance and Resistance of Antarctic Pteropods to Ocean Acidification and Warming

表观遗传机制 DNA 甲基化在南极翼足类动物对海洋酸化和变暖的耐受和抵抗中的作用

• 批准号: 2053726
• 负责人: Gretchen Hofmann
• 金额: $ 30.85万
• 依托单位: University of California-Santa Barbara
• 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: 2021-04-01 至 2025-03-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2053726&HistoricalAwards=false
• 关键词: Role; Epigenetic; Mechanism; DNA; Methylation

Part 1: Non-technical description: With support from the Office of Polar Programs, this project will evaluate how an important part of the food web in the coastal ocean of Antarctica will respond to climate change. The focal study organism in the plankton is a shelled mollusk, the Antarctic pteropod, Limacina helicina antarctica, an Southern Ocean organism that this known to respond to climate driven changes in ocean acidification and ocean warming. Ocean acidification, the lowering of ocean pH via the absorption of atmospheric carbon dioxide in the surface of the ocean, is a change in the ocean that is expected to cross deleterious thresholds of pH within decades. This study will improve understanding of how pteropods will respond, which will provide insight into predicting the resilience of the Antarctic marine ecosystem during future changes, one of the planet’s last marine wildernesses. The project will use tools of molecular biology to examine specifically how gene expression is modulated in the pteropods, and further, how the changes and regulation of genes act to resist the stress of low pH and high temperature. In addition, this project supports the training of Ph.D. graduate students and advances the goal of inclusive excellence in STEM and in marine sciences, in particular. The students involved in this project are from groups traditionally under-represented in marine science including first-generation college students. Overall, the project contributes to the development of the U.S. work force and contributes to diversity and inclusive excellence in the geosciences.Part 2: Technical description: The overarching goal of this project is to investigate the molecular response of the Antarctic thecosome pteropod, Limacina helicina antarctica to ocean acidification (OA) and ocean warming. The project will investigate changes in the epigenome of juvenile L. h. antarctica, by assessing the dynamics of DNA methylation in response to three scenarios of environmental conditions that were simulated in laboratory mesocosm CO2 experiments: (1) present-day pCO2 conditions for summer and winter, (2) future ocean acidification expected within 10-15 years, and (3) a multiple stressor experiment to investigate synergistic interaction of OA and high temperature stress. Recent lab-based mesocosm experiment research showed significant changes in the dynamics of global DNA methylation in the pteropod genome, along with variation in gene expression in response to abiotic changes. Thus, it is clear that juvenile L. h. antarctica are capable of mounting a substantial epigenetic response to ocean acidification. However, it is not known how DNA methylation, as an epigenetic process, is modulating changes in the transcriptome. In order to address this gap in the epigenetic knowledge regarding pteropods, the project will use next-generation sequencing approaches (e.g., RNA sequencing and reduced representation bisulfite sequencing) to integrate changes in methylation status with changes in gene expression in juvenile pteropods. Overall, this investigation is an important step in exploring environmental transcriptomics and phenotypic plasticity of an ecologically important member of Southern Ocean macrozoooplankton in response to anthropogenic climate change.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.

第一部分：非技术性说明：在极地方案办公室的支持下，该项目将评估南极洲沿海海洋食物网的一个重要组成部分将如何应对气候变化。浮游生物中的重点研究生物是一种带壳软体动物，即南极翼足类动物，Limacina helicina anarctica，这是一种南大洋生物，已知会对海洋酸化和海洋变暖的气候变化做出反应。 海洋酸化是指海洋表面吸收大气中的二氧化碳，导致海洋pH值降低，这是一种海洋变化，预计将在几十年内跨越有害的pH值阈值。这项研究将提高对翼足类动物将如何应对的理解，这将为预测南极海洋生态系统在未来变化中的恢复力提供见解，这是地球上最后的海洋荒野之一。该项目将使用分子生物学工具来具体研究翼足类动物中基因表达是如何调节的，以及基因的变化和调节如何抵抗低pH和高温的胁迫。 此外，该项目还支持培养博士生。研究生，并推进在干，特别是在海洋科学的包容性卓越的目标。参与该项目的学生来自传统上在海洋科学中代表性不足的群体，包括第一代大学生。 总体而言，该项目有助于美国劳动力的发展，并有助于地球科学的多样性和包容性卓越。第2部分：技术描述：本项目的总体目标是调查南极thecosome pteropod，Limacina helicina anapartica对海洋酸化（OA）和海洋变暖的分子响应。该项目将研究幼年L. H.通过评估DNA甲基化的动态，以响应实验室围隔生态系统CO2实验中模拟的三种环境条件：（1）目前夏季和冬季的pCO 2条件，（2）预计在10-15年内的未来海洋酸化，以及（3）研究OA和高温胁迫协同作用的多重胁迫实验。 最近的实验室围隔实验研究表明，在翼足类基因组中的整体DNA甲基化的动态变化显着，沿着基因表达的变化，以响应非生物的变化。由此可见，幼年L. H.南极海生动物能够对海洋酸化作出重大的表观遗传反应。 然而，目前还不知道DNA甲基化作为一种表观遗传过程如何调节转录组的变化。 为了解决关于翼足类动物的表观遗传学知识中的这一差距，该项目将使用下一代测序方法（例如，RNA测序和还原型亚硫酸氢盐测序），以整合甲基化状态的变化与幼年翼足类动物基因表达的变化。 总的来说，这项研究是探索南大洋大型浮游动物生态重要成员的环境转录组学和表型可塑性以应对人为气候变化的重要一步。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。