NSFGEO-NERC: The Blueprint for Marine Biomineralization in a Changing Climate

本项目由美国国家科学基金会地球科学理事会（NSF/GEO）和英国国家环境研究委员会（NERC）根据NSF/GEO-NERC牵头机构协议共同资助。该协议允许美国/英国提交一份联合提案，并由其调查员拥有最大比例预算的机构进行同行评审。在成功地共同确定一项奖励后，每个机构为预算的比例和与自己的调查人员有关的调查人员和工作的组成部分提供资金。这个项目将研究一种重要的海洋生物——有孔虫的壳形成。有孔虫是沙粒大小、有壳的浮游生物。它们在现代海洋和化石记录中都很常见。它们的壳成分取决于生长过程中的海洋条件，因此它们的化石被用来记录地球的气候历史。有孔虫壳在碳循环中也起着重要作用。海底沉积的碳中，高达80%是由它们产生的。了解贝壳的形成很重要，因为海洋变暖和pH值的变化威胁着有孔虫的生存。然而，有孔虫壳的形成还没有被很好地理解。部分原因是这些物种的基因组是未知的。需要基因组来识别负责壳形成过程的蛋白质。这项研究将通过鉴定两个物种的关键壳蛋白来缩小这一知识差距。该项目将在模拟未来可能气候的条件下培养标本，并将确定壳蛋白在响应生长条件时的差异。研究结果将为有孔虫提供“壳形成的蓝图”。基因组和蛋白质序列数据集将对海洋生物学和化学、进化、气候科学和材料科学的研究人员有用。更广泛的影响包括研究生和本科生的实地研究经验和培训。国际参与者还将获得在实验室中培育有孔虫的经验。这个多学科项目将在两个单细胞有孔虫模型物种中建立生物矿化的分子生物学控制。这对于量化海洋方解石预算和评估钙化反馈对未来大气二氧化碳的影响至关重要，以及对有孔虫壳地球化学档案进行准确解释，这是未来气候变化预测的基础。尽管对有孔虫如何生物矿化进行了数十年的研究，但由于缺乏对鉴定有孔虫壳基质蛋白（SMPs）至关重要的基因组/转录组信息，我们的理解远远落后于其他海洋钙化物。壳的有机基质层中的SMPs触发碳酸钙成核，并负责壳的形成及其地球化学性质。SMPs的鉴定将有助于我们理解生物矿化如何响应未来的环境变化，因此我们必须解决这些至关重要的海洋钙化物的生物矿化机制。这个项目解决了这个需求。跨学科团队的专业知识将被用于通过单细胞测序产生所需的基因组和转录组数据，并利用创新的高通量微流体方法来识别和表征有孔虫生物矿化过程中的关键SMPs。将进行有孔虫培养实验，以研究分子/蛋白质对不同气候情景的响应。项目团队结合了一套独特的技能，使我们第一次能够调查有孔虫生物矿化过程的生物控制的各个方面。通过连接基因、转录本、蛋白质和方解石形成，我们的目标是生成“生物矿化蓝图”。识别这些关键分子将首次为识别有孔虫SMPs随温度和pH变化的变化提供机会，并评估有孔虫生物矿化对未来气候情景的脆弱性。该奖项反映了美国国家科学基金会的法定使命，并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，被认为值得支持。

This is a project jointly funded by the National Science Foundation Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own investigators and component of the work. This project will study shell formation in an important marine organism, the foraminifera. Foraminifera are sand-grain-sized, shell-forming plankton. They are common in the modern ocean and in the fossil record. Their shell composition depends on ocean conditions during growth, and so their fossils are used to record Earth’s climate history. Foraminifera shells also play an important role in the carbon cycle. They are responsible for up to 80% of the carbon that is deposited on the seafloor. Understanding shell formation is important because changes in ocean warming and pH threatens foraminiferal survival. However, foraminiferal shell formation is not well understood. In part this is because the genome for these species is unknown. A genome is required to identify proteins responsible for shell forming processes. This study will close this knowledge gap by identifying key shell proteins in two species. The project will grow specimens under conditions that mimic likely future climate and will identify differences in shell proteins in response to growth conditions. The results will provide a 'blueprint for shell formation' in foraminifera. The genome and protein sequence datasets will be useful to researchers in marine biology and chemistry, evolution, climate science, and material science. Broader impacts include graduate and undergraduate student field research experience and training. International participants will also gain experience growing foraminifera in the laboratory.This multidisciplinary project will establish the molecular biological controls of biomineralization in two model species of single-celled foraminifera. This is crucial for quantifying the marine calcite budget and assessing the impact of calcification feedbacks on future atmospheric carbon dioxide, as well as producing accurate interpretation of the foraminiferal shell geochemical archive that underpins future climate change projections. Despite decades of research into how foraminifera biomineralization, our understanding lags far behind other marine calcifiers, owing to a lack of genome/transcriptome information that is vital for identification of foraminifera shell matrix proteins (SMPs). SMPs in the shell’s organic matrix layers trigger nucleation of calcium carbonate and are responsible for shell formation and its geochemical properties. The identification of SMPs will aid in our understanding of how biomineralization will respond to future environmental change and thus it is imperative that we resolve biomineralization mechanisms in these critically important marine calcifiers. This project addresses that need. The interdisciplinary team’s expertise will be capitalized to produce the genome and transcriptome data required via Single Cell Sequencing and exploit innovative high throughput microfluidic approaches to identify and characterize key SMPs in foraminifera biomineralization. Foraminifera culturing experiments will be conducted to investigate molecular/protein responses to different climate scenarios. The project team combines a unique set of skills that enable us, for the first time, to investigate all aspects of the biological control of the biomineralization process within the foraminifera. By linking genes, transcripts, proteins, and calcite formation our aim is to generate a ‘blueprint of biomineralization’. Identifying these key molecules will provide the first ever opportunity to identify any changes in the foraminifera SMPs in response to changes in temperature and pH, and assess the vulnerability of foraminiferal biomineralization to future climate scenarios.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.