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

这是一个由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理事会(NERC)通过NSF/GEO-NERC牵头机构协议联合资助的项目。该协定允许美国和英国提交一个单一的联合提案，并由该机构进行同行审查，该机构的调查员在预算中所占比例最大。在成功地联合确定一项裁决后，每个机构将为预算的比例以及与其自己的调查员和工作部分有关的调查员提供资金。这个项目将研究一种重要的海洋生物--有孔虫--的壳形成。有孔虫是沙粒大小的贝壳浮游生物。它们在现代海洋和化石记录中很常见。它们的外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。有孔虫贝壳在碳循环中也扮演着重要角色。它们负责高达80%的沉积在海底的碳。了解贝壳的形成很重要，因为海洋变暖和pH值的变化威胁到有孔虫的生存。然而，有孔虫贝壳的形成还不是很清楚。这在一定程度上是因为这些物种的基因组是未知的。需要一个基因组来识别负责壳形成过程的蛋白质。这项研究将通过识别两个物种中的关键壳蛋白来弥合这一知识差距。该项目将在模拟未来气候的条件下培养标本，并将识别壳蛋白在生长条件下的差异。这一结果将为有孔虫中贝壳的形成提供一张蓝图。基因组和蛋白质序列数据集将对海洋生物和化学、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培育有孔虫的经验。这一多学科项目将在两个单细胞有孔虫模式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以及对支撑未来气候变化预测的有孔虫贝壳地球化学档案的准确解释至关重要。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，我们对有孔虫生物矿化的了解远远落后于其他海洋钙化物。壳层有机基质层中的SMPS触发碳酸钙的成核，并对壳层的形成及其地球化学性质负责。SMPS的鉴定将有助于我们理解生物矿化作用将如何响应未来的环境变化，因此，我们迫切需要解决这些至关重要的海洋钙化物的生物矿化机制。该项目满足了这一需求。跨学科团队将利用其专业知识，通过单细胞测序产生所需的基因组和转录组数据，并开发创新的高通量微流控方法，以识别和表征有孔虫生物矿化中的关键SMP。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反应。项目团队结合了一套独特的技能，使我们能够第一次调查有孔虫内生物矿化过程的生物控制的所有方面。通过将基因、转录本、蛋白质和方解石的形成联系起来，我们的目标是生成一张“生物矿化蓝图”。识别这些关键分子将提供有史以来第一次机会来确定有孔虫SMPS随着温度和pH的变化而发生的任何变化，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NSF的法定使命，并通过使用基金会的智力优势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.