Ocean Acidification: Mechanisms of Coral Biomineralization

这项研究试图了解珊瑚是如何形成骨骼的。石珊瑚的骨骼是至关重要的生物结构，支持着大片热带和亚热带海洋生物，并提供了抵御海浪、风暴和洪水的天然屏障。然而，目前还不知道珊瑚是如何构建它们的骨骼的，也不完全了解海洋酸化将对这一过程产生什么影响。为了解决这些根本问题，该项目采取了双管齐下的方法，利用活珊瑚基因中的信息，结合超高分辨率显微镜和物理化学技术，了解形成石珊瑚骨架的碳酸盐矿物沉淀的机制。这一努力将进一步开发能够培养珊瑚组织和分析珊瑚基因组以推断基因功能的技术。这项研究与了解未来几十年海洋酸化对珊瑚生存的潜在威胁有关。尽管珊瑚中的生物矿化作用已经研究了几十年，但文石骨架沉淀的基本机制仍然是个谜。利用正向遗传方法，最近从常见的石珊瑚Stylophora pistillata中鉴定和克隆了一组高酸性蛋白。所有克隆的蛋白在海水中均有文石沉淀，pH分别为8.2和7.6。然而，目前尚不清楚这些蛋白质在体内的表达是否足以在海水pH值低于~7.8的情况下形成文石骨架。结合分子、生物物理、基因组和细胞生物学的方法，这里要检验的核心假设是，除非受伤或以其他方式将骨骼材料直接暴露在海水、石质和虫草珊瑚中，否则在2100年二氧化碳排放情景预测的pH值下，珊瑚将继续钙化。这种多学科的研究方法旨在告知海洋的pH值如何影响导致虫黄藻硬化性珊瑚钙化的关键生理过程。研究团队将为本科生创建在线学习模块。此外，这项研究将纳入罗格斯大学的教育和公共外联小组，用于K-12学生的海洋科学教育和K-12教师的培训。最后，该项目包括两名博士后研究员的培训和职业发展。

This research seeks to understand how corals make their skeletons. The skeletons of stony corals are critically important biological structures that support huge areas of tropical and subtropical marine life as well as providing natural barriers against waves, storms, and floods. However, it is not yet known how corals construct their skeletons, nor is it fully understood what the effect of ocean acidification will have on this process. To address these fundamental questions, this project follows a two-pronged approach that utilizes information in the genes of living corals coupled with ultra high-resolution microscopy and physical chemical techniques to understand the mechanism that underlies precipitation of the carbonate mineral that forms the skeleton of stony corals. This effort will further develop techniques that will allow the culturing of coral tissues and the analysis of coral genomes to infer gene functions. The research is relevant to understanding the potential threat of ocean acidification to the viability of corals in the coming decades. Although biomineralization in corals has been studied for decades, the basic mechanism responsible for the precipitation of the aragonite skeleton remains enigmatic. Using a forward genetic approach, a group of highly acidic proteins derived from the common stony coral, Stylophora pistillata was recently identified and cloned. All of the cloned proteins precipitate aragonite in seawater at pH 8.2 and at 7.6 in vitro. However, it is not clear if the expression of these proteins in vivo is sufficient for the formation of an aragonite skeleton at seawater pH values below ~7.8. Using a combination of molecular, biophysical, genomic, and cell biological approaches the core hypothesis to be tested here is that, unless wounded or otherwise having skeletal material exposed directly to seawater, stony, zooxanthellate corals will continue to calcify at pH values projected for the CO2 emissions scenarios for 2100. The multi-disciplinary research approach is designed to inform how pH of the ocean influences the key physiological processes responsible for calcification in zooxanthellate scleratinian corals. The research team will create online learning modules for undergraduate students. In addition, the research will be incorporated into the Education and Public Outreach group at Rutgers University for marine science education of K-12 students and training of K-12 teachers. Finally, the project includes training and career development for two post-doctoral fellows.