RUI: Seasonal Turnover of Organic Matrix Collagen in Octocoral Spicules

钙化是一种极其普遍的现象，存在于细菌、植物、海绵、文蛤和人类等各种生物中。在无脊椎动物中，有覆盖或包裹其身体的钙化结构，如珊瑚礁、蜗牛壳、螃蟹外骨骼以及海胆测试和脊椎。其他无脊椎动物形成许多通常是微小的钙化结构，这些结构渗透到身体中，称为骨针或听骨。八珊瑚或海鞭Leptogorgia virulata是动物全身都有精致针状体的极好例子。像大多数无脊椎动物的钙化结构一样，这些针状体包含一个内部有机基质，为碳酸钙的沉积提供了一个框架。然而，不同寻常的是，我们发现这种八珊瑚针状基质含有胶原蛋白，这是一种对骨骼和牙齿的形成至关重要的蛋白质，但很少与无脊椎动物的碳酸钙结构有关。此外，这种八珊瑚胶原蛋白随季节变化，在夏季占主导地位。这个为期三年的项目将深入探索八珊瑚针状物随时间的钙化之间的关系，将使用各种特定的标记进行研究。例如，四环素是一种荧光标记物，45Ca是一种放射性钙化。放射性标记的脯氨酸和我们最近开发的特异性抗体标记物，标记胶原的合成。这些成分可以通过荧光和透射电子显微镜可视化，并通过量化存在的标记物的量来测量。骨骼重塑包括利用酶反应和其他特异性抗体标记物改变酸度和酶毛刺。这个项目的一个重要方面是学生调查员的参与。

Calcification is an extremely widespread phenomenon occurring in organisms as diverse as bacteria, plants, sponges, clams and humans. Among the invertebrates, there are calcified structures that cover or encase their bodies such as coral reefs, snail shells, crab exoskeletons and sea urchin tests and spines. Other invertebrates form numerous usually microscopic calcified structures that impregnate the body called spicules or ossicles. The octocoral or sea whip Leptogorgia virgulata is an excellent example of an animal possessing elaborate spicules throughout its body. Like most invertebrate calcified structures, these spicules contain an internal organic matrix that provides a framework for the deposition of calcium carbonate. What is unusual, however, is our discovery that this octocoral spicule matrix contains collagen, a protein that is critical in the formation of bones and teeth, but is rarely associated with invertebrate calcium carbonate structure. Furthermore, this octocoral collagen varies seasonally, being predominant in the summer. This three-year project will explore in depth the relationships between octocoral spicule calcification over time will be studied using a variety of specific markers. For example, tetracycline is a fluorescent marker and 45Ca is a radioactive calcification. Radiolabelled proline and specific antibody markers that we have recently developed, mark collagen synthesis. These components can be visualized through fluorescence and transmission electron microscopy, and measured by quantifying the amount of label present. Bone remodelling involves changes in acidity and enzyme spicules using enzymatic reactions and other specific antibody markers. An important dimension of this project is the involvement of student investigators.