Adaption and stress defence in intertidal and subtidal Antarctic limpets (Nacella concinna): A Study of the plasticity of molecular and biochemical stress response in Antarctic invertebrates

南极海洋外温动物回顾了数百万年来对持续极端寒冷温度和高氧气浓度的适应（Clarke 1998，2003）。大多数特有种是冷、狭温和狭温的，耐受窗窄，活动范围小。在典型的南极潮下带地区，对非常恒定的环境条件的长期进化适应可能会导致调节可塑性以及分子和生物化学应激耐受性的丧失。南极潮间地区是相对“高压力环境”。有趣的是，在南极半岛周围沿海沃茨的众多潮下带大型动物中，只有一个物种成功地在最容易到达的潮间带定居：帽贝Nacella concinna。该物种分为两个不同的形态型，通常被描述为“潮间和潮下亚群”。除了形态上的差异，潮间带亚群需要行为和生理应激耐受性，上级其潮下同源物。在这个项目中，我们的目标是研究诱导代谢应激反应的能力，区分潮下和潮间N。浓缩标本。HIF-1是低氧生存的主要调节因子，因为它调节许多低氧应激反应基因，并且可以用作研究动物应激反应能力的分子工具。由于ROS正在讨论以几种不同的方式调节HIF-1诱导的应激反应，我们还将研究生理和生化氧化应激标志物和抗氧化防御。我们的目的是澄清，是否潮间带和永久潮下亚群之间的形态分化是沿着适应性变化的分子和生理差异的代谢调节缺氧胁迫。南设得兰群岛是火山岛，其特点是沿海沃茨中颗粒铁的浓度非常高。在大型底栖滤食性动物的组织中发现了极高浓度的铁和其他过渡金属，但也有像N。concinna。铁是一种芬顿催化剂，是活性氧（ROS）形成的主要原因，如果不受铁结合蛋白和螯合剂的密切控制，可能对动物有毒。最重要的是，铁诱导的ROS形成已被证明会干扰哺乳动物的细胞应激信号。本研究的第二个目的是评估铁对N. concinna。

Antarctic marine ectotherms look back on several million years of adaptation to constant extreme cold temperatures and high oxygen concentrations (Clarke 1998, 2003). Most endemic species are cold stenothermal and stenoxic with narrow tolerance windows and have a low scope for activity. Long lasting evolutionary adaptation to very constant environmental lconditions in typically Antarctic subtidal areas could potentially have caused loss of regulatory plasticity and of molecular and biochemical stress tolerance. Intertidal Antarctic areas are comparably "high stress environments". Interestingly, out of the multitude of subtidal macrofauna from the coastal waters surrounding the Antarctic Peninsula, only one species has successfully colonized most accessible intertidal areas: the limpet Nacella concinna. This species splits up into two distinct morphotypes, often described as "intertidal and subtidal subpopulations". In addition to the morphological difference, the intertidal subpopulation needs behavioural and physiological stress tolerance, superior to their subtidal congeners. In this project we aim to study the capacity for the induction of a metabolic stress response, distinguishing between subtidal and intertidal N. concinna specimens. HIF-1 is a master regulator of hypoxic survival, as it regulates a number of hypoxia stress response genes, and can be used as a molecular tool to study animal stress response capacity. As ROS are being discussed to modulate the HIF-1 induced stress response in several different ways, we will also investigate physiological and biochemical oxidative stress markers and antioxidant defence. Our aim is to clarify, whether the morphological differentiation between the intertidal and the permanently subtidal subpopulation is going along with adaptive changes in molecular and physiological differences of metabolic regulation under hypoxic stress. The South Shetland Islands are volcanic islands and characterized by extraordinarily high concentrations of particulate iron in coastal waters. Extremely high concentrations of iron and other transition metals have been found in tissues of macrobenthic filter feeders, but also of grazers like N. concinna. Iron is a Fenton catalyst and a major cause of reactive oxygen species (ROS) formation and can be toxic to animals, if not closely controlled by iron binding proteins and chelators. On top of that, iron induced ROS formation has been shown to interfere with cellular stress signalling in mammals. The second objective of this study is to assess the impact of iron on stress response signalling in N. concinna.