Collaborative Research: Redox Balance in Antarctic Notothenioid Fishes: Do Icefishes Have an Advantage?

南极海峡鱼科冰鱼是在持续寒冷的环境中进化过程中出现的独特生理特征的惊人例子。冰鱼是唯一的脊椎动物，作为成年人，缺乏循环氧结合蛋白血红蛋白（Hb）;在这个家庭中的几个物种也缺乏细胞内氧结合蛋白肌红蛋白（Mb）在他们的心室。Hb和Mb的损失导致心血管系统的显著改变，以确保足够的组织氧合，其中一些是能量昂贵的。最近的研究表明，不表达这些以血红素为中心的蛋白质可能至少有一个好处-与冰鱼相比，在红血脊索鱼中氧化蛋白质和脂质更高。这项研究将解决这样一个假设，即与红血notothenioid鱼相比，Hb和Mb的损失降低了冰鱼的氧化应激，从而降低了蛋白质周转率和能量成本节约。具体而言，该项目将（1）描述红血和白血的notothenioid鱼的氧化应激水平，（2）确定红血和白血的notothenioid鱼在铁的调节方面是否不同，（3）确定冰鱼中较低水平的氧化蛋白质是否会导致较低的蛋白质周转率和能量成本节约，（4）氧结合蛋白是否促进氧化应激的体内和体外研究，其结果将有助于理解铁催化氧化应激与阿尔茨海默病、帕金森病和心血管疾病的进展相关。此外，该研究将增加对可能在沟鱼类成功中发挥关键作用的notothenioid鱼类铁代谢和氧化应激相关因素的了解。更广泛的影响包括开发一个网站，使教师和学生能够更多地了解南极冰鱼的迷人生物学，以及全球气候变化和商业捕鱼活动对南极鱼类的影响。此外，阿拉斯加土著高中和本科生将参与阿拉斯加大学，费尔班克斯的研究。

Antarctic channichthyid icefishes are stunning examples of the unique physiological traits that can arise during evolution in a constantly cold environment. Icefishes are the only vertebrates that as adults, lack the circulating oxygen-binding protein hemoglobin (Hb); several species within this family also lack the intracellular oxygen-binding protein myoglobin (Mb) in their heart ventricle. The loss of Hb and Mb has resulted in striking modifications in the cardiovascular system to ensure adequate tissue oxygenation, some of which are energetically costly. Recent indicate there may be at least one benefit to not expressing these heme-centered proteins - oxidized proteins and lipids are higher in red-blooded notothenioids compared to icefishes. The research will address the hypothesis that the loss of Hb and Mb reduces oxidative stress in icefishes compared to red-blooded notothenioid fishes, resulting in a lower rate of protein turnover and energetic cost savings. Specifically, the project will (1) Characterize levels of oxidative stress in red- and white-blooded notothenioid fishes, (2) Determine if red- and white-blooded notothenioids differ in their regulation of iron, (3) Determine if lower levels of oxidized proteins in icefishes result in lower rates of protein turnover and energetic cost savings, and (4) Determine if oxygen-binding proteins promote oxidative stress in-vivo and in-vitro.The results will contribute to the understanding of iron-catalyzed oxidative stress, which is associated with the progression of Alzheimer's, Parkinson's and cardiovascular diseases. Moreover, the research will increase understanding of factors related to iron metabolism and oxidative stress in notothenioid fishes that may have played key roles in the success of channichthyid icefishes. The broader impacts include development of a website will enable teachers and students to learn more about the fascinating biology of Antarctic icefishes, as well as the impacts of global climate change and commercial fishing activities on Antarctic fishes. Additionally, Alaska Native high school and undergraduate students will be involved in research at the University of Alaska, Fairbanks.