Collaborative Research: Aging in Weddell Seals: Proximate Mechanisms of Age-Related Changes in Adaptations to Breath-Hold Hunting in an Extreme Environment

本研究的主要目的是调查的近端影响的老化潜水能力的威德尔海豹和描述的机制，老化可能会影响觅食生态，通过生理和行为。这种模式鳍足类物种一直是南极洲麦克默多海峡三十年来研究的焦点。 与早期发育和成年期的鳍足类潜水生理学和生态学知识相比，人们对接近正常生殖年龄上限的个体知之甚少。进化衰老理论预测，老年潜水海豹应该表现出衰老。在屏气潜水和狩猎过程中，通过缺氧-复氧产生的氧自由基激增会加剧这种情况，这与细胞线粒体的年龄相关损伤有关。令人惊讶的是，有限的观察非受威胁的鳍足类种群表明，衰老不会发生的水平，生殖输出受到影响。鳍足类动物避免明显衰老的能力提出了两个主要问题：随着年龄的增长，鳍足类动物发生了哪些特定的生理和形态变化，以及这些动物做出了哪些微妙的调整来科普这些变化？这项研究将集中在具体的，功能性的生理和行为的变化与潜水能力随着年龄的增长。研究人员将量化与年龄相关的一般健康和身体状况的变化，并结合外部和内部潜水工作能力的精细评估。具体来说，模式的氧化状态和氧气的使用与年龄将进行检查。将检查年龄对肌肉功能、血管平滑肌收缩能力和通过骨骼肌运动表现的运动能力的影响。数据将比较威德尔海豹在高峰期，接近年底，他们的生殖年龄范围。将对进行外部工作（即潜水）的能力以及肌肉功能（进行内部工作的能力）进行评估。研究人员假设，韦德尔海豹的衰老确实发生在小规模、接近生理效应和表现的水平上，但行为可塑性允许一定程度的补偿。更广泛的影响包括对学生的培训和外联活动，包括为大众媒体撰写的访谈和文章。将在项目网站上向感兴趣的公众提供照片和项目摘要。这项研究也将建立潜水海豹作为一种新的模型，为研究心血管和肌肉生理老化。对威德尔海豹的研究可以验证这一模型，从而为其他物种的类似研究奠定基础。近年来，医学科学对衰老的理解取得了令人印象深刻的进步，研究衰老的新模型的开发对整个社会具有巨大的潜在利益

The primary objectives of this research are to investigate the proximate effects of aging on diving capability in the Weddell Seal and to describe mechanisms by which aging may influence foraging ecology, through physiology and behavior. This model pinniped species has been the focus of three decades of research in McMurdo Sound, Antarctica. Compared to the knowledge of pinniped diving physiology and ecology during early development and young adulthood, little is known about individuals nearing the upper limit of their normal reproductive age range. Evolutionary aging theories predict that elderly diving seals should exhibit senescence. This should be exacerbated by surges in the generation of oxygen free radicals via hypoxia-reoxygenation during breath-hold diving and hunting, which are implicated in age-related damage to cellular mitochondria. Surprisingly, limited observations of non-threatened pinniped populations indicate that senescence does not occur to a level where reproductive output is affected. The ability of pinnipeds to avoid apparent senescence raises two major questions: what specific physiological and morphological changes occur with advancing age in pinnipeds and what subtle adjustments are made by these animals to cope with such changes? This investigation will focus on specific, functional physiological and behavioral changes relating to dive capability with advancing age. The investigators will quantify age-related changes in general health and body condition, combined with fine scale assessments of external and internal ability to do work in the form of diving. Specifically, patterns of oxidative status and oxygen use with age will be examined. The effects of age on muscular function, contractile capacity in vascular smooth muscle, and exercise capacity via exercise performance in skeletal muscle will be examined. Data will be compared between Weddell seals in the peak, and near the end, of their reproductive age range. An assessment will be made of the ability to do external work (i.e. diving) as well as muscle functionality (ability to do internal work). The investigators hypothesize that senescence does occur in Weddell seals at the level of small-scale, proximate physiological effects and performance, but that behavioral plasticity allows for a given degree of compensation. Broader impacts include the training of students and outreach activities including interviews and articles written for the popular media. Photographs and project summaries will be available to the interested public on the project website. This study should also establish diving seals as a novel model for the study of cardiovascular and muscular physiology of aging. Research on Weddell seals could validate this model and thus develop a foundation for similar research on other species. Advancement of the understanding of aging by medical science has been impressive in recent years and the development of new models for the study of aging has tremendous potential benefits to society at large