Mitochondrial plasticity in response to changing abiotic factors in Antarctic fish and cephalopods

温度对生化和酶过程的速度有很大的影响，因此是决定外生生物性能的关键因素。由于单分子的温度窗口在很大程度上超过了整个动物的温度极限，所以温度极限很可能是在分子功能整合到整个生物体功能单元和网络的水平上设定的。线粒体是形成整个生物体能量周转和功能能力的关键要素。最近对南极鱼类线粒体特殊分子特征的洞察提供了一个独特的机会来开发和测试解释这些特征在设定耐热性中的作用的假说。此外，温度极低的南极鱼类和无脊椎动物本已很紧张的耐热窗口可能会因正在进行的海洋酸化过程而缩小。因此，这些生物可能会对气候变暖变得更加敏感。线粒体在这种敏感度变化中的作用尚不清楚。在这个项目中，我们将在线粒体水平上重点研究南极鱼类和头足类动物对温度和二氧化碳因素的反应。虎鱼亚目鱼类生活在极地、亚极地和部分寒冷的温带水域，因此是研究近缘南极鱼类之间热塑性的良好比较模式生物。八足类(头足目)也是如此，它们分布在热带到极地纬度地区。在南极水域，这些高度发达的动物与底栖拟脊椎动物共享相同的空间和生态位，从而直接竞争生态系统中的相同资源。阐述线粒体对南极鱼类和头足类温度和气候敏感性的特殊特征的贡献，似乎是对南极生态系统气候敏感性领域的高度相关和及时的贡献。

Temperature has a large impact on the velocity of biochemical and enzymatic processes and hence is a key factor defining the performance of ectothermic organisms. Since temperature windows of single molecules largely exceed the thermal limits of the whole animal, thermal limits are most probably set at the level of integration of molecular functions into whole organism functional units and networks. Mitochondria are a key element in shaping whole organism energy turnover and functional capacity. Recent insight into the special molecular characters of Antarctic fish mitochondria provides a unique opportunity to develop and test hypotheses explaining the role of these characters in setting thermal tolerance. Furthermore, the already tight thermal tolerance windows of extremely stenothermal Antarctic fish and invertebrates may be narrowed by the ongoing process of ocean acidification (OA). As a result, these organisms may become even more sensitive to warming. The role of mitochondria in contributing to such changes in sensitivity is unclear.. In this project we will focus on the responses of Antarctic fish and cephalopods to the factors temperature and carbon dioxide at the mitochondrial level. Fishes of the sub-order Notothenioidei inhabit polar, sub-polar and in part cold temperate waters and therefore are good comparative model organisms for studies of thermal plasticity among closely related Antarctic fish species. This holds also true for the octopods (order: Cephalopoda), which are found from tropical to polar latitudes. In Antarctic waters, these highly developed animals share the same spatial and ecological niche as benthic notothenioids and thus directly compete for the same resources in the ecosystem. Elaboration of the contribution of mitochondria to the special features of stenothermy and climate sensitivity in Antarctic fishes and cephalopods appears as a highly relevant and timely contribution to the field of climate sensitivity of Antarctic ecosystems.