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

• Applicant: Professor Dr. Hans-Otto Pörtner
• Subject Area: Oceanography
• Term: from 2009 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 130764009

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.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1158: Infrastructure area - Antarctic Research with Comparative Investigations in Arctic Sea Ice Areas
• Participating Person: Dr. Felix Christopher Mark