Differential Cellular Response to Mercury in Non-Farmed Fish Species Based on Mitochondrial DNA Copy Number Variation Analysis
Marta Giuga,
Venera Ferrito,
Giada Santa Calogero,
Anna Traina,
Maria Bonsignore,
Mario Sprovieri,
Anna Maria Pappalardo
Affiliations
Marta Giuga
Department of Biological, Geological and Environmental Sciences, Section of Animal Biology “M. La Greca”, University of Catania, Via Androne 81, 95124 Catania, Italy
Venera Ferrito
Department of Biological, Geological and Environmental Sciences, Section of Animal Biology “M. La Greca”, University of Catania, Via Androne 81, 95124 Catania, Italy
Giada Santa Calogero
Department of Biological, Geological and Environmental Sciences, Section of Animal Biology “M. La Greca”, University of Catania, Via Androne 81, 95124 Catania, Italy
Anna Traina
National Research Council of Italy, Institute of Anthropic Impacts and Sustainability in Marine Environment (CNR-IAS), Lungomare Cristoforo Colombo 452, 90149 Palermo, Italy
Maria Bonsignore
National Research Council of Italy, Institute of Anthropic Impacts and Sustainability in Marine Environment (CNR-IAS), Via del Mare, 91021 Campobello di Mazara, Italy
Mario Sprovieri
National Research Council of Italy, Institute of Marine Sciences (ISMAR-CNR), Tesa 104—Arsenale, Castello 2737/F, 30122 Venezia, Italy
Anna Maria Pappalardo
Department of Biological, Geological and Environmental Sciences, Section of Animal Biology “M. La Greca”, University of Catania, Via Androne 81, 95124 Catania, Italy
Mercury (Hg) pro-oxidant role on biological systems and its biogeochemical cycle represent a serious threat due to its persistence in marine environment. As the mitochondrial genome is exposed to reactive oxygen species (ROS), the aim of the present study is the validation of the variation in the number of mitochondrial DNA copies (mtDNAcn) as biomarker of oxidative stress in aquatic environment. During summer 2021, three selected fish species (Mullus barbatus, Diplodus annularis and Pagellus erythrinus) were collected in Augusta Bay, one of the most Mediterranean contaminated areas remarkable by past Hg inputs, and in a control area, both in the south-east of Sicily. The relative mtDNAcn was evaluated by qPCR on specimens of each species from both sites, characterized respectively by higher and lower Hg bioaccumulation. M. barbatus and P. erythrinus collected in Augusta showed a dramatic mtDNAcn reduction compared to their control groups while D. annularis showed an incredible mtDNAcn rising suggesting a higher resilience of this species. These results align with the mitochondrial dynamics of fission and fusion triggered by environmental toxicants. In conclusion, we suggest the implementation of the mtDNAcn variation as a valid tool for the early warning stress-related impacts in aquatic system.
