The adaptation of rainbow trout to warmer water: Oxidative damage in the germinal line

SEVASTEI, VIANEL; CRICHIGNO, SONIA A.; SANTOS, M. VICTORIA; TROCHINE, ANDREA; PAINEFILÚ, JULIO C.; ZARITZKY, NOEMÍ; CUSSAC, VÍCTOR E.

Aquaculture and Fisheries

KeAi

Lugar: Shanghai; Año: 2023

2468-550X

Contemporary evolution was observed in a feral rainbow trout (Oncorhynchus mykiss) population of a thermalstream (Valcheta) in Northern Patagonia, in terms of juvenile thermal tolerance and preferred temperature.Other authors showed that high-temperature treatment applied to male rainbow trout juveniles increased thethermal tolerance in the next generation. This implies a high mutation rate and/or a modified epigenetic in­heritance. Comparisons were made among a) a rainbow trout strain adapted in terms of upper thermal toleranceand higher preferred temperature (Valcheta stream), b) a wild temperate stream population (Guillelmo stream),and c) two temperate farmed strains. We examined: Oxidative damage (lipid peroxidation) and activities ofantioxidant enzymes; Catalase (CAT), Glutathione S-Transferases (GST), and Superoxide Dismutase (SOD), inliver, testicle, and spermatozoa. Semen fatty acid composition, sperm morphology, sperm motility, and fertil­ization performance in samples before and after the application of cryopreservation procedures were alsoevaluated. The observed responses, mainly related to the sperm membrane, reinforces the idea that ROS canaffect the germinal line of male rainbow trout juveniles subjected to high water temperature. Our results suggestthat the acquired thermal tolerance traits may be part of a wide spectrum of novel characteristics produced as aconsequence of an enhanced mutation rate and/or a different DNA methylation pattern, induced by highertemperatures and mediated by ROS.