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

SEVASTEI, V.; CRICHIGNO, S.; SANTOS, M. VICTORIA; TROCHINE, A. ; PAINEFILU, J. ; ZARITZKY, N. ; CUSSAC, V.

Aquaculture and Fisheries

KeAi Communications Co.

Año: 2023

2096-1758

Contemporary evolution was observed in a feral rainbow trout (Oncorhynchus mykiss) populationof a thermal stream (Valcheta) in Northern Patagonia, in terms of juvenile thermal tolerance andpreferred temperature. Other authors showed that high-temperature treatment applied to malerainbow trout juveniles increased the thermal tolerance in the next generation. This implies a highmutation rate and / or a modified epigenetic inheritance. Comparisons were made among a) arainbow trout strain adapted in terms of upper thermal tolerance and higher preferred temperature(Valcheta stream), b) a wild temperate stream population (Guillelmo stream), and c) two a temperate farmed strains. We examined: Oxidative damage (lipid peroxidation) and activities ofantioxidant enzymes; Catalase (CAT), Glutathione S-Transferases (GST), and SuperoxideDismutase (SOD), in liver, testicle, and spermatozoa. Semen fatty acid composition, spermmorphology, sperm motility, and fertilization performance in samples before and after theapplication of cryopreservation procedures were also evaluated. The observed responses, mainlyrelated to the sperm membrane, reinforces the idea that ROS can affect the germinal line of malerainbow trout juveniles subjected to high water temperature. Our results suggest that the acquiredthermal 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 higher temperatures and mediated by ROS.