A study by researchers from INCAR’s “Aquaculture Genomics” and “Animal Health in Early Salmonid Stages and Native Resources” lines, along with academics from Universidad de Concepción and Universidad Andrés Bello, presented the first detailed exploration of skeletal muscle molecular responses to crowding stress by integrating RNA-seq and whole-genome bisulfite sequencing (WGBS) analyses in rainbow trout.
“These findings provide new insights into the molecular mechanisms underlying stress-induced growth alterations and emphasize the importance of optimizing rearing conditions to improve fish welfare. By integrating transcriptomic and epigenetic data, this research lays the groundwork for more sustainable aquaculture practices capable of mitigating the harmful effects of chronic stress in farmed fish,” the authors explain in their article.
For the study, the researchers characterized physiological, transcriptomic, and epigenomic responses in juvenile rainbow trout (Oncorhynchus mykiss) exposed to high stocking densities for 30 days. Crowding stress led to a weight decrease in the high-density group and resulted in elevated cortisol levels, DNA oxidative damage, and protein carbonylation in skeletal muscle.
Beyond providing valuable information to improve aquaculture practices, this research establishes a basis for future investigations into how cortisol modulates gene-specific methylation—strengthening experimental designs with increased biological and technical replicates per treatment.
