Pedro M Rodrigues
University of Algarve, Portugal
Title: Establishment of farmed fish welfare biomarkers: A multiomics approach
Biography
Biography: Pedro M Rodrigues
Abstract
Fish is of increasing importance as a protein source in human diet. Farmed fish welfare is currently assessed using stress indicators such as the levels of cortisol, glucose and lactate in the blood plasma, but their reliability has been questioned due to high biological variability and fish adaptation processes. A multiomics approach can be a promisor strategy to discover reliable fish welfare biomarkers, since an integrated analysis can offer the possibility of understanding the complete flow of information in the fish biological system under stressful conditions. Our aim is to identify a restricted protein map as putative fish welfare biomarkers using proteomics, and integrate these results with complementary transcriptomics and metabolomics data, in order to validate these biomarkers as to achieve a global picture of the fish response to stress. Sparus aurata was reared under three different stressful conditions, in triplicate: overcrowding, repetitive net handling (air exposure) and hypoxia, using fish reared under optimal conditions as control.
Method: Fish were sampled after 45 days of trial and protein extracts were prepared from liver samples. Proteins were separated by 2D-DIGE and identified by MALDI-TOF/TOF MS. Putative welfare biomarkers were then chosen based on their stressrelated function, fold-change, score and other parameters and used for primer design. Total RNA was extracted from liver
samples using Trizol® reagent, with DNase treatment, and used for cDNA synthesis.
Results: The mRNA levels of the target genes were assessed by real-time PCR. Comparative proteomics show, in the liver, a total of 147 differentially expressed proteins among conditions, from which 24 were indicated as putative welfare biomarkers and chosen for their transcription level analysis.
Conclusion: This joint analysis provides a starter point for the development of more reliable fish welfare assessment measures
to improve aquaculture sustainability.