Expresión y actividad de enzimas digestivas en juveniles de liseta (Chelon labrosus) sometidos a diferentes salinidades ambientales

Abstract

The aim of this study was to evaluate the influence of environmental salinity on the mRNA expression and protein activity of the main digestive enzymes of thick-lipped grey mullet (Chelon labrosus). Specimens of thick-lipped grey mullet were acclimated to different environmental salinities (0, 12, 40 and 55 ppt) during 21 days. Samples of complete digestive system were obtained for mRNA expression analysis and for determining enzymatic activities. Results showed a clear effect of environmental salinity on digestive activity as well as on gene expression of these enzymes. Low salinities had a positive influence on digestive acid proteases, which showed a higher activity and expression in 12 ppt-acclimated specimens salinity, whereas higher mRNA expression levels of alkaline proteases were found in fish maintained at 40 ppt.