A metabolic approach to understanding adaptation to sea water by endangered Persian sturgeon,Acipenser persicusfingerlings

Abstract

In this study, metabolic responses of Persian sturgeon fingerlings to hyperosmotic condition were investigated by NMR-based metabolomics. Persian sturgeon fingerlings (n = 2010, mean total weight: 3.2 AE 0.6 g; mean total length: 8.5 AE 1.5 cm)were held in freshwater (FW) for 96 hr and then acclimated in brackish water (BW) (12 g/L) for 24 hr. Blood samples were taken before and after salinity acclimation.The major metabolite changes corresponding to salinity acclimation were related to amino acids, osmolytes and energy metabolites. The plasma glucose levels increased significantly after 24 hr acclimation in BW (p < .05). Other energetic metabolites (acetate, acetoacetate, beta-hydroxybutyrate, phosphocreatine, creatine, glycerol) showed no significant changes after 24 hr salinity challenge (p > .05). The osmolytes (taurine, trimethylamine-N-oxide, choline, N,N-dimethylglycine) and amino acids (aspartate, glutamate, glutamine, leucine, phenylalanine, b-alanine, histidine, threonine, cysteine) declined significantly after 24 hr acclimation in BW (p < .05). However, the levels of glycine elevated after 24 hr acclimation in BW (p < .05). Other amino acids including aspargine, isoluecine, Tyrosine, Tryptophan, Valine, and Lysine showed no significant changes after salinity challenge (p > .05). The considerable decreases in almost all plasma amino acids and all osmolytes showed specific importance of these metabolites in osmotic adaptation of fish in BW. Also, it seems that Persian sturgeon fingerlings rely more on oxidation of glucose to meet energetic requirements of osmoregulation than oxidation of lipids, as we observed no detectable changes in metabolites associated with lipid oxidation during osmotic acclimation in BW. Our results may help to understand osmoregulation in a chondrostei fish species from a metabolic approach. K E Y W O R D Samino acid, metabolomics, osmolyte, osmoregulation, Persian sturgeon

Effects of Dietary Protein Level on the Gut Microbiome and Nutrient Metabolism in Tilapia (Oreochromis niloticus)

“…studied the effects of sesamin on the liver and white muscle metabolism in Salmo salar using 1 H-NMR metabolomics, the metabolism level of metabolic products related to energy metabolism such as glucose, glycogen, and leucine changed significantly [ 53 ]. In Acipenser baerii exposed to osmotic stress, it was found that the changes of main metabolic products caused by salt acclimation were related to amino acids, osmotic pressure, and energy metabolism [ 54 ]. Additionally, different levels of protein in the diet will lead to different activities of key enzymes in glycolysis and changes in blood sugar content in the body.…”

Changes in Transcriptome and Ultrastructure Reveal Salinity Tolerance of Obscure Puffer Takifugu obscurus

“…Therefore, as the salinity increases, the goblet cells in intestine also increase. Hajirezaee et al (2017) found that Persian sturgeon fingerlings rely more on oxidation of glucose to meet energetic requirements of osmoregulation than oxidation of lipids. TEM showed that serosa was longer and more abundant in the salinity group than that in the freshwater group because serosa could increase the absorption area, thus increasing the absorption of water and nutrients to maintain stable osmotic pressure (Ando et al, 2000).…”