Effect of salinity change on free amino acid content in Pacific oyster
In order to identify free amino acids (FAA) that are importantas intracellular osmolytes in Crassostrea gigas, we investigatedthe change in FAA content in the mantle exposed to an abrupt decreaseor increase in salinity. In hypo-osmotic adaptation, most FAA showedremarkable and synchronous decreases from 2 to 8 h, suggestingthat the non-selective efflux of FAA was mainly responsible forthe decrease in FAA. Taurine that accounted for approximately 80% oftotal FAA content contributed most significantly to the hypo-osmoticadaptation. In hyper-osmotic adaptation, significant increases inglycine, alanine, β-alanine, proline, arginine and taurinewere observed. Of these, alanine showed an immediate increase thatis important to short-term adaptation to hyper-osmolality, whiletaurine showed a slower and substantial increase that contributesto a long-term adaptation to hyper-osmolality.
Document Type: Research Article
Affiliations: 1: Division of Applied Biosciences,Graduate School of Agriculture, Kyoto University, Kyoto, Kyoto 606-8502, 2: Department of Agriculture,Kochi University, Nankoku, Kochi 783-8502 and 3: Departmentof Human Life Studies, Kacho Junior College, Kyoto, Kyoto 605-0062,Japan
Publication date: April 1, 2003