title: Dynamic changes in the accumulation of metabolites in brackish water clam Corbicula japonica associated with alternation of salinity.
abstract: The brackish water clam Corbicula japonica inhabits rivers and brackish waters throughout Japan where the major fishing grounds in the Ibaraki Prefecture, Japan, are located at the Hinuma Lake and Hinuma River. Water salinity in the Lake Hinuma is low and stable due to the long distance from the Pacific Ocean, whereas that in the downstream of the river varies daily due to a strong effect of tidal waters. In the present study, we dissected the gill and foot muscle of brackish water clam collected from these areas, and subjected them to metabolome analysis by capillary electrophoresis-time-of-flight mass spectrometry. More than 200 metabolites including free amino acids, peptides and organic acids were identified, and their amounts from the foot muscle tend to be higher than those from the gill. The principal component analysis revealed that the amount of each metabolite was different among sampling areas and between the gill and foot muscle, whereas no apparent differences were observed between male and female specimens. When the metabolites in the female clam at high salinity were compared with those at low salinity, concentrations of β-alanine, choline, γ-aminobutyric acid, ornithine and glycine betaine were found to be changed in association with salinity. We also compared various metabolites in relation to metabolic pathways, suggesting that many enzymes were involved in their changes depending on salinity.
authors.affiliation: Kitasato University School of Marine Biosciences, Sagamihara, Kanagawa 252-0373, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Koyama
authors.affiliation: Ibaraki Prefectural Fisheries Research Institute, Hitachinaka, Ibaraki 311-1203, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Okamoto
authors.affiliation: Ibaraki Prefectural Fisheries Research Institute, Hitachinaka, Ibaraki 311-1203, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Watanabe
authors.affiliation: Ibaraki Prefectural Fisheries Research Institute, Hitachinaka, Ibaraki 311-1203, Japan.
authors.forename: Naoshige
authors.initials: N
authors.lastname: Hoshino
authors.affiliation: Kitasato University School of Marine Biosciences, Sagamihara, Kanagawa 252-0373, Japan.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Jimbo
authors.affiliation: Kitasato University School of Marine Biosciences, Sagamihara, Kanagawa 252-0373, Japan.
authors.forename: Ko
authors.initials: K
authors.lastname: Yasumoto
authors.affiliation: Kitasato University School of Marine Biosciences, Sagamihara, Kanagawa 252-0373, Japan; Laboratory of Marine Biochemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan. Electronic address: swatabe@kitasato-u.ac.jp.
authors.forename: Shugo
authors.initials: S
authors.lastname: Watabe
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D049874:Corbicula / Q000378:metabolism*; D005260:Female; D005880:Gills / Q000378:metabolism; D008297:Male; D053858:Metabolic Networks and Pathways; D009132:Muscles / Q000378:metabolism; D010455:Peptides / Q000378:metabolism*; D054712:Salinity
chemical_list: D000596:Amino Acids; D010455:Peptides
keywords: Brackish water clam; Corbicula japonica; Metabolome analysis; Salinity