title: Cellular localization of a putative Na(+)/H (+) exchanger 3 during ontogeny in the pronephros and mesonephros of the Japanese black salamander (Hynobius nigrescens Stejneger).
abstract: The cloning of cDNA and an examination of the tissue distribution of Na(+)/H(+) exchanger 3 (NHE3) were carried out in the Japanese black salamander, Hynobius nigrescens. The cellular localization of Hynobius NHE3 was examined by in situ hybridization and immunohistochemistry during ontogeny in the nephron of the pronephros and mesonephros of the salamander. The partial amino acid sequence of Hynobius NHE3 was 81% and 72% identical to rat NHE3 and stingray NHE3, respectively. Hynobius NHE3 mRNA and protein were exclusively expressed along the late portion of the distal tubule to the anterior part of the pronephric duct of premetamorphic larvae (IY stages 43-50). NHE3 mRNA was expressed in the pronephros but not in the external gills in the larvae at the digit differentiation stage (IY stage 50). In the adult, mRNA was strongly expressed in the mesonephros but not in the ventral and dorsal skin. In juvenile and adult specimens, NHE3 immunoreactivity was observed at the apical membrane of the initial parts of the distal tubules of the mesonephric kidney. Immunohistochemical and in situ hybridization studies suggested that Na(+) absorption coupled with H(+) secretion via NHE3 occurred in the distal nephron of the pronephros and mesonephros. This is the first study to indicate NHE3 expression during ontogeny in amphibians.
authors: Department of Biological Science, Graduate School of Science and Engineering, University of Toyama, Toyama, Japan.
authors: Tomoko
authors: T
authors: Kumano
authors: Norifumi
authors: N
authors: Konno
authors: Tatsuya
authors: T
authors: Wakasugi
authors: Kouhei
authors: K
authors: Matsuda
authors: Hideki
authors: H
authors: Yoshizawa
authors: Minoru
authors: M
authors: Uchiyama
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004847:Epithelial Cells / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D005880:Gills / Q000254:growth & development / Q000378:metabolism; D007684:Kidney Tubules / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D008650:Mesonephros / Q000254:growth & development / Q000378:metabolism*; D008969:Molecular Sequence Data; D009399:Nephrons / Q000254:growth & development / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D000074083:Sodium-Hydrogen Exchanger 3; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014562:Caudata / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D025262:Vacuolar Proton-Translocating ATPases / Q000378:metabolism
chemical_list: C000613387:Slc9a3 protein, rat; D000074083:Sodium-Hydrogen Exchanger 3; D017923:Sodium-Hydrogen Exchangers; D025262:Vacuolar Proton-Translocating ATPases; D000254:Sodium-Potassium-Exchanging ATPase