title: Effects of seawater acclimation on mRNA levels of corticosteroid receptor genes in osmoregulatory and immune systems in trout.
abstract: Influence of environmental salinity on expression of distinct corticosteroid receptor (CR) genes, glucocorticoid receptor (GR)-1 and -2, and mineralcorticoid receptor (MR), was examined in osmoregulatory and hemopoietic organs and leucocytes of steelhead trout (Oncorhynchus mykiss). There was no significant difference in plasma cortisol levels between freshwater (FW)- or seawater (SW)-acclimated trout, whereas Na+, K+-ATPase was activated in gill of SW fish. Plasma lysozyme levels also showed a significant increase after acclimation to SW. In SW-acclimated fish, mRNA levels of GR-1, GR-2, and MR were significantly higher in gill and body kidney than those in FW. Head kidney and spleen showed no significant change in these CR mRNA levels after SW-acclimation. On the other hand, leucocytes isolated from head kidney and peripheral blood showed significant decreases in mRNA levels of CR in SW-acclimated fish. These results showed differential regulation of gene expression of CR between osmoregulatory and immune systems.
authors: Freshwater Fisheries Research Division, National Research Institute of Fisheries Science, 2482-3 Chugushi, Nikko, Tochigi 321-1661, Japan. yadat@fra.affrc.go.jp <yadat@fra.affrc.go.jp>
authors: Takashi
authors: T
authors: Yada
authors: Susumu
authors: S
authors: Hyodo
authors: Carl B
authors: CB
authors: Schreck
mesh_terms: D000064:Acclimatization / Q000502:physiology*; D000818:Animals; D005880:Gills / Q000201:enzymology / Q000378:metabolism; D006854:Hydrocortisone / Q000097:blood; D007107:Immune System / Q000502:physiology*; D017686:Oncorhynchus mykiss / Q000378:metabolism / Q000502:physiology*; D009994:Osmolar Concentration; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000235:genetics; D011987:Receptors, Steroid / Q000096:biosynthesis* / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012623:Seawater; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014018:Tissue Distribution; D014882:Water-Electrolyte Balance / Q000235:genetics / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D011987:Receptors, Steroid; D000254:Sodium-Potassium-Exchanging ATPase; D006854:Hydrocortisone