title: A Stenohaline Medaka, Oryzias woworae, Increases Expression of Gill Na(+), K(+)-ATPase and Na(+), K(+), 2Cl(-) Cotransporter 1 to Tolerate Osmotic Stress.
abstract: The present study aimed to evaluate the osmoregulatory mechanism of Daisy's medaka, O. woworae,as well as demonstrate the major factors affecting the hypo-osmoregulatory characteristics of euryhaline and stenohaline medaka. The medaka phylogenetic tree indicates that Daisy's medaka belongs to the celebensis species group. The salinity tolerance of Daisy's medaka was assessed. Our findings revealed that 20‰ (hypertonic) saltwater (SW) was lethal to Daisy's medaka. However, 62.5% of individuals survived 10‰ (isotonic) SW with pre-acclimation to 5‰ SW for one week. This transfer regime, "Experimental (Exp.) 10‰ SW", was used in the following experiments. After 10‰ SW-transfer, the plasma osmolality of Daisy's medaka significantly increased. The protein abundance and distribution of branchial Na(+), K(+)-ATPase (NKA) and Na(+), K(+), 2Cl(-) cotransporter 1 (NKCC1) were also examined after transfer to 10‰ SW for one week. Gill NKA activity increased significantly after transfer to 10‰ SW. Meanwhile, elevation of gill NKA αα-subunit protein-abundance was found in the 10‰ SW-acclimated fish. In gill cross-sections, more and larger NKA-immunoreactive (NKA-IR) cells were observed in the Exp. 10‰ SW medaka. The relative abundance of branchial NKCC1 protein increased significantly after transfer to 10‰ SW. NKCC1 was distributed in the basolateral membrane of NKA-IR cells of the Exp. 10‰ SW group. Furthermore, a higher abundance of NKCC1 protein was found in the gill homogenates of the euryhaline medaka, O. dancena, than in that of the stenohaline medaka, O. woworae.
authors: 1 Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.|† JJJ, CKK, and WKY contributed equally to this paper.
authors: Jiun-Jang
authors: JJ
authors: Juo
authors: 2 Tainan Hydraulics Laboratory, National Cheng Kung University, Tainan 709, Taiwan.|† JJJ, CKK, and WKY contributed equally to this paper.
authors: Chao-Kai
authors: CK
authors: Kang
authors: 1 Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.|† JJJ, CKK, and WKY contributed equally to this paper.
authors: Wen-Kai
authors: WK
authors: Yang
authors: 1 Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.
authors: Shu-Yuan
authors: SY
authors: Yang
authors: 1 Department of Life Sciences, National Chung Hsing University, Taichung 402, Taiwan.|3 Department of Biological Science and Technology, China Medical University,Taichung 404, Taiwan.
authors: Tsung-Han
authors: TH
authors: Lee
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics / Q000502:physiology; D000818:Animals; D015971:Gene Expression Regulation, Enzymologic; D005880:Gills / Q000201:enzymology*; D009990:Oryzias / Q000145:classification / Q000378:metabolism*; D009997:Osmotic Pressure / Q000502:physiology*; D010802:Phylogeny; D054712:Salinity; D028021:Sodium-Potassium-Chloride Symporters / Q000235:genetics / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D014867:Water / Q000737:chemistry
chemical_list: D028021:Sodium-Potassium-Chloride Symporters; D014867:Water; D000254:Sodium-Potassium-Exchanging ATPase
keywords: 2Cl- cotransporter 1; K+; K+-ATPase; Na+; Oryzias woworae; gill; osmotic stress; stenohaline