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Does Japanese medaka (Oryzias latipes) exhibit a gill Na(+)/K(+)-ATPase isoform switch during salinity change?
J Comp Physiol B 2016; 186(4):485-501JC

Abstract

Some euryhaline teleosts exhibit a switch in gill Na(+)/K(+)-ATPase (Nka) α isoform when moving between fresh water (FW) and seawater (SW). The present study tested the hypothesis that a similar mechanism is present in Japanese medaka and whether salinity affects ouabain, Mg(2+), Na(+) and K(+) affinity of the gill enzyme. Phylogenetic analysis classified six separate medaka Nka α isoforms (α1a, α1b, α1c, α2, α3a and α3b). Medaka acclimated long-term (>30 days) to either FW or SW had similar gill expression of α1c, α2, α3a and α3b, while both α1a and α1b were elevated in SW. Since a potential isoform shift may rely on early changes in transcript abundance, we conducted two short-term (1-3 days) salinity transfer experiments. FW to SW acclimation induced an elevation of α1b and α1a after 1 and 3 days. SW to FW acclimation reduced α1b after 3 days with no other α isoforms affected. To verify that the responses were typical, additional transport proteins were examined. Gill ncc and nhe3 expression were elevated in FW, while cftr and nkcc1a were up-regulated in SW. This is in accordance with putative roles in ion-uptake and secretion. SW-acclimated medaka had higher gill Nka V max and lower apparent K m for Na(+) compared to FW fish, while apparent affinities for K(+), Mg(2+) and ouabain were unchanged. The present study showed that the Japanese medaka does not exhibit a salinity-induced α isoform switch and therefore suggests that Na(+) affinity changes involve altered posttranslational modification or intermolecular interactions.

Authors+Show Affiliations

Department of Biological Sciences, University of Arkansas, SCEN 601, Fayetteville, AR, 72701, USA.Department of Biological Sciences, University of Arkansas, SCEN 601, Fayetteville, AR, 72701, USA. Department of Biology, University of Southern Denmark, Campusvej 55, 5230, Odense M, Denmark.Department of Biological Sciences, University of Arkansas, SCEN 601, Fayetteville, AR, 72701, USA.Department of Biological Sciences, University of Arkansas, SCEN 601, Fayetteville, AR, 72701, USA. tipsmark@uark.edu.

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, Non-P.H.S.

Language

eng

PubMed ID

26920794

Citation

Bollinger, Rebecca J., et al. "Does Japanese Medaka (Oryzias Latipes) Exhibit a Gill Na(+)/K(+)-ATPase Isoform Switch During Salinity Change?" Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology, vol. 186, no. 4, 2016, pp. 485-501.
Bollinger RJ, Madsen SS, Bossus MC, et al. Does Japanese medaka (Oryzias latipes) exhibit a gill Na(+)/K(+)-ATPase isoform switch during salinity change? J Comp Physiol B, Biochem Syst Environ Physiol. 2016;186(4):485-501.
Bollinger, R. J., Madsen, S. S., Bossus, M. C., & Tipsmark, C. K. (2016). Does Japanese medaka (Oryzias latipes) exhibit a gill Na(+)/K(+)-ATPase isoform switch during salinity change? Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology, 186(4), pp. 485-501. doi:10.1007/s00360-016-0972-6.
Bollinger RJ, et al. Does Japanese Medaka (Oryzias Latipes) Exhibit a Gill Na(+)/K(+)-ATPase Isoform Switch During Salinity Change. J Comp Physiol B, Biochem Syst Environ Physiol. 2016;186(4):485-501. PubMed PMID: 26920794.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Does Japanese medaka (Oryzias latipes) exhibit a gill Na(+)/K(+)-ATPase isoform switch during salinity change? AU - Bollinger,Rebecca J, AU - Madsen,Steffen S, AU - Bossus,Maryline C, AU - Tipsmark,Christian K, Y1 - 2016/02/26/ PY - 2015/11/18/received PY - 2016/02/12/accepted PY - 2016/02/02/revised PY - 2016/2/28/entrez PY - 2016/2/28/pubmed PY - 2016/12/23/medline KW - Euryhaline teleost KW - Na+/K+-ATPase enzymatic activity KW - Osmoregulation KW - Substrate affinity KW - α-Subunit SP - 485 EP - 501 JF - Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology JO - J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol. VL - 186 IS - 4 N2 - Some euryhaline teleosts exhibit a switch in gill Na(+)/K(+)-ATPase (Nka) α isoform when moving between fresh water (FW) and seawater (SW). The present study tested the hypothesis that a similar mechanism is present in Japanese medaka and whether salinity affects ouabain, Mg(2+), Na(+) and K(+) affinity of the gill enzyme. Phylogenetic analysis classified six separate medaka Nka α isoforms (α1a, α1b, α1c, α2, α3a and α3b). Medaka acclimated long-term (>30 days) to either FW or SW had similar gill expression of α1c, α2, α3a and α3b, while both α1a and α1b were elevated in SW. Since a potential isoform shift may rely on early changes in transcript abundance, we conducted two short-term (1-3 days) salinity transfer experiments. FW to SW acclimation induced an elevation of α1b and α1a after 1 and 3 days. SW to FW acclimation reduced α1b after 3 days with no other α isoforms affected. To verify that the responses were typical, additional transport proteins were examined. Gill ncc and nhe3 expression were elevated in FW, while cftr and nkcc1a were up-regulated in SW. This is in accordance with putative roles in ion-uptake and secretion. SW-acclimated medaka had higher gill Nka V max and lower apparent K m for Na(+) compared to FW fish, while apparent affinities for K(+), Mg(2+) and ouabain were unchanged. The present study showed that the Japanese medaka does not exhibit a salinity-induced α isoform switch and therefore suggests that Na(+) affinity changes involve altered posttranslational modification or intermolecular interactions. SN - 1432-136X UR - https://www.unboundmedicine.com/medline/citation/26920794/Does_Japanese_medaka__Oryzias_latipes__exhibit_a_gill_Na_+_/K_+__ATPase_isoform_switch_during_salinity_change L2 - http://dx.doi.org/10.1007/s00360-016-0972-6 DB - PRIME DP - Unbound Medicine ER -