Marine Biology

, Volume 153, Issue 6, pp 1173–1179 | Cite as

Cloning of urea transporters from the kidneys of two batoid elasmobranchs: evidence for a common elasmobranch urea transporter isoform

  • Michael G. Janech
  • Holly A. Gefroh
  • Emily E. Cwengros
  • James A. Sulikowski
  • David W. Ploth
  • Wayne R. FitzgibbonEmail author
Research Article


One of the two phloretin-sensitive, facilitated urea transporters identified from the kidneys of the myliobatiform, euryhaline elasmobranch, Dasyatis sabina, a 379 amino acid protein ([D. sabina]strUT-2), was very similar to the 380 amino acid isoform (shUT) present in the kidney of the squaliform, dogfish shark, Squalus acanthias (a species that can be considered marginally euryhaline since it utilizes upper estuarine, as well as ocean habitats). To test the proposal that this isoform is a conserved urea transporter (UT) expressed in the kidneys of diverse elasmobranchs, UTs were cloned from the kidneys of a rajiform elasmobranch, the stenohaline skate, Leucoraja ocellata and another dasyatid stingray, the marginally euryhaline, Dasyatis say. Utilizing 5′/3′ RACE, a 2,060 nt cDNA that encoded a phloretin-sensitive, 378 amino acid skate urea transporter ([L. ocellata]skUT-2) and a 1,683 nt cDNA that encoded a stingray 379 amino acid UT ([D. say]strUT-2) were obtained. These deduced UTs have a very high sequence identity with the known elasmobranch Uts. [L. ocellata]skUT-2 was 86% identical to [D. sabina]strUT-2 and 84% identical to [S. acanthias]shUT. [D. say]strUT-2 was 97% identical to the [D. sabina]strUT-2. These findings support the hypothesis that a conserved UT isoform is present in the kidneys of marine elasmobranchs, and is an important pathway for facilitated urea transport in the kidneys of marine elasmobranchs.


Urea Transporter Urea Uptake Atlantic Stingray Marine Elasmobranch Urea Reabsorption 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



This research was supported by Division of Nephrology Research funds and a grant from Dialysis Clinics Inc. W.R.F. was supported in part by a Veteran’s Affairs Merit Award granted to David W. Ploth, M.D. This work was performed using equipment and resources funded, in part, by the Department of Veteran’s Affairs. This work was presented in part at the XXXIV Congress of the International Union of Physiological Sciences, Christchurch, New Zealand, July 2001 and the International Congress on the Biology of Fish, Vancouver Canada, 2002.

Supplementary material

227_2007_889_MOESM1_ESM.doc (38 kb)
(DOC 38 kb)
227_2007_889_MOESM2_ESM.doc (694 kb)
(DOC 694 kb)


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Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Michael G. Janech
    • 1
    • 5
  • Holly A. Gefroh
    • 1
    • 6
  • Emily E. Cwengros
    • 1
    • 7
  • James A. Sulikowski
    • 4
    • 8
  • David W. Ploth
    • 1
    • 2
    • 3
  • Wayne R. Fitzgibbon
    • 1
    • 2
    Email author
  1. 1.Marine Biomedicine and Environmental Sciences CenterMedical University of South CarolinaCharlestonUSA
  2. 2.Division of Nephrology, Department of MedicineMedical University of South CarolinaCharlestonUSA
  3. 3.Ralph H. Johnson VAMCCharlestonUSA
  4. 4.Department of ZoologyUniversity of New HampshireDurhamUSA
  5. 5.Division of Nephrology, Department of MedicineMedical University of South CarolinaCharlestonUSA
  6. 6.Qualyst Inc.RaleighUSA
  7. 7.Division of Thoracic Oncology ResearchSt. Joseph’s Hospital and Medical CenterPhoenixUSA
  8. 8.Department of Biological SciencesUniversity of New EnglandBiddefordUSA

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