spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online June 11, 2007
Journal of Experimental Biology 210, 2070-2081 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.004309
This Article
Right arrow Figures Only
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Jayasundara, N.
Right arrow Articles by Spanings-Pierrot, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Jayasundara, N.
Right arrow Articles by Spanings-Pierrot, C.

Gill-specific transcriptional regulation of Na+/K+-ATPase {alpha}-subunit in the euryhaline shore crab Pachygrapsus marmoratus: sequence variants and promoter structure

Nishad Jayasundara1,*, David W. Towle1,{dagger}, Dirk Weihrauch2 and Céline Spanings-Pierrot3

1 Center for Marine Functional Genomics, Mount Desert Island Biological Laboratory, Salsbury Cove, ME 04672, USA
2 Division of Animal Physiology, University of Osnabrück, D-49076 Osnabrück, Germany
3 Université Montpellier II, Adaptation Ecophysiologique et Ontogenese, UMR 5119 CP092, Pl. E. Bataillon, 34095 Montpellier cédex 5, France

{dagger} Author for correspondence (e-mail: dtowle{at}mdibl.org)

Accepted 27 March 2007

The sodium pump (Na+/K+-ATPase) has been implicated in osmoregulatory ion transport in many aquatic animals. In the euryhaline hyper–hypoosmoregulating shore crab Pachygrapsus marmoratus, induction of Na+/K+-ATPase {alpha}-subunit mRNA varies between gills in response to osmotic stress. Following transfer of crabs from normal seawater (36{per thousand} salinity) to diluted seawater (10{per thousand}), a condition in which gills exhibit net ion uptake, {alpha}-subunit mRNA expression is upregulated in all tested gills, albeit with differing time courses. By contrast, following transfer from seawater to hypertonic (45{per thousand}) seawater, a condition in which the animal is excreting ions, {alpha}-subunit mRNA is induced primarily in gill no. 7 (nine in total), suggesting that this gill may be associated specifically with ion excretion in P. marmoratus.

Full-length sequencing of {alpha}-subunit cDNA revealed the existence of two isoforms differing only in the inclusion of an 81-nucleotide segment within the N-terminal open reading frame of the long (D) form in comparison to the short (C) form. The 81-nucleotide segment encodes a 14-3-3 protein binding site that may facilitate movement of the {alpha}-subunit protein between intracellular compartments and the plasma membrane. mRNA expression of the two forms followed similar patterns upon salinity transfer. Genomic DNA sequencing of the putative promoter region of the {alpha}-subunit gene demonstrated a spectrum of predicted transcription factor binding sites that are likely associated with the complex expression pattern observed among gills following osmotic stress.

Key words: crab gill, osmoregulation, real-time quantitative PCR, salinity, sequence variants, sodium pump, {alpha}-subunit






© The Company of Biologists Ltd 2007