ZFIN ID: ZDB-PUB-070303-12
Gill membrane remodeling with softwater acclimation in Zebrafish (Danio rerio)
Craig, P.M., Wood, C.M., and McClelland, G.B.
Date: 2007
Source: Physiological Genomics   30(1): 53-60 (Journal)
Registered Authors:
Keywords: gene expression, gill, Na+-K+-ATPase, epithelium calcium channel, salinity transfer
MeSH Terms:
  • Acclimatization/drug effects
  • Acclimatization/genetics
  • Animals
  • Blotting, Western
  • Calcium Channels/genetics
  • Calcium Channels/metabolism
  • Carbonic Anhydrases/genetics
  • Carbonic Anhydrases/metabolism
  • Gene Expression Profiling
  • Gene Expression Regulation/drug effects
  • Gills/drug effects
  • Gills/metabolism*
  • Hydrogen-Ion Concentration
  • Ions/pharmacology*
  • Magnesium/metabolism
  • Membrane Transport Proteins/genetics
  • Membrane Transport Proteins/metabolism
  • Potassium/metabolism
  • RNA, Messenger/genetics
  • RNA, Messenger/metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sodium/metabolism
  • Sodium-Potassium-Exchanging ATPase/genetics
  • Sodium-Potassium-Exchanging ATPase/metabolism
  • Time Factors
  • Vacuolar Proton-Translocating ATPases/genetics
  • Vacuolar Proton-Translocating ATPases/metabolism
  • Water/pharmacology*
  • Zebrafish/genetics*
  • Zebrafish/metabolism
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
PubMed: 17299134 Full text @ Physiol. Genomics
Little is known regarding the ionoregulatory abilities of zebrafish exposed to softwater despite the popularity of this model organism for physiology and aquatic toxicology. We examined genomic and nongenomic changes to gills of zebrafish as they were progressively acclimated from moderately hard freshwater to typical softwater over 7 days and held in softwater for another 7 days. Gills were sampled daily and mRNA expression levels of gill Na(+)/K(+)ATPase (NKA) alpha1a subunit, epithelium calcium channel (ECaC), carbonic anhydrase-1 & 2 (CA-1; CA-2), Na(+), H(+)-exchanger (NHE-2), V-type proton (H+)-ATPase and copper transport protein (CTR-1) were quantified by real-time PCR. Changes in enzyme activities of gill NKA were determined and protein levels of NKA and ECaC were quantified by Western blotting. Levels of mRNA for ECaC increased 4-fold after day 6, with an associated increase in ECaC protein levels after 1 week in softwater. CA-1 and CA-2 exhibited a 1.5- and 6-fold increase in gene expression on day 6 and 5, respectively. Likewise, there was a 5 fold increase in NHE-2 expression after day 6. Suprisingly, CTR-1 mRNA showed a large transient increase (over 3-fold) on day 6 while H(+)-ATPase mRNA did not change. These data demonstrate a high degree of phenotypic plasticity in zebrafish gills exposed to an ion-poor environment. This not only enhances our understanding of ionoregulatory processes in fish but also highlights the need for proper experimental design for studies involving pre-acclimation to softwater (e.g. metal toxicity). Key words: zebrafish, gene expression, Na+/K+-ATPase, epithelium calcium channel, gill.