Environmental Physiology of Fish
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University of Massachusetts, Amherst, MA, USA
Conte Anadromous Fish Research Center, Turners Falls, MA, USA
Gill Ion Transport Proteins:
Model of ion transport in seawater and freshwater ionocytes
One of the fundamental structures with which fishes regulate their internal ions and maintain osmotic homeostasis are ionocytes (also known as chloride cells and mitonchondrion-rich cells), located in the gills. These cells are critical for the uptake of ions in freshwater and the excretion of ions in seawater. To help explain the complicated function of these cells, Dr. Arne Christensen developed this video model contrasting chloride cell function in freshwater (FW, first) and seawater (SW, second).
Key to the components of the model:
Grey - Chloride cell
Purple - Accessory cell
SW - Seawater-type chloride cell
CFTR - Cystic Fibrosis Transmembrane Conductance Regulator
NKA - Na+,K+-ATPase [alpha1b subunit]
NKCC - Na+-K+-2Cl-Cotransporter
Kir - inward rectifier K+ channel
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FW - Freshwater-type chloride cell
AE - Anion Exchanger
V-HA - V-type H+-ATPase
ENaC - Epithelial Na+ Channel
NHE - Na+,H+ Exchanger
NCC - Na+-2Cl-Cotransporter
NKA - Na+,K+-ATPase [alpha1a subunit]
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