Characterization of a branchial epithelial calcium channel (ECaC) in freshwater rainbow trout ( Oncorhynchus mykiss )

246

209

Section: Is Type I An Immature Mrc?mentioning

confidence: 99%

Evidence for an apical Na–Cl cotransporter involved in ion uptake in a teleost fish

Hiroi

Yasumasu

McCormick

et al. 2008

246

209

“…Shahsavarani et al, 2006). Samples (50·mg) were size fractionated by reducing SDS-PAGE using 7% separating and 5% stacking polyacrylamide gels and transferred to nitrocellulose membranes (Bio-Rad, Mississanga, ON, Canada).…”

Section: Western Blottingmentioning

confidence: 99%

Fooling a freshwater fish: how dietary salt transforms the rainbow trout gill into a seawater gill phenotype

Perry

Rivero-Lopez

McNeill

et al. 2006

SUMMARY Numerous fish species, including rainbow trout (Oncorhynchus mykiss), are able to inhabit both freshwater and seawater and routinely migrate between the two environments. One of the most critical adjustments allowing such successful migrations is a remodelling of the gill in which a suite of morphological and molecular changes ensure optimal function in the face of reversing requirements for salt and water balance. The remodelling leads to specific freshwater and seawater gill phenotypes that are readily identified by the orientation and/or quantities of specific ion transporters and the presence or absence of specific cell types. The proximate cues promoting gill phenotypic plasticity are unknown. Here, by assessing the consequences of a salt-enriched diet (in the absence of any changes in external salinity) in the freshwater rainbow trout, we demonstrate that internal salt loading alone, is able to induce various elements of the seawater gill phenotype. Specifically, we show upregulation of three ion transport genes, cystic fibrosis transmembrane conductance regulator (CFTR),Na+/K+/2Cl- co-transporter (NKCC1) and Na+/K+-ATPase, which are essential for ionic regulation in seawater, and the appearance of chloride cell-accessory cell complexes,which are normally restricted to fish inhabiting seawater. These data provide compelling evidence that gill remodelling during migration from freshwater to seawater may involve sensing of elevated levels of internal salt.

“…It was undetectable in kidney, intestine, white muscle and blood. A recent study (Shahsavarani et al, 2006) reported that the rainbow trout ECaC was not restricted to mitochondria-rich cells of gills but was also expressed in pavement cells. In the FW zebrafish (Pan et al, 2005), ECaC was ubiquitously expressed in all tissues examined (brain, heart, gills, intestine, liver and kidney); however, expression was highest in the gills and kidney.…”

Section: Tissue-specific Ecac Expressionmentioning

confidence: 97%

“…ECaCs have recently been cloned from rainbow trout (Perry et al, 2003;Shahsavarani et al, 2006), pufferfish (Qiu and Hogstrand, 2004) and zebrafish (Pan et al, 2005). Seemingly there is a single ECaC gene in fish, suggesting that gene duplication occurred after the divergence of fish and mammals (Pan et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Molecular characterization of an epithelial Ca2+ channel-like gene from crayfishProcambarus clarkii

Gao

Wheatly

2007

SUMMARY This study describes the cloning, sequencing and functional characterization of an epithelial Ca2+ channel (ECaC)-like gene isolated from antennal gland (kidney) of the freshwater crayfish Procambarus clarkii. The full-length cDNA consisted of 2687 bp with an open reading frame of 2169 bp encoding a protein of 722 amino acids with a predicted molecular mass of 81.7 kDa. Crayfish ECaC had 76–78% identity at the mRNA level (80–82% amino acid identity) with published fish sequences and 56–62% identity at the mRNA level (52–60% amino acid identity) with mammalian ECaCs. Secondary structure of the crayfish ECaC closely resembled that of cloned ECaCs. Postmolt ECaC expression was exclusively restricted to epithelia associated with Ca2+ influx and was virtually undetectable in non-epithelial tissues (eggs, muscle). Compared with expression levels in hepatopancreas, expression in gill was 10-fold greater and expression was highest in antennal gland (15-fold greater than in hepatopancreas). Compared with baseline expression levels in intermolt stage,expression of ECaC in antennal gland increased 7.4- and 23.8-fold,respectively, in pre- and postmolt stages of the molting cycle. This increase was localized primarily in the labyrinth and nephridial canal, regions of the antennal gland associated with renal Ca2+ reabsorption. The ECaC in crayfish appears to be expressed in epithelia associated with unidirectional Ca2+ influx and relative expression is correlated with rate of Ca2+ influx.