Using RT-PCR with degenerated primers followed by screening of a rainbow trout (Oncorhynchus mykiss) intestinal cDNA library, we have isolated from the new corticosteroid receptor which shows high sequence homology other glucocorticoid receptors (GRs), but is clearly different previous GR (named rtGR1). Phylogenetic analysis these two sequences and GRs known in mammals, amphibians fishes indicate that duplication probably common to most teleost fish. The open reading frame this rtGR2)...

The teleost fish are thought to lack the mineralocorticoid hormone aldosterone but possess receptor (MR) homologs. Here we describe characterization of two rainbow trout (Oncorhynchus mykiss) MRs, called rtMRa and rtMRb. open reading frame cDNA encoded a protein 1041 amino acids. rtMRb predicted sequence is similar, differing in only 10 acids nonconserved A/B domain lacking three-amino acid insertion between zinc fingers C domain. Expression rtMR mRNA (sum both forms), measured juvenile by...

In higher vertebrates, mineralo- (aldosterone) and glucocorticoids (cortisol/corticosterone) exert their multiple actions via specific transcription factors, glucocorticoid (GR) mineralocorticoid (MR) receptors. Teleostean fishes lack aldosterone mineral regulatory processes seem under dominant control by cortisol. Despite the absence of classical aldosterone, teleostean do have an MR with cortisol possibly 11-deoxycorticosterone (DOC) (as alternative for aldosterone) as predominant ligands....

Multiple classes of environmental contaminants have been found in aquatic environments, globally. Understanding internalised concentrations the organism could further improve risk assessment process. The present study is concerned with determination several contaminant (107 compounds) Gammarus pulex collected from 15 sites covering 5 river catchments across Suffolk, UK. Quantitative method performance was acceptable for 67 compounds including pharmaceuticals, pesticides, illicit drugs and...

The branchial uptake mechanism of the nonessential heavy metal silver from very dilute media by gills freshwater rainbow trout was investigated. At concentrations >36 nM AgNO(3), rapidly entered gills, reaching a peak at 1 h, after which time there steady decline in gill concentration and resulting increase body accumulation. Below 36 only gradual over 48-h exposure period. Increasing water sodium ([Na(+)]; 0.05 to 21 mM) significantly reduced uptake, although, contrast, increasing ambient...

Experiments performed on isolated intestinal segments from the marine teleost fish, European flounder (Platichthys flesus), revealed that epithelium is capable of secondary active HCO3(-) secretion in order 0.2-0.3 micromol x cm(-2) h(-1) against apparent electrochemical gradient. The occurs via anion exchange, dependent mucosal Cl(-), results very high concentrations, and contributes significantly to Cl(-) fluid absorption. This present study was conducted under vivo-like conditions, with...

Worldwide, a number of viable populations fish are found in environments heavily contaminated with metals, including brown trout (Salmo trutta) inhabiting the River Hayle South-West England. This population is chronically exposed to water-borne mixture copper and zinc, at concentrations lethal naïve fish. We aimed investigate molecular mechanisms employed by tolerate high metal concentrations. To achieve this, we combined tissue analysis whole-transcriptome profiling using RNA-seq on an...

The application of machine learning has recently gained interest from ecotoxicological fields for its ability to model and predict chemical and/or biological processes, such as the prediction bioconcentration. However, comparison different models bioconcentration in invertebrates not been previously evaluated. A 24 linear is presented herein fish important factors that influenced accumulation identified. R2 root mean square error (RMSE) test data (n = 110 cases) ranged 0.23-0.73 0.34-1.20,...

Cadmium and copper accumulations in gills of zebrafish were measured during a 48 h exposure to 0.025 μM 106Cd 0.05 or 0.5 65Cu as single metal their mixtures. The gill transcript levels genes involved the transport Cu (CTR1 ATP7A), Na (NHE-2), Ca (ECaC), divalent metals (DMT1), Zn (ZIP8) also compared between treatments at 24 h. Cd uptake was significantly suppressed presence Cu, indicating interaction sites, but unaffected by Cd. decrease accumulation rates associated with an increase...

An expansion of anthropogenic activity around Lagos lagoon, Nigeria, has raised concerns over increasing contaminants entering the lagoon's ecosystem. The embryotoxicity, teratogenicity and genotoxicity sediment organic extracts from four sampling zones Ilaje, Iddo, Atlas Cove Apapa, as well dominant polycyclic aromatic hydrocarbons (PAHs) identified in water measured during wet season (naphthalene, phenanthrene, pyrene, benzo[a]pyrene a mixture these), were assessed with Danio rerio...

Abstract The effects of independently altering chloride, calcium, and dissolved organic carbon (DOC) on the toxicity silver (presented as AgNO 3 ) were compared between rainbow trout ( Oncorhynchus mykiss fathead minnows Pimephales promelas ). 96‐h median lethal concentration (LC50) tests for both species performed under same conditions, within containers. In addition, effect [Cl − ] silver‐induced perturbations to body Na + influx gill load was studied. Toxicity conducted in synthetic soft...

Brown trout were exposed for 63 days to five treatments: a control; the purified cyanobacterial hepatotoxin microcystin—LR (MC—LR) (41—57 μg MC—LR 1 −1 ); lysed toxic Microcystis aeruginosa cells (41–68 and 288 chlorophyll non—toxic M. (non—MC—LR containing ammonia (65–325 NH 3 ). All treatments produced significantly reduced growth compared controls ( P <0·05, Fisher test). Exposure resulted weight loss over first 7 followed by increase, though at lower level than in other treatments....

The toxicological effect of natural diets elevated in metals on reproduction fish is poorly understood. reproductive output zebrafish fed the polychaete Nereis diversicolor collected from a metal-impacted estuary, Restronguet Creek, Cornwall, UK, was compared to N. nonmetal impacted Blackwater, Essex, UK. Fish metal laden for 68 days showed reduced output, characterized by cumulative egg production (47%), number spawns (30%), as well average eggs produced per spawn and % hatch rate. mRNA...