Comparative analysis of gene expression in brain, liver, skeletal muscles, and gills of zebrafish (Danio rerio) exposed to environmentally relevant waterborne uranium concentrations
Résumé
The effects of waterborne uranium (U) exposure on gene expression were examined in four organs (brain, liver, skeletal muscles, and gills) of the zebrafish (Danio rerio). Adult male fish were exposed to three treatments: No added uranium (control), 23 ± 6 μg U/L, and 130 ± 34 μg U/L. After 3, 10, 21, and 28 d of exposure and an 8-d depuration period, gene expression and uranium bioaccumulation were analyzed. Bioaccumulation decreased significantly in liver during the depuration phase, and genes involved in detoxification, apoptotic mechanism, and immune response were strongly induced. Among these genes, abcb3l1, which belongs to the adenosine triphosphate (ATP)-binding cassette transporter family, was induced 4- and 24-fold in organisms previously exposed to 23 ± 6 and 130 ± 34 μg U/L, respectively. These results highlight the role of liver in detoxification mechanisms. In gills, at the highest uranium concentration, gpx1a, cat, sod1, and sod2 genes were up-regulated at day 21, indicating the onset of an oxidative stress. Mitochondrial metabolism and DNA integrity also were affected, because cox1, atp5f1, and rad51 genes were up-regulated at day 21 and during the depuration phase. In skeletal muscles, coxI, atp5f1, and cat were induced at day 3, suggesting an impact on the mitochondrial metabolism and production of reactive oxygen species. In brain, glsI also was induced at day 3, suggesting a need in the glutamate synthesis involved with neuron transmission. No changes in gene expression were observed in brain and skeletal muscles at days 21 and 28, although bioaccumulation increased. During the depuration phase, uranium excretion was inefficient in brain and skeletal muscles, and expression of most of the tissue-specific genes was repressed or unchanged. © 2009 SETAC.
Mots clés
oxidative stress
priority journal
skeletal muscle
upregulation
zebra fish
Animals
Base Sequence
Brain
DNA Primers
Gene Expression
Gills
Skeletal
Polymerase Chain Reaction
Water Pollutants
Radioactive
Apoptotic mechanisms
Comparative analysis
Danio rerio
Depuration
Detoxification mechanism
DNA integrity
Immune response
Mitochondrial metabolism
Reactive oxygen species
Skeletal muscle
Tissue-specific genes
Uranium concentration
Zebrafish
Adenosinetriphosphate
Bioaccumulation
Bioactivity
Biochemistry
Detoxification
Gene expression
Liver
Metabolism
Muscle
Nucleic acids
Oxygen
Uranium
Transuranium elements
adenosine triphosphate
DNA
glutamic acid
reactive oxygen metabolite
uranium
apoptosis
bioaccumulation
brain
comparative study
concentration (composition)
cyprinid
detoxification
excretion
gene expression
immune response
metabolism
muscle
article
cell metabolism
controlled study
environmental exposure
enzyme synthesis
gene induction
gill
liver
male
mitochondrion
nerve conduction
nonhuman
nucleotide sequence