Author:

Keywords:

Anguilla anguilla, European eel, Transcriptome, Microarrays, Pollution, Science & Technology, Life Sciences & Biomedicine, Biotechnology & Applied Microbiology, Genetics & Heredity, ANGUILLA-ANGUILLA, ECOLOGICAL GENOMICS, RIVER TIBER, X-RECEPTOR, WATER, RECRUITMENT, METALLOTHIONEIN, BIOACCUMULATION, XENOBIOTICS, POPULATIONS, Amino Acid Sequence, Animals, Cytochrome P-450 CYP3A, Eels, Electron Transport, Endangered Species, Environmental Pollution, Flame Retardants, Gene Expression, Gene Expression Profiling, Gene Expression Regulation, Genome-Wide Association Study, Glutathione Peroxidase, Glutathione Transferase, High-Throughput Nucleotide Sequencing, Italy, Molecular Sequence Data, Oxidative Phosphorylation, Pesticides, Water Pollutants, Chemical, Zebrafish, 06 Biological Sciences, 08 Information and Computing Sciences, 11 Medical and Health Sciences, Bioinformatics, 31 Biological sciences, 32 Biomedical and clinical sciences

Abstract:

Background: Genomic and transcriptomic approaches have the potential for unveiling the genome-wide response to environmental perturbations. The abundance of the catadromous European eel (Anguilla anguilla) stock has been declining since the 1980s probably due to a combination of anthropogenic and climatic factors. In this paper, we explore the transcriptomic dynamics between individuals from high (river Tiber, Italy) and low pollution (lake Bolsena, Italy) environments, which were measured for 36 PCBs, several organochlorine pesticides and brominated flame retardants and nine metals. Results: To this end, we first (i) updated the European eel transcriptome using deep sequencing data with a total of 640,040 reads assembled into 44,896 contigs (Eeelbase release 2.0), and (ii) developed a transcriptomic platform for global gene expression profiling in the critically endangered European eel of about 15,000 annotated contigs, which was applied to detect differentially expressed genes between polluted sites. Several detoxification genes related to metabolism of pollutants were upregulated in the highly polluted site, including genes that take part in phase I of the xenobiotic metabolism (CYP3A), phase II (glutathione-S-transferase) and oxidative stress (glutathione peroxidase). In addition, key genes in the mitochondrial respiratory chain and oxidative phosphorylation were down-regulated at the Tiber site relative to the Bolsena site. Conclusions: Together with the induced high expression of detoxification genes, the suggested lowered expression of genes supposedly involved in metabolism suggests that pollution may also be associated with decreased respiratory and energy production.