Hepatic transcriptome, transcriptional effects and antioxidant responses in Poecilia vivipara exposed to sanitary sewage

• Published in: Marine pollution bulletin Vol. 203; p. 116426
• Main Authors: Piazza, Clei Endrigo, Mattos, Jacó Joaquim, Lima, Daína, Siebert, Marília Nardelli, Zacchi, Flávia Lucena, dos Reis, Ísis Mayna Martins, Ferrari, Fernanda Luiza, Balsanelli, Eduardo, Toledo-Silva, Guilherme, de Souza, Emanuel Maltempi, Bainy, Afonso Celso Dias
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.06.2024
• Subjects: antioxidants; Biomarkers; Biotransformation; ecotoxicology; Endocrine disruptors; environmental quality; enzymes; fish; humans; Illumina MiSeq; liver; marine pollution; Poecilia vivipara; sewage; Sex effect; species; toxicity; transcription (genetics); Transcriptome; xenobiotics; Endocrine disruptors; Biomarkers; Sex effect; Illumina MiSeq; Biotransformation; Transcriptome
• ISSN: 0025-326X; 1879-3363; 1879-3363
• DOI: 10.1016/j.marpolbul.2024.116426

Aquatic environments are subject to threats from multiple human activities, particularly through the release of untreated sanitary sewage into the coastal environments. These effluents contain a large group of natural or synthetic compounds referred to as emerging contaminants. Monitoring the types and quantities of toxic substances in the environment, especially complex mixtures, is an exhausting and challenging task. Integrative effect-based tools, such as biomarkers, are recommended for environmental quality monitoring programs. In this study, fish Poecilia vivipara were exposed for 24 and 96 h to raw untreated sewage diluted 33 % (v/v) in order to identify hepatic genes to be used as molecular biomarkers. Through a de novo hepatic transcriptome assembly, using Illumina MiSeq, 54,285 sequences were assembled creating a reference transcriptome for this guppy species. Transcripts involved in biotransformation systems, antioxidant defenses, ABC transporters, nuclear and xenobiotic receptors were identified and evaluated by qPCR. Sanitary sewage induced transcriptional changes in AhR, PXR, CYP2K1, CYP3A30, NQO1, UGT1A1, GSTa3, GSTmu, ST1C1, SOD, ABCC1 and SOX9 genes from liver of fish, particularly after 96 h of exposure. Changes in hepatic enzyme activities were also observed. The enzymes showed differences in fish exposed to both periods, while in the gills there was a prevalence of significant results after 96 h. The observed differences were associated to gender and/or to sewage exposure. The obtained results support the use of P. vivipara as sentinel and model organism for ecotoxicological studies and evidence the importance of understanding the differential responses associated to gender. [Display omitted] •De novo transcriptome sequencing of liver of P. vivipara was performed through NGS.•Sanitary sewage impacts guppy liver biotransformation, endocrine, and antioxidant pathways.•Biotransformation-related genes were differentially affected in each gender.•Liver was the most responsive organ regarding the enzymatic activity.•P. vivipara is suggested as sentinel and model organism for ecotoxicological studies.