Transcriptional Analyses of Acute Exposure to Methylmercury on Erythrocytes of Loggerhead Sea Turtle

• Published in: Toxics (Basel) Vol. 9; no. 4; p. 70
• Main Authors: Hernández-Fernández, Javier, Pinzón-Velasco, Andrés, López, Ellie Anne, Rodríguez-Becerra, Pilar, Mariño-Ramírez, Leonardo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 29.03.2021; MDPI
• Subjects: Antioxidants; Apoptosis; Aquatic reptiles; Autophagy; Biomarkers; Calcium (mitochondrial); Caretta caretta; Cell cycle; Chelonia mydas; Contamination; differential expression; Dimethylmercury; Endangered & extinct species; Enzymatic activity; Enzyme activity; Erythrocytes; Exposure; Gene expression; Gene regulation; Genes; Mercury (metal); Methylmercury; Mitochondria; Oxidative stress; Pelodiscus sinensis; Phagocytosis; Pollutants; Reactive oxygen species; RNA-seq; Sea turtles; Transcription; Transcriptomes; transcriptomics; United States > US; Germany; methylmercury; transcriptomics; differential expression; RNA-seq; Caretta caretta
• ISSN: 2305-6304; 2305-6304
• DOI: 10.3390/toxics9040070

To understand changes in enzyme activity and gene expression as biomarkers of exposure to methylmercury, we exposed loggerhead turtle erythrocytes (RBCs) to concentrations of 0, 1, and 5 mg L of MeHg and de novo transcriptome were assembled using RNA-seq. The analysis of differentially expressed genes (DEGs) indicated that 79 unique genes were dysregulated (39 upregulated and 44 downregulated genes). The results showed that MeHg altered gene expression patterns as a response to the cellular stress produced, reflected in cell cycle regulation, lysosomal activity, autophagy, calcium regulation, mitochondrial regulation, apoptosis, and regulation of transcription and translation. The analysis of DEGs showed a low response of the antioxidant machinery to MeHg, evidenced by the fact that genes of early response to oxidative stress were not dysregulated. The RBCs maintained a constitutive expression of proteins that represented a good part of the defense against reactive oxygen species (ROS) induced by MeHg.