Análise do transcritoma do mexilhão marrom (Perna perna) sob contaminação por antraceno

Abstract

The brown mussel Perna perna (Linnaeus, 1758) helps the monitoring of chemical compounds in marine ecosystems. However its molecular mechanisms of detoxification and stress response remain unclear. Elucidating these mechanisms is crucial to understand the toxic effects of chemical pollutants and to develop biomarkers to assess marine ecosystems. In this study, P. perna individuals were exposed to anthracene (ANT) and its mRNA complement was sampled sequenced with Illumina technology. Chemical analysis of the soft tissue identified ANT concentrations 268-715 fold higher in the exposed group compared to controls, demonstrating that the exposure procedure was successfully accomplished. Transcriptome sequencing of P. perna generated 273.152.390 paired reads that were assembled in 231.728 contigs of average length 720 bp and N50 1.083 bp , which 66.563 contigs (28,7%) could be annotated using GenBank genes, Pfam domains, Gene Ontology (GO) terms and KEGG pathways. The results obtained from functional annotation suggest gills play a role in xenobiotics biotransformation, antioxidant response, signal transduction, innate immune response, and osmoregulation. It was possible to identify transcripts similar to genes related with biotransformation reactions of phases I, II and III, including CYPs and GSTs. Transcripts similar to CYPs and GSTs isoforms were highly expressed in the group exposed to ANT, however no CYP, GST, or even other genes related with biotransformation reactions were classified as differentially expressed. On the other hand, several hypothetical genes were differentially expressed, which suggests that P. perna uses unknown mechanisms of biotransformation to deal with ANT stress contamination. Immune related-genes were both up and downregulated, as was also observed for Perna viridis exposed to benzo(a)pyrene, suggesting that ANT promotes alteration in the immune response of P. perna.

Ultrastructure of the gill ciliary epithelium of Limnoperna fortunei (Dunker 1857), the invasive golden mussel

“…Each individual has two valves surrounding the body composed of calcium carbonate [16] and its polymorphs aragonite and amorphous calcium carbonate [9]. Gills are in direct contact with the environment, suggesting their importance in xenobiotics biotransformation, antioxidant response, signal transduction, innate immune response, and osmoregulation [17,18]. Furthermore, a giant virus belonging to the Marseilleviridae family was recently found in L. fortunei gills, since the morphophysiological structure of the gills favors microorganism bioaccumulation such as amoebas and viruses [19].…”

Ultrastructure of the gills ciliary epithelium of Limnoperna fortunei (Dunker 1857), the invasive golden mussel

“…Each individual has two valves surrounding the body composed of calcium carbonate [16] and its polymorphs aragonite and amorphous calcium carbonate [9]. Gills are in direct contact with the environment, suggesting their importance in xenobiotics biotransformation, antioxidant response, signal transduction, innate immune response, and osmoregulation [17,18]. Furthermore, a giant virus belonging to the Marseilleviridae family was recently found in L. fortunei gills, since the morphophysiological structure of the gills favors microorganism bioaccumulation such as amoebas and viruses [19].…”