The Brazilian oyster Crassostrea brasiliana was challenged to three common environmental contaminants: phenanthrene, diesel fuel water-accommodated fraction (WAF) and domestic sewage. Total RNA was extracted from the gill and digestive gland, and cDNA libraries were sequenced using the 454 FLX platform. The assembled transcriptome resulted in ~20,000 contigs, which were annotated to produce the first de novo transcriptome for C. brasiliana. Sequences were screened to identify genes potentially involved in the biotransformation of xenobiotics and associated antioxidant defence mechanisms. These gene families included those of the cytochrome P450 (CYP450), 70kDa heat shock, antioxidants, such as glutathione S-transferase, superoxide dismutase, catalase and also multi-drug resistance proteins. Analysis showed that the massive expansion of the CYP450 and HSP70 family due to gene duplication identified in the Crassostrea gigas genome also occurred in C. brasiliana, suggesting these processes form the base of the Crassostrea lineage. Preliminary expression analyses revealed several candidates biomarker genes that were up-regulated during each of the three treatments, suggesting the potential for environmental monitoring.
Bibliographical noteFunding Information:
This research was supported by grants from NERC, UK to JAG and CNPq to ACDB (CT-Petro 550706/2005-4 and CNPq INCT-TA). KHL was a Guest Student at the Marine Biological Association of the United Kingdom and Glasgow Caledonian University and was supported by a CAPES Ph.D. Fellowship and CNPq Ph.D. Sandwich Fellowship, Brazil. ACDB was recipient of the CNPq Productivity Fellowship, Brazil. MSC and MAST were funded by NERC core funding to the British Antarctic Survey. We would like to thank Dr. Fabrício Flores-Nunes, Dr. Tarquin S. Dorrington and M.Sc. Christielly Rodrigues and for the assistance during experiments and Mr Jamie Oliver (British Antarctic Survey) for his help with Figure 2. We are grateful to Dr. Cláudio M.R. Melo and to M.Sc. Carlos H.A.M. Gomes for supplying the oysters used in this study.
© 2015 Elsevier B.V.
- Antioxidant parameters
- Polycyclic aromatic hydrocarbon
- Xenobiotic metabolism