Sublethal responses of the burrowing amphipod Tiburonella viscana exposed to contaminated sediments

• Grant number: 22/07612-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2022
• End date: June 30, 2023
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Biological Oceanography
• Principal Investigator: Lucas Buruaem Moreira
• Grantee: Luara Cardoso Cuartero
• Host Institution: Instituto do Mar (IMar). Universidade Federal de São Paulo (UNIFESP). Campus Baixada Santista. Santos , SP, Brazil
• Associated research grant: 20/00068-8 - Whole transcriptome analysis of benthic organisms as models to estimate toxic effects of contaminated sediments in marine environments, AP.BTA.JP

Abstract

Sediment toxicity bioassays are used for evaluation of the ecological risks produced by contaminants, which is related to biodiversity loss in benthic environments. In Brazil, there are few benthic models for these bioassays, and for those already established, the knowledge is incipient regarding the mechanisms of toxicity that are activated, generating effects at different levels of biological organization. Such models include the excavating amphipod Tiburonella viscana, which has a high sensitivity to contaminants, and the tanaid Monokalliapseudes schubarti, which has a tolerance to different substances. In this research project, we aim to investigate the molecular mechanisms of toxicity in these two species by using transcriptomic analysis of animals collected in the field and exposed to contaminated sediments in the laboratory. We hypothesize that this technique will provide evidence of initiating events of toxic responses in T. viscana, related to a higher susceptibility of the species, and also the potential activation of signaling pathways involved in the tolerance to contaminants of M. schubarti. The project is organized into three phases. In the first one, the experimental design is set to obtain the functional annotation of differential gene expression by using the RNA sequencing technique (RNAseq). The goal is to investigate the molecular mechanisms of tolerance in M. schubarti and activation of toxicity pathways in T. viscana that can be used as biomarkers. The second phase is focused on the validation through the gene expression analysis by means of the real-time polymerase chain reaction (PCR-Real time). The last phase is based on the analysis of biochemical biomarkers, and also lethal and sublethal endpoints (mortality and biomass, respectively), that can be associated with molecular responses. The results will be integrated into an adverse effect pathway framework (AOP). Therefore, the results of this project will provide relevant information on the biological aspects of the species, and also advances in marine ecotoxicology, since the use of a mechanistic approach in sediment evaluations is moving forward with the knowledge on this topic. (AU)