MOREBIVALVES: Molecular strategies to be applied in the depuration of commercial bivalves for elimination of toxic compounds
Bivalve mollusk production is one of the most important aquaculture activities in Portugal representing in 2014 about 45% of national aquaculture production in marine and brackish waters. The future of bivalve production in Portugal depends, however, on a better knowledge of our commercial species and on the development of innovative solutions that address the various challenges identified in this activity such as the presence of toxic microalgae in the production areas and the contamination of bivalves with marine biotoxins. Among the most prevalent in Portugal are the diarrhetic shellfish toxins (DSPs) of the okadaic acid group. The subsequent ban on harvesting and marketing of contaminated bivalves for purposes of public health safety causes significant economic losses in this sector.
It is understood that increased knowledge about the biology and physiology of bivalves and particularly about the dynamics of biotoxins accumulation, and the detoxification metabolism is necessary to enable to find the most effective solutions to this problem. Fundamental knowledge in biology and physiology can be used for instance to develop decontamination strategies applied to bivalves to yield the necessary safety requirements for purposes of marketing and consumption.
The present project aims to develop an efficient depuration model to eliminate biotoxins in two commercial bivalve species, Donax trunculus and Cerastoderma edule. This objective is attained with a novel methodological approach that consists to modulate the endogenous xenobiotic detoxification system of bivalves through the activation of a key regulatory element belonging to the family of nuclear receptors, the pregnane X receptor (PXR). New depuration efficiencies will be abled with this approach if an effective activation of PXR and the xenobiotic detoxification enzymes are accomplished using natural PXR agonist compounds.
This project is carried out combining experimental studies to induce bivalve's depuration, analytical chemistry for the assessment of bivalve's toxicity and advanced OMICs. The results of the experimental studies will be interpreted in light of the metabolic signatures revealed by proteomics and transcriptomics and the PXR gene characterization studies.