Transcriptomic Profile of the Cockle Cerastoderma edule Exposed to Seasonal Diarrhetic Shellfish Toxin Contamination.

Dany Domínguez-Pérez,Daniela Almeida,José Carlos Martins,Pedro Reis Costa,Alexandre Campos,Vitor Vasconcelos

doi:10.3390/toxins13110784

Dany Domínguez-Pérez, Daniela Almeida + Show 4 more

Open Access

https://doi.org/10.3390/toxins13110784

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Abstract

Bivalves constitute an important source of proteins for human consumption, but some accumulate biotoxins such as diarrhetic shellfish toxins (DSTs), constituting a risk to human health. The cockle Cerastoderma edule is one of the most important species harvested in the Portuguese coast but also one of the most affected species due to recurrent DSTs exposure. However, little is known regarding the effects of the toxins produced by blooming dinoflagellates on C. edule. Herein, we explore the Differentially Expressed Genes (DEGs) of two tissues (gills and digestive gland) from wild cockles sampled in Portugal, through their whole transcriptomic response in two different seasons (exposed and not exposed to DSTs). The de novo transcriptome assembly returned 684,723 contigs, N50 of 1049, and 98.53% completeness. Altogether, 1098 DEGs were identified, of which 353 DEGs were exclusive for the digestive gland, 536 unique for the gills and 209 DEGs were common. Among DEGs were identified known DSTs-biomarkers including glutathione peroxidase, glutathione S-transferase, superoxide dismutase, cytochrome P450, ABC transporters, actin and tubulin-related proteins, Heat shock proteins and complement C1Q-like proteins. This study provides the first transcriptomic profile of C. edule, giving new insights about its molecular responses under different environmental conditions of DSTs exposure.

Highlights

Seasonal microalgae blooms constitute an ongoing concern due to their potential impacts on fisheries, seafood safety, tourism and other ecosystem services [1,2,3,4,5]
One of the most impactful marine biotoxins is the group of Diarrhetic Shellfish Toxins (DSTs) [6], comprising okadaic acid (OA) and analogous molecules named dinophysistoxins (DTX−1, −2 and −3) [9]
diarrhetic shellfish toxins (DSTs) Determination by LC-MS/MS in C. edule Sampled in Ria de Aveiro, Portugal

Summary

Introduction

Seasonal microalgae blooms constitute an ongoing concern due to their potential impacts on fisheries, seafood safety, tourism and other ecosystem services [1,2,3,4,5]. The high level of some marine biotoxins produced during these events, known as harmful algal blooms (HABs), can kill fish and other sea organisms on a large scale [6,7,8]. The main source of DSTs in the marine trophic chain are species of the genus Dinophysis, but they can be produced by dinoflagellates belonging to the genera Prorocentrum as well [9]. DSTs are lipophilic toxins that can be filtered and accumulated in the adipose tissues by some marine organisms [11], being shellfish the main route of transmission to humans [12,13]. Shellfish constitutes an important source of protein for humans, but their consumption represents a food safety threat when contaminated with DSTs [13,14,15]. DSTs shellfish contamination occurs every year, between April and October [2], resulting in the temporary banning of shellfish harvesting and trade [10]

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