RNA-Seq Analysis for Assessing the Early Response to DSP Toxins in Mytilus galloprovincialis Digestive Gland and Gill

Abstract

The harmful effects of diarrhetic shellfish poisoning (DSP) toxins on mammalian cell lines have been widely assessed. Studies in bivalves suggest that mussels display a resistance to the cytogenotoxic effects of DSP toxins. Further, it seems that the bigger the exposure, the more resistant mussels become. To elucidate the early genetic response of mussels against these toxins, the digestive gland and the gill transcriptomes of Mytilus galloprovincialis after Prorocentrum lima exposure (100,000 cells/L, 48 h) were de novo assembled based on the sequencing of 8 cDNA libraries obtained using an Illumina HiSeq 2000 platform. The assembly provided 95,702 contigs. A total of 2286 and 4523 differentially expressed transcripts were obtained in the digestive gland and the gill, respectively, indicating tissue-specific transcriptome responses. These transcripts were annotated and functionally enriched, showing 44 and 60 significant Pfam families in the digestive gland and the gill, respectively. Quantitative PCR (qPCR) was performed to validate the differential expression patterns of several genes related to lipid and carbohydrate metabolism, energy production, genome integrity and defense, suggesting their participation in the protective mechanism. This work provides knowledge of the early response against DSP toxins in the mussel M. galloprovincialis and useful information for further research on the molecular mechanisms of the bivalve resistance to these toxins.

Detecting Prognosis Risk Biomarkers for Colon Cancer Through Multi-Omics-Based Prognostic Analysis and Target Regulation Simulation Modeling

“…All the profile dataset of four omics were downloaded from the UCSC Xena database. Briefly, level 3 gene expression profiles with 20,530 gene features recorded in the UCSC Xena database were experimentally generated using the Illumina HiSeq 2000 RNA sequencing platform (Prego-Faraldo et al, 2018) from the University of North Carolina TCGA genome characterization center. The stored exon expression profiles were generated using the same platform as the gene expression profiles, with 239,322 exon features.…”

OMICs Approaches in Diarrhetic Shellfish Toxins Research

“…Interestingly, a number of transcripts associated to OA toxicity like the specific targets PP1 and PP2A and multi-xenobiotic resistance proteins failed to show significant changes in expression [ 81 ]. In a similar study, Prego-Faraldo et al (2018) [ 82 ] assessed the early response (48 h) of the same mussel to P. lima (1 × 10 5 cell L −1 ) using a RNA-Seq analysis showing, in this turn, a higher number of DGEs in gills compared to digestive gland. These included transcripts involved in defense, immunity and metabolism, and since many of them have been described as making part of a common cellular stress response of bivalves to other stimuli [ 83 ], it is suggested that mussel’s resistance mechanism to DSTs is to some extent unspecific [ 82 ].…”

“…In a similar study, Prego-Faraldo et al (2018) [ 82 ] assessed the early response (48 h) of the same mussel to P. lima (1 × 10 5 cell L −1 ) using a RNA-Seq analysis showing, in this turn, a higher number of DGEs in gills compared to digestive gland. These included transcripts involved in defense, immunity and metabolism, and since many of them have been described as making part of a common cellular stress response of bivalves to other stimuli [ 83 ], it is suggested that mussel’s resistance mechanism to DSTs is to some extent unspecific [ 82 ]. Furthermore, results also seem to support a key role of the extracellular exosome and respiratory chain in both mussel tissues in the response to DSTs.…”

“…Given that DSTs can also cause oxidative stress in shellfish (as documented in Section 3 and Section 4 ), it is likely that cytoskeleton proteins like tropomyosin and paramyosin can also be altered in abundance and structure by DSTs via induction of ROS and subsequently alter the allergenic potential of the animal. Furthermore, the study of Prego-Faraldo et al, (2018) [ 82 ] on the transcriptome of M. galloprovincialis revealed responses to DSTs involving defense and immune mechanisms and alterations in energy metabolism and ATP synthesis proteins. Alterations in the levels of ATP may affect another allergenic protein, arginine kinase, that uses ATP to phosphorylate arginine, in the metabolism of arginine and proline [ 114 ].…”

“…Similarly, genes from the immune system of shellfish could also be studied with regard to DSTs exposure ( Table 1 ). Indeed, genes encoding C-type lectins (CLT-6), HSP90, metallothionein (MT), classical complement pathway C1q (mgC1q83 and mgC1q29), macrophage migration inhibitory factor (MIF) or fibrinogen-related protein (FREP) have been found to be modulated by DST-producing P. lima [ 82 , 84 , 141 ].…”