TY - JOUR TI - Oyster transcriptome response to Alexandrium exposure is related to saxitoxin load and characterized by disrupted digestion, energy balance, and calcium and sodium signaling AU - Mat, Audrey M. AU - Klopp, Christophe AU - Payton, Laura AU - Jeziorski, Celine AU - Chalopin, Morgane AU - Amzil, Zouher AU - Tran, Damien AU - Wikfors, Gary H. AU - Hégaret, Helene AU - Soudant, Philippe AU - Huvet, Arnaud AU - Fabioux, Caroline T2 - Aquatic Toxicology AB - Harmful Algal Blooms are worldwide occurrences that can cause poisoning in human seafood consumers as well as mortality and sublethal effets in wildlife, propagating economic losses. One of the most widespread toxigenic microalgal taxa is the dinoflagellate Genus Alexandrium, that includes species producing neurotoxins referred to as PST (Paralytic Shellfish Toxins). Blooms cause shellfish harvest restrictions to protect human consumers from accumulated toxins. Large inter-individual variability in toxin load within an exposed bivalve population complicates monitoring of shellfish toxicity for ecology and human health regulation. To decipher the physiological pathways involved in the bivalve response to PST, we explored the whole transcriptome of the digestive gland of the Pacific oyster Crassostrea gigas fed experimentally with a toxic Alexandrium minutum culture. The largest differences in transcript abundance were between oysters with contrasting toxin loads (1098 transcripts), rather than between exposed and non-exposed oysters (16 transcripts), emphasizing the importance of toxin load in oyster response to toxic dinoflagellates. Additionally, penalized regressions, innovative in this field, modeled accurately toxin load based upon only 70 transcripts. Transcriptomic differences between oysters with contrasting PST burdens revealed a limited suite of metabolic pathways affected, including ion channels, neuro-muscular communication, and digestion, all of which are interconnected and linked to sodium and calcium exchanges. Carbohydrate metabolism, unconsidered previously in studies of harmful algal effects on shellfish, was also highlighted, suggesting energy challenge in oysters with high toxin loads. Associations between toxin load, genotype, and mRNA levels were revealed that open new doors for genetic studies identifying genetically based low toxin accumulation. DA - 2018/06// PY - 2018 DO - 10.1016/j.aquatox.2018.03.030 DP - Web of Science VL - 199 SP - 127 EP - 137 J2 - Aquat. Toxicol. LA - English SN - 0166-445X UR - https://www.sciencedirect.com/science/article/pii/S0166445X18301061 KW - 20% Panorama HCERES 2020 KW - ACCUTOX_ANR-13-CESA-0019 KW - ACL KW - Alexandrium minutum KW - CNRS KW - Crassostrea gigas KW - Elastic-net regression KW - Ifremer KW - Ions channels KW - Paralytic Shellfish Toxins KW - Paralytic shellfish toxins KW - Transcriptomic KW - UBO KW - accumulation KW - channels KW - crassostrea-gigas KW - elastic-net KW - elastic-net regression KW - expression KW - genome KW - harmful algal blooms KW - ions channels KW - minutum KW - panorama KW - paralytic shellfish toxins KW - psp KW - transcriptomic ER -