Exposure to the Neurotoxic Dinoflagellate, Alexandrium catenella, Induces Apoptosis of the Hemocytes of the Oyster, Crassostrea gigas
|Author(s)||Medhioub Walid1, Ramondenc Simon2, Vanhove Audrey2, Vergnes Agnes2, Masseret Estelle2, Savar Veronique3, Amzil Zouher3, Laabir Mohamed2, Rolland Jean-Luc2|
|Affiliation(s)||1 : Inst Natl Sci & Technol Mer, Lab Milieu Marin, Salammbo 2025, Tunisia.
2 : Univ Montpellier I, Univ Montpellier 2, Inst Francais Rech Exploitat Mer, Inst Rech Dev,CNRS,UMR Ecol Syst Marins Cotiers 5, F-34095 Montpellier 5, France.
3 : Inst Francais Rech Exploitat Mer, Lab Environm Microbiol & Phycotoxines, F-44311 Nantes 3, France.
|Source||Marine Drugs (1660-3397) (Mdpi Ag), 2013-12 , Vol. 11 , N. 12 , P. 4799-4814|
|WOS© Times Cited||13|
|Keyword(s)||shellfish, toxins, apoptosis, gene expression|
|Abstract||This study assessed the apoptotic process occurring in the hemocytes of the Pacific oyster, Crassostrea gigas, exposed to Alexandrium catenella, a paralytic shellfish toxins (PSTs) producer. Oysters were experimentally exposed during 48 h to the toxic algae. PSTs accumulation, the expression of 12 key apoptotic-related genes, as well as the variation of the number of hemocytes in apoptosis was measured at time intervals during the experiment. Results show a significant increase of the number of hemocytes in apoptosis after 29 h of exposure. Two pro-apoptotic genes (Bax and Bax-like) implicated in the mitochondrial pathway were significantly upregulated at 21 h followed by the overexpression of two caspase executor genes (caspase-3 and caspase-7) at 29 h, suggesting that the intrinsic pathway was activated. No modulation of the expression of genes implicated in the cell signaling Fas-Associated protein with Death Domain (FADD) and initiation-phase (caspase-2) was observed, suggesting that only the extrinsic pathway was not activated. Moreover, the clear time-dependent upregulation of five (Bcl2, BI-1, IAP1, IAP7B and Hsp70) inhibitors of apoptosis-related genes associated with the return to the initial number of hemocytes in apoptosis at 48 h of exposure suggests the involvement of strong regulatory mechanisms of apoptosis occurring in the hemocytes of the Pacific oyster.|