Molecular Characterization of Voltage-Gated Sodium Channels and Their Relations with Paralytic Shellfish Toxin Bioaccumulation in the Pacific Oyster Crassostrea gigas.
Molecular Characterization of Voltage-Gated Sodium Channels and Their Relations with Paralytic Shellfish Toxin Bioaccumulation in the Pacific Oyster Crassostrea gigas.
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DOI：
10.3390/md15010021
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发表时间：
2017-01-19
期刊：
影响因子：
5.4
通讯作者：
Fabioux C
中科院分区：
文献类型：
--
作者：
Boullot F;Castrec J;Bidault A;Dantas N;Payton L;Perrigault M;Tran D;Amzil Z;Boudry P;Soudant P;Hégaret H;Fabioux C
麻痹性贝类毒素 (PST) 与电压门控钠通道 (Nav) 结合并阻断可兴奋细胞中动作电位的传导。本研究旨在 (i) 表征巨牡蛎中的 Nav 序列，以及 (ii) 研究牡蛎中 Nav 与 PST 生物累积之间的假定关系。系统发育分析强调了 C. gigas 中的两种 Nav：Nav1 (CgNav1) 和 Nav2 (CgNav2)，分别具有钠选择性和钠/钙选择性通道的序列特性。表征了 CgNav1 的三个选择性剪接转录本，即 A、B 和 C。通过原位杂交分析，CgNav1 的表达对于神经细胞和神经肌肉接头对应的结构具有特异性。实时PCR分析显示CgNav1A在横纹肌中强烈表达，而CgNav1B主要在内脏神经节中表达。 CgNav1C 表达无处不在。 CgNav1 变体的 PST 结合位点（结构域 II）拥有一个氨基酸 Q，可能赋予通道部分石房蛤毒素 (STX) 抗性。 CgNav1基因型或选择性剪接并不是决定牡蛎中PST生物累积水平的关键点。
Paralytic shellfish toxins (PST) bind to voltage-gated sodium channels (Nav) and block conduction of action potential in excitable cells. This study aimed to (i) characterize Nav sequences in Crassostrea gigas and (ii) investigate a putative relation between Nav and PST-bioaccumulation in oysters. The phylogenetic analysis highlighted two types of Nav in C. gigas: a Nav1 (CgNav1) and a Nav2 (CgNav2) with sequence properties of sodium-selective and sodium/calcium-selective channels, respectively. Three alternative splice transcripts of CgNav1 named A, B and C, were characterized. The expression of CgNav1, analyzed by in situ hybridization, is specific to nervous cells and to structures corresponding to neuromuscular junctions. Real-time PCR analyses showed a strong expression of CgNav1A in the striated muscle while CgNav1B is mainly expressed in visceral ganglia. CgNav1C expression is ubiquitous. The PST binding site (domain II) of CgNav1 variants possess an amino acid Q that could potentially confer a partial saxitoxin (STX)-resistance to the channel. The CgNav1 genotype or alternative splicing would not be the key point determining PST bioaccumulation level in oysters.