Yan Meng, Leung Priscilla T Y, Ip Jack C H, Cheng Jin-Ping, Wu Jia-Jun, Gu Jia-Rui, Lam Paul K S
State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China; Shenzhen Key Laboratory for the Sustainable Use of Marine Biodiversity, Research Centre for the Oceans and Human Health, City University of Hong Kong Shenzhen Research Institute, Shenzhen, China.
State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China.
Aquat Toxicol. 2017 Apr;185:149-159. doi: 10.1016/j.aquatox.2017.02.006. Epub 2017 Feb 10.
Ciguatoxins are produced by toxic benthic dinoflagellates and cause ciguatera fish poisoning worldwide, but the toxic effects on developing marine fish have not been well investigated. The Pacific ciguatoxin (P-CTX-1), is a potent sodium channel agonist, which is one of the most toxic members among all CTXs. This study evaluated the toxic effects of microinjecting purified Pacific ciguatoxin-1 (P-CTX-1) on embryonic development of marine medaka Oryzias melastigma. A lower 96h-LD value was estimated for eleuthero-embryos (1.32ngg) than that for embryos (1.71ngg), indicating that P-CTX-1 is more lethal to newly hatched medaka larvae. P-CTX-1 induced detrimental effects during embryonic development, including hatching failure, abnormalities in physical development (caudal fin malformation and spinal deformities), internal damage (green coloration of the gall bladder and hemorrhaging), immune dysfunction, and altered muscle physiology (bradycardia and hyperkinetic twitching). The results of a transcriptional expression analysis of genes related to the stress/immune responses, cardiac and bone development, and apoptosis supported the observed developmental abnormalities. This study advanced the understanding of P-CTX-1 mediated toxic mechanisms in the development of early life stages of a fish, and thus contributed to the toxicity assessment of CTXs in marine ecosystems.
雪卡毒素由有毒底栖甲藻产生，在全球范围内导致雪卡鱼中毒，但对海洋幼鱼发育的毒性影响尚未得到充分研究。太平洋雪卡毒素（P-CTX-1）是一种强效钠通道激动剂，是所有雪卡毒素中毒性最强的成员之一。本研究评估了显微注射纯化的太平洋雪卡毒素-1（P-CTX-1）对海洋青鳉鱼（Oryzias melastigma）胚胎发育的毒性作用。估计自由胚胎的96小时半数致死剂量值（1.32纳克/克）低于胚胎（1.71纳克/克），这表明P-CTX-1对刚孵化的青鳉幼鱼更具致死性。P-CTX-1在胚胎发育过程中诱导了有害影响，包括孵化失败、身体发育异常（尾鳍畸形和脊柱畸形）、内部损伤（胆囊变绿和出血）、免疫功能障碍以及肌肉生理改变（心动过缓和运动亢进抽搐）。对应激/免疫反应、心脏和骨骼发育以及细胞凋亡相关基因的转录表达分析结果支持了所观察到的发育异常。本研究增进了对P-CTX-1在鱼类早期生命阶段发育中介导的毒性机制的理解，从而有助于评估海洋生态系统中雪卡毒素的毒性。
