title: Developmental toxicity and molecular responses of marine medaka (Oryzias melastigma) embryos to ciguatoxin P-CTX-1 exposure.
abstract: 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-LD50value was estimated for eleuthero-embryos (1.32ngg-1) than that for embryos (1.71ngg-1), 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.
authors.affiliation: 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. Electronic address: mengyan@cityu.edu.hk.
authors.forename: Meng
authors.initials: M
authors.lastname: Yan
authors.affiliation: 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. Electronic address: priscilla_ty_leung@yahoo.com.hk.
authors.forename: Priscilla T Y
authors.initials: PT
authors.lastname: Leung
authors.affiliation: State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China. Electronic address: jackipchiho@hotmail.com.
authors.forename: Jack C H
authors.initials: JC
authors.lastname: Ip
authors.affiliation: School of Science, Hong Kong University of Science and Technology, Hong Kong, China. Electronic address: jinpingcheng@gmail.com.
authors.forename: Jin-Ping
authors.initials: JP
authors.lastname: Cheng
authors.affiliation: 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. Electronic address: vickywujj@gmail.com.
authors.forename: Jia-Jun
authors.initials: JJ
authors.lastname: Wu
authors.affiliation: 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. Electronic address: jrgu_chary@163.com.
authors.forename: Jia-Rui
authors.initials: JR
authors.lastname: Gu
authors.affiliation: 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; Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong, China. Electronic address: bhpksl@cityu.edu.hk.
authors.forename: Paul K S
authors.initials: PK
authors.lastname: Lam
mesh_terms: D000818:Animals; D001846:Bone Development / Q000187:drug effects / Q000235:genetics; D002922:Ciguatoxins / Q000633:toxicity*; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000378:metabolism; D004781:Environmental Exposure / Q000032:analysis*; D005704:Gallbladder / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D006321:Heart / Q000187:drug effects / Q000196:embryology; D007109:Immunity / Q000187:drug effects / Q000235:genetics; D015999:Multivariate Analysis; D009990:Oryzias / Q000196:embryology*; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D002922:Ciguatoxins; D051546:Cyclooxygenase 2
keywords: Ciguatoxin; Developmental toxicity; Embryo; Gambierdiscus; Medaka; Oryzias melastigma