title: High Specificity of a Quantitative PCR Assay Targeting a Saxitoxin Gene for Monitoring Toxic Algae Associated with Paralytic Shellfish Toxins in the Yellow Sea.
abstract: The identification of core genes involved in the biosynthesis of saxitoxin (STX) offers a great opportunity to detect toxic algae associated with paralytic shellfish toxins (PST). In the Yellow Sea (YS) in China, both toxic and nontoxic Alexandrium species are present, which makes it a difficult issue to specifically monitor PST-producing toxic algae. In this study, a quantitative PCR (qPCR) assay targeting sxtA4, a domain in the sxt gene cluster that encodes a unique enzyme involved in STX biosynthesis, was applied to analyze samples collected from the YS in spring of 2012. The abundance of two toxic species within the Alexandrium tamarense species complex, i.e., A. fundyense and A. pacificum, was also determined with TaqMan-based qPCR assays, and PSTs in net-concentrated phytoplankton samples were analyzed with high-performance liquid chromatography coupled with a fluorescence detector. It was found that the distribution of the sxtA4 gene in the YS was consistent with the toxic algae and PSTs, and the quantitation results of sxtA4 correlated well with the abundance of the two toxic species (r=0.857). These results suggested that the two toxic species were major PST producers during the sampling season and that sxtA-based qPCR is a promising method to detect toxic algae associated with PSTs in the YS. The correlation between PST levels and sxtA-based qPCR results, however, was less significant (r=0.552), implying that sxtA-based qPCR is not accurate enough to reflect the toxicity of PST-producing toxic algae. The combination of an sxtA-based qPCR assay and chemical means might be a promising method for monitoring toxic algal blooms.
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, People's Republic of China University of Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, People's Republic of China rcyu@qdio.ac.cn.
authors.forename: Ren-Cheng
authors.initials: RC
authors.lastname: Yu
authors.affiliation: Plant Functional Biology and Climate Change Cluster, University of Technology, Sydney, New South Wales, Australia.
authors.forename: Shauna A
authors.initials: SA
authors.lastname: Murray
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, People's Republic of China University of Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Jian-Hua
authors.initials: JH
authors.lastname: Chen
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, People's Republic of China University of Chinese Academy of Sciences, Beijing, People's Republic of China.
authors.forename: Zhen-Jun
authors.initials: ZJ
authors.lastname: Kang
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, People's Republic of China.
authors.forename: Qing-Chun
authors.initials: QC
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, People's Republic of China.
authors.forename: Fan-Zhou
authors.initials: FZ
authors.lastname: Kong
authors.affiliation: Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, People's Republic of China.
authors.forename: Ming-Jiang
authors.initials: MJ
authors.lastname: Zhou
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics; D002681:China; D002851:Chromatography, High Pressure Liquid; D004141:Dinoflagellida / Q000235:genetics*; D005810:Multigene Family; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods*; D012530:Saxitoxin / Q000032:analysis* / Q000096:biosynthesis*; D012680:Sensitivity and Specificity; D012758:Shellfish / Q000382:microbiology*
chemical_list: D012530:Saxitoxin