bioRxiv preprint doi: https://doi.org/10.1101/544247; this version posted February 8, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Development of a quantitative PCR assay for the detection and enumeration of a potentially ciguatoxin-producing dinoflagellate, Gambierdiscus lapillus (Gonyaulacales, Dinophyceae). Key words:Ciguatera fish poisoning, Gambierdiscus lapillus, Quantitative PCR assay, Great Barrier Reef Kretzschmar, A.L.1,2, Verma, A.1, Kohli, G.S.1,3, Murray, S.A.1 1Climate Change Cluster (C3), University of Technology Sydney, Ultimo, 2007 NSW, Australia 2ithree institute (i3), University of Technology Sydney, Ultimo, 2007 NSW, Australia,
[email protected] 3Alfred Wegener-Institut Helmholtz-Zentrum fr Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany Abstract Ciguatera fish poisoning is an illness contracted through the ingestion of seafood containing ciguatoxins. It is prevalent in tropical regions worldwide, including in Australia. Ciguatoxins are produced by some species of Gambierdiscus. Therefore, screening of Gambierdiscus species identification through quantitative PCR (qPCR), along with the determination of species toxicity, can be useful in monitoring potential ciguatera risk in these regions. In Australia, the identity, distribution and abundance of ciguatoxin producing Gambierdiscus spp. is largely unknown. In this study we developed a rapid qPCR assay to quantify the presence and abundance of Gambierdiscus lapillus, a likely ciguatoxic species. We assessed the specificity and efficiency of the qPCR assay. The assay was tested on 25 environmental samples from the Heron Island reef in the southern Great Barrier Reef, a ciguatera endemic region, in triplicate to determine the presence and patchiness of these species across samples from Chnoospora sp., Padina sp.