The validation and application of the DinoDTec sxtA-based qPCR assay for early detection of PSP-associated dinoflagellate blooms

The synthesis of saxitoxin in dinoflagellates occupying marine environments has been found to be catalysed by a group of enzymes encoded by sxt genes, beginning with the unusual gene, sxtA. This gene exists in multiple genomic... [ view full abstract ]

The synthesis of saxitoxin in dinoflagellates occupying marine environments has been found to be catalysed by a group of enzymes encoded by sxt genes, beginning with the unusual gene, sxtA. This gene exists in multiple genomic copies in the investigated strains of Alexandrium species. A quantitative PCR assay targeting the sxtA gene to detect saxitoxin-producing dinoflagellates in marine environmental samples has been developed as a tool for marine environmental management. The abundance of sxtA correlates with the abundance of the saxitoxin-producing species of Alexandrium species. Using this assay, detection and quantification of sxtA in HAB events in Australia has also been correlated with saxitoxin uptake in shellfish.
The phytoxigene DinoDTec asay specific to saxitoxin synthesis gene (sxtA) detects low concentration of toxic species in seawater column. Calibration for gene copy number variability of sxtA has been carried out using a set of certified gene standards and used to further evaluate the performance of this assay.
A clear understanding of the biosynthetic pathways of toxin production has long been cited as being critical for the utilisation of better tools in the management of water assets impacted by algal blooms