Molecular probes and microarrays for the detection of toxic algae in the genera Dinophysis and Phalacroma (Dinophyta)

摘要

Dinophysis and Phalacroma species containingdiarrheic shellfish toxins and pectenotoxins occur in coastaltemperate waters all year round and prevent the harvestingof mussels during several months each year in regions inEurope, Chile, Japan, and New Zealand. Toxicity variesamong morphologically similar species, and a precise identificationis needed for early warning systems. Moleculartechniques using ribosomal DNA sequences offer a meansto identify and detect precisely the potentially toxic species.We designed molecular probes targeting the 18S rDNA atthe family and genus levels for Dinophysis and Phalacromaand at the species level for Dinophysis acuminata, Dinophysisacuta, and Dinophysis norvegica, the most commonlyoccurring, potentially toxic species of these genera in WesternEuropean waters. Dot blot hybridizations with polymerasechain reaction (PCR)-amplified rDNA from 17 microalgaewere used to demonstrate probe specificity. The probes weremodified along with other published fluorescence in situhybridization and PCR probes and tested for a microarrayplatform within the MIDTAL project (http://www.midtal.com). The microarray was applied to field samples fromNorway and Spain and compared to microscopic cell counts.These probes may be useful for early warning systems andmonitoring and can also be used in population dynamic studiesto distinguish species and life cycle stages, such as cysts,and their distribution in time and space.