Eukaryotic Associations - Pfiesteria Dinoflagellates

What other eukaryotic organisms co-exist along with Pfiesteria piscicida and P. shumwayae? How do these protists affect the populations, physiology and toxigenesis of the Pfiesteria dinoflagellates? We are answering these questions using molecular approaches, such as denaturing gradient gel electrophoresis (DGGE), that allow us to identify organisms based on the nucleotide sequence of their small subunit ribosomal (SSU) gene. Once obtained, the phylogenetic data are used to develop species-specific molecular probes for real-time PCR (using the ABI "Taqman" gene analyzer) to sensitively detect each species, comparing its abundance to that of P. piscicida and P. shumwayae. This Taqman assay can detect as little as one cell of P. piscicida or P. shumwayae, affording us a powerful tool when seeking answers to questions about population dynamics both in laboratory cultures and in environmental samples.