Alexandrium dinoflagellates

Agelasine, 320 Aiptasia pallida, 304,310 Aiptasia species, toxic protein, 321 Aiptasiolysin, 304,310 Alexandrium dinoflagellates clones, 36,38-3 saxitoxin source, 21 toxicity, 36... 

Paralytic Shellfish Poisoning (PSP) was first determined to be a problem in 1942 after three people and many seabirds died from eating shellfish on the west coast of the United States, near the Columbia River. It is caused by the saxitoxin family (saxitoxin + 18 related compounds) produced by several species of Alexandrium dinoflagellates. The main contamination problems include mussels, clams, crabs, and fish of the Pacific Northwest and Northeast Atlantic. 

Figure 7A. The toxigenic dinoflagellate Alexandrium sp. from Southeast Alaska. Two vegetative cells of clone EC06, from Elfin Cove. Bar is 30 xm. Photomicrography by R. A. Horner.

As discussed above, there is the possibility that toxigenesis in Alexandrium is not intrinsic but due to symbionts. Whichever proves to be the case, the observed patterns of toxin composition, whether they are for the dinoflagellate itself or the isolated assemblage of dinoflagellate and symbiont, are a basis for recognizing and distinguishing the regional populations. 

Some dinoflagellates of the genus Alexandrium produce neurotoxic compounds known as paralytic shellfish poisoning (PSP) toxins. Because these toxins can contaminate filter-feeding shellfish they may threaten public health and create economic problems for fisheries. PSP-toxins include at least a dozen saxitoxins, neosaxitoxins, and gonyautoxins (Scheme 1). 

Rapid-acting paralytic neurotoxins that blocks transient sodium channels and inhibits depolarization of nerve cells. They are some of the causative agents of paralytic shellfish poisoning (PSP). They are obtained from dinoflagellates (Gonyaulax spp., Alexandrium spp.) and cyanobacteria (Anabaena circinalis). 

The paralytic shellfish toxins (PSTs Fig. 5.2a) include saxitoxin (STX) as well as STX analogs such as neo-saxitoxin (neo-STX), gonyautoxin (GTX), and the decar-bamoyltoxins (Sivonen and Jones 1999). These molecules are of particular concern in marine systems, where they have been implicated in human deaths following the consumption of contaminated seafood (Van Dolah 2000). The causative agents in those cases are several genera of marine dinoflagellates that are common components of red tides (e.g., Alexandrium sp. Homer et al. 1997 Van Dolah 2000). 

Colin SP, Dam HG (2002) Latitudinal differentiation in the effects of the toxic dinoflagellate Alexandrium spp. on the feeding and reproduction of populations of the copepod Arcatia hudsonica. Harmful Algae 1 113-125... 

Caretto JI, Lutz VA, De Marco SG, Carignan MO (1990) Fluence and wavelength dependence of mycosporine-like amino acid synthesis in the dinoflagellate Alexandrium excavatum. In Graneli E, Edler L, Sundstrom B, Anderson DM (eds) Toxic marine phytoplankton. Elsevier, Amsterdam, pp 275-279... 

Anderson, D.M. Scholin, C.A. (1997) Genetie markers derived from rRNAs and their use in deteetion of Alexandrium species of dinoflagellates associated with red tides. US Patent 5,582,983. Chem. Abstr., 1997, 126, 101706k. 

Kodama, M. Sato, S. Sakamoto, S. Ogata, T. (1996) Occurrence of tetrodotoxin in Alexandrium tamarense, a causative dinoflagellate of paralytic shellfish poisoning. Toxicon, 34, 1101-5. 

Murakami, M. Okita, Y. Matsuda, H. Okino, T. Yamaguchi, K. (1998) From the dinoflagellate Alexandrium hiranoi. Phytochemistry, 48, 85-8. 

K. Metfies, S. Huljic, M. Lange and L.K. Medlin, Electrochemical detection of the toxic dinoflagellate Alexandrium ostenfeldii with a DNA-bio-sensor, Biosens. Bioelectron., 20 (2005) 1349-1357. 

Carreto, J. I., Lutz, V. A., De Marco, S. G., and Carignan, M. O., Fluence and wavelength dependence of mycosporine amino acid synthesis in the dinoflagellate Alexandrium excavatum, in Toxic Marine Phytoplankton, Graneli, E., Sundstrom, B., Edler, L., and Anderson, D. M., Eds., Elsevier, New York, 1990, 275. 

Figure 18.3. Alexandrium ostenfeldii dinoflagellate obtained from a phytoplankton sample collected in France (bouchot de Loire, May 28, 2004) by Elisabeth Nezan (Ifremer, Nantes). Whole cell (a), and after dissection (b).

Cembella, A.D., Lewis, N.I., and Quilliam, M.A. 1999. Spirolide composition of micro-exfi acted pooled cells isolated from natural plankton assemblages and from cultiwes of file dinoflagellate Alexandrium ostenfeldii. Nat Toxins 7, 197—206. -------. 2000. The marine dinoflagellate Alexandrium ostenfeldii (Dinophyceae) as the causative organism of spirolide shellfish toxin. Phycologia 39, 61-1 A. 

Moestrup, 0., and Hansen, P.J. 1988. On the occurrence of the potentially toxic dinoflagellates Alexandrium tamarense (=Gonyaulax excavatd) and4. ostenfeldii in Danish and Faroese waters. Ophelia 28,195—213. 

The powerful human neurotoxin saxitoxin, present in the dinoflagellate Alexandrium (Gonyauhix) cantenella, incorporates a reduced form of the purine-2,8-diamine cation in its... 

J.I. Carreto, M.O. Carignan, G. Daleo, S.G. De Marco (1990). Occurrence of mycosporine-like amino acids in the red-tide dinoflagellate Alexandrium excavatum UV-photoprotective compounds . J. Plankton Res., 12,909-921. 

J.I. Carreto, M.O. Carignan, N.G. Montoya (2001). Comparative studies on mycosporine-like amino acids, paralytic shellfish toxins and pigment profiles of the toxic dinoflagellates Alexandrium tamarense, A. catanella and A. minutum. Mar. Ecol. Prog. Ser., 223,49-60. 

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