Morphogenetic diversity and biotoxin composition of Alexandrium (Dinophyceae) in Irish coastal waters

By N. Touzet, J. Franco, R. Raine. 2008

126 citations recorded by the source corpus.

Abstract The diversity of Alexandrium spp. in Irish coastal waters was investigated through the morphological examination of resting cysts and vegetative cells, the determination of PSP toxin and spirolide profiles and the sequence analysis of rDNA genes. Six morphospecies were characterised: A. tamarense , A. minutum , A. ostenfeldii , A. peruvianum , A. tamutum and A. andersoni . Both PSP toxin producing and non-toxic strains of A. tamarense and A. minutum were observed. The average toxicities of toxic strains for both cultured species were respectively 11.3 (8.6 S.D.) and 2.3 (0.5 S.D.) pg STX equiv. cell −1 . Alexandrium ostenfeldii and A. peruvianum did not synthesise PSP toxins but HPLC–MS analysis of two strains showed distinct spirolide profiles. A cyst-derived culture of A. peruvianum from Lough Swilly mainly produced spirolides 13 desmethyl-C and 13 desmethyl-D whereas one of A. ostenfeldii , from Bantry Bay, produced spirolides C and D. Species identification was confirmed through the analyses of SSU, ITS1-5.8S-ITS2 and LSU rDNA genes. Some nucleotide variability was observed among clones of toxic strains of A. tamarense , which all clustered within the North American clade. However, rDNA sequencing did not allow discrimination between the toxic and non-toxic forms of A. minutum . Phylogenetic analysis also permitted the differentiation of A. ostenfeldii from A. peruvianum . Resting cysts of PSP toxin producing Alexandrium species were found in Cork Harbour and Belfast Lough, locations where shellfish contamination events have occurred in the past, highlighting the potential for the initiation of harmful blooms from cyst beds. The finding of supposedly non-toxic and biotoxin-producing Alexandrium species near aquaculture production sites will necessitate the use of reliable discriminative methods in phytoplankton monitoring.

Subfields: Environmental Chemistry, Molecular Biology, Oceanography

View Paper: https://www.semanticscholar.org/paper/83347d89cec01eb0b5ec50332dd489e95a55698b

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Citations in the corpus

Evidence for saxitoxins production by the cyanobacterium Aphanizomenon gracile in a French recreational water body (2010, background): “, 2007) and marine environments for the STXs producers Alexandrium and Gymnodinium (e.g. Cho et al., 2008; Touzet et al., 2008).”
The globally distributed genus Alexandrium: multifaceted roles in marine ecosystems and impacts on human health (2012, methodology): “…A. saotanum and A. taylori consistently form a well-supported clade that diverges early from all species of the subgenus Alexandrium, two species of the subgenus Gessnerium (A. margalefii and Alexandrium insuetum) do not fall into this clade (Hong et al., 2008; Touzet et al., 2008a,b; Fig.”
Paralytic shellfish toxins or spirolides? The role of environmental and genetic factors in toxin production of the Alexandrium ostenfeldii complex (2013, background): “Of the spirolide analogs, 13dmC seems to dominate in NW Atlantic (coastal Canada and USA, but also Spain, France, England, Ireland, Denmark; Cembella et al., 2000; MacKinnon et al., 2004; Percy et al., 2004; Villar González et al., 2006; Amzil et al., 2007; Touzet et al., 2008; Van Wagoner et al., 2”