Toxin variability in cultured and natural populations of Alexandrium tamarense from southern South America – Evidences of diversity and environmental regulation

Analysis of the hydrographic conditions and cyst beds in the San Jorge Gulf, Argentina, that favor dinoflagellate population development including toxigenic species and their toxins

“…Both strains displayed almost identical PSP profiles consisting of approximately 41% C1/2, 57% GXT1/4 and 2% NEO. This profile has been reported several times for Argentinean strains of A. tamarense (Carreto et al, 2001;Montoya et al, 2010). The fact that the field samples displayed a different toxin profile than the local A. tamarense isolates, may be due to a 3-months delay of the sample transport from Argentina to the laboratory in Germany.…”

Intraregional variation among Alexandrium catenella (Dinophyceae) strains from southern Chile: Morphological, toxicological and genetic diversity

“…Most of the available information is related to morphological, toxicological and/or molecular data for the A. tamarense species complex from New Zealand (Mackenzie et al, 2004), South Africa (Ruiz-Sebastiá n et al, 2005;Pitcher et al, 2007), Australia (Bolch and de Salas, 2007), Argentina and Brazil (Persich et al, 2006;Montoya et al, 2010). In general, these studies have contributed to interpret the local species in the context of global diversity, showing that the presence of each species could be part of a wider paleogeographical pattern (John et al, 2003) or explained by a recent introduction or a natural range expansion from a neighboring region (Bolch and de Salas, 2007).…”

“…Nevertheless, most of these studies are based on only a few isolates of each species, which limits their conclusions or the possibility of finding hidden distribution patterns. For instance, when several isolates from the same region have been included in a study, better evidence about introduced species was obtained (Penna et al, 2005;Bolch and de Salas, 2007) and unexpected patterns of diversity were found (e.g., Montoya et al, 2010).…”

Bioactive compounds of marine dinoflagellate isolates from western Greenland and their phylogenetic association within the genus Alexandrium

“…These findings are surprising in the sense that the Alexandrium tamarense species complex typically produces high molar relative amounts of the N-sulfocarbamoyl B-and C-toxins in natural populations and cultured isolates from many regions of the world (Cembella, 1998), including the south Atlantic (Montoya et al, 2010), north Atlantic and North Sea (Brown et al, 2010), south Pacific (Contreras et al, 2012), and the northeastern (Gu et al, 2013a) and northwestern (Cembella et al, 1987) Pacific. This general pattern is also consistent within A. tamarense Group I ribotype strains from the western Arctic (Chukchi Sea), where the N-sulfocarbamoyl toxin C2 dominated, followed by STX and GTX2/ 3, with lesser amounts of GTX1/4 and NEO in decreasing relative molar ratios (Gu et al, 2013b).…”