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Toxin Profiles (toxin + profile)

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Life Sciences100%

Selected Abstracts

Genetic Diversity: Geographical Distribution and Toxin Profiles of Microcystis Strains (Cyanobacteria) in China

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 3 2007
Zhong-Xing Wu
Abstract Twenty strains of Microcystis Kütz were isolated from different freshwater bodies in China to analyze the diversity, geographical distribution and toxin profiles. Based on whole-cell polymerase chain reaction of cpcBA-IGS nucleotide sequence, the derived neighbor-joining (NJ) and maximum parsimony (MP) trees indicate that these strains of Microcystis can be divided into four clusters. The strains from south, middle and north region of China formed distinct lineages, suggesting high diversity and a geographical distribution from south to north locations. Moreover, the results being indicating high variable genotypes of the strains of the Microcystis strains from the same lake show that there is high diversity of Microcystis within a water bloom population. Comparing the results of the present study with those reported for compared with 43 strains of Microcystis from other locations, also reveals Chinese strains have high similarity with those from regions in the North Hemispherical. This suggests that the Microcystis strains in the world might have a geographical distribution. Analysis of 30 strains using the primers MCF/TER and TOX2P/TOX2M showed that there was no correlation between the gene of cpcBA-IGS and the presence of mcy. Toxic strains were founded to be predominant in different water bodies throughout China. [source]

Geographic differences in paralytic shellfish poisoning toxin profiles among Japanese populations of Alexandrium tamarense and A. catenella (Dinophyceae)

PHYCOLOGICAL RESEARCH, Issue 1 2001
Takashi Yoshida
SUMMARY To reconsider whether toxin profile could be used as a marker for populations from different geographical areas, clonal isolates of the toxic dinoflagellates Alexandrium tamarense (Lebour) Balech and Alexandrium catenella (Whedon et Kofoid) Balech from Ofunato Bay (Iwate Prefecture), Atsumi Bay (Aichi Prefecture), Tanabe Bay (Wakayama Prefecture), Harima-Nada (Kagawa Prefecture), Uranouchi Bay (Kochi Prefecture), Hiroshima Bay (Hiroshima Prefecture) and Yamakawa Bay (Kagoshima Prefecture), which were identified on the basis of morphotaxonomy, immunological and molecular biological techniques, were subjected to analysis of paralytic shellfish poisoning toxins by high performance liquid chromatography-fluorometric method. All the isolates except A. tamarense OF152 from Ofunato Bay contained mainly N-sulfocarbamoyl toxins (C1 +2) with various amounts of derivatives, and a typical north-to-south trend of decreasing toxicity was observed. In both A. tamarense and A. catenella, toxin profiles were rather constant within a geographical area and divergent among different geographical areas. The toxin profiles of A. tamarense from Harima-Nada were well conserved among different bloom years. Toxin profile showed that isolates of A. tamarense from Ofunato Bay, A. tamarense from Harima-Nada isolated in 1988 and A. catenella from Uranouchi Bay were heterogeneous. However, only two or three groups of isolates with different toxin profiles were observed in a geographical region, suggesting that several representative isolates express the genotype in a given region. These observations confirmed that toxin composition could be used as a marker to discriminate different geographical populations of these species. [source]

In vivo exposure to microcystins induces DNA damage in the haemocytes of the zebra mussel, Dreissena polymorpha, as measured with the comet assay

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2007
Guillaume Juhel
Abstract The Comet assay was used to investigate the potential of the biotoxin microcystin (MC) to induce DNA damage in the freshwater zebra mussel, Dreissena polymorpha. Mussels maintained in the laboratory were fed daily, over a 21-day period, with one of four strains of the cyanobacterium, Microcystis aeruginosa. Three of the strains produced different profiles of MC toxin, while the fourth strain did not produce MCs. The mussels were sampled at 0, 7, 14, and 21 days by withdrawing haemocytes from their adductor muscle. In addition, a positive control was performed by exposing a subsample of the mussels to water containing cadmium chloride (CdCl2). Cell viability, measured with the Fluorescein Diacetate/Ethidium Bromide test, indicated that the MC concentrations, to which the mussels were exposed, were not cytotoxic to the haemocytes. The Comet assay performed on the haemocytes indicated that exposure to CdCl2 produced a dose-responsive increase in DNA damage, demonstrating that mussel haemocytes were sensitive to DNA-damaging agents. DNA damage, measured as percentage tail DNA (%tDNA), was observed in mussels exposed to the three toxic Microcystis strains, but not in mussels exposed to the nontoxic strain. Toxin analysis of the cyanobacterial cultures confirmed that the three MC-producing strains exhibit different toxin profiles, with the two MC variants detected being MC-LF and MC-LR. Furthermore, the DNA damage that was observed appeared to be strain-specific, with high doses of MC-LF being associated with a higher level of genotoxicity than low concentrations of MC-LR. High levels of MC-LF also seemed to induce relatively more persistent DNA damage than small quantities of MC-LR. This study is the first to demonstrate that in vivo exposure to MC-producing strains of cyanobacteria induces DNA damage in the haemocytes of zebra mussels and confirms the sublethal toxicity of these toxins. Environ. Mol. Mutagen., 2007. © 2006 Wiley-Liss, Inc. [source]

Genetic Diversity: Geographical Distribution and Toxin Profiles of Microcystis Strains (Cyanobacteria) in China

JOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 3 2007
Zhong-Xing Wu
Abstract Twenty strains of Microcystis Kütz were isolated from different freshwater bodies in China to analyze the diversity, geographical distribution and toxin profiles. Based on whole-cell polymerase chain reaction of cpcBA-IGS nucleotide sequence, the derived neighbor-joining (NJ) and maximum parsimony (MP) trees indicate that these strains of Microcystis can be divided into four clusters. The strains from south, middle and north region of China formed distinct lineages, suggesting high diversity and a geographical distribution from south to north locations. Moreover, the results being indicating high variable genotypes of the strains of the Microcystis strains from the same lake show that there is high diversity of Microcystis within a water bloom population. Comparing the results of the present study with those reported for compared with 43 strains of Microcystis from other locations, also reveals Chinese strains have high similarity with those from regions in the North Hemispherical. This suggests that the Microcystis strains in the world might have a geographical distribution. Analysis of 30 strains using the primers MCF/TER and TOX2P/TOX2M showed that there was no correlation between the gene of cpcBA-IGS and the presence of mcy. Toxic strains were founded to be predominant in different water bodies throughout China. [source]

Geographic differences in paralytic shellfish poisoning toxin profiles among Japanese populations of Alexandrium tamarense and A. catenella (Dinophyceae)

PHYCOLOGICAL RESEARCH, Issue 1 2001
Takashi Yoshida
SUMMARY To reconsider whether toxin profile could be used as a marker for populations from different geographical areas, clonal isolates of the toxic dinoflagellates Alexandrium tamarense (Lebour) Balech and Alexandrium catenella (Whedon et Kofoid) Balech from Ofunato Bay (Iwate Prefecture), Atsumi Bay (Aichi Prefecture), Tanabe Bay (Wakayama Prefecture), Harima-Nada (Kagawa Prefecture), Uranouchi Bay (Kochi Prefecture), Hiroshima Bay (Hiroshima Prefecture) and Yamakawa Bay (Kagoshima Prefecture), which were identified on the basis of morphotaxonomy, immunological and molecular biological techniques, were subjected to analysis of paralytic shellfish poisoning toxins by high performance liquid chromatography-fluorometric method. All the isolates except A. tamarense OF152 from Ofunato Bay contained mainly N-sulfocarbamoyl toxins (C1 +2) with various amounts of derivatives, and a typical north-to-south trend of decreasing toxicity was observed. In both A. tamarense and A. catenella, toxin profiles were rather constant within a geographical area and divergent among different geographical areas. The toxin profiles of A. tamarense from Harima-Nada were well conserved among different bloom years. Toxin profile showed that isolates of A. tamarense from Ofunato Bay, A. tamarense from Harima-Nada isolated in 1988 and A. catenella from Uranouchi Bay were heterogeneous. However, only two or three groups of isolates with different toxin profiles were observed in a geographical region, suggesting that several representative isolates express the genotype in a given region. These observations confirmed that toxin composition could be used as a marker to discriminate different geographical populations of these species. [source]