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Berry O, Briand E, Bagot A, Chaigné M, Meslet-Cladière L, Wang J, Grovel O, Jansen JJ, Ruiz N, du Pont TR, Pouchus YF, Hess P, Bertrand S. Deciphering interactions between the marine dinoflagellate Prorocentrum lima and the fungus Aspergillus pseudoglaucus. Environ Microbiol 2023; 25:250-267. [PMID: 36333915 PMCID: PMC10100339 DOI: 10.1111/1462-2920.16271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 10/28/2022] [Indexed: 11/07/2022]
Abstract
The comprehension of microbial interactions is one of the key challenges in marine microbial ecology. This study focused on exploring chemical interactions between the toxic dinoflagellate Prorocentrum lima and a filamentous fungal species, Aspergillus pseudoglaucus, which has been isolated from the microalgal culture. Such interspecies interactions are expected to occur even though they were rarely studied. Here, a co-culture system was designed in a dedicated microscale marine-like condition. This system allowed to explore microalgal-fungal physical and metabolic interactions in presence and absence of the bacterial consortium. Microscopic observation showed an unusual physical contact between the fungal mycelium and dinoflagellate cells. To delineate specialized metabolome alterations during microalgal-fungal co-culture metabolomes were monitored by high-performance liquid chromatography coupled to high-resolution mass spectrometry. In-depth multivariate statistical analysis using dedicated approaches highlighted (1) the metabolic alterations associated with microalgal-fungal co-culture, and (2) the impact of associated bacteria in microalgal metabolome response to fungal interaction. Unfortunately, only a very low number of highlighted features were fully characterized. However, an up-regulation of the dinoflagellate toxins okadaic acid and dinophysistoxin 1 was observed during co-culture in supernatants. Such results highlight the importance to consider microalgal-fungal interactions in the study of parameters regulating toxin production.
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Affiliation(s)
- Olivier Berry
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
| | | | - Alizé Bagot
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
- IFREMER, PHYTOX, Nantes, France
| | - Maud Chaigné
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
- IFREMER, PHYTOX, Nantes, France
| | - Laurence Meslet-Cladière
- Univ Brest, INRAE, Laboratoire Universitaire de Biodiversité et Écologie Microbienne, Plouzané, France
| | - Julien Wang
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
| | - Olivier Grovel
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
| | - Jeroen J Jansen
- Radboud University, Institute for Molecules and Materials, Nijmegen, The Netherlands
| | - Nicolas Ruiz
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
| | - Thibaut Robiou du Pont
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
| | - Yves François Pouchus
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
| | | | - Samuel Bertrand
- Institut des Substances et Organismes de la Mer, ISOMer, Nantes Université, UR 2160, Nantes, France
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Zhang D, Liu S, Zhang J, Zhang JK, Hu C, Liu Y. In vivo effects of Aphanizomenon flos-aquae DC-1 aphantoxins on gas exchange and ion equilibrium in the zebrafish gill. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 177:484-493. [PMID: 27424100 DOI: 10.1016/j.aquatox.2016.06.024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 06/27/2016] [Accepted: 06/28/2016] [Indexed: 06/06/2023]
Abstract
Aphantoxins, neurotoxins or paralytic shellfish poisons (PSPs) generated by Aphanizomenon flos-aquae, are a threat to environmental safety and human health in eutrophic waters worldwide. The molecular mechanisms of neurotoxin function have been studied; however, the effects of these neurotoxins on oxidative stress, ion transport, gas exchange, and branchial ultrastructure in fish gills are not fully understood. Aphantoxins extracted from A. flos-aquae DC-1 were detected by high-performance liquid chromatography. The major ingredients were gonyautoxins 1 and 5 and neosaxitoxin, which comprised 34.04%, 21.28%, and 12.77% of the total, respectively. Zebrafish (Danio rerio) were administered A. flos-aquae DC-1 aphantoxins at 5.3 or 7.61μg saxitoxin equivalents (eq)/kg (low and high doses, respectively) by intraperitoneal injection. The activities of Na(+)-K(+)-ATPase (NKA), carbonic anhydrase (CA), and lactate dehydrogenase (LDH), ultrastructural alterations in chloride and epithelial cells, and reactive oxygen species (ROS) and total antioxidative capacity (T-AOC) were investigated in the gills during the first 24h after exposure. Aphantoxins significantly increased the level of ROS and decreased the T-AOC in zebrafish gills from 3 to 12h post-exposure, suggesting an induction of oxidative stress and inhibition of antioxidant capacity. Reduced activities of NKA and CA demonstrated abnormal ion transport and gas exchange in the gills of aphantoxin-treated fish. Toxin administration also resulted in increased LDH activity and ultrastructural alterations in chloride and epithelial cells, suggesting a disruption of function and structure in zebrafish gills. The observed abnormalities in zebrafish gills occurred in a time- and dose-dependent manner. These findings demonstrate that aphantoxins or PSPs may inhibit ion transport and gas exchange, increase LDH activity, and result in ultrastructural damage to the gills through elevations in oxidative stress and reduced antioxidant capacity. These effects of aphantoxins in the gills of zebrafish suggest an induction of respiratory toxicity. The parameters investigated in this study may be also considered as biomarkers for studying aphantoxin/PSP exposure and cyanobacterial blooms in nature.
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Affiliation(s)
- Delu Zhang
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China.
| | - Siyi Liu
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China
| | - Jing Zhang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Jian Kong Zhang
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China
| | - Chunxiang Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
| | - Yongding Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
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Zhang DL, Liu SY, Zhang J, Zhang JK, Hu CX, Liu YD. Respiratory toxicity of cyanobacterial aphantoxins from Aphanizomenon flos-aquae DC-1 in the zebrafish gill. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2016; 176:106-115. [PMID: 27130970 DOI: 10.1016/j.aquatox.2016.04.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 04/12/2016] [Accepted: 04/13/2016] [Indexed: 06/05/2023]
Abstract
Aphantoxins from Aphanizomenon flos-aquae are frequently identified in eutrophic waterbodies worldwide. These toxins severely endanger environmental safety and human health due to the production of paralytic shellfish poisons (PSPs). Although the molecular mechanisms of aphantoxin neurotoxicity have been studied, many questions remain to be resolved such as in vivo alterations in branchial histology and neurotransmitter inactivation induced by these neurotoxins. Aphantoxins extracted from a naturally isolated strain of A. flos-aquae DC-1 were determined by high performance liquid chromatography. The basic components of the isolated aphantoxins identified were gonyautoxin 1 (GTX1), gonyautoxin 5 (GTX5), and neosaxitoxin (neoSTX), which comprised 34.04, 21.28, and 12.77% of the total, respectively. Zebrafish (Danio rerio) was administrated 5.3 or 7.61mg STX equivalents (eq)/kg (low and high doses, respectively) of the A. flos-aquae DC-1 aphantoxins by intraperitoneal injection. Histological alterations and changes in neurotransmitter inactivation in the gills of zebrafish were investigated for 24h following exposure. Aphantoxin exposure significantly increased the activities of gill alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and resulted in histological alterations in the gills during the first 12h of exposure, indicating the induction of functional and structural damage. Gill acetylcholinesterase (AChE) and monoamine oxidase (MAO) activities were inhibited significantly, suggesting an alteration of neurotransmitter inactivation in zebrafish gills. The observed alterations in gill structure and function followed a time- and dose-dependent pattern. The results demonstrate that aphantoxins or PSPs lead to structural damage and altered function in the gills of zebrafish, including changes in histological structure and increases in the activities of AST and ALT. The inhibition of the activities of AChE and MAO suggest that aphantoxins or PSPs could induce respiratory toxicity in the zebrafish gill. Furthermore, these parameters may be used as bioindicators for investigating aphantoxin exposure and cyanobacterial blooms in nature.
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Affiliation(s)
- De Lu Zhang
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China.
| | - Si Yi Liu
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China
| | - Jing Zhang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Jian Kun Zhang
- Department of Lifescience and Biotechnology, College of Chemistry, Chemical Engineering and Life Sciences, Wuhan University of Technology, Wuhan 430070, PR China
| | - Chun Xiang Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
| | - Yong Ding Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
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Zhang DL, Liu SY, Zhang J, Hu CX, Li DH, Liu YD. Antioxidative responses in zebrafish liver exposed to sublethal doses Aphanizomenon flos-aquae DC-1 aphantoxins. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2015; 113:425-432. [PMID: 25544652 DOI: 10.1016/j.ecoenv.2014.12.029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Revised: 12/15/2014] [Accepted: 12/16/2014] [Indexed: 06/04/2023]
Abstract
Aphanizomenon flos-aquae secretes paralytic shellfish poisons (PSPs), termed aphantoxins, and endangers environmental and human health via eutrophication of water worldwide. Although the molecular mechanism of neuronal PSP toxicity has been well studied, several issues remain unresolved, notably the in vivo hepatic antioxidative responses to this neurotoxin. Aphantoxins extracted from a natural isolate of A. flos-aquae DC-1 were resolved by high performance liquid chromatography. The primary components were gonyautoxins 1 and 5 and neosaxitoxin. Zebrafish (Danio rerio) were treated intraperitoneally with either 5.3 or 7.61 (low and high doses, respectively) μg saxitoxin (STX) equivalents (eq)/kg of A. flos-aquae DC-1 aphantoxins. Antioxidative responses in zebrafish liver were examined at different timepoints 1-24h post-exposure. Aphantoxin administration significantly enhanced hepatic malondialdehyde (MDA) content 1-12h post-exposure, indicative of oxidative stress and lipid peroxidation. By contrast, levels of reduced glutathione (GSH) in zebrafish liver declined significantly after 3-24h exposure, suggesting that GSH participates in MDA metabolism. A significant upregulation of the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) was observed, suggesting that aphantoxins induce lipid peroxidation in zebrafish liver and are likely to be hepatotoxic. Hepatic levels of MDA and GSH, and of the three enzymes (SOD, CAT, and GPx), therefore provide potential biomarkers for studying environmental exposure to aphantoxins/PSPs from cyanobacterial blooms.
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Affiliation(s)
- De Lu Zhang
- Department of Lifescience and Biotechnology, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, PR China.
| | - Si Yi Liu
- Department of Lifescience and Biotechnology, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, PR China
| | - Jing Zhang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Chun Xiang Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
| | - Dun Hai Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Yong Ding Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
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5
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Zhang DL, Zhang J, Hu CX, Wang GH, Li DH, Liu YD. Morphological alterations and acetylcholinesterase and monoamine oxidase inhibition in liver of zebrafish exposed to Aphanizomenon flos-aquae DC-1 aphantoxins. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2014; 157:215-224. [PMID: 25456236 DOI: 10.1016/j.aquatox.2014.10.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 10/18/2014] [Accepted: 10/21/2014] [Indexed: 06/04/2023]
Abstract
Aphanizomenon flos-aquae is a cyanobacterium that produces neurotoxins or paralytic shellfish poisons (PSPs) called aphantoxins, which present threats to environmental safety and human health via eutrophication of water bodies worldwide. Although the molecular mechanisms of this neurotoxin have been studied, many questions remain unsolved, including those relating to in vivo hepatic neurotransmitter inactivation, physiological detoxification and histological and ultrastructural alterations. Aphantoxins extracted from the natural strain of A. flos-aquae DC-1 were analyzed by high-performance liquid chromatography. The main components were gonyautoxins 1 and 5 (GTX1, GTX5) and neosaxitoxin (neoSTX), which comprised 34.04%, 21.28%, and 12.77% respectively. Zebrafish (Danio rerio) were exposed intraperitoneally to 5.3 or 7.61 μg STX equivalents (eq)/kg (low and high doses, respectively) of A. flos-aquae DC-1 aphantoxins. Morphological alterations and changes in neurotransmitter conduction functions of acetylcholinesterase (AChE) and monoamine oxidase (MAO) in zebrafish liver were detected at different time points 1-24h post-exposure. Aphantoxin significantly enhanced hepatic alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities and histological and ultrastructural damage in zebrafish liver at 3-12 h post-exposure. Toxin exposure increased the reactive oxygen species content and reduced total antioxidative capacity in zebrafish liver, suggesting oxidative stress. AChE and MAO activities were significantly inhibited, suggesting neurotransmitter inactivation/conduction function abnormalities in zebrafish liver. All alterations were dose- and time-dependent. Overall, the results indicate that aphantoxins/PSPs induce oxidative stress through inhibition of AChE and MAO activities, leading to neurotoxicity in zebrafish liver. The above parameters may be useful as bioindicators for investigating aphantoxins/PSPs and cyanobacterial blooms in nature.
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Affiliation(s)
- De Lu Zhang
- Department of Lifescience and Biotechnology, School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, Wuhan 430070, PR China.
| | - Jing Zhang
- College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, PR China
| | - Chun Xiang Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China.
| | - Gao Hong Wang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Dun Hai Li
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
| | - Yong Ding Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, PR China
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6
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Zhang DL, Hu CX, Li DH, Liu YD. Zebrafish locomotor capacity and brain acetylcholinesterase activity is altered by Aphanizomenon flos-aquae DC-1 aphantoxins. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2013; 138-139:139-149. [PMID: 23792258 DOI: 10.1016/j.aquatox.2013.04.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/20/2013] [Accepted: 04/22/2013] [Indexed: 06/02/2023]
Abstract
Aphanizomenon flos-aquae (A. flos-aquae) is a source of neurotoxins known as aphantoxins or paralytic shellfish poisons (PSPs) that present a major threat to the environment and to human health. Generally, altered neurological function is reflected in behavior. Although the molecular mechanism of action of PSPs is well known, its neurobehavioral effects on adult zebrafish and its relationship with altered neurological functions are poorly understood. Aphantoxins purified from a natural isolate of A. flos-aquae DC-1 were analyzed by HPLC. The major analogs found in the toxins were the gonyautoxins 1 and 5 (GTX1 and GTX5; 34.04% and 21.28%, respectively) and the neosaxitoxin (neoSTX, 12.77%). Zebrafish (Danio rerio) were intraperitoneally injected with 5.3 and 7.61 μg STXeq/kg (low and high dose, respectively) of A. flos-aquae DC-1 aphantoxins. The swimming activity was investigated by observation combined with video at 6 timepoints from 1 to 24 h post-exposure. Both aphantoxin doses were associated with delayed touch responses, reduced head-tail locomotory abilities, inflexible turning of head, and a tailward-shifted center of gravity. The normal S-pattern (or undulating) locomotor trajectory was replaced by a mechanical motor pattern of swinging the head after wagging the tail. Finally, these fish principally distributed at the top and/or bottom water of the aquarium, and showed a clear polarized distribution pattern at 12 h post-exposure. Further analysis of neurological function demonstrated that both aphantoxin doses inhibited brain acetylcholinesterase activity. All these changes were dose- and time-dependent. These results demonstrate that aphantoxins can alter locomotor capacity, touch responses and distribution patterns by damaging the cholinergic system of zebrafish, and suggest that zebrafish locomotor behavior and acetylcholinesterase can be used as indicators for investigating aphantoxins and blooms in nature.
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Affiliation(s)
- De Lu Zhang
- Department of Lifescience and Biotechnology, College of Science, Wuhan University of Technology, Wuhan 430070, PR China.
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Stüken A, Orr RJS, Kellmann R, Murray SA, Neilan BA, Jakobsen KS. Discovery of nuclear-encoded genes for the neurotoxin saxitoxin in dinoflagellates. PLoS One 2011; 6:e20096. [PMID: 21625593 PMCID: PMC3097229 DOI: 10.1371/journal.pone.0020096] [Citation(s) in RCA: 153] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2011] [Accepted: 04/12/2011] [Indexed: 11/26/2022] Open
Abstract
Saxitoxin is a potent neurotoxin that occurs in aquatic environments worldwide.
Ingestion of vector species can lead to paralytic shellfish poisoning, a severe
human illness that may lead to paralysis and death. In freshwaters, the toxin is
produced by prokaryotic cyanobacteria; in marine waters, it is associated with
eukaryotic dinoflagellates. However, several studies suggest that saxitoxin is
not produced by dinoflagellates themselves, but by co-cultured bacteria. Here,
we show that genes required for saxitoxin synthesis are encoded in the nuclear
genomes of dinoflagellates. We sequenced >1.2×106 mRNA
transcripts from the two saxitoxin-producing dinoflagellate strains
Alexandrium fundyense CCMP1719 and A.
minutum CCMP113 using high-throughput sequencing technology. In
addition, we used in silico transcriptome analyses, RACE, qPCR
and conventional PCR coupled with Sanger sequencing. These approaches
successfully identified genes required for saxitoxin-synthesis in the two
transcriptomes. We focused on sxtA, the unique starting gene of
saxitoxin synthesis, and show that the dinoflagellate transcripts of
sxtA have the same domain structure as the cyanobacterial
sxtA genes. But, in contrast to the bacterial homologs, the
dinoflagellate transcripts are monocistronic, have a higher GC content, occur in
multiple copies, contain typical dinoflagellate spliced-leader sequences and
eukaryotic polyA-tails. Further, we investigated 28 saxitoxin-producing and
non-producing dinoflagellate strains from six different genera for the presence
of genomic sxtA homologs. Our results show very good agreement
between the presence of sxtA and saxitoxin-synthesis, except in
three strains of A. tamarense, for which we amplified
sxtA, but did not detect the toxin. Our work opens for
possibilities to develop molecular tools to detect saxitoxin-producing
dinoflagellates in the environment.
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Affiliation(s)
- Anke Stüken
- Microbial Evolution Research Group (MERG), Department of Biology,
University of Oslo, Oslo, Norway
| | - Russell J. S. Orr
- Microbial Evolution Research Group (MERG), Department of Biology,
University of Oslo, Oslo, Norway
| | - Ralf Kellmann
- Department of Molecular Biology, University of Bergen, Bergen,
Norway
| | - Shauna A. Murray
- School of Biotechnology and Biomolecular Sciences and Australian Centre
for Astrobiology, University of New South Wales, Sydney, Australia
- Sydney Institute of Marine Sciences, Mosman, New South Wales,
Australia
| | - Brett A. Neilan
- School of Biotechnology and Biomolecular Sciences and Australian Centre
for Astrobiology, University of New South Wales, Sydney, Australia
- Sydney Institute of Marine Sciences, Mosman, New South Wales,
Australia
| | - Kjetill S. Jakobsen
- Microbial Evolution Research Group (MERG), Department of Biology,
University of Oslo, Oslo, Norway
- Department of Biology, Centre for Ecological and Evolutionary Synthesis
(CEES), University of Oslo, Oslo, Norway
- * E-mail:
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Dittmar T, Zänker KS. Horizontal gene transfers with or without cell fusions in all categories of the living matter. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2011; 714:5-89. [PMID: 21506007 PMCID: PMC7120942 DOI: 10.1007/978-94-007-0782-5_2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
This article reviews the history of widespread exchanges of genetic segments initiated over 3 billion years ago, to be part of their life style, by sphero-protoplastic cells, the ancestors of archaea, prokaryota, and eukaryota. These primordial cells shared a hostile anaerobic and overheated environment and competed for survival. "Coexist with, or subdue and conquer, expropriate its most useful possessions, or symbiose with it, your competitor" remain cellular life's basic rules. This author emphasizes the role of viruses, both in mediating cell fusions, such as the formation of the first eukaryotic cell(s) from a united crenarchaeon and prokaryota, and the transfer of host cell genes integrated into viral (phages) genomes. After rising above the Darwinian threshold, rigid rules of speciation and vertical inheritance in the three domains of life were established, but horizontal gene transfers with or without cell fusions were never abolished. The author proves with extensive, yet highly selective documentation, that not only unicellular microorganisms, but the most complex multicellular entities of the highest ranks resort to, and practice, cell fusions, and donate and accept horizontally (laterally) transferred genes. Cell fusions and horizontally exchanged genetic materials remain the fundamental attributes and inherent characteristics of the living matter, whether occurring accidentally or sought after intentionally. These events occur to cells stagnating for some 3 milliard years at a lower yet amazingly sophisticated level of evolution, and to cells achieving the highest degree of differentiation, and thus functioning in dependence on the support of a most advanced multicellular host, like those of the human brain. No living cell is completely exempt from gene drains or gene insertions.
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Affiliation(s)
- Thomas Dittmar
- Inst. Immunologie, Universität Witten/Herdecke, Stockumer Str. 10, Witten, 58448 Germany
| | - Kurt S. Zänker
- Institute of Immunologie, University of Witten/Herdecke, Stockumer Str. 10, Witten, 58448 Germany
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Sieg RD, Poulson-Ellestad KL, Kubanek J. Chemical ecology of the marine plankton. Nat Prod Rep 2011; 28:388-99. [DOI: 10.1039/c0np00051e] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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10
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Wiese M, D’Agostino PM, Mihali TK, Moffitt MC, Neilan BA. Neurotoxic alkaloids: saxitoxin and its analogs. Mar Drugs 2010; 8:2185-211. [PMID: 20714432 PMCID: PMC2920551 DOI: 10.3390/md8072185] [Citation(s) in RCA: 429] [Impact Index Per Article: 30.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 07/12/2010] [Accepted: 07/16/2010] [Indexed: 11/25/2022] Open
Abstract
Saxitoxin (STX) and its 57 analogs are a broad group of natural neurotoxic alkaloids, commonly known as the paralytic shellfish toxins (PSTs). PSTs are the causative agents of paralytic shellfish poisoning (PSP) and are mostly associated with marine dinoflagellates (eukaryotes) and freshwater cyanobacteria (prokaryotes), which form extensive blooms around the world. PST producing dinoflagellates belong to the genera Alexandrium, Gymnodinium and Pyrodinium whilst production has been identified in several cyanobacterial genera including Anabaena, Cylindrospermopsis, Aphanizomenon Planktothrix and Lyngbya. STX and its analogs can be structurally classified into several classes such as non-sulfated, mono-sulfated, di-sulfated, decarbamoylated and the recently discovered hydrophobic analogs--each with varying levels of toxicity. Biotransformation of the PSTs into other PST analogs has been identified within marine invertebrates, humans and bacteria. An improved understanding of PST transformation into less toxic analogs and degradation, both chemically or enzymatically, will be important for the development of methods for the detoxification of contaminated water supplies and of shellfish destined for consumption. Some PSTs also have demonstrated pharmaceutical potential as a long-term anesthetic in the treatment of anal fissures and for chronic tension-type headache. The recent elucidation of the saxitoxin biosynthetic gene cluster in cyanobacteria and the identification of new PST analogs will present opportunities to further explore the pharmaceutical potential of these intriguing alkaloids.
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Affiliation(s)
- Maria Wiese
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails: (M.W.); (T.K.M.)
| | - Paul M. D’Agostino
- School of Biomedical and Health Sciences, University of Western Sydney, Campbelltown, NSW, 2560, Australia; E-Mails: (P.M.D.); (M.C.M.)
| | - Troco K. Mihali
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails: (M.W.); (T.K.M.)
| | - Michelle C. Moffitt
- School of Biomedical and Health Sciences, University of Western Sydney, Campbelltown, NSW, 2560, Australia; E-Mails: (P.M.D.); (M.C.M.)
| | - Brett A. Neilan
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia; E-Mails: (M.W.); (T.K.M.)
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