Cyanobacteria are well known producers of bioactive metabolites, including harmful substances. The recently discovered "eagle killer" neurotoxin aetokthonotoxin (AETX) is produced by the epiphytic cyanobacterium Aetokthonos hydrillicola growing on invasive water thyme (Hydrilla verticillata). The biosynthetic gene cluster of AETX was previously identified from an Aetokthonos strain isolated from the J. Strom Thurmond Reservoir, Georgia, USA. Here, a PCR protocol for easy detection of AETX-producers in environmental samples of plant-cyanobacterium consortia was designed and tested. Three different loci of the AETX gene cluster were amplified to confirm the genetic potential for AETX production, along with two variable types of rRNA ITS regions to confirm the homogeneity of the producer´s taxonomic identity. In samples of Hydrilla from three Aetokthonos-positive reservoirs and one Aetokthonos-negative lake, the PCR of all four loci provided results congruent with the Aetokthonos presence/absence detected by light and fluorescence microscopy. The production of AETX in the Aetokthonos-positive samples was confirmed using LC-MS. Intriguingly, in J. Strom Thurmond Reservoir, recently Hydrilla free, an Aetokthonos-like cyanobacterium was found growing on American water-willow (Justicia americana). Those specimens were positive for all three aet markers but contained only minute amounts of AETX. The obtained genetic information (ITS rRNA sequence) and morphology of the novel Aetokthonos distinguished it from all the Hydrilla-hosted A. hydrillicola, likely at the species level. Our results suggest that the toxigenic Aetokthonos spp. can colonize a broader array of aquatic plants, however the level of accumulation of the toxin may be driven by host-specific interactions such as the locally hyper-accumulated bromide in Hydrilla.

• Klíčová slova
• Aetokthonos, Cyanotoxin, Hydrilla, Justicia, Vacuolar myelinopathy, rRNA ITS,
• MeSH
• chromatografie kapalinová MeSH
• hmotnostní spektrometrie MeSH
• jezera * MeSH
• polymerázová řetězová reakce MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aetokthonotoxin MeSH Prohlížeč

Vacuolar myelinopathy is a fatal neurological disease that was initially discovered during a mysterious mass mortality of bald eagles in Arkansas in the United States. The cause of this wildlife disease has eluded scientists for decades while its occurrence has continued to spread throughout freshwater reservoirs in the southeastern United States. Recent studies have demonstrated that vacuolar myelinopathy is induced by consumption of the epiphytic cyanobacterial species Aetokthonos hydrillicola growing on aquatic vegetation, primarily the invasive Hydrilla verticillata Here, we describe the identification, biosynthetic gene cluster, and biological activity of aetokthonotoxin, a pentabrominated biindole alkaloid that is produced by the cyanobacterium A. hydrillicola We identify this cyanobacterial neurotoxin as the causal agent of vacuolar myelinopathy and discuss environmental factors-especially bromide availability-that promote toxin production.

• MeSH
• Accipitridae * MeSH
• bakteriální geny MeSH
• bakteriální toxiny biosyntéza   chemie   izolace a purifikace   toxicita   MeSH
• brom analýza   MeSH
• bromidy metabolismus   MeSH
• Caenorhabditis elegans účinky léků   MeSH
• dánio pruhované MeSH
• demyelinizační nemoci chemicky indukované   veterinární   MeSH
• Hydrocharitaceae metabolismus   mikrobiologie   MeSH
• indolové alkaloidy chemie   izolace a purifikace   toxicita   MeSH
• kur domácí MeSH
• LD50 MeSH
• multigenová rodina MeSH
• nemoci ptáků chemicky indukované   MeSH
• neurotoxiny biosyntéza   chemie   izolace a purifikace   toxicita   MeSH
• sinice * genetika   růst a vývoj   metabolismus   MeSH
• tryptofan metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, P.H.S. MeSH
• Geografické názvy
• jihovýchod USA MeSH
• Názvy látek
• bakteriální toxiny MeSH
• brom MeSH
• bromidy MeSH
• indolové alkaloidy MeSH
• neurotoxiny MeSH
• tryptofan MeSH