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Kohli et al 2015-Gambierdiscus PKS-BMC Genomics .pdf (1.59 MB)

Polyketide synthesis genes associated with toxin production in two species of Gambierdiscus (Dinophyceae)

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posted on 2023-05-18, 16:35 authored by Kohli, GS, John, U, Figueroa, RI, Rhodes, LL, Harwood, DT, Groth, M, Christopher BolchChristopher Bolch, Murray, SA

Background

Marine microbial protists, in particular, dinoflagellates, produce polyketide toxins with ecosystem-wide and human health impacts. Species of Gambierdiscus produce the polyether ladder compounds ciguatoxins and maitotoxins, which can lead to ciguatera fish poisoning, a serious human illness associated with reef fish consumption. Genes associated with the biosynthesis of polyether ladder compounds are yet to be elucidated, however, stable isotope feeding studies of such compounds consistently support their polyketide origin indicating that polyketide synthases are involved in their biosynthesis.

Results

Here, we report the toxicity, genome size, gene content and transcriptome of Gambierdiscus australes and G. belizeanus. G. australes produced maitotoxin-1 and maitotoxin-3, while G. belizeanus produced maitotoxin-3, for which cell extracts were toxic to mice by IP injection (LD50 = 3.8 mg kg-1). The gene catalogues comprised 83,353 and 84,870 unique contigs, with genome sizes of 32.5 ± 3.7 Gbp and 35 ± 0.88 Gbp, respectively, and are amongst the most comprehensive yet reported from a dinoflagellate. We found three hundred and six genes involved in polyketide biosynthesis, including one hundred and ninty-two ketoacyl synthase transcripts, which formed five unique phylogenetic clusters.

Conclusions

Two clusters were unique to these maitotoxin-producing dinoflagellate species, suggesting that they may be associated with maitotoxin biosynthesis. This work represents a significant step forward in our understanding of the genetic basis of polyketide production in dinoflagellates, in particular, species responsible for ciguatera fish poisoning.

Funding

Australian Research Council

History

Publication title

BMC Genomics

Volume

16

Article number

410

Number

410

Pagination

1-10

ISSN

1471-2164

Department/School

Institute for Marine and Antarctic Studies

Publisher

Biomed Central Ltd

Place of publication

Middlesex House, 34-42 Cleveland St, London, England, W1T 4Lb

Rights statement

© 2015 Kohli et al. Licensed under Creative Commons Attribution 4.0 International (CC BY 4) http://creativecommons.org/licenses/by/4.0/

Repository Status

  • Open

Socio-economic Objectives

Fisheries - wild caught not elsewhere classified

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