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. 2023 Jan;70(1):e12929.
doi: 10.1111/jeu.12929. Epub 2022 Jun 20.

Sterols of Testudodinium testudo (formerly Amphidinium testudo): Production of the Δ8 (14) sterol gymnodinosterol and chemotaxonomic relationship to the Kareniaceae

Jeffrey D Leblond  1 , Lindsey C Elkins  1 , Kyra Sabir  1 , Jori E Graeff  1
Affiliations

Sterols of Testudodinium testudo (formerly Amphidinium testudo): Production of the Δ8 (14) sterol gymnodinosterol and chemotaxonomic relationship to the Kareniaceae

Jeffrey D Leblond et al. J Eukaryot Microbiol. 2023 Jan.

Abstract

Testudodinium testudo is a peridinin-containing dinoflagellate recently renamed from Amphidinium testudo. While T. testudo has been shown via phylogenetic analysis of small subunit ribosomal RNA genes to reside in a clade separate from the genus Amphidinium, it does possess morphological features similar to Amphidinium sensu stricto. Previous studies of Amphidinium carterae and Amphidinium corpulentum have found the sterols to be enriched in Δ8(14) sterols, such as 4α-methyl-5α-ergosta-8(14),24(28)-dien-3β-ol (amphisterol), uncommon to most other dinoflagellate taxa and thus considered possible biomarkers for the genus Amphidinium. Here, we provide an examination of the sterols of T. testudo and show they are dominated not by amphisterol, but rather by a different Δ8(14) sterol, (24R)-4α-methyl-5α-ergosta-8(14),22-dien-3β-ol (gymnodinosterol), previously thought to be a major sterol only within the Kareniaceae genera Karenia, Karlodinium, and Takayama. Also found to be present at low levels were 4α-methyl-5α-ergosta-8,14,22-trien-3β-ol, a sterol previously observed in Karenia brevis to be an intermediate in the production of gymnodinosterol, and cholesterol, a sterol common to many other dinoflagellates. The presence of gymnodinosterol in T. testudo is the first report of this sterol as the sole major sterol in a dinoflagellate outside of the Kareniaceae. The implication of this chemotaxonomic relationship to the Kareniaceae is discussed.

Keywords: Amphidinium; Testudodinium; Dinophyceae; dinoflagellate; lipid; sterol.

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References

REFERENCES

    1. Borchhardt, N., Chomerát, N., Bilien, G., Zentz, F., Rhodes, L., Murray, S.A. et al. (2021) Morphology and molecular phylogeny of Bindiferia gen. nov. (Dinophyceae), a new marine, sand-dwelling dinoflagellate genus formerly classified within Amphidinium. Phycologia, 60, 631-643.
    1. Calada, A.J. & Moestrup, Ø. (2005) On the freshwater dinoflagellates presently included in the genus Amphidinium, with a description of Prosoaulax gen. nov. Phycologia, 44, 112-119.
    1. Chu, F.-L.E., Lund, E.D., Littreal, P.R., Ruck, K.E. & Harvey, E. (2009) Species-specific differences in long-chain n-3 essential fatty acid, sterol, and steroidal ketone production in six heterotrophic protist species. Aquatic Biology, 6, 159-172.
    1. Dufourc, E.J. (2008) Sterols and membrane dynamics. Journal of Chemical Biology, 1, 63-77.
    1. Flø Jørgensen, M., Murray, S. & Daugbjerg, N. (2004a) Amphidinium revisited. I. Redefinition of Amphidinium (Dinophyceae) based on cladistic and molecular phylogenetic analyses. Journal of Phycology, 40, 351-365.