title: Morphology, molecular phylogeny and azaspiracid profile of Azadinium poporum (Dinophyceae) from the Gulf of Mexico.
abstract: Azadinium poporum produces a variety of azaspiracids and consists of several ribotypes, but information on its biogeography is limited. A strain of A. poporum (GM29) was incubated from a Gulf of Mexico sediment sample. Strain GM29 was characterized by a plate pattern of po, cp, x, 4', 3a, 6″, 6C, 5S, 6‴, 2⁗, a distinct ventral pore at the junction of po and the first two apical plates, and a lack of an antapical spine, thus fitting the original description of A. poporum. The genus Azadinium has not been reported in waters of the United States of America before this study. Molecular phylogeny, based on large subunit ribosomal DNA (LSU rDNA) and internal transcribed spacer (ITS) sequences, reveals that strain GM29 is nested within the well-resolved A. poporum complex, but forms a sister clade either to ribotype B (ITS) or ribotype C (LSU). It is, therefore, designated as a new ribotype, termed as ribotype D. LSU and ITS sequences similarity among different ribotypes of A. poporum ranges from 95.4% to 98.2%, and from 97.1% to 99.2% respectively, suggesting that the LSU fragment is a better candidate for molecular discrimination. Azaspiracid profiles were analyzed using LC-MS/MS and demonstrate that strain GM29 produces predominantly AZA-2 with an amount of 45fg/cell. The results suggest that A. poporum has a wide distribution and highlights the risk potential of azaspiracid intoxication in the United States.
authors.affiliation: College of Life Science and Technology, Jinan University, Guangzhou 510632, China; Third Institute of Oceanography, SOA, Xiamen 361005, China.
authors.forename: Zhaohe
authors.initials: Z
authors.lastname: Luo
authors.affiliation: Alfred Wegener Institute for Polar and Marine Research, Am Handelshafen 12, D-27570 Bremerhaven, Germany. Electronic address: bernd.krock@awi.de.
authors.forename: Bernd
authors.initials: B
authors.lastname: Krock
authors.affiliation: Research Unit for Palaeontology, Ghent University, Krijgslaan 281 S8, 9000 Ghent, Belgium.
authors.forename: Kenneth Neil
authors.initials: KN
authors.lastname: Mertens
authors.affiliation: Department of Geography, McGill University, Burnside Hall, 805 Sherbrooke Street West, Montreal, QC, Canada H3A OB9.
authors.forename: Andrea Michelle
authors.initials: AM
authors.lastname: Price
authors.affiliation: Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA 70803, USA.
authors.forename: Robert Eugene
authors.initials: RE
authors.lastname: Turner
authors.affiliation: Louisiana Universities Marine Consortium, Chauvin, LA 70344, USA.
authors.forename: Nancy N
authors.initials: NN
authors.lastname: Rabalais
authors.affiliation: Third Institute of Oceanography, SOA, Xiamen 361005, China. Electronic address: guhaifeng@tio.org.cn.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Gu
mesh_terms: D004275:DNA, Ribosomal / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D004141:Dinoflagellida / Q000737:chemistry / Q000145:classification / Q000166:cytology / Q000235:genetics; D060851:Gulf of America; D008387:Marine Toxins / Q000737:chemistry*; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013141:Spiro Compounds / Q000737:chemistry*; D000095702:Polyether Toxins
chemical_list: D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D008387:Marine Toxins; D013141:Spiro Compounds; C406592:azaspiracid; D000095702:Polyether Toxins
keywords: AZA-2; AZA-2 phosphate; Biogeography; LC–MS/MS; LSU rDNA; Ribotype D