Ultrastructure and LSU rDNA-based revision of Peridinium group palatinum (Dinophyceae) with the description of Palatinus gen. nov.

TY - JOUR

T1 - Ultrastructure and LSU rDNA-based revision of Peridinium group palatinum (Dinophyceae) with the description of Palatinus gen. nov.

AU - Craveiro, Sandra

AU - Calado, Antonio J.

AU - Daugbjerg, Niels

AU - Moestrup, Øjvind

N1 - KEYWORDS Dinophyceae • Glenodinium apiculatum • LSU rDNA • Palatinus apiculatus • Peridinium palatinum • phylogeny • ultrastructure

PY - 2009

Y1 - 2009

N2 - The name Peridinium palatinum Lauterborn currently designates a freshwater peridinioid with 13 epithecal and six cingular plates, and no apical pore complex. Freshwater dinoflagellate floras classify it in Peridinium group palatinum together with P. pseudolaeve M. Lefèvre. General ultrastructure, flagellar apparatus, and pusular components of P. palatinum were examined by serial section TEM and compared to P. cinctum (O. F. Müll.) Ehrenb. and Peridiniopsis borgei Lemmerm., respectively, types of Peridinium and Peridiniopsis. Partial LSU rDNA sequences from P. palatinum, P. pseudolaeve and several peridinioids, woloszynskioids, gymnodinioids, and other dinoflagellates were used for a phylogenetic analysis. General morphology and tabulation of taxa in group palatinum were characterized by SEM. Differences in plate numbers, affecting both the epitheca and the cingulum, combine with differences in plate ornamentation and a suite of internal cell features to suggest a generic-level distinction between Peridinium group palatinum and typical Peridinium. The branching pattern of the phylogenetic tree is compatible with this conclusion, although with low support from bootstrap values and posterior probabilities, as are sequence divergences estimated between species in group palatinum, and typical Peridinium and Peridiniopsis. Palatinus nov. gen. is proposed with the new combinations Palatinus apiculatus nov. comb. (type species; syn. Peridinium palatinum), P. apiculatus var. laevis nov. comb., and P. pseudolaevis nov. comb. Distinctive characters for Palatinus include a smooth or slightly granulate, but not areolate, plate surface, a large central pyrenoid penetrated by cytoplasmic channels and radiating into chloroplast lobes, and the presence of a peduncle-homologous microtubular strand. Palatinus cells exit the theca through the antapical-postcingular area.

AB - The name Peridinium palatinum Lauterborn currently designates a freshwater peridinioid with 13 epithecal and six cingular plates, and no apical pore complex. Freshwater dinoflagellate floras classify it in Peridinium group palatinum together with P. pseudolaeve M. Lefèvre. General ultrastructure, flagellar apparatus, and pusular components of P. palatinum were examined by serial section TEM and compared to P. cinctum (O. F. Müll.) Ehrenb. and Peridiniopsis borgei Lemmerm., respectively, types of Peridinium and Peridiniopsis. Partial LSU rDNA sequences from P. palatinum, P. pseudolaeve and several peridinioids, woloszynskioids, gymnodinioids, and other dinoflagellates were used for a phylogenetic analysis. General morphology and tabulation of taxa in group palatinum were characterized by SEM. Differences in plate numbers, affecting both the epitheca and the cingulum, combine with differences in plate ornamentation and a suite of internal cell features to suggest a generic-level distinction between Peridinium group palatinum and typical Peridinium. The branching pattern of the phylogenetic tree is compatible with this conclusion, although with low support from bootstrap values and posterior probabilities, as are sequence divergences estimated between species in group palatinum, and typical Peridinium and Peridiniopsis. Palatinus nov. gen. is proposed with the new combinations Palatinus apiculatus nov. comb. (type species; syn. Peridinium palatinum), P. apiculatus var. laevis nov. comb., and P. pseudolaevis nov. comb. Distinctive characters for Palatinus include a smooth or slightly granulate, but not areolate, plate surface, a large central pyrenoid penetrated by cytoplasmic channels and radiating into chloroplast lobes, and the presence of a peduncle-homologous microtubular strand. Palatinus cells exit the theca through the antapical-postcingular area.

U2 - 10.1111/j.1529-8817.2009.00739.x

DO - 10.1111/j.1529-8817.2009.00739.x

M3 - Journal article

C2 - 27032362

SN - 0022-3646

VL - 45

SP - 1175

EP - 1194

JO - Journal of Phycology

JF - Journal of Phycology

IS - 5

ER -