Pigment-based chloroplast types in dinoflagellates (original) (raw)
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Proceedings of the National Academy of Sciences, 2002
The most widely distributed dinoflagellate plastid contains chlorophyll c 2 and peridinin as the major carotenoid. A second plastid type, found in taxa such as Karlodinium micrum and Karenia spp., contains chlorophylls c 1 ؉ c2 and 19-hexanoyloxy-fucoxanthin and͞or 19-butanoyloxy-fucoxanthin but lacks peridinin. Because the presence of chlorophylls c 1 ؉ c2 and fucoxanthin is typical of haptophyte algae, the second plastid type is believed to have originated from a haptophyte tertiary endosymbiosis in an ancestral peridinin-containing dinoflagellate. This hypothesis has, however, never been thoroughly tested in plastid trees that contain genes from both peridinin-and fucoxanthin-containing dinoflagellates. To address this issue, we sequenced the plastid-encoded psaA (photosystem I P700 chlorophyll a apoprotein A1), psbA (photosystem II reaction center protein D1), and ''Form I'' rbcL (ribulose-1,5-bisphosphate carboxylase͞oxygenase) genes from various red and dinoflagellate algae. The combined psaA ؉ psbA tree shows significant support for the monophyly of peridinin-and fucoxanthin-containing dinoflagellates as sister to the haptophytes. The monophyly with haptophytes is robustly recovered in the psbA phylogeny in which we increased the sampling of dinoflagellates to 14 species. As expected from previous analyses, the fucoxanthin-containing dinoflagellates formed a wellsupported sister group with haptophytes in the rbcL tree. Based on these analyses, we postulate that the plastid of peridinin-and fucoxanthin-containing dinoflagellates originated from a haptophyte tertiary endosymbiosis that occurred before the split of these lineages. Our findings imply that the presence of chlorophylls c 1 ؉ c2 and fucoxanthin, and the Form I rbcL gene are in fact the primitive (not derived, as widely believed) condition in dinoflagellates.
Journal of Phycology, 1998
The absorbance and fluorescence emission spectra for three species of Dinophysis, D. caudata Saville-Kent, D. fortii Pavillard, and D. acuminata Claparède et Lachmann, were obtained through an in vivo microanalytical technique using a new type of transparent filter. The pigment signatures of these Dinophysis species were compared to those of Synechococcus Nägeli, a cryptophyte, and two wild rhodophytes, as well as those of another dinoflagellate, a diatom, and a chlorophyte. Phycobilins are not considered a native protein group for dinoflagellates, yet the absorption and fluorescence properties of the three Dinophysis species were demonstrated to closely resemble phycobilins and chlorophylls of Rhodomonas Karsten (Cryptophyceae). Analyses of Dinophysis species using epifluorescence microscopy found no additional nucleus or nuclear remnant as would be contributed by an endosymbiont.
Journal of Plankton Research, 2012
Despite the discussion around the nature of plastids in Dinophysis, a comparison of pigment signatures in the three-culture system (Dinophysis, the ciliate Mesodinium rubrum and the cryptophyte Teleaulax amphioxeia) has never been reported. We observed similar pigment composition, but quantitative differences, in four Dinophysis species (D. acuminata, D. acuta, D. caudata and D. tripos), Mesodinium and Teleaulax. Dinophysis contained 59-221-fold higher Chl a per cell than T. amphioxeia (depending on the light conditions and species). To explain this result, several reasons (e.g. more chloroplasts than previously appreciated and synthesis of new pigments) are suggested.
We examined palatability of 37 species of nonencrusting macroalgae from the Antarctic Peninsula. This represents approximately 30% of the entire antarctic macroalgal flora and 75% of the 49 nonencrusting species we collected. Organic extracts from most species were also prepared and mixed into artificial foods. We examined palatability using feeding bioassays with three common, macroalgaconsuming animals (an omnivorous antarctic rockfish, Notothenia coriiceps; an omnivorous sea star, Odontaster validus; and a herbivorous amphipod, Gondogenia antarctica). Thallus pieces from 23 of 34 macroalgal species tested with the fish (68%) were rejected. Of the 23 species rejected as thallus, organic extracts of 16 were bioassayed using the fish with 9 (56%) unpalatable. Thallus pieces from 21 of 36 macroalgal species tested with the sea star (58%) were rejected. Of the 21 species rejected as thallus, organic extracts of 20 were bioassayed using the sea stars and 14 (70%) were unpalatable. Overall, 28 of the 37 species assayed as thallus (76%) were rejected by either or both the fish and sea stars. The amphipod assay was not suitable for use with thallus but was utilized with organic extracts of 23 macroalgal species that were rejected as thallus by either or both the fish and sea stars. Of these, 14 (61%) of the species' extracts were rejected by the amphipods. Unpalatability was highest among the brown algae examined with only an ephemeral, ectocarpoid species not rejected as thallus out of 10 species tested. Of the remaining nine brown algal species, six of seven tested were also unpalatable as extracts, including all the ecologically dominant, perennial species in the area. We conclude that unpalatability to herbivores is common in antarctic macroalgae and that chemical defenses may play an important role in the unpalatability of many algal species (NSF OPP9814538, OPP9901076).
PLoS ONE, 2011
The Dinophysis genus is an ecologically and evolutionarily important group of marine dinoflagellates, yet their molecular phylogenetic positions and ecological characteristics such as trophic modes remain poorly understood. Here, a population of Dinophysis miles var. indica was sampled from South China Sea in March 2010. Nuclear ribosomal RNA gene (rDNA) SSU, ITS1-5.8S-ITS2 and LSU, mitochondrial genes encoding cytochrome B (cob) and cytochrome C oxidase subunit I (cox1), and plastid rDNA SSU were PCR amplified and sequenced. Phylogenetic analyses based on cob, cox1, and the nuclear rRNA regions showed that D. miles was closely related to D. tripos and D. caudata while distinct from D. acuminata. Along with morphology the LSU and ITS1-5.8S-ITS2 molecular data confirmed that this population was D. miles var. indica. Furthermore, the result demonstrated that ITS1-5.8S-ITS2 fragment was the most effective region to distinguish D. miles from other Dinophysis species. Three distinct types of plastid rDNA sequences were detected, belonging to plastids of a cryptophyte, a haptophyte, and a cyanobacterium, respectively. This is the first documentation of three photosynthetic entities associated with a Dinophysis species. While the cyanobacterial sequence likely represented an ectosymbiont of the D. miles cells, the detection of the cryptophyte and haptophyte plastid sequences indicates that the natural assemblage of D. miles likely retain more than one type of plastids from its prey algae for temporary use in photosynthesis. The result, together with recent findings of plastid types in other Dinophysis species, suggests that more systematic research is required to understand the complex nutritional physiology of this genus of dinoflagellates.
Protist, 2019
Marine unarmored dinoflagellates in the family Kareniaceae are known to possess chloroplasts of haptophyte origin, which contain fucoxanthin and its derivatives as major carotenoids, and lack peridinin. In the present study, the first species with the peridinin-type chloroplast in this family, Gertia stigmatica gen. et sp. nov., is described on the basis of ultrastructure, photosynthetic pigment composition, and molecular phylogeny inferred from nucleus-and chloroplast-encoded genes. Cells of G. stigmatica were small and harboring a chloroplast with an eyespot and two pyrenoids. The apical structure complex was straight, similar to Karenia and Karlodinium. Under transmission electron microscopy, the chloroplast was surrounded by two membranes, and the eyespot was composed of a single layer of osmiophilic globules (eyespot type A); this was never previously reported from the Kareniaceae. High performance liquid chromatography demonstrated the chloroplast contains peridinin, and neither fucoxanthin nor 19-acyloxyfucoxanthins was identified. A phylogeny based on nucleus-encoded rDNAs suggested a position of G. stigmatica in the Kareniaceae, but not clustered within the previously described genera, i.e., Karenia, Karlodinium and Takayama. A phylogeny of chloroplast-encoded psbA, psbC and psbD indicated the chloroplast is of peridinin-type typical of dinoflagellates, but the most related species remains unclear.
Proceedings of the Royal Society of London, 1990
Affinity-purified antibodies prepared against the peridinin-chlorophyll aprotein (POP) complex from the dinoflagellate pygmaea were employed to study the immunological similarity of PCP among 28 dinoflagellate species, representing eight genera in four families. The anti-HpPCP antibodies cross-reacted with the subunits of PCP apoproteins from all dinoflagellates tested, but did not cross-react with pigment proteins from the chrysophyte Cricosphaera establishing its specificity for dinoflagellate pigment-protein complexes. Among the dinoflagellates, the PCP apoprotein occurs either as a monomer of about 35 kDa or as an apparent homodimer of about 15 kDa. In some instances, both subunit polypeptides are present simultaneously. The occurrence of different quaternary structures of the PCP apoprotein in different algae can serve as a taxonomic tool, when used in conjunction with other characters. Abbreviations used in the text: PCP, peridinin-chlorophyll a-protein; anti-HpPCP, antibodies against PCP from Heterocapsa ; SDS-page, sodium dodecyl sulphate polyacrylamide gel electrophoresis.