The Experts below are selected from a list of 48 Experts worldwide ranked by ideXlab platform
Richard W Jordan - One of the best experts on this subject based on the ideXlab platform.
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diversity within the triparma strigata triparma verrucosa group Bolidophyceae including five new taxa from polar subpolar regions
Phycologia, 2021Co-Authors: Kazuki Hoshina, Hisashi Narita, Naomi Harada, Richard W JordanAbstract:A re-investigation of phytoplankton assemblages on old membrane filters from polar–subpolar waters has revealed the presence of seven taxa within the Triparma strigata–Triparma verrucosa group (Bol...
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triparma laevis f marchantii f nov Bolidophyceae from the southern ocean and comparison with other infraspecific taxa of t laevis
Phycologia, 2021Co-Authors: Kazuki Hoshina, Hisashi Narita, Naomi Harada, Richard W JordanAbstract:A form of Triparma laevis (Parmales, Bolidophyceae), not formally described yet, has been reported in Southern Ocean phytoplankton surveys for more than 30 years. A re-examination of some filtered ...
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parmales Bolidophyceae assemblages in the subarctic pacific ocean during the mid 1960s
Phycologia, 2021Co-Authors: Kazuki Hoshina, Yuki Uezato, Richard W JordanAbstract:A large collection of old membrane filters from the American cruises of the R/V Vema and R/V Robert D. Conrad has been recently curated and provides a unique opportunity to study microplankton dist...
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tropical parmales Bolidophyceae assemblages from the sulu sea and south china sea including the description of five new taxa
Phycologia, 2017Co-Authors: Ryohei Fujita, Richard W JordanAbstract:Abstract: Despite numerous studies on Parmales (Bolidophyceae) from polar regions, there have been few reports on tropical assemblages, especially on their ecology and diversity. Filtered water samples collected at two hydrocast stations during a 1996–1997 survey of the western Pacific and eastern Indian Ocean were recently investigated and revealed for the first time the presence of tropical Parmales in the Sulu Sea and South China Sea. The absolute abundances of total Parmales were very low (< 1300 cells l−1) and restricted to the deep photic zone (100–150 m). The Sulu Sea assemblages were dominated by Triparma columacea f. longiseta and Triparma laevis f. mexicana, while those in the South China Sea were dominated by Tetraparma silverae. Of the seven taxa encountered at these stations, two are described as new species (Te. silverae and Tetraparma trullifera) and three as new formae (Triparma columacea f. longiseta, Triparma laevis f. fusiformis and Triparma retinervis f. tortispina).
Daniel Vaulot - One of the best experts on this subject based on the ideXlab platform.
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Bolidophyceae a sister picoplanktonic group of diatoms a review
Frontiers in Marine Science, 2018Co-Authors: Akira Kuwata, Daniel Vaulot, Kazumasa Yamada, Mutsuo Ichinomiya, Shinya Yoshikawa, Margot Tragin, Adriana Lopes Dos SantosAbstract:Pico- and nano-phytoplankton (respectively, 0.2-2 and 2-20 µm in cell size) play a key role in many marine ecosystems. In this size range, Bolidophyceae is a group of eukaryotes that contains species with cells surrounded by 5 or 8 silica plates (Parmales) as well as naked flagellated species (formerly Bolidomonadales). Bolidophyceae share a common ancestor with diatoms, one of the most successful groups of phytoplankton. This review summarizes the current information on taxonomy, phylogeny, ecology and physiology obtained by recent studies using a range of approaches including metabarcoding. Despite their rather small contribution to the phytoplankton communities (on average less than 0.1%), Bolidophyceae are very widespread throughout marine systems from the tropics to the pole. This review concludes by discussing similarities and differences between Bolidophyceae and diatoms.
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Diversity and oceanic distribution of the Parmales (Bolidophyceae), a picoplanktonic group closely related to diatoms
ISME Journal, 2016Co-Authors: Mutsuo Ichinomiya, Shinya Yoshikawa, Adriana Lopes Dos Santos, Priscillia Gourvil, Mitsunobu Kamiya, Kaori Ohki, Stéphane Audic, Colomban De Vargas, Mary-hélène Noël, Daniel VaulotAbstract:Bolidomonas is a genus of picoplanktonic flagellated algae that is closely related to diatoms. Triparma laevis, a species belonging to the Parmales, which are small cells with a siliceous covering, has been shown to form a monophyletic group with Bolidomonas. We isolated several novel strains of Bolidophyceae that have permitted further exploration of the diversity of this group using nuclear, plastidial and mitochondrial genes. The resulting phylogenetic data led us to formally emend the taxonomy of this group to include the Parmales within the Bolidophyceae, to combine Bolidomonas within Triparma and to define a novel species, Triparma eleuthera sp. nov. The global distribution of Bolidophyceae was then assessed using environmental sequences available in public databases, as well as a large 18S rRNA V9 metabarcode data set from the Tara Oceans expedition. Bolidophyceans appear ubiquitous throughout the sampled oceans but always constitute a minor component of the phytoplankton community, corresponding to at most ~ 4% of the metabarcodes from photosynthetic groups (excluding dinoflagellates). They are ~ 10 times more abundant in the small size fraction (0.8– 5 μm) than in larger size fractions. T. eleuthera sp. nov. constitutes the most abundant and most widespread operational taxonomic unit (OTU) followed by T. pacifica, T. mediterranea and the T. laevis clade. The T. mediterranea OTU is characteristic of Mediterranean Sea surface waters and the T. laevis clade OTU is most prevalent in colder waters, in particular off Antarctica.
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analysis of photosynthetic picoeukaryote diversity at open ocean sites in the arabian sea using a pcr biased towards marine algal plastids
Aquatic Microbial Ecology, 2006Co-Authors: Nicholas J. Fuller, Daniel Vaulot, Florence Le Gall, Colin Campbell, David J Allen, Frances D Pitt, Katrin Zwirglmaier, David J. ScanlanAbstract:Marine photosynthetic picoeukaryotes (PPEs), representing organisms <3 µm in size, are major contributors to global carbon cycling. However, the key members of the PPE community and hence the major routes of carbon fixation, particularly in the open ocean environment, are poorly described. Here, we have accessed PPE community structure using the plastid encoded 16S rRNA gene. Plastid 16S rRNA genes were sequenced from 65 algal cultures, about half being PPEs, representing 14 algal classes. These included sequences from 5 classes where previously no such sequences from cultured representatives had been available (Bolidophyceae, Dictyochophyceae, Eustigmatophyceae, Pelagophyceae and Pinguiophyceae). Sequences were also obtained for 6 of the 7 (according to 18S rRNA gene sequence) prasinophyte clades. Phylogenetic analysis revealed plastids from the same class as clustering together. Using all the obtained sequences, as well as plastid sequences currently in public databases, a non-degenerate marine algal plastid-biased PCR primer, PLA491F, was developed to minimize amplification of picocyanobacteria, which often dominate numerically environmental samples. Clone libraries subsequently constructed from the pico-sized fraction from 2 open ocean sites in the Arabian Sea, revealed an abundance of 16S rRNA gene clones phylogenetically related to chrysophytes, whilst prymnesiophyte, clade II prasinophyte (Ostreococcus-like) and pelagophyte clones were also well represented. The finding of a wealth of novel clones related to the Chrysophyceae highlights the utility of a PCR biased towards marine algal plastids as a valuable complement to 18S rDNA based studies of PPE diversity.
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diversity and abundance of Bolidophyceae heterokonta in two oceanic regions
Applied and Environmental Microbiology, 1999Co-Authors: Laure Guillou, Seungyeo Moonvan Der Staay, Herve Claustre, Frederic Partensky, Daniel VaulotAbstract:The diversity and abundance of the Bolidophyceae (Heterokonta), a newly described picoplanktonic algal class which is a sister group to the diatoms, was assessed in the equatorial Pacific Ocean and in the Mediterranean Sea by culture isolation, molecular biology techniques, and pigment analyses. Eight strains of Bolidophyceae were isolated in culture from different mesotrophic and oligotrophic areas. The corresponding small subunit (SSU) rRNA gene sequences allowed us to design two probes specific for the Bolidophyceae. These probes have been used in natural samples (i) to selectively amplify and detect Bolidophyceae sequences and (ii) to quantify the relative abundance of Bolidophyceae within the picoeukaryote community. Sequences available to date indicate that the class Bolidophyceae comprises at least three different clades, two corresponding to the previously described species Bolidomonas pacifica and Bolidomonas mediterranea and the third one corresponding to a subspecies of B. pacifica. Amplification of the SSU rRNA gene from natural samples with universal primers and hybridization using a Bolidomonas-specific probe followed by a eukaryote-specific probe allowed us to estimate the contribution of the Bolidophyceae to the eukaryotic DNA in both Pacific and Mediterranean waters to be lower than 1%. Similarly, high-performance liquid chromatography analyses of fucoxanthin, the major carotenoid present in Bolidophyceae, indicated that less than 4% of the total chlorophyll a in the picoplanktonic fraction in the equatorial Pacific was due to Bolidophyceae. Consequently, although strains of Bolidophyceae have been isolated from samples collected at several stations, this new class seems to have been a minor component of the natural picoeukaryotic populations in the ecosystems investigated, at least during the periods sampled.
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bolidomonas a new genus with two species belonging to a new algal class the Bolidophyceae heterokonta
Journal of Phycology, 1999Co-Authors: Laure Guillou, Herve Claustre, Mariejosephe Chretiennotdinet, Linda K Medlin, Susan Loiseauxde Goer, Daniel VaulotAbstract:A new algal class, the Bolidophyceae (Heterokonta), is described from one genus, Bolidomonas, gen. nov., and two species, Bolidomonas pacifica, sp. nov and Bolidomonas mediterranea, sp. nov., isolated from the equatorial Pacific Ocean and the Mediterranean Sea, respectively. Both species are approximately 1.2 mm in diameter and have two unequal flagella; the longer flagellum bears tubular hairs, whereas the shorter is smooth. The flagellar basal apparatus is restricted to two basal bodies, and there is no transitional helix. Cells are naked, devoid of walls or siliceous structures. The internal cellular organization is simple with a single plastid containing a ring genophore and a girdle lamella, one mitochondrion with tubular cristae, and one Golgi apparatus close to the basal bodies. The Mediterranean and the Pacific species differ in the insertion angle between their flagella and their pattern of swimming, these differences possibly being linked to each other. Analyses of the SSU rDNA gene place the two strains as a sister group to the diatoms. Moreover, pigment analyses confirm this position, as fucoxanthin is found as the major carotenoid in both lineages. These data strongly suggest that the ancestral heterokont that gave rise to the diatom lineage was probably a biflagellated unicell.
Kazuki Hoshina - One of the best experts on this subject based on the ideXlab platform.
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diversity within the triparma strigata triparma verrucosa group Bolidophyceae including five new taxa from polar subpolar regions
Phycologia, 2021Co-Authors: Kazuki Hoshina, Hisashi Narita, Naomi Harada, Richard W JordanAbstract:A re-investigation of phytoplankton assemblages on old membrane filters from polar–subpolar waters has revealed the presence of seven taxa within the Triparma strigata–Triparma verrucosa group (Bol...
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triparma laevis f marchantii f nov Bolidophyceae from the southern ocean and comparison with other infraspecific taxa of t laevis
Phycologia, 2021Co-Authors: Kazuki Hoshina, Hisashi Narita, Naomi Harada, Richard W JordanAbstract:A form of Triparma laevis (Parmales, Bolidophyceae), not formally described yet, has been reported in Southern Ocean phytoplankton surveys for more than 30 years. A re-examination of some filtered ...
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parmales Bolidophyceae assemblages in the subarctic pacific ocean during the mid 1960s
Phycologia, 2021Co-Authors: Kazuki Hoshina, Yuki Uezato, Richard W JordanAbstract:A large collection of old membrane filters from the American cruises of the R/V Vema and R/V Robert D. Conrad has been recently curated and provides a unique opportunity to study microplankton dist...
Mutsuo Ichinomiya - One of the best experts on this subject based on the ideXlab platform.
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draft whole genome sequence of triparma laevis f inornata parmales Bolidophyceae isolated from the oyashio region western north pacific ocean
Microbiology Resource Announcements, 2020Co-Authors: Akira Kuwata, Mutsuo Ichinomiya, Kenji Saitoh, Yoji Nakamura, Naoki SatoAbstract:ABSTRACT We present the first draft whole-genome sequence for the Parmales (Bolidophyceae, Heterokonta), a picoplanktonic sister group of diatoms, using a Triparma laevis f. inornata strain that was isolated from the Oyashio region in the western North Pacific Ocean.
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Bolidophyceae a sister picoplanktonic group of diatoms a review
Frontiers in Marine Science, 2018Co-Authors: Akira Kuwata, Daniel Vaulot, Kazumasa Yamada, Mutsuo Ichinomiya, Shinya Yoshikawa, Margot Tragin, Adriana Lopes Dos SantosAbstract:Pico- and nano-phytoplankton (respectively, 0.2-2 and 2-20 µm in cell size) play a key role in many marine ecosystems. In this size range, Bolidophyceae is a group of eukaryotes that contains species with cells surrounded by 5 or 8 silica plates (Parmales) as well as naked flagellated species (formerly Bolidomonadales). Bolidophyceae share a common ancestor with diatoms, one of the most successful groups of phytoplankton. This review summarizes the current information on taxonomy, phylogeny, ecology and physiology obtained by recent studies using a range of approaches including metabarcoding. Despite their rather small contribution to the phytoplankton communities (on average less than 0.1%), Bolidophyceae are very widespread throughout marine systems from the tropics to the pole. This review concludes by discussing similarities and differences between Bolidophyceae and diatoms.
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ultrastructural analysis of siliceous cell wall regeneration in the stramenopile triparma laevis parmales Bolidophyceae
Phycologia, 2016Co-Authors: Kazumasa Yamada, Akira Kuwata, Mutsuo Ichinomiya, Shinya Yoshikawa, Kaori Ohki, Taizo Motomura, Chikako NagasatoAbstract:Abstract The marine alga Triparma laevis NIES-2565, belonging to the Parmales (Bolidophyceae), possesses a siliceous cell wall that is composed of shield, ventral, dorsal and girdle plates. The cell wall is lost under silicate-deficient culture conditions. Regeneration of the cell wall occurs with the addition of sufficient silicate ions into the culture medium. In this study, the formation of the siliceous cell wall was observed by transmission electron microscopy. Silica deposition vesicles (SDVs) forming the shield and ventral plates were initially found around the chloroplast, moving toward the plasma membrane as they expanded, with siliceous plates being built within the SDV. The SDV membrane was tightly adpressed to the siliceous plate. In contrast, SDVs for dorsal and girdle plates were formed adjacent to the plasma membrane. Extracellular secretion of mature siliceous plates began with shield plates, followed in turn by ventral, dorsal and girdle plates. The dorsal and girdle plates were inserted ...
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Diversity and oceanic distribution of the Parmales (Bolidophyceae), a picoplanktonic group closely related to diatoms
ISME Journal, 2016Co-Authors: Mutsuo Ichinomiya, Shinya Yoshikawa, Adriana Lopes Dos Santos, Priscillia Gourvil, Mitsunobu Kamiya, Kaori Ohki, Stéphane Audic, Colomban De Vargas, Mary-hélène Noël, Daniel VaulotAbstract:Bolidomonas is a genus of picoplanktonic flagellated algae that is closely related to diatoms. Triparma laevis, a species belonging to the Parmales, which are small cells with a siliceous covering, has been shown to form a monophyletic group with Bolidomonas. We isolated several novel strains of Bolidophyceae that have permitted further exploration of the diversity of this group using nuclear, plastidial and mitochondrial genes. The resulting phylogenetic data led us to formally emend the taxonomy of this group to include the Parmales within the Bolidophyceae, to combine Bolidomonas within Triparma and to define a novel species, Triparma eleuthera sp. nov. The global distribution of Bolidophyceae was then assessed using environmental sequences available in public databases, as well as a large 18S rRNA V9 metabarcode data set from the Tara Oceans expedition. Bolidophyceans appear ubiquitous throughout the sampled oceans but always constitute a minor component of the phytoplankton community, corresponding to at most ~ 4% of the metabarcodes from photosynthetic groups (excluding dinoflagellates). They are ~ 10 times more abundant in the small size fraction (0.8– 5 μm) than in larger size fractions. T. eleuthera sp. nov. constitutes the most abundant and most widespread operational taxonomic unit (OTU) followed by T. pacifica, T. mediterranea and the T. laevis clade. The T. mediterranea OTU is characteristic of Mediterranean Sea surface waters and the T. laevis clade OTU is most prevalent in colder waters, in particular off Antarctica.
A V Troitsky - One of the best experts on this subject based on the ideXlab platform.
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metagenomics of Bolidophyceae in plankton and ice of the white sea
Biochemistry, 2017Co-Authors: T A Belevich, L V Ilyash, Irina A Milyutina, Maria D Logacheva, A V TroitskyAbstract:The molecular diversity of poorly studied algae of Bolidophyceae class was first estimated by Illumina sequencing of V4 region of 18S rRNA gene in ice, under-ice water and summer water of the subarctic White Sea. We used two clustering thresholds - 93 and 97% - and revealed 31 phylotypes of Bolidophyceae. Triparma pacifica and T. strigata were identified to species level. The association of individual phylotypes to certain biotopes (ice or plankton) and stages of seasonal succession (under ice or summer plankton) has been established. Some phylotypes are found in different biotopes and over a wide temperature range. Due to changing their genetic composition, Bolidophyceae are a constant component of the photoautotrophic plankton and ice communities.