The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Bente Edvardsen - One of the best experts on this subject based on the ideXlab platform.
-
Neighbour-Joining trees of OTU99% obtained after the different filtering procedures, in sample DNA-Hap454.
2013Co-Authors: Elianne Egge, Lucie Bittner, Tom Andersen, Stéphane Audic, Colomban De Vargas, Bente EdvardsenAbstract:Constructed from unique OTUs at a clustering level of 99% similarity, obtained after the filtering procedures (A) Initial Filtering, (B) Quality Score, (C) PyroNoise and (D) AmpliconNoise. The numbers next to the branches indicate the placement of the reference sequences from the strains used in this study. (1) Chrysochromulina throndsenii (AJ246279), (2) Diacronema ennorea (JF714242), (3) Emiliania huxleyi (AF184167), (4) Haptolina fragaria (AM491013), (5) Imantonia rotunda (AJ246267), (6) Isochrysis galbana (AJ246266), (7) Phaeocystis globosa (AF182111), (8) Pleurochrysis pseudoroscoffensis (AM490973), (9) Prymnesium kappa (AJ246271), (10) Prymnesium parvum (AJ246269), (11) Prymnesium polylepis (AJ004866).
-
Ribosomal DNA phylogenies and a morphological revision provide the basis for a revised taxonomy of the Prymnesiales (Haptophyta)
European Journal of Phycology, 2011Co-Authors: Bente Edvardsen, Wenche Eikrem, Jahn Throndsen, Alberto G. Sáez, Ian Probert, Linda MedlinAbstract:Nucleotide sequences of the nuclear-encoded small subunit (18S rDNA) and partial large subunit (28S rDNA) ribosomal DNA were determined in 30 different species of the haptophyte genera Prymnesium, Chrysocampanula, Chrysochromulina, Imantonia and Platychrysis, all belonging to the order Prymnesiales. Phylogenies based on these and other available haptophyte 18S, 28S and plastid 16S rDNA sequences were reconstructed, and compared with available morphological and ultrastructural data. The rDNA phylogenies indicate that the genus Chrysochromulina is paraphyletic and is divided into two major clades. This is supported by ultrastructural and morphological data. There is a major split between Chrysochromulina species with a saddle-shaped cell form (clade B2) and the remaining species in the genus (clade B1). Clade B2 includes the type species C. parva and taxa belonging to this clade thus retain the name Chrysochromulina. The non-saddle-shaped Chrysochromulina species analysed are closely related to Hyalolithus, Prymnesium and Platychrysis species. Imantonia species are sister taxa to these species within clade B1. An amendment to the classification of the order Prymnesiales and the genera Prymnesium, Platychrysis and Chrysochromulina is proposed with one new and one emended family (Chrysochromulinaceae and Prymnesiaceae, respectively), two new genera (Haptolina and Pseudohaptolina), and one new species (Pseudohaptolina arctica). We suggest a revision of the taxonomy of the Prymnesiales that is in accordance with available molecular evidence and supported by morphological data.
-
Ribosomal DNA phylogenies and a morphological revision provide the basis for a revised taxonomy of the Prymnesiales (Haptophyta
2011Co-Authors: Bente Edvardsen, Wenche Eikrem, Jahn Throndsen, Ian Probert, Alberto G. Sáez, K. MedlinAbstract:Nucleotide sequences of the nuclear-encoded small subunit (18S rDNA) and partial large subunit (28S rDNA) ribosomal DNA were determined in 30 different species of the haptophyte genera Prymnesium, Chrysocampanula, Chrysochromulina, Imantonia and Platychrysis, all belonging to the order Prymnesiales. Phylogenies based on these and other available hapto-phyte 18S, 28S and plastid 16S rDNA sequences were reconstructed, and compared with available morphological and ultrastructural data. The rDNA phylogenies indicate that the genus Chrysochromulina is paraphyletic and is divided into two major clades. This is supported by ultrastructural and morphological data. There is a major split between Chrysochromulina species with a saddle-shaped cell form (clade B2) and the remaining species in the genus (clade B1). Clade B2 includes the type species C. parva and taxa belonging to this clade thus retain the name Chrysochromulina. The non-saddle-shaped Chrysochromulina species analysed are closely related to Hyalolithus, Prymnesium and Platychrysis species. Imantonia species are sister taxa to these species within clade B1. An amendment to the classification of the order Prymnesiales and the genera Prymnesium, Platychrysis and Chrysochromulina is proposed with one new and one emended family (Chrysochromulinaceae and Prymnesiaceae, respectively), two new genera (Haptolina and Pseudohaptolina), and one new species (Pseudohaptolina arctica). We suggest a revision of the taxonomy of the Prymnesiales that is in accordance with available molecular evidenc
-
Chrysochromulina palpebralis sp. nov. (Prymnesiophyceae): a Haptophyte, Possessing Two Alternative Morphologies
Phycologia, 2009Co-Authors: Sergio Seoane, Wenche Eikrem, Richard N. Pienaar, Bente EdvardsenAbstract:S. SEOANE ,W. E IKREM ,R. P IENAAR AND B. EDVARDSEN. 2009. Chrysochromulina palpebralis sp. nov. (Prymnesio- phyceae): a haptophyte, possessing two alternative morphologies. Phycologia 48: 165-176. DOI: 10.2216/08-63.1. A marine haptophyte flagellate, Chrysochromulina palpebralis sp. nov., is described from cultures originating from the Nervion River estuary in the Cantabrian Sea, northern Spain. In addition, cultures of similar organisms originating from Japanese and South African waters have been studied. Cells of C. palpebralis had an ovoid shape with an anterior shoulder and were 8-13 mm long and 6-9 mm wide. The cells possessed two equal to subequal flagella that measured 20- 27 mm and a haptonema (7-15 mm long) that was flexible and shorter than the flagella. The life cycle included two motile cell forms indistinguishable at the light microscope level. At the electron microscope level, the two cell forms could be distinguished by having different types of body scales. Flow cytometric ploidy analysis showed that the nuclei of the two forms differ in DNA content by a factor of about four. One cell form ,f .palpebralis, assumed to be tetraploid, was covered by three scale types, one with a central spiny projection and a peripheral rim with about 20 projections and two types of ovoid plate scales. The other form, f. bisquamata, assumed to be haploid, had two types of plate scales. The first cell form is known from the literature as 'eyelash Chrysochromulina' and has previously been recorded from coastal waters in Australia, Japan and South Africa. Phylogenetic analyses based on the nuclear encoded SSU and LSU ribosomal DNA sequences suggest that C. palpebralis is closely related to some nonsaddle-shaped Chrysochromulina species, clustering with C. polylepis and C. kappa as its closest relatives. Chrysochromulina palpebralis was nontoxic to nauplii of brine shrimp.
-
environmental forcing as a main determinant of bloom dynamics of the Chrysochromulina algae
Proceedings of The Royal Society B: Biological Sciences, 2006Co-Authors: Kyrre Lekve, Bente Edvardsen, Espen Bagoien, Einar Dahl, Morten D Skogen, Nils Chr StensethAbstract:In this paper, we demonstrate that the seasonal dynamics in the abiotic factors, without including seasonal changes in the biological relationships, can appropriately account for the seasonal dynamics of Chrysochromulina spp. This is through the analysis of data on the population dynamics of Chrysochromulina spp. off southern Norway that is evaluated in relation to environmental factors and season by the analyses of 12 year monthly time-series. Chrysochromulina spp. abundance, nutrient concentrations, hydrographical properties, as well as current and wind data were analysed on a monthly scale by means of autoregressive moving average models, principal component analyses (PCA), and linear and nonlinear regression models. Seasonal development of the Chrysochromulina assemblage was well predicted from regression models forced with two PCA components representing seasonal variation in nutrient and chlorophyll a levels and ratios, inflow of North Seawater to the Skagerrak and northeasterly wind along the Norwegian coast. Assuming these to be general results, we might hypothesis that marine algal communities are governed by seasonally varying abiotic factors to a large extent.
Wenche Eikrem - One of the best experts on this subject based on the ideXlab platform.
-
Ribosomal DNA phylogenies and a morphological revision provide the basis for a revised taxonomy of the Prymnesiales (Haptophyta)
European Journal of Phycology, 2011Co-Authors: Bente Edvardsen, Wenche Eikrem, Jahn Throndsen, Alberto G. Sáez, Ian Probert, Linda MedlinAbstract:Nucleotide sequences of the nuclear-encoded small subunit (18S rDNA) and partial large subunit (28S rDNA) ribosomal DNA were determined in 30 different species of the haptophyte genera Prymnesium, Chrysocampanula, Chrysochromulina, Imantonia and Platychrysis, all belonging to the order Prymnesiales. Phylogenies based on these and other available haptophyte 18S, 28S and plastid 16S rDNA sequences were reconstructed, and compared with available morphological and ultrastructural data. The rDNA phylogenies indicate that the genus Chrysochromulina is paraphyletic and is divided into two major clades. This is supported by ultrastructural and morphological data. There is a major split between Chrysochromulina species with a saddle-shaped cell form (clade B2) and the remaining species in the genus (clade B1). Clade B2 includes the type species C. parva and taxa belonging to this clade thus retain the name Chrysochromulina. The non-saddle-shaped Chrysochromulina species analysed are closely related to Hyalolithus, Prymnesium and Platychrysis species. Imantonia species are sister taxa to these species within clade B1. An amendment to the classification of the order Prymnesiales and the genera Prymnesium, Platychrysis and Chrysochromulina is proposed with one new and one emended family (Chrysochromulinaceae and Prymnesiaceae, respectively), two new genera (Haptolina and Pseudohaptolina), and one new species (Pseudohaptolina arctica). We suggest a revision of the taxonomy of the Prymnesiales that is in accordance with available molecular evidence and supported by morphological data.
-
Ribosomal DNA phylogenies and a morphological revision provide the basis for a revised taxonomy of the Prymnesiales (Haptophyta
2011Co-Authors: Bente Edvardsen, Wenche Eikrem, Jahn Throndsen, Ian Probert, Alberto G. Sáez, K. MedlinAbstract:Nucleotide sequences of the nuclear-encoded small subunit (18S rDNA) and partial large subunit (28S rDNA) ribosomal DNA were determined in 30 different species of the haptophyte genera Prymnesium, Chrysocampanula, Chrysochromulina, Imantonia and Platychrysis, all belonging to the order Prymnesiales. Phylogenies based on these and other available hapto-phyte 18S, 28S and plastid 16S rDNA sequences were reconstructed, and compared with available morphological and ultrastructural data. The rDNA phylogenies indicate that the genus Chrysochromulina is paraphyletic and is divided into two major clades. This is supported by ultrastructural and morphological data. There is a major split between Chrysochromulina species with a saddle-shaped cell form (clade B2) and the remaining species in the genus (clade B1). Clade B2 includes the type species C. parva and taxa belonging to this clade thus retain the name Chrysochromulina. The non-saddle-shaped Chrysochromulina species analysed are closely related to Hyalolithus, Prymnesium and Platychrysis species. Imantonia species are sister taxa to these species within clade B1. An amendment to the classification of the order Prymnesiales and the genera Prymnesium, Platychrysis and Chrysochromulina is proposed with one new and one emended family (Chrysochromulinaceae and Prymnesiaceae, respectively), two new genera (Haptolina and Pseudohaptolina), and one new species (Pseudohaptolina arctica). We suggest a revision of the taxonomy of the Prymnesiales that is in accordance with available molecular evidenc
-
Chrysochromulina palpebralis sp. nov. (Prymnesiophyceae): a Haptophyte, Possessing Two Alternative Morphologies
Phycologia, 2009Co-Authors: Sergio Seoane, Wenche Eikrem, Richard N. Pienaar, Bente EdvardsenAbstract:S. SEOANE ,W. E IKREM ,R. P IENAAR AND B. EDVARDSEN. 2009. Chrysochromulina palpebralis sp. nov. (Prymnesio- phyceae): a haptophyte, possessing two alternative morphologies. Phycologia 48: 165-176. DOI: 10.2216/08-63.1. A marine haptophyte flagellate, Chrysochromulina palpebralis sp. nov., is described from cultures originating from the Nervion River estuary in the Cantabrian Sea, northern Spain. In addition, cultures of similar organisms originating from Japanese and South African waters have been studied. Cells of C. palpebralis had an ovoid shape with an anterior shoulder and were 8-13 mm long and 6-9 mm wide. The cells possessed two equal to subequal flagella that measured 20- 27 mm and a haptonema (7-15 mm long) that was flexible and shorter than the flagella. The life cycle included two motile cell forms indistinguishable at the light microscope level. At the electron microscope level, the two cell forms could be distinguished by having different types of body scales. Flow cytometric ploidy analysis showed that the nuclei of the two forms differ in DNA content by a factor of about four. One cell form ,f .palpebralis, assumed to be tetraploid, was covered by three scale types, one with a central spiny projection and a peripheral rim with about 20 projections and two types of ovoid plate scales. The other form, f. bisquamata, assumed to be haploid, had two types of plate scales. The first cell form is known from the literature as 'eyelash Chrysochromulina' and has previously been recorded from coastal waters in Australia, Japan and South Africa. Phylogenetic analyses based on the nuclear encoded SSU and LSU ribosomal DNA sequences suggest that C. palpebralis is closely related to some nonsaddle-shaped Chrysochromulina species, clustering with C. polylepis and C. kappa as its closest relatives. Chrysochromulina palpebralis was nontoxic to nauplii of brine shrimp.
-
eco physiology bio optics and toxicity of the ichthyotoxic Chrysochromulina leadbeateri prymnesiophyceae
Journal of Phycology, 1999Co-Authors: Geir Johnsen, Wenche Eikrem, Catherine Legrand, Runar Dalløkken, Jan Aure, Hein Rune SkjoldalAbstract:A toxic phytoplankton bloom, dominated by the prymnesiophyte Chrysochromulina leadbeateri Estep, developed in the Ofotfjord–Tysfjord area (North Norway) in mid-May and ended in late June 1991 in Vestfjorden and the adjacent fjord areas. Chrysochromulina leadbeateri dominated at total cell densities of >2 × 106 cells·L−1; at lower total cell densities, C. leadbeateri was accompanied by other Chrysochromulina species, peridinin-containing dinoflagellates, and diatoms. Bio-optical characteristics and pigmentation in laboratory and field strains of C. leadbeateri allowed for the interpretation of the optical signatures within the bloom. The bio-optical data suggested healthy and actively growing cells during the bloom. About 600 metric tons of pen-raised Atlantic salmon were killed by the C. leadbeateri bloom. A laboratory study was conducted to assess the potential impact of finfish on C. leadbeateri growth. It was found that the polyamine putrescine enhanced cell biomass and hemolytic activity. Given this, a possible scenario for the development of this bloom and the level of toxicity is hypothesized: (1) The nutrient loading in the Ofotfjord area was enhanced during the winter of 1990–1991 due to the overwintering of 1.5 × 106 metric tons of herring from a depth of 0–250 m. This may have sustained a large stock of the mixotrophic C. leadbeateri in early spring before light regime (irradiance, spectral irradiance, and day length) made net photosynthesis possible. (2) The release of polyamines during the decay of dead fish (e.g. putrescine, cadaverine, and histamine) may have acted as cofactors with ichthyotoxins making “hypertoxic complexes” with the polyamines enhancing growth in the mixotrophic C. leadbeateri.
-
Chrysochromulina FRAGARIA SP. NOV. (PRYMNESIOPHYCEAE), A NEW HAPTOPHYTE FLAGELLATE FROM NORWEGIAN WATERS
Phycologia, 1999Co-Authors: Wenche Eikrem, Bente EdvardsenAbstract:Abstract Chrysochromulina fragaria sp. nov. was one of the dominant species during the 1994 and 1995 Chrysochromulina blooms off the southern coast of Norway. It was isolated by the serial dilution culture method from a surface water sample collected during the bloom in May–June 1994. The cells are spherical, 4 to 8 μm in diameter, and possess a coiling haptonema that is shorter than the two equal to subequal flagella. Each cell contains two chloroplasts, a nucleus, and one mitochondrion, which appears to be reticulate. The periplast is covered by monomorphic scales (scale faces with identical pattern) of two types arranged in layers. The scale faces have a pattern of radiating ribs arranged in quadrants. One type has inflexed rims, whereas the other type has erect rims. The first internal transcribed spacer (ITS1) rDNA sequence and scale morphology of C. fragaria are compared with that of Chrysochromulina sp. CCMP 1204. Despite the great similarities in scale morphology, their ITS1 rDNA regions are very ...
Jeanmichel Claverie - One of the best experts on this subject based on the ideXlab platform.
-
comparative genomics of Chrysochromulina ericina virus and other microalga infecting large dna viruses highlights their intricate evolutionary relationship with the established mimiviridae family
Journal of Virology, 2017Co-Authors: Lucie Gallotlavallee, Guillaume Blanc, Jeanmichel ClaverieAbstract:Chrysochromulina ericina virus CeV-01B (CeV) was isolated from Norwegian coastal waters in 1998. Its icosahedral particle is 160 nm in diameter and encloses a 474-kb double-stranded DNA (dsDNA) genome. This virus, although infecting a microalga (the haptophyceae Haptolina ericina, formerly Chrysochromulina ericina), is phylogenetically related to members of the Mimiviridae family, initially established with the acanthamoeba-infecting mimivirus and megavirus as prototypes. This family was later split into two genera (Mimivirus and Cafeteriavirus) following the characterization of a virus infecting the heterotrophic stramenopile Cafeteria roenbergensis (CroV). CeV, as well as two of its close relatives, which infect the unicellular photosynthetic eukaryotes Phaeocystis globosa (Phaeocystis globosa virus [PgV]) and Aureococcus anophagefferens (Aureococcus anophagefferens virus [AaV]), are currently unclassified by the International Committee on Viral Taxonomy (ICTV). The detailed comparative analysis of the CeV genome presented here confirms the phylogenetic affinity of this emerging group of microalga-infecting viruses with the Mimiviridae but argues in favor of their classification inside a distinct clade within the family. Although CeV, PgV, and AaV share more common features among them than with the larger Mimiviridae, they also exhibit a large complement of unique genes, attesting to their complex evolutionary history. We identified several gene fusion events and cases of convergent evolution involving independent lateral gene acquisitions. Finally, CeV possesses an unusual number of inteins, some of which are closely related despite being inserted in nonhomologous genes. This appears to contradict the paradigm of allele-specific inteins and suggests that the Mimiviridae are especially efficient in spreading inteins while enlarging their repertoire of homing genes.IMPORTANCE Although it infects the microalga Chrysochromulina ericina, CeV is more closely related to acanthamoeba-infecting viruses of the Mimiviridae family than to any member of the Phycodnaviridae, the ICTV-approved family historically including all alga-infecting large dsDNA viruses. CeV, as well as its relatives that infect the microalgae Phaeocystic globosa (PgV) and Aureococcus anophagefferens (AaV), remains officially unclassified and a source of confusion in the literature. Our comparative analysis of the CeV genome in the context of this emerging group of alga-infecting viruses suggests that they belong to a distinct clade within the established Mimiviridae family. The presence of a large number of unique genes as well as specific gene fusion events, evolutionary convergences, and inteins integrated at unusual locations document the complex evolutionary history of the CeV lineage.
-
Comparative Genomics of Chrysochromulina Ericina Virus and Other Microalga-Infecting Large DNA Viruses Highlights Their Intricate Evolutionary Relationship with the Established Mimiviridae Family
Journal of Virology, 2017Co-Authors: Lucie Gallot-lavallée, Guillaume Blanc, Jeanmichel ClaverieAbstract:Chrysochromulina Ericina Virus CeV-01B was isolated from Norwegian coastal waters in 1998. Its icosahedral particle is 160 nm in diameter and encloses a 474-kb dsDNA genome. This virus, although infecting a microalgae (the haptophycea Haptolina ericina, formerly Chrysochromulina ericina), is phylogenetically related to members of the Mimiviridae family, initially established with the acanthamoeba-infecting Mimivirus and Megavirus as prototypes. This family was latter split into two genera (Mimivirus and Cafetariavirus) following the characterization of a virus infecting the heterotrophic stramenopile Cafeteria roenbergensis (CroV). CeV, as well as two of its close relatives infecting the unicellular photosynthetic eukaryotes Phaeocystis globosa (PgV) and Aureococcus anophagefferens (AaV), are currently unclassified by ICTV. The detailed comparative analysis of the CeV genome presented here confirms the phylogenetic affinity of this emerging group of microalgae-infecting viruses with the Mimiviridae, but argue in favor of their classification inside a distinct clade within the family. Although CeV, PgV, AaV share more common features between them than with the larger Mimiviridae, they also exhibit a large complement of unique genes attesting of their complex evolutionary history. We identified several gene fusion events and cases of convergent evolution involving independent lateral gene acquisitions. Finally, CeV possesses an unusual number of inteins, some of which are closely related despite been inserted in non-homologous genes. This appears to contradict the paradigm of allele-specific inteins and suggests that Mimiviridae might be especially efficient in spreading inteins while enlarging their repertoire of homing genes.
-
Comparative genomics of Chrysochromulina Ericina Virus (CeV) and other microalgae-infecting large DNA viruses highlight their intricate evolutionary relationship with the established Mimiviridae family.
Journal of Virology, 2017Co-Authors: Lucie Gallot-lavallée, Guillaume Blanc, Jeanmichel ClaverieAbstract:Chrysochromulina Ericina Virus CeV-01B (CeV) was isolated from Norwegian coastal waters in 1998. Its icosahedral particle is 160 nm in diameter and encloses a 474-kb dsDNA genome. This virus, although infecting a microalgae (the haptophyceae Haptolina ericina, formerly Chrysochromulina ericina), is phylogenetically related to members of the Mimiviridae family, initially established with the acanthamoeba-infecting Mimivirus and Megavirus as prototypes. This family was latter split into two genera (Mimivirus and Cafetariavirus) following the characterization of a virus infecting the heterotrophic stramenopile Cafeteria roenbergensis (CroV). CeV, as well as two of its close relatives infecting the unicellular photosynthetic eukaryotes Phaeocystis globosa (PgV) and Aureococcus anophagefferens (AaV), are currently unclassified by ICTV. The detailed comparative analysis of the CeV genome presented here confirms the phylogenetic affinity of this emerging group of microalgae-infecting viruses with the Mimiviridae, but argues in favor of their classification inside a distinct clade within the family. Although CeV, PgV, AaV share more common features between them than with the larger Mimiviridae, they also exhibit a large complement of unique genes attesting to their complex evolutionary history. We identified several gene fusion events and cases of convergent evolution involving independent lateral gene acquisitions. Finally, CeV possesses an unusual number of inteins, some of which are closely related despite been inserted in non-homologous genes. This appears to contradict the paradigm of allele-specific inteins and suggests that Mimiviridae might be especially efficient in spreading inteins while enlarging their repertoire of homing genes.
-
The 474-Kilobase-Pair Complete Genome Sequence of CeV-01B, a Virus Infecting Haptolina (Chrysochromulina) ericina (Prymnesiophyceae)
Genome announcements, 2015Co-Authors: Lucie Gallot-lavallée, Ruthanne Sandaa, Gunnar Bratbak, António Pagarete, Matthieu Legendre, Sébastien Santini, Heinz Himmelbauer, Hiroyuki Ogata, Jeanmichel ClaverieAbstract:ABSTRACT We report the complete genome sequence of CeV-01B, a large double-stranded DNA virus infecting the unicellular marine phytoplankton Haptolina (formerly Chrysochromulina) ericina. CeV-01B and its closest relative Phaeocystis globosa virus define an emerging subclade of the Megaviridae family with smaller genomes and particles than the originally described giant Mimiviridae infecting Acanthamoeba.
Shawn R. Starkenburg - One of the best experts on this subject based on the ideXlab platform.
-
Chrysochromulina: Genomic assessment and taxonomic diagnosis of the type species for an oleaginous algal clade
Algal Research, 2019Co-Authors: Blake T. Hovde, Chloe R. Deodato, Shawn R. Starkenburg, Steven B. Barlow, Robert A. Andersen, Rose Ann CattolicoAbstract:Abstract Background Until recent studies documented their extensive contribution to primary productivity and carbon sequestration, haptophytes remained underappreciated players in global ecosystem processes. Contemporary analyses, augmented by the use of molecular probes, show the haptophyte taxon Chrysochromulina to be seminal to the ecology of both marine and freshwater ecosystems. Unfortunately, description for the type species for this clade remains enigmatic. Results Chrysochromulina parva Lackey was re-isolated from Big Walnut Creek (Ohio), the site where the original isolate was obtained. The sequenced haploid genome of this organism is 65.7 Mb in size. Several noteworthy nuclear-encoded genes identified include a novel ftsZ (mediates organelle division) that phylogenetically clusters with the Chloroarachniophytes. Also revealed, is a complement of genes associated with meiosis and DNA repair, indicating the presence of a sexual cycle in this alga. Mitochondrial genes lost to the nucleus include all extrinsic components of the nad complex, completing a punctate pattern of transfer that is observed among algal taxa. Comparison of the newly sequenced Chrysochromulina parva Lacky isolate was made with that of Chrysochromulina tobinii (59.1 Mb) – a fresh water strain isolated from a lake in Colorado. Conclusion Genomic analysis suggests that fresh water Chrysochromulina isolates, though geographically well separated, from a related clade. The name of the type species of Chrysochromulina parva Lacky is anchored with a lectotype and epitype, and the second isolate is described as Chrysochromulina tobinii sp. nov. Chrysochromulina represents a new, extremely tractable model organism for experimental studies. This oleaginous alga has a small genome and because it represents only the second haptophyte taxon to be sequenced and assembled, presents new opportunity to examine the evolution of an algal taxon that plays an intrinsic role in ecosystem function.
-
Genome Sequences of Eight Bacterial Species Found in Coculture with the Haptophyte Chrysochromulina tobin
Genome announcements, 2016Co-Authors: Kathryn R. Fixen, Blake T. Hovde, Chloe R. Deodato, Shawn R. Starkenburg, Shannon L. Johnson, Hajnalka E. Daligault, Karen W. Davenport, Caroline S. Harwood, Rose Ann CattolicoAbstract:ABSTRACT The microalgal division Haptophyta uses a range of nutritional sourcing, including mixotrophy. The genome of a member of this taxon, Chrysochromulina tobin, suggests that interactions with its bacterial cohort are critical for C. tobin physiology. Here, we report the genomes of eight bacterial species in coculture with C. tobin.
-
Genome Sequence and Transcriptome Analyses of Chrysochromulina tobin: Metabolic Tools for Enhanced Algal Fitness in the Prominent Order Prymnesiales (Haptophyceae)
PLoS genetics, 2015Co-Authors: Blake T. Hovde, Chloe R. Deodato, Heather M. Hunsperger, Scott A. Ryken, Will Yost, Ramesh K. Jha, Johnathan Patterson, Raymond J. Monnat, Steven B. Barlow, Shawn R. StarkenburgAbstract:Haptophytes are recognized as seminal players in aquatic ecosystem function. These algae are important in global carbon sequestration, form destructive harmful blooms, and given their rich fatty acid content, serve as a highly nutritive food source to a broad range of eco-cohorts. Haptophyte dominance in both fresh and marine waters is supported by the mixotrophic nature of many taxa. Despite their importance the nuclear genome sequence of only one haptophyte, Emiliania huxleyi (Isochrysidales), is available. Here we report the draft genome sequence of Chrysochromulina tobin (Prymnesiales), and transcriptome data collected at seven time points over a 24-hour light/dark cycle. The nuclear genome of C. tobin is small (59 Mb), compact (∼40% of the genome is protein coding) and encodes approximately 16,777 genes. Genes important to fatty acid synthesis, modification, and catabolism show distinct patterns of expression when monitored over the circadian photoperiod. The C. tobin genome harbors the first hybrid polyketide synthase/non-ribosomal peptide synthase gene complex reported for an algal species, and encodes potential anti-microbial peptides and proteins involved in multidrug and toxic compound extrusion. A new haptophyte xanthorhodopsin was also identified, together with two “red” RuBisCO activases that are shared across many algal lineages. The Chrysochromulina tobin genome sequence provides new information on the evolutionary history, ecology and economic importance of haptophytes.
-
Chrysochromulina MATE domain detail.
2015Co-Authors: Blake T. Hovde, Chloe R. Deodato, Heather M. Hunsperger, Scott A. Ryken, Will Yost, Ramesh K. Jha, Johnathan Patterson, Raymond J. Monnat, Steven B. Barlow, Shawn R. StarkenburgAbstract:Chrysochromulina MATE domain detail.
-
Chrysochromulina tobin genome statistics.
2015Co-Authors: Blake T. Hovde, Chloe R. Deodato, Heather M. Hunsperger, Scott A. Ryken, Will Yost, Ramesh K. Jha, Johnathan Patterson, Raymond J. Monnat, Steven B. Barlow, Shawn R. StarkenburgAbstract:Chrysochromulina tobin genome statistics.
Blake T. Hovde - One of the best experts on this subject based on the ideXlab platform.
-
naked Chrysochromulina haptophyta isolates from lake and river ecosystems an electron microscopic comparison including new observations on the type species of this taxon
Algal Research-Biomass Biofuels and Bioproducts, 2019Co-Authors: Chloe R. Deodato, Blake T. Hovde, Steven B. Barlow, Rose Ann CattolicoAbstract:Abstract Background Chrysochromulina (Haptophyta) species are recognized as seminal contributors to marine and freshwater ecosystem function. Historically, scale vestiture is used to augment taxonomic identification of these algae, and a large literature exists concerning the morphology of many scale-covered representatives. Scale-less freshwater isolates present a new challenge. Details concerning the microanatomy of naked cells remain essentially unreported. Insight into morphological similarities/differences between scaled and naked cells provides information on the evolution of the taxon, especially as discussions defining cryptic species complexes become more germane. Using light, scanning, and transmission microscopy, we present an analysis of the cellular structure for three Chrysochromulina freshwater isolates. Results Chrysochromulina tobinii Cattolico, Chrysochromulina parva Lackey and ChrysochromulinaAND cells are approximately 5 μm wide, saddle-shaped to globose, and devoid of scales. A lipid body is nestled close to each of two chloroplasts and numerous mitochondria. Plastoglobuli are frequently associated with thylakoidal membranes that encircle an internal pyrenoid. The Golgi apparatus has large, club-shaped cisternae. The haptonema consists of 9 microtubules within the cytoplasm, but 6 or 7 microtubules in the external portion. A rootlet system anchors the two flagella that are sub-apically inserted adjacent to the haptonema. The flagellar complex is anchored in the cytoplasm by a flat ribbon of microtubules and microtubular rootlets associated with each basal body. Fibrous rootlets, several of which are cross-banded, interconnect the two flagellar basal bodies and haptonema. Conclusion Three freshwater, scale-less Chrysochromulina isolates are almost indistinguishable in ultrastructure, even though extensive genome sequencing studies verify their distinctiveness. These freshwater representatives certainly comprise members of a cryptic species complex. Extensive morphological similarity also occurs between freshwater and scaled marine isolates. Importantly, this report addresses the misidentification of Chrysochromulina tobinii Cattolico as Chrysochromulina parva Lackey and clarifies a complex literature regarding the morphological description of the type species for this algal clade.
-
Chrysochromulina: Genomic assessment and taxonomic diagnosis of the type species for an oleaginous algal clade
Algal Research, 2019Co-Authors: Blake T. Hovde, Chloe R. Deodato, Shawn R. Starkenburg, Steven B. Barlow, Robert A. Andersen, Rose Ann CattolicoAbstract:Abstract Background Until recent studies documented their extensive contribution to primary productivity and carbon sequestration, haptophytes remained underappreciated players in global ecosystem processes. Contemporary analyses, augmented by the use of molecular probes, show the haptophyte taxon Chrysochromulina to be seminal to the ecology of both marine and freshwater ecosystems. Unfortunately, description for the type species for this clade remains enigmatic. Results Chrysochromulina parva Lackey was re-isolated from Big Walnut Creek (Ohio), the site where the original isolate was obtained. The sequenced haploid genome of this organism is 65.7 Mb in size. Several noteworthy nuclear-encoded genes identified include a novel ftsZ (mediates organelle division) that phylogenetically clusters with the Chloroarachniophytes. Also revealed, is a complement of genes associated with meiosis and DNA repair, indicating the presence of a sexual cycle in this alga. Mitochondrial genes lost to the nucleus include all extrinsic components of the nad complex, completing a punctate pattern of transfer that is observed among algal taxa. Comparison of the newly sequenced Chrysochromulina parva Lacky isolate was made with that of Chrysochromulina tobinii (59.1 Mb) – a fresh water strain isolated from a lake in Colorado. Conclusion Genomic analysis suggests that fresh water Chrysochromulina isolates, though geographically well separated, from a related clade. The name of the type species of Chrysochromulina parva Lacky is anchored with a lectotype and epitype, and the second isolate is described as Chrysochromulina tobinii sp. nov. Chrysochromulina represents a new, extremely tractable model organism for experimental studies. This oleaginous alga has a small genome and because it represents only the second haptophyte taxon to be sequenced and assembled, presents new opportunity to examine the evolution of an algal taxon that plays an intrinsic role in ecosystem function.
-
Genome Sequences of Eight Bacterial Species Found in Coculture with the Haptophyte Chrysochromulina tobin
Genome announcements, 2016Co-Authors: Kathryn R. Fixen, Blake T. Hovde, Chloe R. Deodato, Shawn R. Starkenburg, Shannon L. Johnson, Hajnalka E. Daligault, Karen W. Davenport, Caroline S. Harwood, Rose Ann CattolicoAbstract:ABSTRACT The microalgal division Haptophyta uses a range of nutritional sourcing, including mixotrophy. The genome of a member of this taxon, Chrysochromulina tobin, suggests that interactions with its bacterial cohort are critical for C. tobin physiology. Here, we report the genomes of eight bacterial species in coculture with C. tobin.
-
Genome Sequence and Transcriptome Analyses of Chrysochromulina tobin: Metabolic Tools for Enhanced Algal Fitness in the Prominent Order Prymnesiales (Haptophyceae)
PLoS genetics, 2015Co-Authors: Blake T. Hovde, Chloe R. Deodato, Heather M. Hunsperger, Scott A. Ryken, Will Yost, Ramesh K. Jha, Johnathan Patterson, Raymond J. Monnat, Steven B. Barlow, Shawn R. StarkenburgAbstract:Haptophytes are recognized as seminal players in aquatic ecosystem function. These algae are important in global carbon sequestration, form destructive harmful blooms, and given their rich fatty acid content, serve as a highly nutritive food source to a broad range of eco-cohorts. Haptophyte dominance in both fresh and marine waters is supported by the mixotrophic nature of many taxa. Despite their importance the nuclear genome sequence of only one haptophyte, Emiliania huxleyi (Isochrysidales), is available. Here we report the draft genome sequence of Chrysochromulina tobin (Prymnesiales), and transcriptome data collected at seven time points over a 24-hour light/dark cycle. The nuclear genome of C. tobin is small (59 Mb), compact (∼40% of the genome is protein coding) and encodes approximately 16,777 genes. Genes important to fatty acid synthesis, modification, and catabolism show distinct patterns of expression when monitored over the circadian photoperiod. The C. tobin genome harbors the first hybrid polyketide synthase/non-ribosomal peptide synthase gene complex reported for an algal species, and encodes potential anti-microbial peptides and proteins involved in multidrug and toxic compound extrusion. A new haptophyte xanthorhodopsin was also identified, together with two “red” RuBisCO activases that are shared across many algal lineages. The Chrysochromulina tobin genome sequence provides new information on the evolutionary history, ecology and economic importance of haptophytes.
-
Chrysochromulina MATE domain detail.
2015Co-Authors: Blake T. Hovde, Chloe R. Deodato, Heather M. Hunsperger, Scott A. Ryken, Will Yost, Ramesh K. Jha, Johnathan Patterson, Raymond J. Monnat, Steven B. Barlow, Shawn R. StarkenburgAbstract:Chrysochromulina MATE domain detail.