Multigene phylogeny reveals a cryptic diversity in the genus (Chrysophyceae) with integrative description of five new species.

Introduction: The genus is one of the most recognizable chrysophyte genera, characterized by dendroid colonies with a biflagellate inside each cellulosic lorica. The representative forms of lorica are cylindrical, conical, vase, or funnel shaped, with undulation on the lorica wall. Traditionally, the morphological characteristics of the lorica and the colony organization have been used for the delimitation of species.

Gene loss, pseudogenization, and independent genome reduction in non-photosynthetic species of Cryptomonas (Cryptophyceae) revealed by comparative nucleomorph genomics.

Background: Cryptophytes are ecologically important algae of interest to evolutionary cell biologists because of the convoluted history of their plastids and nucleomorphs, which are derived from red algal secondary endosymbionts. To better understand the evolution of the cryptophyte nucleomorph, we sequenced nucleomorph genomes from two photosynthetic and two non-photosynthetic species in the genus Cryptomonas. We performed a comparative analysis of these four genomes and the previously published genome of the non-photosynthetic species Cryptomonas paramecium CCAP977/2a.

Evolutionary Dynamics and Lateral Gene Transfer in Raphidophyceae Plastid Genomes.

The Raphidophyceae is an ecologically important eukaryotic lineage of primary producers and predators that inhabit marine and freshwater environments worldwide. These organisms are of great evolutionary interest because their plastids are the product of eukaryote-eukaryote endosymbiosis. To obtain deeper insight into the evolutionary history of raphidophycean plastids, we sequenced and analyzed the plastid genomes of three freshwater and three marine species.

Molecular Phylogeny and Taxonomy of the Genus (Chrysophyceae) Based on Morphological and Molecular Evidence.

The genus , established by Cienkowsky in 1870, is characterized by omnivory, two (rarely three) flagella, a short stick-like structure beneath the flagella, a threadlike stalk, cell division via constriction and cyst formation. Since the first phylogenetic study of -like flagellates, their paraphyly has consistently been shown, with separation into several genera. More recently, was carefully investigated using molecular and morphological data to propose seven new species.

Comparative Plastid Genomics of Non-Photosynthetic Chrysophytes: Genome Reduction and Compaction.

-like heterotrophic chrysophytes are important eukaryotic microorganisms that feed on bacteria in aquatic and soil environments. They are characterized by their lack of pigmentation, naked cell surface, and extremely small size. Although -like chrysophytes have lost their photosynthetic ability, they still possess a leucoplast and retain a plastid genome.

Comparative mitochondrial genomics of cryptophyte algae: gene shuffling and dynamic mobile genetic elements.

Background: Cryptophytes are an ecologically important group of algae comprised of phototrophic, heterotrophic and osmotrophic species. This lineage is of great interest to evolutionary biologists because their plastids are of red algal secondary endosymbiotic origin. Cryptophytes have a clear phylogenetic affinity to heterotrophic eukaryotes and possess four genomes: host-derived nuclear and mitochondrial genomes, and plastid and nucleomorph genomes of endosymbiotic origin.

Feeding and grazing impact by the bloom-forming euglenophyte Eutreptiella eupharyngea on marine eubacteria and cyanobacteria.

The phototrophic euglenophyte Eutreptiella eupharyngea often causes blooms in the coastal waters of many countries, but its mode of nutrition has not been assessed. This species has previously been considered as exclusively auxotrophic. To explore whether E.

Deletion of the chloroplast LTD protein impedes LHCI import and PSI-LHCI assembly in Chlamydomonas reinhardtii.

Nuclear-encoded light-harvesting chlorophyll- and carotenoid-binding proteins (LHCPs) are imported into the chloroplast and transported across the stroma to thylakoid membrane assembly sites by the chloroplast signal recognition particle (CpSRP) pathway. The LHCP translocation defect (LTD) protein is essential for the delivery of imported LHCPs to the CpSRP pathway in Arabidopsis. However, the function of the LTD protein in Chlamydomonas reinhardtii has not been investigated.

Evolutionary Dynamics of Cryptophyte Plastid Genomes.

Cryptophytes are an ecologically important group of largely photosynthetic unicellular eukaryotes. This lineage is of great interest to evolutionary biologists because their plastids are of red algal secondary endosymbiotic origin and the host cell retains four different genomes (host nuclear, mitochondrial, plastid, and red algal nucleomorph). Here, we report a comparative analysis of plastid genomes from six representative cryptophyte genera.

Euglenophycin is produced in at least six species of euglenoid algae and six of seven strains of Euglena sanguinea.

Euglena sanguinea is known to produce the alkaloid toxin euglenophycin and is known to cause fish kills and inhibit mammalian tissue and microalgal culture growth. An analysis of over 30 species of euglenoids for accumulation of euglenophycin identified six additional species producing the toxin; and six of the seven E. sanguinea strains produced the toxin.

The fate of cryptophyte cell organelles in the ciliate Mesodinium cf. rubrum subjected to starvation.

Mesodinium rubrum Lohmann is a mixotrophic ciliate and one of the best studied species exhibiting acquired phototrophy. To investigate the fate of cryptophyte organelles in the ciliate subjected to starvation, we conducted ultrastructural studies of a Korean strain of M. cf.

Cryptophyte gene regulation in the kleptoplastidic, karyokleptic ciliate Mesodinium rubrum.

Photosynthesis in the ciliate Mesodinium rubrum is achieved using a consortium of cryptophyte algal organelles enclosed in its specialized vacuole. A time-series microarray analysis was conducted on the photosynthetic ciliate using an oligochip containing 15,654 primers designed from EST data of the cryptophyte prey, Teleaulax amphioxeia. The cryptophycean nuclei were transcriptionally active over 13 weeks and approximately 13.

Do All Dinoflagellates have an Extranuclear Spindle?

The syndinean dinoflagellates are a diverse assemblage of alveolate endoparasites that branch basal to the core dinoflagellates. Because of their phylogenetic position, the syndineans are considered key model microorganisms in understanding early evolution in the dinoflagellates. Closed mitosis with an extranuclear spindle that traverses the nucleus in cytoplasmic grooves or tunnels is viewed as one of the morphological features shared by syndinean and core dinoflagellates.

Assessing the evolutionary history of the class Synurophyceae (Heterokonta) using molecular, morphometric, and paleobiological approaches.

Premise Of The Study: Heterokont algae of the class Synurophyceae, characterized by distinctive siliceous scales that cover the surface of the cell, are ecologically important in inland waters, yet their evolutionary history remains enigmatic. We explore phylogenetic relationships within this group of algae relative to geologic time, with a focus on evolution of siliceous components.

Methods: We combined an expansive five-gene and time-calibrated molecular phylogeny of synurophyte algae with an extensive array of fossil specimens from the middle Eocene to infer evolutionary trends within the group.

The Plastid Genome of the Cryptomonad Teleaulax amphioxeia.

Teleaulax amphioxeia is a photosynthetic unicellular cryptophyte alga that is distributed throughout marine habitats worldwide. This alga is an important plastid donor to the dinoflagellate Dinophysis caudata through the ciliate Mesodinium rubrum in the marine food web. To better understand the genomic characteristics of T.

Molecular Phylogeny and Cryptic Diversity of the Genus Phacus (Phacaceae, Euglenophyceae) and the Descriptions of Seven New Species.

The photosynthetic euglenoid genus Phacus is commonly found in freshwater; it is characterized by a rigid to semi-rigid cell, usually flat with numerous small discoid chloroplasts without pyrenoids. To understand the phylogenetic relationships among Phacus species, we used combined cytoplasmic SSU and LSU rDNA and plastid-encoded SSU and LSU rDNA sequence data from 82 strains, including seven Lepocinclis, three Discoplastis, one Eutreptia, and two Eutreptiella strains, as well as morphological data. The combined molecular dataset was analyzed using Bayesian and maximum likelihood methods.

Ultrastructure and molecular phylogeny of Mesodinium coatsi sp. nov., a benthic marine ciliate.

Mesodinium is a globally distributed ciliate genus forming frequent and recurrent blooms in diverse marine habitats. Here, we describe a new marine species, Mesodinium coatsi n. sp.

A rapid phenol toxicity test based on photosynthesis and movement of the freshwater flagellate, Euglena agilis Carter.

Phenol, a monosubstituted aromatic hydrocarbon with various commercial uses, is a major organic constituent in industrial wastewaters. The ecotoxic action of phenol for aquatic environment is well known. In this study, rapid phenol toxicity tests (1h) were developed based on chlorophyll a (Chl a) fluorescence and the movement parameters of the freshwater flagellate, Euglena agilis Carter.

The effect of starvation on plastid number and photosynthetic performance in the kleptoplastidic dinoflagellate Amylax triacantha.

The dinoflagellate Amylax triacantha is known to retain plastids of cryptophyte origin by engulfing the mixotrophic ciliate Mesodinium rubrum, itself a consumer of cryptophytes. However, there is no information on the fate of the prey's organelles and the photosynthetic performance of the newly retained plastids in A. triacantha.

Cryptic Speciation in the Genus Cryptoglena (Euglenaceae) Revealed by Nuclear and Plastid SSU and LSU rRNA Gene.

The photosynthetic euglenoid genus Cryptoglena is differentiated from other euglenoid genera by having a longitudinal sulcus, one chloroplast, two large trough-shaped paramylon plates positioned between the chloroplast and pellicle, and lack of metaboly. The genus contains only two species. To understand genetic diversity and taxonomy of Cryptoglena species, we analyzed molecular and morphological data from 25 strains.

Phylogenetic Reappraisal of the Genus Monomorphina (Euglenophyceae) Based on Molecular and Morphological Data.

A morphological and molecular examination of the genus Monomorphina was conducted on 46 strains isolated mainly from Korea. The strains were divided into two types based on morphological data: Monomorphina aenigmatica and M. pyrum - like species.

Ultrastructure of the oral apparatus of Mesodinium rubrum from Korea.

Mesodinium rubrum Lohmann is a photosynthetic marine ciliate that has functional chloroplasts of cryptophyte origin. Little is known about the oral ultrastructure of M. rubrum compared with several reports on the sequestration of nuclei and plastids from prey organisms, such as Geminigera cryophila and Teleaulax species.

UV-B affects photosynthesis, ROS production and motility of the freshwater flagellate, Euglena agilis Carter.

The effects of ultraviolet B (UV-B; 295-320 nm) radiation on certain vital physiological (photosynthesis), biochemical (production of reactive oxygen species - ROS) and behavioral (motility and orientation) characteristics were investigated in the unicellular photoautotroph, Euglena agilis Carter. The photosynthetic performance of E. agilis was recorded after exposure of between 15 and 60 min followed by a period of recovery lasting 6-24h under dim light (5-10 μmol photons m(-2) s(-1)).

Heterotrophic feeding as a newly identified survival strategy of the dinoflagellate Symbiodinium.

Survival of free-living and symbiotic dinoflagellates (Symbiodinium spp.) in coral reefs is critical to the maintenance of a healthy coral community. Most coral reefs exist in oligotrophic waters, and their survival strategy in such nutrient-depleted waters remains largely unknown.