| a hypothesis for the evolution of nuclear-encoded, plastid-targeted glyceraldehyde-3-phosphate dehydrogenase genes in "chromalveolate" members. | eukaryotes bearing red alga-derived plastids--photosynthetic alveolates (dinoflagellates plus the apicomplexan toxoplasma gondii plus the chromerid chromera velia), photosynthetic stramenopiles, haptophytes, and cryptophytes--possess unique plastid-targeted glyceraldehyde-3-phosphate dehydrogenases (henceforth designated as "gapc1"). pioneering phylogenetic studies have indicated a single origin of the gapc1 enzymes in eukaryotic evolution, but there are two potential idiosyncrasies in the gapc1 ... | 2009 | 19270733 |
| a common red algal origin of the apicomplexan, dinoflagellate, and heterokont plastids. | the discovery of a nonphotosynthetic plastid in malaria and other apicomplexan parasites has sparked a contentious debate about its evolutionary origin. molecular data have led to conflicting conclusions supporting either its green algal origin or red algal origin, perhaps in common with the plastid of related dinoflagellates. this distinction is critical to our understanding of apicomplexan evolution and the evolutionary history of endosymbiosis and photosynthesis; however, the two plastids are ... | 2010 | 20534454 |
| nonreductive iron uptake mechanism in the marine alveolate chromera velia. | chromera velia is a newly cultured photosynthetic marine alveolate. this microalga has a high iron requirement for respiration and photosynthesis, although its natural environment contains less than 1 nm of this metal. we found that this organism uses a novel mechanism of iron uptake, differing from the classic reductive and siderophore-mediated iron uptake systems characterized in the model yeast saccharomyces cerevisiae and present in most yeasts and terrestrial plants. c. velia has no trans-p ... | 2010 | 20724644 |
| identification of plant-like galactolipids in chromera velia, a photosynthetic relative of malaria parasites. | apicomplexa are protist parasites that include plasmodium spp., the causative agents of malaria, and toxoplasma gondii, responsible for toxoplasmosis. most apicomplexa possess a relict plastid, the apicoplast, which was acquired by secondary endosymbiosis of a red alga. despite being nonphotosynthetic, the apicoplast is otherwise metabolically similar to algal and plant plastids and is essential for parasite survival. previous studies of toxoplasma gondii identified membrane lipids with some str ... | 2011 | 21712377 |
| Red and problematic green phylogenetic signals among thousands of nuclear genes from the photosynthetic and apicomplexa-related Chromera velia. | The photosynthetic and basal apicomplexan Chromera velia was recently described, expanding the membership of this otherwise nonphotosynthetic group of parasite protists. Apicomplexans are alveolates with secondary plastids of red algal origin, but the evolutionary history of their nuclear genes is still actively discussed. Using deep sequencing of expressed genes, we investigated the phylogenetic affinities of a stringent filtered set of 3,151 expressed sequence tag-contigs by generating cluster ... | 2011 | 21965651 |
| budding of the alveolate alga vitrella brassicaformis resembles sexual and asexual processes in apicomplexan parasites. | ease of cultivation and availability of genomic data promoted intensive research of free-living phototrophic relatives of apicomplexans, i.e. chromera velia and vitrella brassicaformis. chromera and vitrella differ significantly in their physiology, morphology, phylogenetic position and genomic features, but vitrella has not gained as much attention. here we describe two types of vitrella zoosporangia. one contains zoospores surrounded by roughly structured matter, with an intracytoplasmic axone ... | 2017 | 28061382 |
| high photochemical trapping efficiency in photosystem i from the red clade algae chromera velia and phaeodactylum tricornutum. | in the present work, we report the first comparative spectroscopic investigation between photosystem i (psi) complexes isolated from two red clade algae. excitation energy transfer was measured in psi from chromera velia, an alga possessing a split psaa protein, and from the model diatom phaeodactylum tricornutum. in both cases, the estimated effective photochemical trapping time was in the 15-25ps range, i.e. twice as fast as higher plants. in contrast to green phototrophs, the trapping time wa ... | 2017 | 27737767 |
| pigment structure in the fcp-like light-harvesting complex from chromera velia. | resonance raman spectroscopy was used to evaluate pigment structure in the fcp-like light-harvesting complex of chromera velia (chromera light-harvesting complex or clh). this antenna protein contains chlorophyll a, violaxanthin and a new isofucoxanthin-like carotenoid (called ifx-l). we show that ifx-l is present in two non-equivalent binding pockets with different conformations, having their (0,0) absorption maxima at 515 and 548nm respectively. in this complex, only one violaxanthin populatio ... | 2016 | 27544823 |
| wider than thought phylogenetic occurrence of apicortin, a characteristic protein of apicomplexan parasites. | apicomplexan parasites cause serious illnesses, including malaria, in humans and domestic animals. the presence of apicortins is predominantly characteristic of this phylum. all the apicomplexan species sequenced contain an apicortin which unites two conserved domains: dcx and partial p25alpha. this paper identifies novel apicortin orthologs in silico and corrects in several cases the erroneous sequences of hypothetical apicortin proteins of cryptosporidium, eimeria, and theileria genera publish ... | 2016 | 27282556 |
| violaxanthin inhibits nonphotochemical quenching in light-harvesting antenna of chromera velia. | non-photochemical quenching (npq) is a photoprotective mechanism in light-harvesting antennae. npq is triggered by chloroplast thylakoid lumen acidification and is accompanied by violaxanthin de-epoxidation to zeaxanthin, which further stimulates npq. in the present study, we show that violaxanthin can act in the opposite direction to zeaxanthin because an increase in the concentration of violaxanthin reduced npq in the light-harvesting antennae of chromera velia. the correlation overlapped with ... | 2016 | 26988983 |
| architecture of the light-harvesting apparatus of the eustigmatophyte alga nannochloropsis oceanica. | we present proteomic, spectroscopic, and phylogenetic analysis of light-harvesting protein (lhc) function in oleaginous nannochloropsis oceanica (eustigmatophyta, stramenopila). n. oceanica utilizes lhcs of multiple classes: lhcr-type proteins (related to red algae lhci), lhcv (vcp) proteins (violaxanthin-containing lhcs related to lhcf/fcp proteins of diatoms), lhcx proteins (related to lhcx/lhcsr of diatoms and green algae), and lhc proteins related to red-clh of chromera velia. altogether, 17 ... | 2016 | 26913864 |
| primary structure of 28s rrna gene confirms monophyly of free-living heterotrophic and phototrophic apicomplexans (alveolata). | phylogenetic analysis of large subunit ribosomal rna (lsu rrna or 28s rrna) gene sequences from free-living predatory flagellates colpodella angusta, voromonas pontica, and alphamonas edax (apicomplexa) confirms their close relationship with chromerids chromera velia and vitrella brassicaformis, which possess a functional photosynthetic plastid. together these organisms form a sister group to parasitic apicomplexans (coccidians and gregarines, or sporozoans sensu lato). this result agrees with t ... | 2015 | 26615441 |
| diversity of extracellular proteins during the transition from the 'proto-apicomplexan' alveolates to the apicomplexan obligate parasites. | the recent completion of high-coverage draft genome sequences for several alveolate protozoans - namely, the chromerids, chromera velia and vitrella brassicaformis; the perkinsid perkinsus marinus; the apicomplexan, gregarina niphandrodes, as well as high coverage transcriptome sequence information for several colpodellids, allows for new genome-scale comparisons across a rich landscape of apicomplexans and other alveolates. genome annotations can now be used to help interpret fine ultrastructur ... | 2016 | 26585326 |
| different response of carbonyl carotenoids to solvent proticity helps to estimate structure of the unknown carotenoid from chromera velia. | in order to estimate the possible structure of the unknown carbonyl carotenoid related to isofucoxanthin from chromera velia denoted as isofucoxanthin-like carotenoid (ifx-l), we employed steady-state and ultrafast time-resolved spectroscopic techniques to investigate spectroscopic properties of ifx-l in various solvents. the results were compared with those measured for related carotenoids with known structure: fucoxanthin (fx) and isofucoxanthin (ifx). the experimental data were complemented b ... | 2015 | 26362118 |
| chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites. | the eukaryotic phylum apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. we sequenced nuclear genomes of chromera velia and vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adapt ... | 2015 | 26175406 |
| phylogenetic analysis of nucleus-encoded acetyl-coa carboxylases targeted at the cytosol and plastid of algae. | the understanding of algal phylogeny is being impeded by an unknown number of events of horizontal gene transfer (hgt), and primary and secondary/tertiary endosymbiosis. through these events, previously heterotrophic eukaryotes developed photosynthesis and acquired new biochemical pathways. acetyl-coa carboxylase (accase) is a key enzyme in the fatty acid synthesis and elongation pathways in algae, where accase exists in two locations (cytosol and plastid) and in two forms (homomeric and heterom ... | 2015 | 26131555 |
| the organellar genomes of chromera and vitrella, the phototrophic relatives of apicomplexan parasites. | apicomplexa are known to contain greatly reduced organellar genomes. their mitochondrial genome carries only three protein-coding genes, and their plastid genome is reduced to a 35-kb-long circle. the discovery of coral-endosymbiotic algae chromera velia and vitrella brassicaformis, which share a common ancestry with apicomplexa, provided an opportunity to study possibly ancestral forms of organellar genomes, a unique glimpse into the evolutionary history of apicomplexan parasites. the structura ... | 2015 | 26092225 |
| sterol composition and biosynthetic genes of vitrella brassicaformis, a recently discovered chromerid: comparison to chromera velia and phylogenetic relationship with apicomplexan parasites. | vitrella brassicaformis is the second discovered species in the chromerida, and first in the family vitrellaceae. chromera velia, the first discovered species, forms an independent photosynthetic lineage with v. brassicaformis, and both are closely related to peridinin-containing dinoflagellates and nonphotosynthetic apicomplexans; both also show phylogenetic closeness with red algal plastids. we have utilized gas chromatography/mass spectrometry to identify two free sterols, 24-ethylcholest-5-e ... | 2015 | 25996517 |
| divergent mitochondrial respiratory chains in phototrophic relatives of apicomplexan parasites. | four respiratory complexes and atp-synthase represent central functional units in mitochondria. in some mitochondria and derived anaerobic organelles, a few or all of these respiratory complexes have been lost during evolution. we show that the respiratory chain of chromera velia, a phototrophic relative of parasitic apicomplexans, lacks complexes i and iii, making it a uniquely reduced aerobic mitochondrion. in chromera, putative lactate:cytochrome c oxidoreductases are predicted to transfer el ... | 2015 | 25660376 |
| highly efficient energy transfer from a carbonyl carotenoid to chlorophyll a in the main light harvesting complex of chromera velia. | we report on energy transfer pathways in the main light-harvesting complex of photosynthetic relative of apicomplexan parasites, chromera velia. this complex, denoted clh, belongs to the family of fcp proteins and contains chlorophyll (chl) a, violaxanthin, and the so far unidentified carbonyl carotenoid related to isofucoxanthin. the overall carotenoid-to-chl-a energy transfer exhibits efficiency over 90% which is the largest among the fcp-like proteins studied so far. three spectroscopically d ... | 2014 | 24928296 |
| unusual features of the high light acclimation of chromera velia. | in the present study, the high light (hl) acclimation of chromera velia (chromerida) was studied. hl-grown cells exhibited an increased cell volume and dry weight compared to cells grown at medium light (ml). the chlorophyll (chl) a-specific absorption spectra ([formula: see text]) of the hl cells showed an increased absorption efficiency over a wavelength range from 400 to 750 nm, possibly due to differences in the packaging of chl a molecules. in hl cells, the size of the violaxanthin (v) cycl ... | 2014 | 24906888 |
| the effect of nitrogen limitation on acetyl-coa carboxylase expression and fatty acid content in chromera velia and isochrysis aff. galbana (tiso). | lipids from microalgae have become a valuable product with applications ranging from biofuels to human nutrition. while changes in fatty acid (fa) content and composition under nitrogen limitation are well documented, the involved molecular mechanisms are poorly understood. acetyl-coa carboxylase (accase) is a key enzyme in the fa synthesis and elongation pathway. plastidial and cytosolic accases provide malonyl-coa for de novo fa synthesis in the plastid and fa elongation in the endoplasmic ret ... | 2014 | 24731716 |
| chromera velia, endosymbioses and the rhodoplex hypothesis--plastid evolution in cryptophytes, alveolates, stramenopiles, and haptophytes (cash lineages). | the discovery of chromera velia, a free-living photosynthetic relative of apicomplexan pathogens, has provided an unexpected opportunity to study the algal ancestry of malaria parasites. in this work, we compared the molecular footprints of a eukaryote-to-eukaryote endosymbiosis in c. velia to their equivalents in peridinin-containing dinoflagellates (pcd) to reevaluate recent claims in favor of a common ancestry of their plastids. to this end, we established the draft genome and a set of full-l ... | 2014 | 24572015 |
| novel type of red-shifted chlorophyll a antenna complex from chromera velia: ii. biochemistry and spectroscopy. | a novel chlorophyll a containing pigment-protein complex expressed by cells of chromera velia adapted to growth under red/far-red illumination [1]. purification of the complex was achieved by means of anion-exchange chromatography and gel-filtration. the antenna is shown to be an aggregate of ~20kda proteins of the light-harvesting complex (lhc) family, unstable in the isolated form. the complex possesses an absorption maximum at 705nm at room temperature in addition to the main chlorophyll a ma ... | 2014 | 24486443 |
| novel type of red-shifted chlorophyll a antenna complex from chromera velia. i. physiological relevance and functional connection to photosystems. | chromera velia is an alveolate alga associated with scleractinian corals. here we present detailed work on chromatic adaptation in c. velia cultured under either blue or red light. growth of c. velia under red light induced the accumulation of a light harvesting antenna complex exhibiting unusual spectroscopic properties with red-shifted absorption and atypical 710nm fluorescence emission at room temperature. due to these characteristic features the complex was designated "red-shifted chromera l ... | 2014 | 24480388 |
| evolution of chloroplast transcript processing in plasmodium and its chromerid algal relatives. | it is well understood that apicomplexan parasites, such as the malaria pathogen plasmodium, are descended from free-living algae, and maintain a vestigial chloroplast that has secondarily lost all genes of photosynthetic function. recently, two fully photosynthetic relatives of parasitic apicomplexans have been identified, the 'chromerid' algae chromera velia and vitrella brassicaformis, which retain photosynthesis genes within their chloroplasts. elucidating the processes governing gene express ... | 2014 | 24453981 |
| the flagellar contribution to the apical complex: a new tool for the eukaryotic swiss army knife? | apicomplexa are an ancient group of single-celled pathogens of humans and animals that include the etiological agents of such devastating plagues as malaria, toxoplasmosis, and coccidiosis. the defining feature of the apicomplexa is the apical complex, the invasion machinery used to gain access to host cells. evidence gathered from apicomplexans and their closest relatives argues that the apical complex is an extreme example of flagellum adaptability. the value of non-apicomplexan models, such a ... | 2014 | 24411691 |
| increased growth and pigment content of chromera velia in mixotrophic culture. | the alveolate microalga chromera velia is an evolutionarily significant organism, representing the closest photosynthetic relative of the parasitic apicomplexa. chromera velia has been detected in and isolated from several stony corals and can be readily cultured in vitro under strictly autotrophic conditions. however, little is known about the ecology of this organism in the coral holobiont, an environment in which it could potentially access abundant organic carbon sources. to understand the r ... | 2014 | 24372150 |
| combined amplicon pyrosequencing assays reveal presence of the apicomplexan "type-n" (cf. gemmocystis cylindrus) and chromera velia on the great barrier reef, australia. | the coral is predominantly composed of the metabolically dependent coral host and the photosynthetic dinoflagellate symbiodinium sp. the system as a whole interacts with symbiotic eukaryotes, bacteria and viruses. gemmocystiscylindrus (cf. "type-n" symbiont) belonging to the obligatory parasitic phylum apicomplexa (alveolata) is ubiquitous in the caribbean coral, but its presence in the great barrier reef coral has yet to be documented. approaches allowing identification of the healthy community ... | 2013 | 24098768 |
| evidence of intraflagellar transport and apical complex formation in a free-living relative of the apicomplexa. | since its first description, chromera velia has attracted keen interest as the closest free-living relative of parasitic apicomplexa. the life cycle of this unicellular alga is complex and involves a motile biflagellate form. flagella are thought to be formed in the cytoplasm, a rare phenomenon shared with plasmodium in which the canonical mode of flagellar assembly, intraflagellar transport, is dispensed with. here we demonstrate the expression of intraflagellar transport components in c. velia ... | 2014 | 24058169 |
| split photosystem protein, linear-mapping topology, and growth of structural complexity in the plastid genome of chromera velia. | the canonical photosynthetic plastid genomes consist of a single circular-mapping chromosome that encodes a highly conserved protein core, involved in photosynthesis and atp generation. here, we demonstrate that the plastid genome of the photosynthetic relative of apicomplexans, chromera velia, departs from this view in several unique ways. core photosynthesis proteins psaa and atpb have been broken into two fragments, which we show are independently transcribed, oligou-tailed, translated, and a ... | 2013 | 23974208 |
| chromera velia: the missing link in the evolution of parasitism. | since the pivotal publication announcing the discovery of chromera velia in 2008, there has been a flurry of interest and research into this novel alga. found by chance while studying the symbionts of corals in australian reefs, c. velia has turned out to be a very important organism. it holds a unique position as the evolutionary intermediate between photosynthetic dinoflagellate algae and parasitic apicomplexans. biological characterization has revealed similarities to both dinoflagellates and ... | 2013 | 23942150 |
| light harvesting complexes of chromera velia, photosynthetic relative of apicomplexan parasites. | the structure and composition of the light harvesting complexes from the unicellular alga chromera velia were studied by means of optical spectroscopy, biochemical and electron microscopy methods. two different types of antennae systems were identified. one exhibited a molecular weight (18-19kda) similar to fcp (fucoxanthin chlorophyll protein) complexes from diatoms, however, single particle analysis and circular dichroism spectroscopy indicated similarity of this structure to the recently char ... | 2013 | 23428396 |
| a broad phylogenetic survey unveils the diversity and evolution of telomeres in eukaryotes. | telomeres, ubiquitous and essential structures of eukaryotic chromosomes, are known to come in a variety of forms, but knowledge about their actual diversity and evolution across the whole phylogenetic breadth of the eukaryotic life remains fragmentary. to fill this gap, we employed a complex experimental approach to probe telomeric minisatellites in various phylogenetically diverse groups of algae. our most remarkable results include the following findings: 1) algae of the streptophyte class kl ... | 2013 | 23395982 |
| photosynthesis in chromera velia represents a simple system with high efficiency. | chromera velia (alveolata) is a close relative to apicomplexan parasites with a functional photosynthetic plastid. even though c. velia has a primitive complement of pigments (lacks chlorophyll c) and uses an ancient type ii form of rubisco, we found that its photosynthesis is very efficient with the ability to acclimate to a wide range of irradiances. c. velia maintain similar maximal photosynthetic rates when grown under continual light-limited (low light) or light-saturated (high light) condi ... | 2012 | 23071705 |
| chromera velia is endosymbiotic in larvae of the reef corals acropora digitifera and a. tenuis. | scleractinian corals occur in symbiosis with a range of organisms including the dinoflagellate alga, symbiodinium, an association that is mutualistic. however, not all symbionts benefit the host. in particular, many organisms within the microbial mucus layer that covers the coral epithelium can cause disease and death. other organisms in symbiosis with corals include the recently described chromera velia, a photosynthetic relative of the apicomplexan parasites that shares a common ancestor with ... | 2013 | 23063731 |
| re-evaluating the green versus red signal in eukaryotes with secondary plastid of red algal origin. | the transition from endosymbiont to organelle in eukaryotic cells involves the transfer of significant numbers of genes to the host genomes, a process known as endosymbiotic gene transfer (egt). in the case of plastid organelles, egts have been shown to leave a footprint in the nuclear genome that can be indicative of ancient photosynthetic activity in present-day plastid-lacking organisms, or even hint at the existence of cryptic plastids. here, we evaluated the impact of egt on eukaryote genom ... | 2012 | 22593553 |
| sterol composition and biosynthetic genes of the recently discovered photosynthetic alveolate, chromera velia (chromerida), a close relative of apicomplexans. | chromera velia is a recently discovered, photosynthetic, marine alveolate closely related to apicomplexan parasites, and more distantly to perkinsids and dinoflagellates. to date, there are no published studies on the sterols of c. velia. because apicomplexans and perkinsids are not known to synthesize sterols de novo, but rather obtain them from their host organisms, our objective was to examine the composition of the sterols of c. velia to assess whether or not there is any commonality with di ... | 2012 | 22313428 |
| identification of chromera velia by fluorescence in situ hybridization. | chromera velia is evolutionarily the closest free-living and photosynthetic organism to the medically important obligatory parasitic apicomplexans that cause diseases including malaria and toxoplasmosis. in this study, a novel oligonucleotide probe targeting c. velia's small subunit ribosomal rna was designed. to enable usage of this probe as a detection tool, a fluorescence in situ hybridization (fish) protocol was optimized. the results obtained showed that when used in combination, the c. vel ... | 2012 | 22211939 |
| phylogenetic analysis of the light-harvesting system in chromera velia. | chromera velia is a newly discovered photosynthetic eukaryotic alga that has functional chloroplasts closely related to the apicoplast of apicomplexan parasites. recently, the chloroplast in c. velia was shown to be derived from the red algal lineage. light-harvesting protein complexes (lhc), which are a group of proteins involved in photon capture and energy transfer in photosynthesis, are important for photosynthesis efficiency, photo-adaptation/accumulation and photo-protection. although thes ... | 2012 | 22161624 |
| morphology, ultrastructure and life cycle of vitrella brassicaformis n. sp., n. gen., a novel chromerid from the great barrier reef. | chromerida are photoautotrophic alveolates so far only isolated from corals in australia. it has been shown that these secondary plastid-containing algae are closely related to apicomplexan parasites and share various morphological and molecular characters with both apicomplexa and dinophyta. so far, the only known representative of the phylum was chromera velia. here we provide a formal description of another chromerid, vitrella brassicaformis gen. et sp. nov., complemented with a detailed stud ... | 2012 | 22055836 |
| tetrapyrrole synthesis of photosynthetic chromerids is likely homologous to the unusual pathway of apicomplexan parasites. | most photosynthetic eukaryotes synthesize both heme and chlorophyll via a common tetrapyrrole biosynthetic pathway starting from glutamate. this pathway was derived mainly from cyanobacterial predecessor of the plastid and differs from the heme synthesis of the plastid-lacking eukaryotes. here, we show that the coral-associated alveolate chromera velia, the closest known photosynthetic relative to apicomplexa, possesses a tetrapyrrole pathway that is homologous to the unusual pathway of apicompl ... | 2011 | 21963666 |
| non-photochemical fluorescence quenching in chromera velia is enabled by fast violaxanthin de-epoxidation. | non-photochemical quenching (npq) is a mechanism protecting photosynthetic organisms against excessive irradiation. here, we analyze a unique npq mechanism in the alga chromera velia, a recently discovered close relative of apicomplexan parasites. npq in c. velia is enabled by an operative and fast violaxanthin de-epoxidation to zeaxanthin without accumulation of antheraxanthin. in c. velia violaxanthin also serves as a main light-harvesting pigment. therefore, in c. velia violaxanthin acts as a ... | 2011 | 21570974 |
| effect of nutrient concentration and salinity on immotile-motile transformation of chromera velia. | chromera velia (chromerida: alveolata) is a photosynthetic, unicellular organism closely related to parasitic apicomplexa. diurnal rhythmicity of an immotile-motile transformation has been observed but its role in the life cycle remains largely unknown. using a multiwell system, we show that salinity and f-medium concentration significantly affect the percentage of motile c. velia cells. an inverse relationship between salinity and motility in c. velia occurred, and flagellation was also suppres ... | 2015 | 20662995 |
| surface and flagella morphology of the motile form of chromera velia revealed by field-emission scanning electron microscopy. | chromera velia(chromerida; alveolata) is an autotrophic protist isolated from stony corals.ch. veliapossesses a chloroplast thought to be most closely related to the apicoplasts of non-photosynthetic apicomplexa. phylogenetic analyses placech. veliaas a close relative of parasitic apicomplexa and predatory colpodellids. we have used field-emission scanning electron microscopy of cells sputter-coated with gold or chromium and non-coated cells to characterise the surface ultrastructure of the moti ... | 2011 | 20643581 |
| morphology and ultrastructure of multiple life cycle stages of the photosynthetic relative of apicomplexa, chromera velia. | chromera veliais a photosynthetic alga with a secondary plastid that represents the closest known photosynthetic relative of the apicomplexan parasites. the original description of this organism was based on brownish, immotile coccoid cells, which is the predominating stage ofc. veliain the culture. here we provide a detailed light and electron microscopy description of coccoid cells ofc. veliaand a previously undocumented bi-flagellated stage that is highly motile and moves in a characteristic ... | 2011 | 20643580 |
| evolution of the apicoplast and its hosts: from heterotrophy to autotrophy and back again. | the photosynthetic origin of apicomplexan parasites was proposed upon the discovery of a reduced non-photosynthetic plastid termed the apicoplast in their cells. although it is clear that the apicoplast has evolved through a secondary endosymbiosis, its particular origin within the red or green plastid lineage remains controversial. the recent discovery of chromera velia, the closest known photosynthetic relative to apicomplexan parasites, sheds new light on the evolutionary history of alveolate ... | 2009 | 18822291 |