bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mixotrophy in the Phototrophic Harmful Alga Cochlodinium polykrikoides (Dinophycean): Prey Species, the Effects of Prey Concentration, and Grazing Impact
Authors: JEONG HAE JIN , YOO YEONG DU , KIM JAE SEONG , KIM TAB HOON , KIM JONG HYEOK , KANG NAM SEON , YIH WONHO 
Published: July 2005

ABSTRACTWe first reported here that the harmful alga Cochlodinium polykrikoides, which had been previously known as an autotrophic dinoflagellate, was a mixotrophic species. We investigated the kinds of prey species and the effects of the prey concentration on the growth and ingestion rates of C. polykrikoides when feeding on an unidentified cryptophyte species (Equivalent Spherical Diameter, ESD = 5.6 μm). We also calculated grazing coefficients by combining field data on abundances of C. polykrikoides and co occurring cryptophytes with laboratory data on ingestion rates obtained in the present study. Cocholdinium polykrikoides fed on prey cells by engulfing the prey through the sulcus. Among the phytoplankton prey offered, C. polykrikoides ingested small phytoplankton species that had ESD's ≤ 11 μm (e.g. the prymnesiophyte Isochrysis galbana, an unidentified cryptophyte, the cryptophyte Rhodomonas salina, the raphidophyte Heterosigma akashiwo, and the dinoflagellate Amphidinium carterae). It did not feed on larger phytoplankton species that had ESD's ≥ 12 μm (e.g. the dinoflagellates Heterocapsa triquetra, Prorocentrum minimum, Scrippsiella sp., Alexandrium tamarense. Prorocentrum micans, Gymnodinium catenatum, Akashiwo sanguinea, and Lingulodinium polyedrum). Specific growth rates of C. polykrikoides on a cryptophyte increased with increasing mean prey concentration, with saturation at a mean prey concentration of approximately 270 ng C ml−1 (i.e. 15,900 cells ml−1)‐ The maximum specific growth rate (mixotrophic growth) of C. polykrikoides on a cryptophyte was 0.324 d∼’, under a 14:10 h light‐dark cycle of 50 μE m−2 s−1, while its growth rate (phototrophic growth) under the same light conditions without added prey was 0.166 d−. Maximum ingestion and clearance rates of C. polykrikoides on a cryptophyte were 0.16 ng C grazer−1d 1 (9.4 cells grazer 1d−1) and 0.33 μ1 grazer 1h−1, respectively. Calculated grazing coefficients by C. polykri koides on cryptophytes were 0.001–0.745 h−1 (i.e. 0.1–53% of cryptophyte populations were removed by a C. polykrikoides population in 1 h). The results of the present study suggest that C. polykrikoides sometimes has a considerable grazing impact on populations of cryptophytes.
Infection of Mouse Dermal Fibroblasts by the Monoxenous Trypanosomatid Protozoa Crithidia deanei and Herpetomonas roitmani
Authors: SANTOS DILVANI O. , BOURGUIGNON SAULO C. , CASTRO HELENA CARLA , SILVA JONATAN S. , FRANCO LEONARDO S. , HESPANHOL RENATA , SOARES MAURILIO J. , CORTE‐REAL SUZANA 
Published: July 2005

ABSTRACTTraditionally, monoxenous trypanosomatid protozoa are not believed to infect vertebrate cells. Using light and electron microscopy, we show that the monoxenous trypanosomatids Crithidia deanei and Herpetomonas roitmani are able to infect dermal mouse fibroblasts in vitro. We present experimental evidence of phagocytosis of these trypanosomatids, and demonstrate their survival in vertebrate cells. This paper raises the question about the role of C. deanei and H. roitmani, and perhaps other monoxenous trypanosomatid species, in opportunistic infections of immunocompromised individuals and cutaneos lesions in vertebrate hosts.Key Words. In vitro infection, monoxenous trypanosomatids, optical and electron microscopy.
Soil Ciliate Species Richness and Abundance Associated with the Rhizosphere of Different Subtropical Plant Species
Authors: ACOSTA‐MERCADO DIMARIS , LYNN DENIS H. 
Published: July 2005

ABSTRACTSoil protozoa, and ciliates in particular, represent a microbial group abundant in the rhizosphere with an influential role on nutrient cycling. Under laboratory conditions, ciliates regulate the size and the composition of bacterial communities, and appear to stimulate ammonification and nitrification. In spite of their important ecological role, our understanding about the factors that control their diversity and abundance in natural forest ecosystems is still rudimentary. Plant species‐specific interactions have been demonstrated between plants and soil bacteria and mycorrhizal fungi, due in part to the release of phytohormones and C‐ and N‐rich exudates. We tested the hypothesis that the rhizosphere environments of different plant species also influence the species richness and abundance of soil ciliates. Plant effect, soil pH, moisture content, microbial biomass C, and inorganic nitrogen were measured among five plant species to determine the best predictor variables for soil ciliate species richness and total abundance in a subtropical moist forest in Puerto Rico. Based on an analysis of variance, we rejected the hypothesis that there was a plant species‐specific effect on soil ciliates, unlike other microbial groups mentioned above. Using multiple regression analysis, we demonstrated that the flush of total inorganic nitrogen was the best predictor variable for both species richness and abundance of ciliates.
Current Progress in the Fatty Acid Metabolism in Cryptosporidium parvum1
Authors: ZHU GUAN 
Published: July 2005

ABSTRACT Cryptosporidium parvum is one of the apicomplexans that can cause severe diarrhea in humans and animals. The slow development of anti‐cryptosporidiosis chemotherapy is primarily due to the poor understanding on the basic metabolic pathways in this parasite. Many well‐defined or promising drug targets found in other apicomplexans are either absent or highly divergent in C. parvum. The recently discovered apicoplast and its associated Type n fatty acid synthetic enzymes in Plasmodium, Toxoplasma, and Eimeria apicomplexans are absent in C. parvum, suggesting this parasite is unable to synthesize fatty acids de novo. However, C. parvum possesses a giant Type I fatty acid synthase (CpFASl) that makes very long chain fatty acids using mediate or long chain fatty acids as precursors. Cryptosporidium also contains a Type I polyketide synthase (CpPKSl) that is probably involved in the production of unknown polyketide(s) from a fatty acid precursor. In addition to CpFASl and CpPKSl, a number of other enzymes involved in fatty acid metabolism have also been identified. These include a long chain fatty acyl elongase (LCE), a cytosolic acetyl‐CoA carboxylase (ACCase), three acyl‐CoA synthases (ACS), and an unusual “long‐type” acyl‐CoA binding protein (ACBP), which allows us to hypothetically reconstruct the highly streamlined fatty acid metabolism in this parasite. However, C. parvum lacks enzymes for the oxidation of fatty acids, indicating that fatty acids are not an energy source for this parasite. Since fatty acids are essential components of all biomembranes, molecular and functional studies on these critical enzymes would not only deepen our understanding on the basic metabolism in the parasites, but also point new directions for the drug discovery against C. parvum and other apicomplexan‐based diseases.
Trichonosema algonquinensis n. sp. (Phylum Microsporidia) in Pectinatella magnificd (Bryozoa: Phylactolaemata) from Algonquin Park, Ontario, Canada
Authors: DESSER SHERWIN S. , KOEHLER ANNE , BARTA JOHN R. , KAMYAB JUBIN , RINGUETTE MAURICE J. 
Published: July 2005

ABSTRACTA new species of microsporidian, Trichonosema algonquinensis, is described from a freshwater bryozoan, Pectinatella magnifica from Ontario, Canada. The parasite develops in epithelial cells and appears as white, spherical masses throughout the tissues. Trichonosema algonquinensis is diplokaryotic, diploblastic and undergoes development in direct contact with the cytoplasm of the host cell. Mature spores are ovoid, tapered at one end, and measure 8.5 ± 0.3 × 4.4 ± 0.1 μm. The polar filament is wound in 20 to 23 helical coils. Although the parasite resembles T. pectinatellae described from the same host in Michigan and Ohio, it differs in the length of the spore and number of coils of the polar filament. Analysis of 16S rDNA by maximum likelihood, parsimony and Baysian inference, complements the morphological data in supporting the placement of T. algonquinensis as a sister species of T. pectinatellae.
The Microtubule Analog Protein, FtsZ, in the Endosymbiont of Trypanosomatid Protozoa
Authors: MOTTA MARIA CRISTINA M. , PICCHI GISELE FERNANDA A. , PALMIÉ‐PEKOTO ISABELLA V. , ROCHA MARCIA R. , DE CARVALHO TÉCIA MARIA U. , MORGADO‐DIAZ JOSE , DE SOUZA WANDERLEY , GOLDENBERG SAMUEL , FRAGOSO STENIO P. 
Published: July 2005

ABSTRACT Blastocrithidia culicis and Crithidia deanei are trypanosomatids that harbor an endosymbiotic bacterium in their cytoplasm. In prokaryotes, numerous proteins are essential for cell division, such as FtsZ, which is encoded by filament‐forming temperaturesensitive (fts) genes. FtsZ is the prokaryotic homolog of eukaryotic tubulin and is present in bacteria and archaea, and has also been identified in mitochondria and chloroplasts. FtsZ plays a key role in the initiation of cytokinesis. It selfassembles into the Z ring, which establishes the division plane during septation. In this study, immunoblotting analysis using a FtsZ polyclonal antibody, revealed a 40‐kDa band characteristic of FtsZ in endosymbiont fractions and in whole trypanosomatid homogenates, but not in whole cell extracts of aposymbiotic strains. Confocal microscopy and ultrastructural analysis revealed a specific and dispersed labeling over the endosymbiont. Bars and ring‐like structures, which are suggestive of the presence of Z‐rings, were never observed, even during the division of the symbiont. This peculiar distribution of FtsZ may represent an arrangement of cytoskeleton protein intermediate between prokaryotic and eukaryotic cells. The endosymbiont ftsz gene was completely sequenced after amplification of DNA from symbiont‐bearing trypanosomatids or from pure endosymbiont fractions, using PCR and specific primers. The sequences obtained from the endosymbionts from C. deanei and B. culicis were very similar, and were most closely related to bacteria from the genus Pseudomonas.
Ribosomal RNA Phylogeny of Bodonid and Diplonemid Flagellates and the Evolution of Euglenozoa
Authors: VON DER HEYDEN SOPHIE , CHAO EMA E. , VICKERMAN KEITH , CAVALIER‐SMITH THOMAS 
Published: July 2005

ABSTRACTEuglenozoa is a major phylum of excavate protozoa (comprising euglenoids, kinetoplastids, and diplonemids) with highly unusual nuclear, mitochondrial, and chloroplast genomes. To improve understanding of euglenozoan evolution, we sequenced nuclear small‐subunit rRNA genes from 34 bodonids (Bodo, Neobodo, Parabodo, Dimastigella‐like, Rhynchobodo, Rhynchomonas, and unidentified strains), nine diplonemids (Diplonema, Rhynchopus), and a euglenoid (Entosiphon). Phylogenetic analysis reveals that diplonemids and bodonids are more diverse than previously recognised, but does not clearly establish the branching order of kinetoplastids, euglenoids, and diplonemids. Rhynchopus is holophyletic; parasitic species arose from within free‐living species. Kinetoplastea (bodonids and trypanosomatids) are robustly holophyletic and comprise a major clade including all trypanosomatids and most bodonids (‘core bodonids’) and a very divergent minor one including Ichthyobodo. The root of the major kinetoplastid clade is probably between trypanosomatids and core bodonids. Core bodonids have three distinct subclades. Clade 1 has two distinct Rhynchobodo‐like lineages; a lineage comprising Dimastigella and Rhynchomonas; and another including Cruzella and Neobodo. Clade 2 comprises Cryptobial Trypanoplasma, Procryptobia, and Parabodo. Clade 3 is an extensive Bodo saltans species complex. Neobodo designis is a vast genetically divergent species complex with mutually exclusive marine and freshwater subclades. Our analysis supports three phagotrophic euglenoid orders: Petalomonadida (holophyletic), Ploeotiida (probably holophyletic), Peranemida (paraphyletic).
Identification and Assignment of Function to the Genes of Aspergillus fumigatus Expressed at 37 °C
Authors: SHANKAR JATA , NIGAM SHAILLY , SAXENA SHWETA , MADAN TARUNA , SARMA P. USHA 
Published: July 2005

ABSTRACT Aspergillus fumigatus, a fungal pathogen, causes a spectrum of allergic and invasive disorders. In order to rapidly identify genes of this fungus relevant for pathogenesis and as potential antifungal drug targets, 125 expressed sequence tags (ESTs) were generated from 200 phage clones of a non‐normalized cDNA library. Out of a novel 68 ESTs, 45 were assigned putative functions based on the sequence similarity. The identities of some of these genes suggest that they may be involved in pathogenesis or autoimmune reactions. Additional genes were identified that are possible targets for the development of antifungal drugs or that may be of use in diagnosing fungal infections.
Molecular Phylogeny of Phyllopharyngean Ciliates and their Group I Introns
Authors: SNOEYENBOS‐WEST OONA L. O. , COLE JEFFREY , CAMPBELL ANNA , COATS D. WAYNE , KATZ LAURA A. 
Published: July 2005

ABSTRACTWe analyzed small subunit ribosomal DNA (ssu‐rDNA) sequences to evaluate both the monophyly of the ciliate class Phyllopharyngea de Puytorac et al. (1974), and relationships among subclasses. Classifications based on morphology and ultrastructure divide the Phyllopharyngea into four subclasses, the Phyllopharyngia, Chonotrichia, Rhynchodia, and Suctoria. Our analyses of ssu‐rDNA genealogies derived from sequence data collected from diverse members representing three of the four subclasses of Phyllopharyngea (Suctoria: Ephelota spp., Prodiscophyra collini, Acineta sp.; Phyllopharyngia: Chlamydodon exocellatus, Chlamydodon triquetrus, Dysteria sp.; and Chonotrichia: Isochona sp.) provide strong support for the monophyly of the Phyllopharyngea, and show that the Chonotrichia emerge from within the Phyllopharyngia. Based on this initial sampling, suctorian budding types are monophyletic, and exogenous budding appears to be basal to evaginative and endogenous budding. Further, we report the discovery of a group I intron at position 891 in the Suctoria Acineta sp. and Tokophrya lemnarum, and a second group I intron at position 1506 in T. lemnarum. These introns represent only the second examples of group I introns in a ciliate ribosomal gene, since the discovery of ribozymes in the LSU rRNA gene of Tetrahymena thermophila. Phylogenetic analyses of Group I introns suggest a complex evolutionary history involving either multiple loses or gains of introns within endogenously budding Suctoria.
Strombidinopsis jeokjo n. sp. (Ciliophora: Choreotrichida) from the Coastal Waters off Western Korea: Morphology and Small Subunit Ribosomal DNA Gene Sequence
Authors: JEONG HAE JIN , KIM JAE SEONG , KIM SANGHEE , SONG JAE YOON , LEE ILHA , LEE GEON‐HYOUNG 
Published: July 2005

ABSTRACTThe planktonic ciliate Strombidinopsis jeokjo n. sp. is described from Quantitative Protargol‐Stained (QPS) preparations, and the sequence of the small subunit rDNA (SSU rDNA) from cultured cells is reported. This species is ovoid and bluntly tapered towards the posterior. The ranges (and mean ± standard deviation, n = 31) of cell length, cell width, and oral diameter of the QPS‐stained specimens were 100–190 μm (149 ± 25), 60–105 μm (79 ± 13), and 55–80 μm (64 ± 5), respectively. Fifteen to seventeen external oral polykinetids had oral membranelle cilia 20–35 μm long. Twenty‐six to twenty‐eight somatic kineties were equally spaced around the cell body and extended from the oral to the posterior regions with 23–44 dikinetids per kinety. Both kinetosomes of each kinetid bore cilia 3–7 μm long. Strombidinopsis jeokjo had two ovoid macronuclei of 25–38 μm × 12–15 μm. When properly aligned, the sequence of the SSU rDNA of S. jeokjo (GenBank Accession No. AJ628250) was approximately 2% different from that of an unidentified Strombidinopsis species (GenBank Accession No. AF399132‐AF399135), the closest species in the SSU rDNA sequence.
Predicted Secondary Structure of the Foraminiferal SSU 3′ Major Domain Reveals a Molecular Synapomorphy for Granuloreticulosean Protists
Authors: HABURA ANDREA , ROSEN DANIEL R. , BOWSER SAMUEL S. 
Published: July 2005

ABSTRACTThe small subunit ribosomal RNA genes of foraminiferal protists are the largest and most divergent of any eukaryote. We demonstrate that this foraminiferal sequence alteration represents a substantial modification to the small subunit ribosomal RNA structure, including a large (up to 350 nt) novel helix in a very well‐conserved portion of the head domain. This modification dates from the beginning of the foraminiferal radiation and, within modern orders, is partially conserved at the sequence level, suggesting that it is a functional part of the ribosome. The pattern of conservation makes it particularly useful for determining lower‐taxon relationships in morphologically ambiguous allogromiid foraminifera.
Differential Stimulation of Microglial Pro‐Inflammatory Cytokines by Acanthamoeba culbertsoni versus Acanthamoeba castellanii
Authors: MARCIANO‐CABRAL FRANCINE , LUDWICK CHRISTINA , PUFFENBARGER ROBYN A. , CABRAL GUY A. 
Published: July 2005

ABSTRACT Acanthamoeba spp. are opportunistic pathogens that cause granulomatous amebic encephalitis. We compared the highly pathogenic species A. culbertsoni to the relatively less pathogenic species A. castellanii for its capacity to elicit from neonatal rat microglia the gene expression of pro‐inflammatory cytokines. Acanthamoeba culbertsoni elicited a robust cytokine gene response by neonatal rat microglia in vitro as compared to A. castellanii. The preponderant cytokine elicited at the mRNA and protein levels was interleukin‐1β. In addition, transmission electron microscopy revealed that microglial cells were capable of phagocytozing A. castellanii. In contrast, A. culbertsoni destroyed microglia. Collectively, these results suggest that a combined action of pro‐inflammatory cytokines and destruction of host cells by amebae contribute to the pathology caused by the more pathogenic species.
Vertical Micro‐Distribution and Response to Nitrogen Deposition of Testate Amoebae in Sphagnum
Authors: MITCHELL EDWARD A. D. , GILBERT DANIEL 
Published: July 2005

ABSTRACTPrevious studies have shown the existence of a vertical micro‐distribution of testate amoebae in the first centimeters of Sphagnum and their response to nutrient enrichment. In order to test the response of testate amoebae to depth and N addition in dry moss carpets recolonizing cutover peatlands, we sampled Sphagnum that had received 0, 1, 3, or 10g N m−2 yr1 for three years. The mosses were cut into three segments: 0–1cm, 1–3cm and 3–5cm and analyzed for testate amoebae. The overall diversity (22 taxa) was high considering the dryness of the site, but the species richness of individual samples was low (mean 6.6). The presence of several species characteristic of wetter conditions suggests that they have a broader tolerance than usually believed and/or have a high colonization potential. Species richness increased with depth. Assulina muscorum was most abundant in the top segment, while Phryganella acropodia, Heleopera rosea and Nebela militaris were most abundant in the deepest segment. Neither the metabolism type nor the shell characteristics significantly explained the vertical distribution of species. There was no overall response of testate amoebae to N, although one species, Bullinularia indica, was significantly more abundant in the fertilized than in the control plots.
Comparative Effectiveness of Light‐Microscopic Techniques and PCR in Detecting Thelohania solenopsae (Microsporidia) Infections in Red Imported Fire Ants (Solenopsis invicta)
Authors: MILKS MAYNARD L. , SOKOLOVA YULIYA Y. , ISAKOVA IRINA A. , FUXA JAMES R. , MITCHELL FORREST , SNOWDEN KAREN F. , VINSON S. BRADLEIGH 
Published: July 2005

ABSTRACT. The main goal of this study was to compare the effectiveness of three staining techniques (calcofluor white M2R, Giemsa and modified trichrome), and the polymerase chain reaction (PCR) in detecting the microsporidium Thelohania solenopsae in red imported fire ants (Solenopsis invicta). The effect of the number of ants in a sample on the sensitivity of the staining techniques and the PCR, and the effect of three DNA extraction protocols on the sensitivity of PCR were also examined. In the first protocol, the ants were macerated and the crude homogenate was used immediately in the PCR. In the second protocol, the homogenate was placed on a special membrane (FTA card) that traps DNA, which is subsequently used in the PCR. In the third protocol, the DNA was purified from the homogenate by traditional phenol‐chloroform extraction. Except for PCR using FTA cards, the sensitivity (number of samples positive for T. solenopsae) of all detection techniques increased with the number of ants in the sample. Overall, Giemsa was the least sensitive of all detection techniques. Calcofluor was more sensitive than modified trichrome with ants from one site and was equally as sensitive as PCR with crude DNA or a FTA card with ants from both sites. Trichrome staining was equally as sensitive as PCR with a FTA card at both sites, but it was less sensitive than PCR with crude DNA at one site. PCR on FTA cards was less sensitive than PCR with crude DNA for ants from one site but not the other. There was no difference whether crude or phenol‐chloroform purified DNA was used as template.In summary, the results of this study show that PCR based on a crude DNA solution is equal to or more sensitive in detecting T. solenopsae than the other detection techniques investigated, and that it can be used as a reliable diagnostic tool for screening field samples of S. invicta for T. solenopsae. Nevertheless, ant smear stained with calcofluor or modified trichrome should be used to buttress findings from PCR.
Nematopsis gigas n. sp. (Apicomplexa), a Parasite of Nerita ascencionis (Gastropoda, Neritidae) from Brazil
Authors: AZEVEDO CARLOS , PADOVAN ISAÍRAS 
Published: July 2005

ABSTRACT. A new species of Nematopsis (Apicomplexa, Porosporidae) is described from the mantle tissues of the seawater gastropod, Nerita ascencionis (Neritidae), collected in the Atlantic North off the coast of “Fernando de Noronha” Island (3° 47′ 57″ S, 32° 25′ 12″ W) situated about 350 km from the northeast coast of Brazil. Numerous oocysts, each contained in a parasitophorous vacuole, were found in the cytoplasm of phagocytes in the mantle tissue of the host. The phagocytes were surrounded by a thin wall composed of lucent material. The phagocyte cytoplasm contained a nucleus surrounded by numerous vesicles and some dense masses. The oocysts were 21.9 ± 0.5 μm long, and 11.5 ± 0.6 μm wide. The oocyst wall was 0.18–0.25 μm thick, and the apical zone contained a micropyle, 1.0–1.2 μm in diameter, covered by a canopy‐like operculum about 0.25 μm thick. Externally, the oocyst wall was surrounded by numerous anastomosing microfibrils attached to the wall and extending towards the periphery of the parasitophorous vacuole. Some microfibrils formed a dense complex network that surrounded the oocyst in the middle of the parasitophorous vacuole, which opened only at the apical zone near the external region of the opercular system.On the basis of the data obtained by light and transmission electron microscopy and host specificity, the gregarine Nematopsis gigas is distinguished from the nearest species as a new species. The taxonomic affinities and morphological comparisons with other similar species of the same genus are discussed.