bluuebunny/crossref_metadata_2025 huggingface dataset:
Coccidian Parasites (Apicomplexa: Eimeriidae) from Insectivores. IV. Four New Species in Talpa europaea from England1
Authors: DUSZYNSKI DONALD W. , WATTAM ALICE R.
Published: May 2007

ABSTRACT. Moles from England were examined for coccidian oocysts and all 64 Talpa europaea were infected; of 64 infected hosts, 56 (88%) had multiple infections representing two to six coccidian species when examined. Oocysts in 31 of the 64 samples remained unsporulated. Three eimerians and one isosporan were studied from the 33 fecal samples that had sporulated oocysts and these are described as new species; Cyclospora talpae Pellérdy & Tanyi, 1968, and Isospora sofiae (Golemansky, 1978) Levine & Ivens, 1979, are redescribed; and Cyclospora sp., similar to C. talpae, is discussed. Sporulated oocysts of C. talpae are ellipsoidal, 14.3 × 9.6 (12–19 × 6–13) μm with sporocysts ovoid, 9.4 × 5.7 (6–13 × 4–8) μm; it was found in 21 of the 33 (63.6%) sporulated samples. Sporulated oocysts of Cyclospora sp. are subspheroidal to ellipsoidal, 12.5 × 8.9 (10–14 × 6–12) μm with sporocysts ovoid, 8.6 × 5.3 (6–10 × 4–6) μm; it was found in 21 of the 33 (63.6%) sporulated samples. Sporulated oocysts of Eimeria avonensis n. sp. are elongate‐ellipsoidal, 15.0 × 9.6 (13–20 × 7–12) μm with sporocysts ovoid, 6.6 × 3.6 (5–9 × 3–7) μm; it was found in 15 of the 33 (45.5%) sporulated samples. Sporulated oocysts of Eimeria berea n. sp. are subspheroidal, 12.1 × 10.5 (10–15 × 8–14) μm with sporocysts ovoid, 6.3 × 3.9 (5–10 × 2–5) μm; it was found in 8 of the 33 (24.2%) sporulated samples. Sporulated oocysts of Eimeria globula n. sp. are spheroidal, 20.9 × 19.9 (19–24 × 17–21) μm with sporocysts elongate‐ovoid, 11.5 × 6.9 (9–16 × 6–9) μm; it was found in 3 of the 33 (9.1%) sporulated samples. Sporulated oocysts of Isospora sporopointaea n. sp. are subellipsoidal to ellipsoidal, 17.1 × 11.4 (13–21 × 8–14) μm with sporocysts ellipsoidal with both ends pointed, 11.9 × 5.9 (9–16 × 4–8) μm; it was found in 27 of the 33 (81.8%) sporulated samples. Sporulated oocysts of I. sofiae are spheroidal to subspheroidal, 12.2 × 11.0 (9–16 × 8–15) μm with sporocysts ovoid, 9.1 × 5.2 (6–13 × 3–8) μm; it was found in 25 of the 33 (75.8%) sporulated samples. To date, the coccidian parasites of talpids include two cyclosporans, 12 eimerians, and six isosporans, exclusive of the four new species described here.
Linkage Disequilibrium in Natural Populations of Trypanosoma cruzi (Flagellate), the Agent of Chagas’ Disease1
Authors: ZHANG QIFA , TIBAYRENC M. , AYALA F. J.
Published: May 2007

ABSTRACT. We have studied linkage disequilibrium in natural populations of Trypanosoma cruzi, the agent of Chagas’ disease, by analyzing (i) a set of 524 stocks from the whole geographical range of the parasite, characterized at four gene loci coding for enzymes; (ii) a subsample of 121 stocks characterized at 12 enzyme loci; and (iii) a subset of 386 stocks from six locations in Bolivia, characterized by four enzyme loci. Our results show that the linkage disequilibrium reaches the maximum possible value, given the observed allelic frequencies, for almost all the locus pairs. This result is most consistent with the hypothesis that genetic recombination is absent or very rare in T. cruzi natural populations. Partition of the linkage disequilibrium variance for the six Bolivian populations shows that both inter‐ and intrapopulation components are substantial and that the relationships among the components are DIS2 < DST2, and D'IS2 < D'ST2. These inequalities are interpreted as the result of an interplay between genetic drift, rare or absent mating, and clonal selection in generating linkage disequilibrium in T. cruzi populations.
A New Family, Genus, and Seven New Species of Entodiniomorphida (Protozoa) from the Gut of African Rhinoceros
Authors: VAN HO YEN W. , GILCHRIST F. M. C. , HAMILTON‐ATTWELL V. L.
Published: May 2007

ABSTRACT. This report deals with a group of ciliated protozoa with short ciliary bands found mainly in the cecum of black rhinoceros, Diceros bicornis (Linnaeus, 1758), and white rhinoceros, Ceratotherium simum (Burchell, 1817) from southern Africa. A new genus, Rhinozeta, based on the sum total of the characteristics of seven new related species is described. The species described are R. rhinozeta n. sp., R. triciliata n. sp., R. caecalis n. sp., R. addoensis n. sp., R. cristata n. sp., R. multiplatus n. sp., and R. unilaminatus n. sp. The specific features of the new genus make it incompatible with any of the known families of the Order Entodiniomorphida containing the ciliates present in the digestive tract of herbivorous mammals. This merits the creation of a new family, the Rhinozetidae.
Trypanosoma cruzi: A Specific Surface Marker for the Amastigote Form1
Authors: LIMA MARIA F. , BELTZ LISA A. , KIERSZENBAUM FELIPE
Published: May 2007

ABSTRACT. Among the known life cycle stages of Trypanosoma cruzi only the amastigote form bound lactoferrin (LF), a glycoprotein produced by neutrophils. This capacity was readily demonstrable by indirect immunofluorescence in amastigotes derived from mice, a mammalian cell culture, or grown in an axenic medium. No LF binding was detectable on trypomastigotes from blood or mammalian cells, insect‐derived metacyclics or epimastigotes, or on epimastigotes grown in Warren's medium. Serum levels of LF were increased in mice acutely infected with T. cruzi, and amastigotes from the spleens of these animals were found to have the glycoprotein on their surface. The amastigote LF receptor may have biological significance in parasite‐host interaction since mononuclear phagocytes also express a LF receptor, and treatment of these cells with LF has been shown to increase their capacities to take up and kill T. cruzi amastigotes in vitro. The LF receptor is the first marker for T. cruzi amastigotes for which a naturally occurring ligand has been described.
Fluorescence‐Activated Cell‐Sorting Analysis of Fibronectin Peptides Binding to Trypanosoma cruzi Trypomastigotes1
Authors: OUAISSI M. ALI , KUSNIERZ J. P. , GRAS‐MASSE H. , DROBECQ H. , VELGE P. , CORNETTE J. , CAPRON A. , TARTAR A.
Published: May 2007

ABSTRACT. The binding of synthetic peptides modeled from the sequence of the cell attachment site of fibronectin to T. cruzi trypomastigote surface receptors was investigated by fluorescence‐activated cell‐sorting analysis using fluorescein‐labeled peptides. Peptides with the sequence Arg‐Gly‐Asp‐Ser bound to the parasite surface. A low percentage of fresh parasites recently liberated from infected fibroblasts had the capacity to bind the peptide. In contrast, these parasites showed a time‐dependent several‐fold increase in their ability to bind the Arg‐Gly‐Asp‐Ser‐containing peptides during extracellular incubation. From these observations, it appears that the expression of surface receptors on a particular, mature stage of the parasite parallels its ability to adhere to and infect host cells.
Clonal and Geographic Distribution of a Surface Antigen of Tritrichomonas foetus1
Authors: BURGESS DONALD E.
Published: May 2007

ABSTRACT. Geographically diverse strains and clones of Tritrichomonas foetus have been examined with respect to their expression of a major surface antigen of approximately 150,000 relative molecular weight (Mr), designated the 150 Ag. Radioiodination and 13S‐methionine labeling of T. foetus followed by immunoprecipitation with monoclonal antibodies (MAbs), separation of polypeptides by SDS‐PAGE, and autoradiography or fluorography confirmed the parasite origin of the 150 Ag. The results of flow cytometry analysis employing a panel of MAbs against live T. foetus parasites revealed that from 5 to 84% of individuals in a given population of T. foetus expressed a particular epitope of the 150 Ag. All strains and clones were positive for surface expression of epitopes of this antigen. These results show that the 150 Ag is widely distributed in populations of T. foetus, confirm the surface location of this antigen, and suggest its importance as a target for protective immune responses.
Plasmodium falciparum Glycolipid Synthesis: Constant and Variant Molecules of Isolates and of Strains with Differing Knob and Cytoadherence Phenotype
Authors: SHERWOOD JAMES A. , SPITALNIK STEVEN L. , SUAREZ SUZANNE C. , MARSH KEVIN , HOWARD RUSSELL J.
Published: May 2007

ABSTRACT. Plasmodium falciparum‐infecled erythrocytes were metabolically labeled with tritiated glucosamine. Lipid extracts were analyzed by high‐performance thin‐layer chromatography to compare labeled molecules of eleven isolates from patients, six cytoadherent in vitro strains, and two knobbed and two knobless strains from Aotus monkeys. Up to nineteen labeled bands were identified. Glycolipid GL1, previously identified in Malayan Camp, was present in all isolates and strains. Other molecules, between CG and GM1 and between GM1 and GD1a, varied in mobility or presence. There was no apparent association between labeled molecules and the presence of knobs or the property of cytoadherence.
Ultrastructural Features of Three Ectocommensal Protozoa Attached to the Gills of the Red Swamp Crawfish, Procambarus clarkii (Crustacea: Decapoda)1
Authors: VOGELBEIN WOLFGANG K. , THUNE RONALD L.
Published: May 2007

Because heavy branchial infestations are thought to interfere with respiration, we examined the attachment of three stalked ciliates commonly found in the branchial chambers of Louisiana crawfish. Attachments by Cothurnia sp., Epistylis sp. and Acineta sp. differ in their fine structure. Stalks of the peritrichous ciliates. Cothurnia and Epistylis, contain striated tubules that differ in their arrangement, diameter, and in the periodicity of their striations. In both species the striated tubules branch within the basal disk and attach to a pad of adhesive material secreted by the organism during initial attachment to the gill surface. The stalk of the suctorian Acineta is composed of a striated honeycomb‐like matrix. Within the basal disc the matrix is disorganized; however, striated elements anchor the stalk to a pad of adhesive material. Attachment sites also differ in the amount of secretory material deposited. Cothurnia forms a multi‐layered, granular pad; Epistylis forms an indistinct, microfibrillar layer, and Acineta deposits a thick mucoid pad. None of the ciliates appear to damage the gill epicuticle nor is there an obvious host response. Harmful effects are probably limited to a decrease in respiratory surface area and disruption of normal water flow patterns. This may impair respiration sufficiently to increase the susceptibility of crawfish to low dissolved oxygen concentrations encountered periodically in commercial crawfish ponds.
Eimeria sinaitae n. sp. (Apicomplexa: Eimeriidae) from the Rock Agama (Agama sinaita) in Saudi Arabia
Authors: KASIM AHMED A. , AL SHAWA YASER R.
Published: May 2007

Eimeria sinaitae n. sp. is described from the gall bladder of Agama sinaita from Wasie, Saudi Arabia. Sporulated oocysts are elongate‐ellipsoid 34.4 times 22.0 (29.0–40.0 times 17.4–24.5) μm. Oocyst wall is smooth, greenish yellow, 1.2 (1.0–1.4) μm thick, and two‐layered. Micropyle, polar granule, and oocyst residuum are absent. Sporocysts are ellipsoid 11.4 times 7.6 (9.8–15.0 times 6.7–9.0) μm. Sporocyst residuum is present. The sporocysts lack a Stieda body. Sporozoites are crescent‐shaped, blunt at one end and tapered at the other. Eimeria species from Agamidae are compared.
Euplotes Cytoskeleton: Tubulin and Microtubular Systems in Interphase1,2
Authors: DELGADO PILAR , CALVO PURIFICACION , TORRES ANTONIO
Published: May 2007

The Euplotes cytoskeleton obtained by treatment with Triton X‐100 in a microtubule‐stabilizing buffer has been studied by electron microscopy and SDS‐polyacrylamide electrophoresis. An antiserum has been prepared using the tubulin band from preparative gels of Euplotes cytoskeletons as an antigen. This antiserum reacts with the tubulin from different ciliated protozoa but fails to recognize the vertebrate tubulin by immunoblotting. Immunoblotting studies have demonstrated a slower electrophoretic mobility for the α‐tubulin of Euplotes and Oxytricha than that of Paramecium and Tetrahymena. A cytoplasmic microtubular network in Euplotes has been revealed by indirect immunoftuorescence using both an anti‐α‐tubulin monoclonal antibody directed against chick brain tubulin and an antiserum raised against the tubulin of Euplotes.
Purification of Plasma Membrane from Acanthamoeba castellanii1
Authors: CLARKE BARBARA J. , HOHMAN THOMAS C. , BOWERS BLAIR
Published: May 2007

A simple method for isolation of plasma membrane from Acanthamoeba using self‐generating gradients of Percoll is described. To obtain a membrane marker, intact amoebae were radioiodinated and the distribution of the radiolabel was followed through the plasma membrane isolation procedure. The purity of isolated plasma membrane was assessed by enrichment of radiolabel, by electron microscopy, and by enzymatic assays for contaminating membranes. As judged from enrichment of radiolabel, a 37‐fold purification of plasma membrane was obtained. We estimate that 80% of the total protein was from plasma membrane and 10% from membrane‐associated actin.
Virulence of Paramoeba invadens Jones (Amoebida, Paramoebidae) from Monoxenic and Polyxenic Culture1
Authors: JELLETT JOANNE F. , SCHEIBLING ROBERT E.
Published: May 2007

Paramoeba invadens is a pathogenic marine amoeba responsible for mass mortalities of sea urchins (Strongylocentrotus droebachiensis) along the Atlantic coast of Nova Scotia in the early 1980's. The amoeba has been maintained in vivo in S. droebachiensis for five years in the laboratory without observable loss of virulence. Paramoeba invadens was cultured polyxenically (on mixed marine bacteria) and monoxenically (on a single strain of Pseudomonas nautica) on non‐nutrient agar for 58 weeks and 19 weeks respectively. Pathogenicity tests showed some loss of virulence in monoxenic culture after 15 weeks and in polyxenic culture after 58 weeks. Polyxenic culture is recommended for long‐term culture of P. invadens although periodic passage of the amoeba through the sea urchin host may be required to maintain virulence for periods exceeding one year.
Impairment of T‐Helper Function by a Plasmodium berghei‐Derived Immunosuppressive Factor1
Authors: SROUR EDWARD F. , SEGRE MARIANGELA , SEGRE DIEGO
Published: May 2007

Mice injected with an immunosuppressive factor (ISF) extracted from Plasmodium berghei‐infected rat erythrocytes have a reduced antibody response to unrelated antigens. T‐cells from ISF‐treated mice failed to provide adequate help to naive, syngeneic B‐cells in the primary IgM response in vitro to sheep red blood cells and to dinitrophenylated keyhole limpet hemocyanin. The same T‐cells, however, were able to cooperate with memory B‐cells in the secondary IgG response. No other cellular deficit was delected in ISF‐treated mice; B‐cells and macrophages behaved normally, and there was no detectable excess of suppressor cells. The T‐cell impairment was not reflected in decreased production of interleukin 2, but was also shown by the diminished delayed type hyperaensitivity reaction to sheep red blood cells of ISF‐treated mice.
Transmission Electron Microscopical Observations on Stomatogenesis during Metamorphosis of Eufolliculina uhligi (Ciliophora: Heterotrichida)1
Authors: MULISCH MARIA , HAUSMANN KLAUS
Published: May 2007

Stomatogenesis during metamorphosis of the marine loricate ciliate, Eufolliculina uhligi, was observed by transmission electron microscopy. Kinetosome proliferation in the stomatogenic territory leads to the formation of an anarchic field. This separates into the left adoral and the right paroral primordia. Both primordia consist of pairs of kinetosomes. One kinetosome of a pair is associated with one transverse and two postciliary microtubules; the other has one transverse microtubule. The postciliary microtubules of the adoral kinetosomes become divergent; those of the paroral kinetosomes become convergent. The adoral kinetosomes arrange in promembranelles. Then a third row of kinetosomes is produced anteriorly to each promembranelle. This third row is short at the peristome but longer in the buccal area. The paroral kinetosomes form a stichodyad. The buccal part of the paroral primordium is resorbed during formation of the buccal cavity. Stomatogenesis ends with the development of a functioning cytostome. During this process, the postciliary microtubules of the buccal adoral membranelles elongate and become associated with cytopharyngeal vesicles. Fusion of these vesicles with the cytostome has been observed some time after the completion of the oral structures.
Genetic Characterization and Use of a Restriction Fragment Length Variant in the Hypotrichous Ciliate Euplotes crassus1
Authors: BAIRD SCOTT E. , KLOBUTCHER LAWRENCE A.
Published: May 2007

Two forms of a macronuclear DNA molecule differing in the presence or absence of a restriction endonuclease recognition site have been detected in the hypotrichous ciliate Euplotes crassus. Through a series of genetic crosses the two forms were shown to be allelic, being derived from a single micronuclear genetic locus. This restriction fragment length variant (RFLV) was used as a genetic marker to determine that the migratory and stationary pronuclei generated during mating can be genetically non‐identical. In addition, the RFLV was used to investigate the efficiency of processing of the alternate alleles during macronuclear development and their subsequent transmission during vegetative growth. Little or no bias in the processing and/or amplification of the two alleles was observed during macronuclear development. During vegetative growth, however, changes in the relative amounts of the two alleles were observed.
Identification of C3 Acceptors Responsible for Complement Activation in Crithidia fasciculata1
Authors: GÜTHER MARIA LUCIA S. , TRAVASSOS L. R. , SCHENKMAN S.
Published: May 2007

Crithidia fasciculata, an insect trypanosomatid is readily lysed by normal human serum at concentrations as low as 3%. Lysis occurs in the presence of Mg+2‐EGTA and is antibody independent, indicating that the alternative pathway of complement activation is involved. Analysis of [131I]C3 deposition on C. fasciculata cells using C8‐deficient serum, revealed that about 4 times 105 C3 molecules bound to each cell. Most of the C3 was bound to cells as C3b, part of it forming high molecular weight complexes, which could be dissociated by methylamine treatment at alkaline pH. To characterize the C3 acceptors on C. fasciculata, surface‐iodinated cells were incubated with C8D or heat‐inactivated serum, extracted and immunoprecipitated with anti‐C3 or anti‐arabinogalactan antisera. Analysis of the immunoprecipitated material on SDS gels showed high‐molecular weight components, which disappeared after methylamine treatment, giving rise to a component of 200 kDa molecular size. This 200‐kDa component corresponded to a purified arabinogalactan complex, which was immunoprecipitated from labeled cell extracts, without incubation with C8D, using anti‐arabinogalactan antibodies. These results suggest that the arabinogalactan glycoconjugate is a C3 acceptor in C. fasciculata during complement activation. Purified arabinogalactan complexes were able to inactivate C3 in vitro. Solubilization in KOH to cleave the peptide moiety rendered it unable to inactivate C3. Apparently, the aggregated state of the purified arabinogalactan component at the cell surface is important for C3 deposition and activation.
Trypanosoma cruzi: Cell Biological Behavior of Epimastigote and Amastigote Forms in Axenic Culture
Authors: ENGEL JUAN C. , DVORAK JAMES A.
Published: May 2007

A simple protocol to maintain Trypanosoma cruzi amastigote stocks indefinitely in axenic culture is described. The growth characteristics of amastigotes differ markedly from epimastigotes cultured under identical conditions. The amastigotes replicate for two generations, followed by a transformation to epimastigotes and resumption of growth. By changing the culture medium at the end of the second amastigote generation, transformation to epimastigotes is inhibited. Therefore, the protocol used to maintain amastigotes in culture is based upon changing the culture medium at preselected intervals. Flow cytometric analyses indicate that at the end of the exponential phase of growth the amastigote population consists of predominately G1 cells; changing the medium induces the amastigotes to begin a para‐synchronous round of DNA synthesis without a pre‐replicative lag phase. In contrast, when exponentially growing or stationary‐phase epimastigotes are transferred to fresh culture medium, they grow asynchronously until reaching a limiting cell density. Amastigotes also differ from epimastigotes in being resistant to the lytic activity of human complement. These data demonstrate that marked differences in phenotypic expression exist between developmental stages of T. cruzi even when cultured under identical conditions.
Demonstration of Acid Phosphatase in Eimeria spp.: Partial Characterization of the Enzyme in E. vermiformis1,2
Authors: HOSEK JAMES E. , TODD KENNETH S. , KUHLENSCHMIDT MARK S.
Published: May 2007

Sporozoite extracts of E. vermiformis, E. stiedai, and E. tenella are rich in acid phosphatase activity. They contain specific enzyme activities equal to or greater than those reported for other highly virulent protozoan parasites. The absolute amount of enzyme activity per oocyst dramatically increases during sporulation of E. stiedai and E. vermiformis. Partial characterization of the acid phosphatase activity of E. vermiformis indicates that sporozoites account for greater than 92% of the total activity in sporubted oocysts, that the enzyme is resistant to inhibition by tartrate, and that it can be separated into two forms by anion exchange chroma‐tography.
Axenic Cultivation of Phytomonas (Trypanosomatidae) Associated with Laticiferous Plants in Suriname1
Authors: KASTELEIN PIETER , PARSADI MALA
Published: May 2007

Using variously enriched media, axenic cultures were obtained of Phytomonas spp. associated with Allamanda cathartica, Mandevilla scabra, and Rhabdadenia biflora (Apocynaceae), and Blepharodon nitidus (Asdepiadaceae) and Euphorbia hirta (Euphor‐biaceae). Cultures were usually subcultured once every week for many weeks in succession. Attempts to grow the flagellates from Bonafousia tetrastachya (Apocynaceae), Cecropia palmata (Cecropiaceae), and Euphorbia hyssopifolia (Euphorbiaceae) were unsuccessful. The “phytomonads” in latex of different host plants showed morphological differences, whereas the cultured flagellates were similar in morphology whatever the host plant source or culture medium.
Two New Species of Eimeria from Peacocks (Pavo cristatus) in Saudi Arabia1
Authors: AMOUDI MIKKY A.
Published: May 2007

Fifteen fecal samples from peacocks (Pavo cristatus) in Saudi Arabia contained oocysts of Eimeria riyadhae n. sp. in two peacocks and oocysts of E. arabica n. sp. in one peacock. Sporulated oocysts of Eimeria riyadhae are ellipsoidal, 27–30.5 times 20.5–25 (28.8 ± 1.3 × 22.4 ± 1.6) μm, with a two‐layered wall and bilobed polar body, but without a micropyle or residuum. The sporocysts are ovoid, 11–14.5 × 6.5–8 (13.2 ± 1.2 × 7.2 ± 0.6) μm with a thick, knob‐like Stieda body and a residuum. Sporulated oocysts of Eimena arabica are spheroidal, 17.5–21.5 × 17.5–21.5 (19.2 ± 1.6 × 19.2 ± 1.6) μm, with a two‐layered wall and two refractile polar bodies, but without a micropyle or residuum. The sporocysts are elongate ovoid, 9.5–12 × 4–6.5 (11.2 ± 0.9 × 5.5 ± 0.88), with a small crescent‐shaped Stieda body. The host bird belongs to the order Galliformis.
Ichthyophthirius (Ciliophora): Population Studies Suggest Reproduction in Host Epithelium1
Authors: EWING MARGARET S. , EWING S. A. , KOCAN KATHERINE M.
Published: May 2007

Evidence that Ichthyophthirius multifiliis trophonts may reproduce within the epithelium of the host was obtained from experimental infections of channel catfish. Mean number of parasites spontaneously leaving the fish increased from 0 on day 3 postexposure (PE) to 66.5 per fish on day 7 PE. Mean population density in fin, however, increased five‐fold from day 3 to day 5 PE in the absence of opportunity for reinfection. At day 3 PE, 100% of parasite loci in fin and gill arches contained solitary trophonts. At day 4 PE, 10% of loci in fin contained clusters of two trophonts; at day 7 PE, 69% contained clusters of two or more trophonts. The first clusters of four trophonts in fin were observed day 5 PE and of eight trophonts, day 8 PE. Trophonts in clusters were flattened against one another.
Isolation and Characterization of Chlamydomonas reinhardtii Mutants with Defects in the Induction of Flagellar Protein Synthesis after Deflagellation1,2
Authors: LEFEBVRE PAUL A. , BARSEL SARA‐ELLEN , WEXLER DANIEL E.
Published: May 2007

Amputating the flagella of Chlamydomonas reinhardtii stimulates increased synthesis of many flagellar proteins within 30 min. We have isolated a series of mutants which are defective in this stimulation, taking advantage of the fact that cells which cannot stimulate flagellar protein synthesis cannot regenerate flagella. More than a dozen mutants which have flagella, but cannot regenerate them after amputation, were isolated and studied by in vivo labeling to identify those non‐regenerator mutants which were specifically defective in the induction of flagellar protein synthesis. Ten such mutants have been identified, and in each of them flagellar amputation does not stimulate the synthesis of any of the major flagellar proteins. At least four of the mutants display an interesting conditional phenotype. The synthesis of flagellar proteins after deflagellation is defective only in gametic cells; vegetative cells of these mutants are capable of flagellar protein synthesis after flagellar amputation.
Scanning Electron Microscopy of the Adoral Ciliary Zone of Cycloposthium Bundle (Ciliophora, Entodiniomorphida)1
Authors: IMAI SOICHI , YAMAZAKI YASUYO
Published: May 2007

The adoral ciliary zone of Cycloposthium spp., inhabiting the large intestine of the horse, was studied by scanning electron microscopy. It could be divided into four parts: outer, inner, left, and right zones. The outer zone, extending on the anterior periphery of the apical cone of the body, had 20 tuft‐like syncilia arranged radially around the longitudinal axis. Each ciliary tuft consisted of about 170 cilia, and in cross section it had a rectangular shape. The cilia of the inner zone, situated at the top of the apical cone, were aggregated irregularly to form shorter bundles than the tufts of the outer zone. The innermost cilia of this zone were shorter than the outermost. There was a distinct non‐ciliated border between the outer and inner zones. A horseshoe‐like operculum having no cilia was present at the center of the adoral ciliary zone, and the opening of the vestibulum was situated as a cleft crossing from the center to the right periphery of this zone. No cilia extended onto the vestibular wall. The left ciliary zone was situated beneath the outer zone and consisted of five short rows of barren kinetosomes of which only the central row possessed very short cilia. The right ciliary zone, consisting of a few rows of cilia situated at the bottom of the inner adoral lip, was also easily distinguished from the other ciliary zones. This zone was interpreted as an extension of the outer adoral zone passing along the right side of the apical cone. These ciliary zones were considered to be highly differentiated and useful for both movement of and ingestion of food.
Improved Method for High‐Yield Excystation and Purification of Infective Sporozoites of Eimeria spp.1
Authors: HOSEK JAMES E. , TODD KENNETH S. , KUHLENSCHMIDT MARK S.
Published: May 2007

This report describes a new, gentle procedure for rapid and efficient excystation of large numbers of infective sporozoites of Eimeria vermiformis and Eimeria stiedai. Excysted sporozoites are purified using modifications of a previously described ion‐exchange chromatography method. The procedure avoids physical breakage of oocysts and results in greater than 70% recovery of the sporozoites present as sporulated oocysts (i.e. 5–6 sporozoites per sporulated oocyst). The recovered sporozoites are greater than 95% pure and are infective in vivo. We routinely isolate greater than 2 times 108 sporozoites without the use of specialized or expensive equipment.
Organization of the Euplotes crassus Micronuclear Genome1
Authors: JAHN CAROLYN L. , NILLES LAURA A. , KRIKAU MARK F.
Published: May 2007

Euplotes crassus, like other hypotrichous ciliated protozoa, eliminates most of its micronuclear chromosomal DNA in the process of forming the small linear DNA molecules that comprise the macronuclear genome. By characterizing randomly selected lambda phage clones of E. crassus micronuclear DNA, we have determined the distribution of repetitive and unique sequences and the arrangement of macronuclear genes relative to eliminated DNA. This allows us to compare the E. crassus micronuclear genome organization to that of another distantly related hypotrichous ciliate, Oxytricha nova. The clones from E. crassus segregate into three prevalent classes: those containing primarily eliminated repetitive DNA (Class I); those containing macronuclear genes in addition to repetitive sequences (Class II); and those containing only eliminated unique sequence DNA (Class III). All of the repetitive sequences in these clones belong to the same highly abundant repetitive element family. Our results demonstrate that the sequence organization of the E. crassus and O. nova micronuclear genomes is related in that the macronuclear genes are clustered together in the micronuclear genome and the eliminated unique sequences occur in long stretches that are uninterrupted by repetitive sequences. In both organisms a single repetitive element family comprises the majority of the eliminated interspersed middle repetitive DNA and appears to be preferentially associated with the macronuclear sequence clusters. The similarities in the sequence organization in these two organisms suggest that clustering of macronuclear genes plays a role in the chromosome fragmentation process.
Fine Structure of Pseudokeronopsis carnea (Ciliophora, Hypotrichida)1
Authors: WIRNSBERGER ERNA , HAUSMANN KLAUS
Published: May 2007

ABSTRACT Two kinds of pigment structures, pigment vacuoles and pigmentocysts, cause the orange‐red color of Pseudokeronopsis carnea (Cohn, 1866). The pigment vacuoles are undischargeable and two to five layers of them form a characteristic ectoplasmic zone. The pigmentocysts mainly surround the infraciliature and show a unique channel which is probably used for extrusion. Previous data on the fine structure of subpellicular granules and extrusomes of hypotrich ciliates are summarized. Their obviously diverse organization argues for a great value of these structures in species identification. The basic structural features of the infraciliature and the cytoplasmic organelles of P. carnea are similar to those found in other hypotrichs; however, a special kind of linear microtubular array borders the longer sides of the cirral bases and the margins of the adoral membranelles and those of the membranes in the right buccal area. To the left of the endoral membrane, these microtubular arrays result in a highly ordered structure reminiscent of oral ribs. This peculiar arrangement of microtubules in cirri and paramembranelles has also been found in the related form, Thigmokeronopsis jahodai, probably indicating a homogeneity of the fine structure of urostylid hypotrichs. In P. carnea, the basal bodies of the paroral membrane are proximally connected like a polykinetid. Its cilia are unlinked, whereas those of the endoral membrane are fused by microfibrillar material. The terms diplostichomonad and polystichomonad only refer to quantitative aspects and omit the evident, high diversity of microtubular and microfibrillar associates occurring in the membranes in the right buccal area. These terms need to be redefined on the basis of more material that is better described.
Coccidian Parasites (Apicomplexa: Eimeriidae) from Insectivores. VI. Six New Species from the Eastern Mole, Scalopus aquaticus1
Authors: FORD PAULETTE L. , DUSZYNSKI DONALD W.
Published: May 2007

ABSTRACT Thirteen eastern moles, Scalopus aquaticus, collected in West Texas were examined for coccidian oocysts; 11 (85%) were infected and eight (73%) of these had multiple infections representing two or more species. One cyclosporan, three eimerians, and two isosporans were studied and all are described as new species. Sporulated oocysts of Cyclospora megacephali n. sp. were subspheroidal, 18.5 × 15.7 (14–21 × 12–18) μm; they had sporocysts pointed at one end with Stieda bodies nearly as wide as the sporocysts themselves, and were 15.0 × 7.2 (11–17 × 6–9) μm; C. megacephali was found in four (31%) hosts. Sporulated oocysts of Eimeria scalopi n. sp. were spheroidal to subspheroidal, 13.6 × 12.6 (11–17 × 11–15) μm with sporocysts lemon‐shaped, 8.7 × 5.5 (7–10 × 4–7) μm; it was found in six (46%) hosts. Sporulated oocysts of Eimeria aquatici n. sp. were asymmetrically ellipsoidal, 17.0 × 10.6 (14–20 × 9–14) μm, with sporocysts elongately ovoidal, 9.0 × 5.2 (8–11 × 4–6) μm; it was found in two (15%) hosts. Sporulated oocysts of Eimeria motleiensis n. sp. were subspheroidal, 17.0 × 15.3 (15–20 × 13–18) μm with sporocysts ovoidal, 10.7 × 6.8 (10–13 × 6–8) μm; it was found in seven (54%) hosts. Sporulated oocysts of Isospora motleiensis n. sp. were spheroidal to subspheroidal, 13.6 × 12.0 (10–17 × 8–15) μm with sporocysts broadly ovoidal, 9.5 × 6.7 (7–11 × 4–8) μm; it was found in nine (69%) hosts. Sporulated oocysts of Isospora aquatici n. sp. were subspheroidal, 20.9 × 18.4 (15–24 × 13–21) μm with sporocysts ellipsoidal, 11.8 × 9.0 (9–14 × 7–11) μm; it was found in two (15%) hosts.
A Somatic Kinetid Study of the Pycnotrichid Ciliate Vestibulongum corlissi N. G., N. Sp. (Class: Litostomatea), Symbiont in the Intestines of the Surgeonfish, Acanthurus xanthopterus1
Authors: GRIM J. NORMAN
Published: May 2007

ABSTRACT The ciliate Vestibulongum corlissi n. g., n. sp. was collected from the intestines of surgeonfish, Acanthurus xanthopterus, in the summer of 1986. In has been examined in the light microscope after protargol staining and by scanning and transmission electron microscopy. Its form is distinct from that of other pycnotrichid ciliates at the generic level. Somatic kinetids were examined; these demonstrate that its cytostome is posterior and that the kinetid structures and the presence of a second transverse microtubular ribbon confirm its placement in the class Litostomatea.
Effects of Bile Salt‐Stimulated Lipase‐Treated Triglycerides and Free Fatty Acids on Extracellular Stages of Eimeria tenella
Authors: WINTERROWD C. A. , FOLZ S. D. , HEINRIKSON R. L. , GEARY T. G.
Published: May 2007

Normal human milk (NHM) has antiprotozoal activity unrelated to immunological components; this activity extends to sporozoites of Eimeria tenella. This activity may be due to free fatty acids (FFA) enzymatically hydrolyzed from tnacyl glycerols by a bile salt‐stimulated lipase (BSSL) found in NHM. Sporozoites were therefore incubated in the presence of several saturated and unsaturated FFA. Anticoccidial activity was observed for many unsaturated fatty acids and for some saturated fatty acids. In addition, sporozoites were added to solutions of triglycerides (trilinolein, triolein and trilinolenin) preincubated with BSSL and sodium cholate. which resulted in killing of the parasites. Triglycerides alone showed no anticoccidial activity. These results were duplicated with first generation merozoites. Intracellular stages of E. tenella were affected by FFA only at concentrations that inhibited host cells.
Large Genetic Heterogeneity Within Amoebas of the Species Naegleria gruberi and Evolutionary Affinities to the Other Species of the Genus
Authors: PERNIN PIERRE , CARIOU MARIE LOUISE
Published: May 2007

The allozyme survey was extended to 7 strains of Naegleria gruberi and N. jadini in order to further characterize the genetic structure of these free‐living amoebas. As formerly known for several characters the electrophoretic evidence reveals considerable heterogeneity at the genetic level among N. gruberi strains. Moreover, 2 distinct gene pools, that might likely represent natural taxa, are clearly identified. The single strain of N. jadini appears evolutionarily related to 1 group of N. gruberi which is also related to N. a. australiensis.
Biochemistry and Metabolism of Giardia
Authors: JARROLL EDWARD L. , MANNING PAUL , BERRADA ABDELKRIM , HARE DAWN , LINDMARK DONALD G.
Published: May 2007

Giardia lamblia, an aerotolerant anaerobe, respires in the presence of oxygen by a flavin, iron‐sulfur protein‐mediated electron transport system. Glucose appears to be the only sugar catabolized by the Embden‐Meyerhof‐Pamas and hexose monophosphate pathways, and energy is produced by substrate level phosphorylation. Substrates are incompletely oxidized to CO2, ethanol and acetate by nonsedimentable enzymes.

The lack of incorporation of inosine, hypoxanthine, xanthine, formate or glycine into nucleotides indicates an absence of de novo purine synthesis. Only adenine, adenosine, guanine and guanosine are salvaged, and no interconversion of these purines was detected. Salvage of these purines and their nucleosides is accomplished by adenine phosphoribosyltransferase, adenosine hydrolase, guanosine phosphonbosyltransferase and guanine hydrolase.

The absence of de novo pyrimidine synthesis was confirmed by the lack of incorporation of bicarbonate, orotate and aspartate into nucleotides, and by the lack of detectable levels of the enzymes of de novo pyrimidine synthesis. Salvage appears to be accomplished by the action of uracil phosphoribosyltransferase, uridine hydrolase, uridine phosphotransferase, cytidine deaminase, cytidine hydrolase, cytosine phosphoribosyltransferase and thymidine phosphotransferase. Nucleotides of uracil may be converted to nucleotides of cytosine by cytidine triphosphate synthetase, but thymidylate synthetase and dihydrofolate reductase activities were not detected.

Uptake of pyrmidine nucleosides, and perhaps pyrimidines, appears to be accomplished by carrier‐mediated transport, and the common site for uptake of uridine and cytidine is distinct from the site for thymidine. Thymine does not appear to be incorporated into nucleotide pools.

Giardia trophozoites appear to rely on preformed lipids rather than synthesizing them de novo. Major lipids include phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingomyelin, sterol (probably cholesterol) and mono‐, di‐ and triacylglycer‐ides. The lipid composition of the cysts of G. lamblia isolated from gerbils and G. muris isolated from mice are similar to those obtained from the trophozoites of G. lamblia grown in vitro.

The activities of several hydrolases of G. lamblia have been shown to be confined to a single lysosome‐like particle population with an equilibrium density of approximately 1.15 in sucrose. Contrary to the trophozoites of Entamoeba and the trichomonads, Giardia trophozoites appear to lack most carbohydrate splitting hydrolases.

Calmodulin has been reported in G. lamblia trophozoites, and it appears to have properties similar to the calmodulin isolated from other eucaryotic cells.
Ornithine Decarboxylase and Trypanothione Reductase Genes in Leishmania braziliensis guyanensis
Authors: KEITHLY JANET S.
Published: May 2007

. Ornithine decarboxylase and trypanothione reductase are the key enzymes in polyamine and trypanothione metabolism in kinetoplastids. Using a heterologous Trypanosoma brucei brucei probe for ornithine decarboxylase and a mixed synthetic probe of 29 oligonucleotides for trypanothione reductase, we have detected the putative genes for these enzymes by Southern blot hybridization using genomic DNA of Leishmania braziliensis guyanensis MHOM/SR/80/CUMC I. The trypanothione reductase probe was constructed both from the conserved codon usage of the redox active site for other flavin oxidoreductases over a wide evolutionary scale, and the preferred codon usage for other genes in species of Leishmania.
I. Extracellular Cultivation and Morphological Characterization of Amastigote‐Like Forms of Leishmania panamensis and L. braziliensis
Authors: EPERON SIMONE , McMAHON‐PRATT DIANE
Published: May 2007

. Two strains of the Leishmania braziliensis complex have been adapted to grow extracellularly at elevated temperature as amastigote‐like forms in a cell‐free medium. These parasites can be serially cultivated and maintained at 32°C for L. panamensis (WR442; L. braziliensis panamensis) and at 28°C for L. braziliensis (M5052; L. braziliensis braziliensis). Several observations are presented that the forms adapted at elevated temperature are amastigote‐like. Morphologically, the amastigote‐like organisms appear rounded to ovoid and are immotile and smaller than promastigotes; the flagellum of the amastigote‐like forms does not extend beyond the flagellar pocket. In comparison, the promastigotes are very elongated, with a nucleus at mid‐cell length and a very long flagellum. By electron microscopy, the short flagellum of the amastigote‐like form is within a distended flagellar pocket; the 9 + 2 axonemal configuration is present but the paraxial rod is not observed. By contrast, the flagellum of the promastigote has a paraxial rod which extends from the axosome level. In addition, these amastigote‐like forms of Leishmania are able to infect, to survive and to divide within the macrophage cell line J774.
Extracellular Amastigote‐Like Forms of Leishmania panamensis and L. braziliensis. II. Stage‐ and Species‐Specific Monoclonal Antibodies
Authors: EPERON SIMONE , McMAHON‐PRATT DIANE
Published: May 2007

Immunochemical evidence, employing monoclonal antibodies, shows that the forms of L. braziliensis complex axenically grown at elevated temperature are amastigote‐like. The monoclonal antibodies were raised against membrane proteins of amastigote‐like forms, strains of both L. panamensis (WR442) and L. braziliensis (M5052), which were grown axenically. The specificities of these antibodies were examined by indirect radioimmune binding assay, indirect immunofluorescent assay and Western blot analyses. Two distinct groups of monoclonal antibodies were obtained and their specificities were consistent with the 3 methods used. Four antibodies are specific for the species L. panamensis and react with both developmental stages. Six antibodies specifically recognize amastigote‐like forms grown at elevated temperature and intracellular amastigotes of both L. panamensis (WR442) and L. braziliensis (M5052). These monoclonal antibodies do not bind to promastigotes of these species, nor to promastigotes of any other species of Leishmania. Therefore these antibodies are specific for amastigotes of L. panamensis (WR442) and L. braziliensis (M5052), and suggest that immunochemically both amastigote forms (culture and macrophage) are developmentally very close, if not identical. The molecules associated with the amastigote‐specific antigenic determinants consist of a Mr 12‐kD component and a heterogeneous component (Mr from 50 kD to >200 kD); these molecules appear to be identical for both amastigote‐like forms and amastigotes isolated from macrophages.
Mating Structure Differences Demonstrated by Freeze‐Fracture Analysis of Fusion‐Defective Chlamydomonas Gametes
Authors: FOREST CHARLENE L. , OJAKIAN GEORGE K.
Published: May 2007

While the mating structure of unmated mating type minus (mt‐) gametes of Chlamydomonas reinhardtii has few intramembrane particles (IMPs), activation results in movement of IMPs to its center. Analysis of freeze‐fractured replicas of wild type (wt) mt‐ and 3 mt‐ fusion‐defective mutants, gam‐1, gam‐10 and gam‐11, before and after activation with wt+ flagella, provides a basis for suggesting that some of the IMPs in mt‐ mating structures, particularly a subset of particles that partitions to the E face, may be fusion‐controlling molecules. Unmated gametes of gam‐10 show a full range of images, from particle‐free to fully activated, with both the P and E face of the mating structure revealing approximately twice as many IMPs as those observed on wt. Unactivated gametes of gam‐1 and gam‐11 appear identical to wt‐. After activation, the mating structures of all of these gametes appear to have approximately the same number of IMPs. If the sizes of particles for these mutants are compared to wild type at the restrictive temperature, all 3 mutants have significantly smaller IMPs on the E face; before mating, in the plasma membrane and after mating, in the mating structure. At 34° C, the gam‐1‐II mating structure appears to be missing most of the particles from 15.5 to 16.5 nm in diameter, while all gametes with the ability to fuse have an equivalent percentage of their mating structure particles in this size range. The possibility that an IMP in this size range represents a protein that may be responsible for gamete fusion is discussed.
Characterization of a Cytochalasin D‐Resistant Mutant of Entamoeba histolytica
Authors: GARZA MIREYA DE LA , GALLEGOS BRIGIDO , MEZA ISAURA
Published: May 2007

Characterization of a cytochalasin D‐resistant mutant of the human parasite Entamoeba histolytica capable of growing at 10 μM cytochalasin is described. The mutant cells also show resistance to 5 mM colchicine and 100 μM cytochalasin B, drugs proved deleterious for wild type trophozoites. The mutants show increased osmotic fragility and electric mobility but reduced phagocytic activity, and agglutination by Concanavalin A. On the other hand pinocytic activity remains unaltered when compared with the wild type cells. Polymerized actin, seen by staining with phalloidin, often appears polarized to one end of the trophozoites and forms few of the endocytic invaginations found in wild type amebas. An altered distribution of part of the actin could explain the differences in surface properties and motility observed in the mutant amebas.
Redescription of Lagenophrys eupagurus Kellicott (Ciliophora, Peritricha, Lagenophryidae) and a Comparison of It with Three Similar Species
Authors: CLAMP JOHN C.
Published: May 2007

Lagenophrys eupagurus, a poorly known loricate peritrich ectocommensal on the hermit crab Pagurus longicarpus, has been rediscovered and is redescribed. Lagenophrys lunatus and L. articularis were found to be conspecific with L. eupagurus based on close similarities, especially with regard to structure of the lorica aperture and proportions of the lorica. Lagenophrys callinectes, although resembling L. eupagurus, was determined to be a separate species because of distinct, consistent differences in structure of the lorica aperture and proportions of the lorica. Lagenophrys eupagurus and L. callinectes share some features of the lorica aperture with 3 other species of Lagenophrys, prompting the speculation that the 5 species may constitute a cluster of related species within the genus. Lagenophrys eupagurus utilizes a relatively wide variety of hosts compared to other species of Lagenophrys and appears to subsist mainly on phytoplankton. In some cases, the feeding behavior of the host may assist L. eupagurus in obtaining food. Lagenophrys callinectes appears to be restricted to brachyuran crabs of the genus Callinectes. It appears to be a bacterivore and is probably assisted in obtaining food by the preference of its hosts for estuarine areas that are rich in organic material.