bluuebunny/crossref_metadata_2025 huggingface dataset:
Fine Structure and Development of Pilosporella chapmani (Microspora: Thelohaniidae) in the Mosquito, Aedes triseriatus (Say)1
Authors: BECNEL JAMES J. , HAZARD EDWIN I. , FUKUDA TOKUO
Published: May 2007

ABSTRACT. New information on the life cycle and fine structure of Pilosporella chapmani, a microsporidium of the mosquito Aedes triseriatus, is presented. Pilosporella chapmani is shown to have two sporulation sequences, one of them being involved in transovarial transmission. One sequence, involving meiosis and production of a moniliform sporogonial plasmodium, occurs in the larval fat body, resulting in eight uninucleate, spherical, and fully developed spores. The other occurs in oenocytes of adult mosquitoes and results in isolated, binucleate, elongate, and thin‐walled spores. Also, for the first time, metabolic products are shown to be expelled into the surrounding host tissues through the wall of the sporocyst.
A Comparison of Endogenous Development of Three Isolates of Cryptosporidium in Suckling Mice1
Authors: CURRENT WILLIAM L. , REESE NORMAN C.
Published: May 2007

ABSTRACT. Suckling mice were used as a model host to compare the endogenous development of three different isolates of Cryptosporidium: one from a naturally infected calf, one from an immunocompetent human with a short‐term diarrheal illness, and one from a patient with acquired immune deficiency syndrome (AIDS) and persistent, life‐threatening, gastrointestinal cryptosporidiosis. After oral inoculation of mice with oocysts, no differences were noted among developmental stages of the three isolates in their sites of infection, times of appearance, and duration, morphology, and fine structure. Sporozoites excysted within the lumen of the duodenum and ileum, penetrated into the microvillous region of villous enterocytes, and developed into type I meronts with six or eight merozoites. Type I merozoites penetrated enterocytes and underwent cyclic development as type I meronts or they became type II meronts with four merozoites. Type II merozoites did not exhibit cyclic development but developed directly into sexual forms. Microgamonts produced £16 small, bullet‐shaped microgametes, which were observed attaching to and penetrating macrogametes. Approximately 80% of the oocysts observed in enterocytes had a thick, two‐layered wall. After sporulating within the parasitophorous vacuole, these thick‐walled oocysts passed through the gut unaltered and were the resistant forms that transmitted the infection to a new host. Approximately 20% of the oocysts in enterocytes consisted of four sporozoites and a residuum surrounded only by a single oocyst membrane that ruptured soon after the parasite was released from the host cell. The presence of thin‐walled, autoinfective oocysts and recycling of type I meronts may explain why a small oral inoculum can produce an overwhelming infection in a suitable host and why immune deficient persons can have persistent, life‐threatening cryptosporidiosis in the absence of repeated oral exposure to thick‐walled oocysts.
Detection of Babesia bovis Using DNA Hybridization1
Authors: McLAUGHLIN G. L. , EDLIND T. D. , IHLER G. M.
Published: May 2007

ABSTRACT. Plasmids containing inserts of Babesia bovis DNA were prepared and clones suitable for use in the diagnosis of B. bovis infections were isolated. Dot blot hybridization with DNA from these plasmids, which probably contain repetitive sequences, can detect after an overnight exposure 100 pg of B. bovis DNA, which corresponds to the amount of DNA present in 50 μl of 0.01% parasitemic erythrocytes. No detectable cross‐hybridization was observed with Babesia microti, Plasmodium falciparum, Plasmodium vivax, Boophilus, or cow DNA. A small amount of cross‐hybridization was observed with 10 ng Babesia bigemina DNA. Use of these probes in a hybridization assay may be helpful in the diagnosis of babesiosis in cattle and ticks, in the confirmation of strain identities, and in correlating virulence with particular strains of Babesia.
An Unusual Structure in the Primary Cyst Wall of Sarcocystis hemionilatrantis1
Authors: SPEER C. A. , DUBEY J. P.
Published: May 2007

ABSTRACT. Disc‐shaped plaques were found in the primary cyst wall of sarcocysts of Sarcocystis hemionilatrantis in mule deer in Montana. Ultrastructurally, the plaques were 190.5 nm in diameter, 161.6 nm thick and consisted of six distinct layers with microfilaments arising from the innermost layer. These unusual plaques have not been reported previously for any species of Sarcocystis.
Flow Cytometric Analysis of Immunoglobulin and Complement Component C3 on the Surface of Trypanosoma lewisi1
Authors: STURTEVANT JOY E. , BALBER ANDREW E.
Published: May 2007

ABSTRACT. We have reinvestigated whether surface immunoglobulin (sIg) on Trypanosoma lewisi is antibody directed toward parasite antigen by using flow cytometry to analyze parasites stained with fluoresceinated F(ab′)2 fragments of antibodies to rat IgG and IgM. We have confirmed that IgG antibody to the parasites is present both in the serum of rats and on the surface of parasites between the fourth and twentieth days of infection, that the amount of sIg per cell increases as the infection progresses, and that considerably more IgG is present on parasites harvested from intact rats than on those from rats that had been immunosuppressed by whole body γ‐irradiation. In addition sIgM was detected on trypanosomes from intact, but not on parasites from irradiated rats. We have also made two observations suggesting that not all sIg is specific antibody made in response to T. lewisi. First, a low but significant amount of sIgG was detected on parasites throughout infection in irradiated rats; no sIgM was detected on these parasites. Second, when parasites harvested from immunosuppressed rats were incubated in normal rat serum, the amount of both sIgG and sIgM detected by flow immunofluorescence increased. Parasites harvested from intact animals bound IgM but not IgG from normal rat serum. These results suggest either that natural antibody to the trypanosomes is present in the serum of uninfected rats or that some rat immunoglobulins bind to structures on the trypanosome surface in ways that do not depend on usual antigen‐antibody interactions. Finally, flow immunofluorescence was also used to detect complement component C3 on the surface of both intact and trypsinized bloodstream forms harvested from intact or immunosuppressed rats. The amount of sC3 per cell did not increase until late in the infection and consequently did not correlate with the increase of sIgG. Therefore, T. lewisi avoids destruction by the immune system although immune effector molecules, IgG, IgM, and C3, are on its surface.
Observations on the Taiwanese Strain of Leucocytozoon caulleryi (Haemosporina) in Chickens
Authors: MORII T. , NAKAMURA K. , LEE Y. C. , IIJIMA T. , HOJI K.
Published: May 2007

ABSTRACT. The Taiwanese strain of Leucocytozoon caulleryi was isolated from an infected chicken in Taipei, Taiwan, and established in chickens and biting midges Culicoides arakawae from Japan. Sporogony of the strain in C. arakawae was completed on day 3 after the infective blood meals at 25°C. Sporozoites isolated from the salivary glands of C. arakawae on days 3 or 4 after feeding caused infection in all the chickens inoculated. The strain showed high pathogenicity for chickens. Mortality of chickens rose with an increase in the number of sporozoites inoculated. The prepatent period for chickens inoculated with sporozoites was 14 days. Parasites appeared in the peripheral blood of chickens on day 15 and disappeared on day 26 after sporozoite inoculation. Soluble antigens were found in the sera of chickens infected with the strain between 10 and 17 days after inoculation, and homologous antibodies appeared after 17 days. Antigens prepared from sera, schizonts, merozoites, and gametocytes of the Taiwanese strain reacted with the sera of chickens infected witt the same strain or the strain isolated in Japan. The chickens that recovered from a primary infection with the Taiwanese strain demonstrated complete resistance to reinfection with the same strain or the strain isolated in Japan.
Inhibition of Trichomonas vaginalis Replication by the Microtubule Stabilizer Taxol
Authors: JULIANO C. , MONACO G. , RUBINO S. , CAPPUCCINELLI P.
Published: May 2007

ABSTRACT. Taxol, a plant alkaloid stabilizer of microtubules, inhibits in vitro the replication of the human pathogenic flagellate Trichomonas vaginalis in a dose‐dependent fashion. Micromolar concentrations of the drug induce massive assembly of microtubules, resistant to antimicrotubule agents, and block the mitosis of the protozoa at an early stage preceding the formation of the spindle fibers and the depolymerization of the axostylar microtubules. Some hypotheses involving the inactivation of the microtubule‐organizing centers and the stabilization of axostylar microtubules are formulated to explain the mechanism of action of taxol.
Coccidian Parasites (Apicomplexa: Eimeriidae) from Insectivores. II. Six New Species from Japanese Shrew Moles (Talpidae)1
Authors: DUSZYNSKI DONALD W. , MOORE DWIGHT W.
Published: May 2007

ABSTRACT. Thirty‐eight of 51 (74.5%) shrew moles collected in Japan were infected with from one to four species of Eimeria and/or Isospora including six of six Dymecodon pilirostris and 32 of 45 (71.1%) Urotrichus talpoides. Four eimerians and two isosporans were identified and all are described as new species. Sporulated oocysts of Eimeria amorphospora n. sp. were subspheroid/ellipsoid, 21.1 × 17.9(18‐25 × 16‐21) μm. Sporocysts were amorphous, gelatinoid envelopes 20.3 × 7.5 (17–24 × 7–9) μm. Sporozoites were enclosed together within a membrane in each sporocyst. This species was found in 9 of 45 (20%) U. talpoides. Sporulated oocysts of Eimeria gonocilia n. sp. were subspheroid/ellipsoid, 28.8 × 24.4 (25–30 × 21–28) μm; a highly ornate outer oocyst wall gave the appearance of a ciliated ball. Sporocysts ovoid, pointed at both ends, were 17.0 × 9.0 (15–19 × 7–11) μm; this species was found in 4 of 45 (8.9%) U. talpoides. Sporulated oocysts of Eimeria talpoidei n. sp. were asymmetrical ovoid, 20.6 × 13.3 (18–23 × 12–15) μm, with sporocysts lacrimiform, 12.0 × 5.8 (10–14 × 5–7) μm. This species was found in 7 of 45 (15.6%) U. talpoides. Sporulated oocysts of Eimeria honshuensis n. sp. were ellipsoid, 15.5 × 11.4 (13–18 × 10–13) μm, with sporocysts ovoid, 9.1 × 5.2 (8–10 × 4–6) μm. This species was found in 10 of 45 (22.2%) U. talpoides and in 5 of 6 (83.3%) D. pilirostris. Sporulated oocysts of Isospora dymecodi n. sp. were subspheroid/ellipsoid, 15.8 × 12.6 (13–17 × 11–13) μm, with sporocysts ellipsoid, 10.9 × 6.9 (10–13 × 6–8). This species was found in six of six D. pilirostris. Sporulated oocysts of Isospora urotrichi n. sp. were spheroid/subspheroid, 13.4 × 12.4 (11–16 × 9–14) μm, with sporocysts ovoid, 9.2 × 6.3 (8–11 × 5–7) μm. This species was found in 27 of 45 (60%) U. talpoides. Only 14 of 38 (36.8%) infected hosts (one D. pilirostris, 13 U. talpoides) were seen to be naturally infected with only one coccidian species when sampled.
Eimeria tarentolae n. sp. from the Moorish Gecko, Tarentola mauritanica
Authors: MATUSCHKA F.‐R. , BANNERT B.
Published: May 2007

ABSTRACT. A new species of Eimeria from the Moorish gecko, Tarentola mauritanica, of Minorca, Spain, is described. Oocysts of Eimeria tarentolae are ellipsoidal and measure 17.8 (17.6–18.7) μm by 13.5 (12.9–14.0) μm. Micropyle, oocyst residuum, and polar granule are absent. Each oocyst contains four spherical to slightly subspherical sporocysts 6.8 (6.4–7.0) μm in diameter. A sporocyst residuum is present, while a Stieda body is lacking. Sporulation is completed within 24–32 h at 21 ± 2°C.
Ultrastructural Studies of Microgametogenesis and Macrogametogenesis of Eimeria truncata of the Lesser Snow Goose1
Authors: GAJADHAR ALVIN A. , STOCKDALE P. H. G.
Published: May 2007

ABSTRACT. Microgamonts and macrogamonts of Eimeria truncata were observed in renal epithelial cells of collecting tubules and ducts and occasionally in macrophages of experimentally infected lesser snow geese (Anser c. caerulescens) beginning 8.5 days post inoculation. Intraparasitophorous vesicles in parasitophorous vacuoles of both types of gamonts appeared to originate in host cell cytoplasm and enter gamonts through micropores by budding of plasmalemma or by pinocytosis. Within the parasite's cytoplasm, the vesicles were broken down in Golgi‐associated vacuoles. The surfaces of microgamonts were highly invaginated to facilitate extrusion of numerous microgametes. Formation and maturation of microgametes were similar to those of other eimerian species. Each microgamete had two flagella, a mitochondrion, and a peculiarly shaped electron‐dense nucleus that was oval anteriorly in cross section and somewhat dumbbell‐shaped posteriorly. A longitudinally arranged inner membrane complex lay between a portion of the mitochondrion and the plasmalemma. About five subpellicular microtubules extended the length of the microgamete body. Macrogametogony differed little from that described in other eimerian species. Type 1 wall‐forming bodies (WFB) formed in Golgi complexes early in macrogametogony, and type 2 WFB formed in cisternae of endoplasmic reticulum in intermediate stages of macrogamont development.
Studies of Macrostome Formation of Low‐Transforming Tetrahymena vorax. Transformation Enhancers, Generation Time, and Membrane Fluidity1
Authors: RYALS PHILLIP E. , SMITH‐SOMERVILLE HARRIETT E.
Published: May 2007

ABSTRACT. Periodically, stocks of Tetrahymena vorax, which normally yield 70–90% macrostomes when subjected to heat shock or other induction methods, become low‐transformers and yield ≥30% macrostomes. The addition to the post‐heat‐shock wash buffer (pH 6.8) of 2.7 × 10‐4 M Fe3+, 1.6 × 10‐5 M Cu2+, 1 × 10‐4 M retinol palmitate or the adjustment of the buffer to a pH of 4 to 5 boosts transformation significantly over controls in inorganic medium alone. The addition of Fe2+ or Cu1+ has a similar, but less pronounced effect on transformation. Ferric ion (2.7 × 10‐4 M) will significantly increase transformation in starved non‐heat‐shocked cells, whereas Fe2+, copper, retinol palmitate, and hydrogen ion concentration have no effect. The agents that boost transformation appear to act by delaying cell division in pre‐transformants. Membrane fluidity, as inferred by fluorescence polarization measurements of 1,6‐diphenyl‐1,3,5‐hexatriene, is altered in a consistent manner by starvation and heat shock. Enhancing agents, including compounds previously shown to boost heat‐shock‐induced macrostome formation, produce diverse shifts in membrane fluidity. Their effect on transformation of these low‐transforming cells therefore appears to be attributable to some mechanism or mechanisms other than a direct alteration of membrane physical properties.
A Light and Electron Microscopical Study of a New, Polymorphic Free‐Living Amoeba, Phreatamoeba balamuthi n. g., n. sp.1
Authors: CHAVEZ LAWRENCE A. , BALAMUTH WILLIAM , GONG THOMAS
Published: May 2007

ABSTRACT. A new amoeba, isolated from well water in Gambia, West Africa, is described and named Phreatamoeba balamuthi n. g., n. sp. Requiring anaerobic conditions for growth, it is easily cultured monoxenically with Escherichia coli or axenically in complex, undefined organic media. Three phenotypes have been observed in the life cycle: an amoeba, a flagellate, and a cyst. The amoeba moves by monopodia, is predominantly multinucleate, and varies from 11 to 160 μm in length. The flagellate has a single flagellum and is from 6 to 50 μm long. The cyst is surrounded by a resistant wall that lacks pores and ranges from 9 to 18 μm in diameter. The transformation from amoeba to flagellate can be induced nutritionally, the exact inducing factor(s) being unknown. Sexual reproduction has not been observed.
Light and Electron Microscopic Description of a Colorless Euglenoid, Serpenomonas costata n. g., n. sp.1
Authors: TRIEMER RICHARD E.
Published: May 2007

ABSTRACT. A new genus of rigid, colorless, phagotrophic euglenoid is described from a standing pond on a salt marsh. The cell body measures 21–25 μm long, is about 18 μm wide, has a slight dorso‐ventral flattening, and is marked by distinct pellicular ridges. The organism, described as Serpenomonas costata, has two unequal, antapically inserted, heterodynamic flagella. The shorter flagellum is anteriorly directed during swimming and the longer one trails posteriorly. Cells move along the substrate with a creeping motion. The ingestion apparatus is composed of separate ribs extending the length of the cell and is incorporated into the ventral pellicular ridge. The apparatus is independent of the canal and reservoir and is not protrusible. The taxonomic affinities of Serpenomonas with other euglenoids are discussed.
Characteristics of Membrane Protein Phosphorylation in Plasmodium berghei‐Infected Mouse Erythrocytes1
Authors: CHAIMANEE PORNTIP , YUTHAVONG YONGYUTH
Published: May 2007

ABSTRACT. Membrane protein phosphorylation in Plasmodium berghei‐infected erythrocytes was studied by incubating intact cells with (32P)orthophosphate and incubating isolated membrane with (γ‐32P)ATP. Phosphorylated proteins were detected by autoradiography after sodium dodecylsulfate (SDS)‐polyacrylamide gel electrophoresis or isoelectric focusing followed by gel electrophoresis. New phosphorylated proteins were found in membrane from infected erythrocytes, including a protein with electrophoretic mobility identical to band 5, with M, 43,000. The molar ratio of phosphate to protein ranged between 0.1 and 0.5. Isoelectric focusing‐SDS polyacrylamide gel electrophoresis, peptide mapping, extractability properties, and reduction of susceptibility to DNase I inhibition suggested that this protein is phosphorylated actin. In contrast, spectrin phosphorylation in infected erythrocytes was mostly unchanged.
Vairimorpha invictae N. Sp. (Microspora: Microsporida), a Parasite of the Red Imported Fire Ant, Solenopsis invicta Buren (Hymenoptera: Formicidae)12
Authors: JOUVENAZ DONALD P. , ELLIS E. ANN
Published: May 2007

ABSTRACT. Vairimorpha invictae n. sp. infects the red imported fire ant, Solenopsis invicta Buren, in Brazil. The parasite is dimorphic, producing two morphologically distinct types of spores, which develop sequentially in the same fat cells or oenocytes in the fat body. The binucleate free spores develop from disporous sporonts; the uninucleate octospores develop from multinucleate sporonts within a sporophorous vesicle. Infected cells are transformed into large sacs which contain both types of spores in mature adult hosts. Mature free spores are often present by the time the larvae pupate, but mature octospores are found only in adult hosts. Masses of spores may be seen through the intact cuticle by low power phase‐contrast microscopy; there are no other physical signs and no behavioral signs of infection. Attempts to transmit the infection in the laboratory failed.
Pyrotheca hydropsycheae N. Sp., a Microsporidian Parasite of Caddis Fly Larvae, Hydropsyche siltalai Döhler, 1963 (Trichoptera, Hydropsychidae)1
Authors: XIE W.‐D. , CANNING ELIZABETH U.
Published: May 2007

ABSTRACT. Pyrotheca hydropsycheae n. sp. is described from caddis fly larvae, Hydropsyche siltalai Döhler, 1963. All stages were found in oenocytes and fat body cells. Meronts were uni‐ or binucleate with simple surface membranes. The sporogonic stages were recognized ultrastructurally by the separation of an envelope, the sporophorous vesicle, from their surfaces. Mature sporogonial plasmodia were tetranucleate and gave rise by longitudinal fission to four uninucleate elongate sporoblasts with polar nuclei. Spores were lageniform with an inflated posterior end, containing the polar tube coils and the nucleus, and a narrow anterior section comprising two‐thirds of the length, containing the polaroplast and straight part of the polar tube. The polaroplast consisted of an anterior region of loosely packed membranes arranged as partitions at angles to one another and a posterior region of increasingly closely packed parallel membranes. The spore wall consisted of an electron‐dense exospore with a fuzzy coat and a thin electron‐lucent endospore. All four spores derived from a sporont faced in the same direction in the sporophorous vesicle. Spores measured 8.7 μm long and extruded polar filaments were about 20 μm.
Cytolytic Activity of Naegleria fowleri Cell‐free Extract1
Authors: FULFORD DAVID E. , MARCIANO‐CABRAL FRANCINE
Published: May 2007

ABSTRACT. The cytotoxic activity of a cell‐free extract of Naegleria fowleri amebae on B103 rat nerve cells in culture was investigated. The cell‐free extract was prepared by subjecting lysed amebae to centrifugation at 100,000 g for 1 h, precipitation of the supernatant fluid with 30–60% saturated ammonium sulfate, and desalting by group exclusion chromatography utilizing Sephadex G‐25. The supernatant fluid recovered from this procedure was termed the soluble fraction. The Naegleria cytotoxic activity present in the soluble fraction was assayed by 51Cr released from labeled B103 cells. The Naegleria soluble fraction, when added to nerve cells, elicited blebs on the B103 target cell surface within 5 min after exposure to the fraction. Later, holes were observed in the B103 cell plasma membrane. These alterations were never observed on untreated B103 cells. Phospholipase A, phospholipase C, and protease activities were associated with the desalted ammonium sulfate‐precipitable cytotoxic activity of N. fowleri cell‐free lysate. The cytotoxic activity was impaired by ethylenediamine‐tetraacetate (EDTA), phospholipase A inhibitor (Rosenthal's reagent), heating at 50°C for 15 min, or incubation at pH 10 for 60 min. Repeated freeze‐thawing and inhibitors of proteolytic enzymes had no effect on the cytotoxic activity. Small amounts of ethanol (5% v/v) enhanced cytotoxic activity of the fraction. Phospholipases A and C, as well as other as yet unidentified cytolytic factors may be responsible for producing 51Cr release from target cells by the soluble fraction of N. fowleri extracts.
Enzydmatic Characterization of Babesia bovis1
Authors: RODRIGUEZ S. D. , BUENING G. M. , VEGA C. A. , CARSON C. A.
Published: May 2007

ABSTRACT. Agarose gel electrophoresis was used to identify metabolic enzymes in Babesia bovis and B. bigemina. Glutamate dehydrogenase, lactate dehydrogenase, glucose phosphate isomerase, and hexokinase were identified in B. bovis‐ and B. bigemina‐infected erythrocytes and B. bovis merozoite preparations. A specific electrophoretic mobility was observed for each enzyme. Malate dehydrogenase, glucose 6‐phosphate dehydrogenase, 6‐phosphogluconate dehydrogenase, and adenylate kinase were only detected in normal erythrocyte preparations. Inter‐species, but not intra‐species, variation was noted when comparing electrophoretograms of both species. Kinin‐activating activity was not detected in B. bovis‐infected erythrocyte or merozoite preparations at pH 4.2 or 7.6.
Concentration and Enzyme Content of In Vitro‐Cultured Babesia bigemina‐Infected Erythrocytes1
Authors: VEGA CARLOS A. , BUENING GERALD M. , RODRIGUEZ SERGIO D. , CARSON C. ANDREW
Published: May 2007

ABSTRACT. Clones of in vitro‐cultured Babesia bigemina‐infected erythrocytes were concentrated by several density gradient procedures. The density range of infected erythrocytes containing pairs of parasites was 1.077 to 1.089 g/ml, whereas the density range of infected erythrocytes containing single parasites was 1.092 to 1.100 g/ml. Three enzymes‐lactate dehydrogenase, glucose‐phosphate isomerase, and glutamate dehydrogenase‐were found associated with infected erythrocytes. The parasite‐specific enzyme and/or isoenzymes were shown to have different mobility patterns in starch gel electrophoresis from those found in the normal bovine erythrocytes. The enzyme 6‐phosphogluconate dehydrogenase was not detected as a parasite‐specific enzyme in B. bigemina‐infected erythrocytes.
Studies of the Phoront of Hyalophysa chattoni (Ciliophora, Apostomatida) Encysted on Grass Shrimp1
Authors: LANDERS STEPHEN C.
Published: May 2007

ABSTRACT. The apostomatous ciliate Hyalophysa chattoni, an ectosymbiont of the grass shrimp Palaemonetes pugio, encysts and dedifferentiates within 48 h from the migratory tomite to a phoretic stage devoid of complex ciliary fields. The presettlement crawling and pivoting of the tomite may play a role in its initial attachment to the shrimp. Metamorphosis of exuviotrophic apostomes has been previously observed to take place immediately prior to host ecdysis. The study has found that Hyalophysa's metamorphosis to the feeding stage on grass shrimp is initiated by a cue from the premolt host and begins during earlier stages of the molt cycle (D0 and D1). Due to the long premolt stage of the host's diecdysic molt cycle, metamorphosis is initiated well before ecdysis (over six days). Hyalophysa was able to encyst and metamorphose within 41/4 h when exposed to shrimp in a late premolt stage, indicating that the control of apostome metamorphosis is solely host‐dependent.
A New Species of Perezia (Microsporida: Pereziidae) from the Argentine Grasshopper Dichroplus elongatus (Orthoptera: Acrididae)1
Authors: LANGE CARLOS E.
Published: May 2007

The new microsporidium (Microsporida: Pereziidae), Perezia dichroplusae n. sp., infects the epithelial cells of the Malpighian tubules of the Argentine grasshopper Dichroplus elongatus. Characteristics of the pathogen include the following: development in direct contact with the host cell cytoplasm; bi‐, tetra‐, and sometimes multinucleate diplokaryotic meronts, rounded or elongate in shape; unikaryotic sporonts and sporogonial plasmodia, elongate in shape; sporoblasts and spores uninucleated; spores highly variable in size (1.6–6.7 by 1.0–2.7 μm, x̄= 3.5 ± 0.09 by 1.5 ± 0.02, n = 100) with eight or fewer polar tube coils and showing a posterior electron‐dense inclusion body.
Evidence for Phosphorylation of the Extracellular Acid Phosphatase of Leishmania donovani1
Authors: LOVELACE JAMES K. , GOTTLIEB MICHAEL
Published: May 2007

The presence of two phosphorylated molecular species in the culture supernatants of axenically cultivated Leishmania donovani promastigotes was demonstrated by biosynthetically labeling cultures with [32P]phosphate. One of these species was resolved into two bands with Mr's of 149,000 and 97,000 by dissociating polyacrylamide gel electrophoresis and copurified with the extracellular acid phosphatase activity produced by the promastigotes. The site of phosphorylation of the extracellular acid phosphatase is not yet known.
Observations on Opisthonecta henneguyi Fauré‐Fremiet: Infraciliature, Argyrome, and Myonemic System
Authors: GUINEA A. , FERNÁNDEZ‐GALIANO D.
Published: May 2007

The infraciliature, argyrome, and myonemic system of Opisthonecta henneguyi have been examined after impregnation with the Fernández‐Galiano silver impregnation method. The oral infraciliature is formed by one haplokinety and three polykineties while the aboral infraciliature is formed by the trochal band—six kinetosomes wide—and the scopula. The trochal band has three fibrillar systems: orally directed fibers, aboral fibers, and oblique fibers. The argyrome is formed by 90 to 135 fine circular striations, which cover the whole organism with the exception of the peristome. The myonemic system is located in two regions: the oral and the aboral ones. The oral myonemic system is formed by a fibrous ring which surrounds the peristome underneath the spiral of the peristomial infraciliature and by a group of fibers which depart from the peristomial disc. The aboral myonemic system is much simpler, and it is formed by fibers which extend radially from the scopula. Biometrical characterizations of the vegetative cells and living cysts were also made, and our data are compared with the results obtained previously by other authors.
The Fine Structure of the Paralabial Organelle in the Rumen Ciliate Ophryoscolex purkinjei Stein, 1858
Authors: SCHRENK HANS‐GÜNTHER , BARDELE CHRISTIAN F.
Published: May 2007

The paralabial organelle of the rumen ciliate Ophryoscolex purkinjei, located on the ventral side of the ciliophor, is a highly specialized part of the somatic cortex. It consists of alternating rows of short modified cilia and thin pellicular folds which form a ridge‐like structure. The central “top kinety” is composed of monokinetids which bear cilia with 9 + 2 axonemes and 2 μm in length. The top kinety is accompanied by a comb‐shaped fold on its distal side and by a broad wedge‐shaped fold on its proximal side. To both sides there follow two or three lateral kineties made of dikinetids. The anterior kinetosome of each pair bears a clavate cilium, only 0.5–0.7 μm in length and with a 9 + 0 axoneme while the cilium of the posterior kinetosome is even shorter. Lateral folds with numerous microtubules cover these lateral kineties and rows of barren basal bodies. The fine structure of this supposed sensory organelle show a basic pattern in four other ophryoscolecids, and its increasing complexity parallels the suggested phylogenetic line of evolution of these ciliates.
Encystment in the Hypotrichous Ciliate Paraurostyla weissei: Ultrastructure and Cytochemistry1
Authors: DELGADO PILAR , CALVO PURIFICACION , TORRES ANTONIO
Published: May 2007

The cyst wall of Paraurostyla weissei consists of four morphologically distinct layers. It shows an ultrastructure and composition similar to that of the previously described kinetosome‐resorbing cysts, and its cytoplasm displays characteristics of “urostylid‐type” cysts. Therefore it is possible to consider it a “transition ciliate” between Stichotrichina and Sporadotrichina.
The Kinetid Structures of the Choreotrichous Ciliate Strobilidium velox and an Assessment of Its Evolutionary Lineage1
Authors: GRIM J. NORMAN
Published: May 2007

The ciliary (kinetid) structures of the ciliate Strobilidium velox have been examined with scanning and transmission electron microscopes. Somatic kineties consist of a linear row of kinetosomes (monokinetids) and short cilia lying partially beneath a thin fold of cytoplasm. The only fibrillar kinetid structure extending from the kinetosomes is a transverse ribbon of microtubules. The paroral membrane is a single‐file polykinetid possessing a possible transverse ribbon of microtubules and a nematodesma. The oral polykinetids or membranelles are complex, with microtubules extending from both anterior and posterior rows of cilia. While the kinetid structures do not satisfy the criteria for the order Choreotrichida, they are similar to the tintinnids in several other relevant ways. Strobilidium velox is proposed to be an unusual ciliate that is an exception to the concept that somatic kinetids are conservative and reliable phylogenetic indicator structures.
Electrophoretic Characterization of Members of the Crypthecodinium cohnii (Dinophyceae) Species Complex1
Authors: BEAM CARL A. , HIMES MARION
Published: May 2007

Eighty‐seven axenic clones of the colorless inshore dinoflagellate Crypthecodinium cohnii were found by mating experiments to fall into 52 sibling species, seven wide ranging (two possibly global)—called major sibling species—and 45 found only once—minor sibling species. Electrophoretic analysis of three soluble enzymes from these strains revealed the following: 1) Despite some polymorphism most members of major sibling species closely resemble one another electrophoretically. 2) Major sibling species and most minor ones are electrophoretically distinct. 3) Sharing of electromorphs is sufficiently extensive, however, that no major sibling species is totally unrelated to all others. 4) Some minor sibling species are electrophoretically indistinguishable from a member of a major sibling species or from one another, suggesting recent origin by sexual isolation in situ. 5) Other minor sibling species differ from majors by one, two, or all three of the enzymes studied. A “model” of sexual isolation and diversification is offered.
New Observations on First‐Generation Merogony of Eimeria tuskegeensis in Sigmodon hispidus1
Authors: GARGUS ELIZABETH B. , SUNDERMANN CHRISTINE A. , LINDSAY DAVID S. , BLAGBURN BYRON L.
Published: May 2007

First‐generation development of Eimeria tuskegeensis was evaluated using light microscopy. Sporozoite‐shaped meronts containing a prominent refractile body were observed in small intestinal cells of an experimentally infected cotton rat at 24 h post inoculation (PI). Mature spherical or subspherical meronts containing crescent‐shaped merozoites were observed at 36 h PI. Refractile bodies were observed in some of these merozoites. Sporozoite‐shaped meronts that were isolated from host intestinal cells and inoculated onto human fetal lung cell cultures penetrated the cultured cells by 2 h PI. A mature, subspherical, first‐generation meront containing seven merozoites was observed at 9 h PI in cell culture, indicating that sporozoite‐shaped meronts isolated from the host retained their infectivity.
Life Cycle of Culicospora magna (Kudo, 1920) (Microsporida: Culicosporidae) in Culex restuans Theobald with Special Reference to Sexuality1
Authors: BECNEL JAMES J. , HAZARD EDWIN I. , FUKUDA TOKUO , SPRAGUE VICTOR
Published: May 2007

The life cycle of Culicospora magna (Kudo, 1920) Weiser, 1977, consists of two major developmental sequences that alternate in host individuals of successive generations, each of the sequences starting with a sporoplasm and ending with spores. The first sequence occurs in larval, pupal, and adult stages of a parental generation of the host mosquito, Culex restuans Theobald; it begins with a sporoplasm from an ingested uninucleate spore and progresses through stages in gametogony, plasmogamy, nuclear association, merogony, karyogamy, and disporous sporulation with production of binucleate spores that discharge sporoplasms into the oocytes. The second sequence occurs in egg and larval stages of a filial generation of the same host species; it begins with the binucleate sporoplasm that entered the egg, includes stages in merogony, nuclear dissociation, and mictosporous sporulation, and ends with uninucleate spores. These spores are released into the environment following death of the host and are capable of infecting new parental generation host individuals. The life cycle is conceived as an alternation of generations related to haploidy and diploidy in the nuclei, the transition from haploidy to diploidy occurring with nuclear association and the transition from diploidy to haploidy occurring with nuclear dissociation.
The Glyceryl Ethers of Paramecium Phospholipids and Phosphonolipids1
Authors: Kaneshiro Edna S. , Meyer Kaniaulono B. , Rhoads Dennis E.
Published: May 2007

Two glyceryl ethers, 1‐O‐hexadecyl glycerol and 1‐O‐cis‐octadec‐11‐enyl glycerol, chimyl and paramecyl alcohol respectively, were quantified in total phospholipids and five glycerophospholipid classes from cells and cilia of the ciliated protozoon Parammecium tetraurelia. The ether content of 2‐aminoethyl phosphonoglycerolipid was 85–90 mole %. Concentrations of ethers were greatest in the ethanolamine phosphonolipids > phosphatidylcholines > phosphatidylserines > phosphatidylethanolamines > phosphatidylinositols. The glyceryl ether concentrations in total cellular phospholipids increased with culture age in P. tetraurelia and P. multimteronucleatum cells. The glyceryl ether concentrations in the phospholipids of P. tetraurelia cilia remained constant from mid log to stationary phase of culture growth. Paramecium tetraurelia phospholipid glyceryl ether concentrations were made greater by supplementation of cultures with chimyl alcohol.
Identification of a Developmentally Regulated Calcium‐Binding Protein in Trypanosoma brucei1
Authors: Ruben Larry
Published: May 2007

Calcium ions mediate cellular activity by binding to specific cellular proteins. The following study systematically examines the cellular complement of calcium‐binding proteins in different cell fractions and life cycle stages of Trypanosoma brucei. Using a 45Ca‐gel overlay procedure, eight calcium‐binding proteins were consistently observed. The majority of proteins were cytosolic (84, 70, 64, 22, and 15 kd) while the remainder (55, 46, and 29 kd) were particulate. Although calmodulin was detected amongst the calcium‐binding proteins, it did not represent the majority of calcium‐binding activity. Of special interest was the 46 kd calcium‐binding protein which was associated with 3‐fold more calcium in cultured procyclic forms than in slender bloodstream forms. By contrast, promastigote forms of Leishmania mexicana did not contain the 46 kd calcium‐binding protein. These data suggest that responsiveness to calcium signals may vary during the trypanosome life cycle as a result of changes in the cellular complement of calcium‐binding proteins.
Studies on the Development of Metacyclic Trypanosoma brucei sspp. Cultivated at 27°C with Insect Cell Lines1
Authors: Kaminsky Ronald , Beaudoin Esther , Cunningham Isabel
Published: May 2007

When transformed procyclic trypanosomes of three stocks of Trypanosoma brucei brucei and one stock of T. b. rhodesiense were grown at 27°C in 25‐cm2 flasks containing Anopheles gambiae cells, some of them developed into forms infective for mice. Infectivity titrations on trypanosome suspensions revealed that up to 2.8 × 105 metacyclic forms per ml could be produced, and the cultures remained infective for varying periods of up to 72 days when they were terminated. Of the various culture media tested, a mixture of three volumes of trypanosome medium and one volume of Anopheles medium was the most successful. Control cultures of trypanosomes grown in medium without cells were generally not infective, but two of the stocks gave rise to a few sporadic infections. Trypanosome populations could be subpassaged in the Anopheles cell cultures without loss of infectivity. Metacyclic forms separated from infective cultures by DEAE‐cellulose columns had a surface coat.
Trypanosoma cruzi: Analysis of the Population Dynamics of Heterogeneous Mixtures1
Authors: Finley Richard W. , Dvorak James A.
Published: May 2007

Utilizing the previously reported inter‐clonal differences in total DNA/organism, flow cytometry was used to analyze the population dynamics of Trypanosoma cruzi clone mixtures growing in liquid medium or vertebrate cells. The growth of clone mixtures in liquid medium can be described by unique parameters reflecting exponential growth rate (r), stationary phase population density (1/k), and the interaction between the clones (h). The relative numbers of each clone in the population change rapidly with time and the results arc in quantitative agreement with mathematical models of competitive population growth. The relationship between the parameters for T. cruzi is such that, in general, there is no dynamic equilibrium with coexistence of clones with different growth rates; under all culture protocols, the faster growing clone will prevail. A computer simulation of the vertebrate cell cycle of T. cruzi suggests that clone mixtures grow relatively independently; the basic attributes of the model were substantiated experimentally. Although wide fluctuations in the proportion of each clone released occurred, the faster growing clone again predominated. Finally, these results underline the importance of working with well‐defined clones in the laboratory to avoid inconsistencies and paradoxical results and stress the importance of the rapid isolation of single cell clones from clinical specimens when studying the relationship of the parasite to human disease.
Multiple Sequence Versions of the Oxytricha fallax 81‐MAC Alternate Processing Family1
Authors: Herrick Glenn , Cartinhour Samuel W. , Williams Kevin R. , Kotter Kenneth P.
Published: May 2007

The 81‐MAC family consists of three sizes of macronuclear chromosomes in Oxytricha fallax. Clones of these and of micronuclcar homologs have been classified according to DNA sequence into three highly homologous (95.9–97.9%), but distinct versions. Version A is represented by a micronuclear clone and by clones of two different‐sized macronuclear chromosomes, showing that alternate processing of micronuclear DNA is responsible for the variety of sizes of macronuclcar chromosomes. Three Internal Eliminated Sequences (IES's) are demonstrated in Version A micronuclcar DNA. Two have been sequenced and show short, flanking direct repeats but no inverted terminal repeats. Version C micronuclear DNA has interruptions in the macronuclear homology which correspond closely to the Version A IES's. Whether they are true IES's is unknown because no Version C macronuclear DNA has been demonstrated. Version C micronuclear DNA may be “macronuclear‐homologous” but “micronucleus‐limited” and not “macronucleusdestined.” Version B is represented by macronuclear DNA clones, but no micronuclear clones. Vegetative micronuclear aneuploidy is suggested. The possible role of micronuclear defects in somatic karyonidai senescence is discussed in light of the precise macronuclear chromosome copy controls demonstrated within the 81‐MAC family. These controls apparently operate throughout karyonidai life to mairitain 1) a constant absolute amount of 81‐MAC sequences in the macronuclcus and 2) a constant sioichiometry within the family, both according to version and chromosome size.
Effect of Biogenic Amines on Phagocytosis in Tetrahymena thermophila1
Authors: Quiñones‐Maldonado Vanya , Renaud Fernando L.
Published: May 2007

Stimulation of phagocytosis by serotonin and catecholamincs in Tetrahymena grown in proteose‐peptone medium proved to be concentration dependent, the optimal concentrations being ∼0.1 to 1.0 μM. The serotonergic antagonists, spiperone, and metergoline, also stimulated the process, whereas the β‐ and α‐adrenergic antagonists, propranolol, alprenolol, and ergocryptine, had no effect or inhibited phagocytosis. A wide variety of derivatives of the biogenic amines had no effect on phagocytosis, demonstrating the specificity of recognition mechanism for neurohormones in Tetrahymena. Such hormones act by at least two independent mechanisms, one for adrenergic agonists, another for dopamine. Presumably, recognition mechanisms for hormones in protozoa resemble in some respects those in multicellular organisms, therefore bespeaking a common origin.
Two New Species of Coccidia (Apicomplexa: Eimeriidae) from Madagascar Gekkonids
Authors: Upton Steve J. , Barnard Susan M.
Published: May 2007

Two new species of coccidia (Apicomplexa: Eimeriidae) are described from the Madagascar giant day gecko, Phelsuma madagascariensis grandis, and the Golddust day gecko, P. laticauda. Both species of coccidia were found to infect the anterior one‐half of the small intestine. Oocysts of Eimeria brygooi n. sp. are spherical or subspherical, 23.0 × 21.3 (18.8–25.2 × 16.4–23.2) μm; shape index (L/W) 1.1 (1.0–1.2). A micropyle, oocyst residuum, and polar granule are absent. Sporocysts are ovoid, 9.2 × 7.9 (8.0–10.0 × 7.2–8.8) μm; shape index 1.2 (1.0–1.3), with a Goussia‐type suture; Stieda and substieda bodies are absent. A sporocyst residuum is present, 4.2 × 3.0 (3.2–6.4 × 2.4–4.0) μm. Sporozoites are elongate, with anterior and posterior refractile bodies. This coccidian was found to infect five of six (83%) P. m. grandis and one of five (20%) P. laticauda examined. Oocysts of Isospora gekkonis n. sp. are spherical or subspherical, 24.2 × 22.0 (21.6–26.4 × 20.0–23.6) μm; shape index 1.1 (1.0–1.2). A micropyle and oocyst residuum are absent; polar granule present. Sporocysts are ovoid, 12.2 × 9.4 (11.2–12.8 × 8.4–10.0) μm, with Stieda and substieda bodies; shape index 1.3 (1.2–1.4). A sporocyst residuum is present, cither compact, 5.1 × 4.2 (4.0–7.2 × 3.2–5.6) μm or diffuse. Sporozoites arc elongate, with anterior and posterior refractile bodies. Isospora gekkonis was found in two of six (33%) P. m. grandis and one of five (20%) P. laticauda. In addition, oocysts of Cryptosporidium sp. were found in the cloacas of two of six (33%) necropsied P. m. grandis.
Cell Adhesion in Trypanosoma: In Vitro Studies of the Interaction of Trypanosoma vivax with Immobilized Organic Dyes1
Authors: Fish Wallace R. , Nelson Robert T. , Hirumi Hiroyuki
Published: May 2007

Certain bloodstream forms of Trypanosoma vivax have been shown to attach to Amicon Matrex™ Gel Green A dye beads in a manner similar to the in vivo binding of T. vivax to the inner surface of the tsetse fly proboscis. We now report an in vitro assay for trypanosome‐bead attachment and show that only the 9,10‐anthraquinone portion of the dye molecule is involved in the binding of trypanosomes to beads and that bead‐bound dyes with similar structures also support binding to differing degrees. The binding is dependent upon the amount of dye on the beads and this, and other evidence, suggests that an array of dye molecules, rather than individual molecules, may be the actual recognition site. Various external effectors, including temperature, soluble protein‐dye complexes, and serum of mice with chronic T. vivax infections, reduce trypanosome binding, indicating that at least one immunogenic trypanosome macromolecule is involved. The trypanosome‐bead interaction mimics the in vivo binding to tsetse proboscis and warrants closer examination as a model of trypanosome cell adhesion in the tsetse fly.
Fish Infected with Sphaerospora spp. Thélohan (Myxosporea) from Waters Enzootic for Proliferative Kidney Disease of Salmonids1
Authors: HEDRICK R. P. , KENT M. L. , TOTH R. J. , MORRISON J. K.
Published: May 2007

ABSTRACT. Sphaerospores were found among three species of fish examined from waters known to be enzootic for proliferative kidney disease (PKD) of salmonids. They were detected in the renal tubules of both hatchery‐reared rainbow trout (Salmo gairdneri) exposed to the infectious stage of PKD and in chubs (Gila bicolor) in the headwaters of a hatchery where PKD is enzootic. Sticklebacks (Gasterosteus aculeatus) collected near net pens where Pacific salmon had experienced a PKD epizootic were also found to harbor sphaerospores in the lumen of the kidney tubules. The latter two host species contained developmental stages of a myxosporidan in the blood and in the lumen of the kidney tubules which are similar to those of PKX, the causative agent of PKD in salmonid fish. The sphaerospores observed in the rainbow trout are the first to be observed in this species. The similarity to previously observed developmental stages, rarity, and presence of these sphaerospores in salmonid fish from a hatchery where PKD is enzootic suggest that they are the most mature stage of the PKX myxosporidan yet observed.
An Integrated Study of the Species Problem in the Euplotes crassus‐minuta‐vannus Group1
Authors: VALBONESI A. , ORTENZI C. , LUPORINI P.
Published: May 2007

ABSTRACT. In an attempt to solve the ambiguity in the taxonomy of the Euplotes crassus, minuta, and vannus group, 19 strains were tested for mating interactions, electrophoresed for isozymic variations, and analyzed by multivariate morphometrics of the conventional diagnostic traits. The overall results supported the validity of the three named species. Inter‐specific mating occurred only in a few crassus x vannus strain combinations and was usually inviable. Isozymic variations, in particular of amylases, malic enzyme, and malic dehydrogenase, were very restricted within conspecific strains and were great between non‐conspecifics. The species ascertainment of the strains was possible on the basis of clustering and principal component analyses of morphological measures.
Ultrastructure of the Contractile Vacuole and Its Periphery in Amoeba proteus: Evolution of Vesicles During the Cycle1
Authors: AKBARIEH MOSTAFA , COUILLARD PIERRE
Published: May 2007

ABSTRACT. The population of organelles in the periphery of the contractile vacuole of Amoeba proteus has been studied throughout the cycle using proper fixation and dehydration procedures on serial semithin and thin sections. Three distinct types of perivacuolar vesicles which arise successively from one another in the course of the cycle have been described. Size relationships have been determined by stereology.