bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Kinetic and Analytical Complexities of the DNA Genomes of Certain Marine and Fresh‐Water Ciliates1
Authors: SOLDO A. T. , BRICKSON S. A. , LARIN F. 
Published: May 2007

ABSTRACTWe investigated the macronuclear DNA genomes of several marine and fresh‐water ciliates. The marine forms studied were: Uronema nigricans, Parauronema virginianum, Parauronema acutum, and two strains of Miamiensis avidus; the fresh‐water ciliates included: Tetrahymena pyriformis, Paramecium octaurelia, and P. caudatum. The organisms were cultured axenically and the DNA extracted from isolated and purified macronuclear preparations. Reassociation rate constants of purified DNA preparations used to calculate kinetic complexity were determined both optically and by hydroxyapatite chromatography. Analytical complexity was determined chemically. Ciliate macronuclear DNA appeared to reassociate as a single unique sequence, except for a small fraction (4% of the total DNA) that was repetitive and renatured rapidly. Values for the kinetic complexities of macronuclear DNA in these forms varied over a relatively narrow range, from 1.5 to 3.8 times 1010 daltons, and were only 7–15x larger than that of the bacterium Escherichia coli. On the other hand, values for analytical complexities of macronuclear DNA of marine and fresh‐water ciliates varied over two orders of magnitude and were related to the size of the animals. It is suggested that ploidy levels of macronuclear DNA in these ciliates may represent a functionally permanent amplification of the genome.
Glycogen Phosphorylase and Synthase Activities of Rumen Ciliates of the Genus Entodinium
Authors: HOSHINO SADAO , WAKITA MASAAKI , IIDA AKIO 
Published: May 2007

ABSTRACTGlycogen phosphorylase and synthase activities were detected in the sonic lysate of rumen ciliates of the genus Entodinium. The ciliate phosphorylase had the following properties. The pH optimum was narrow and centered at pH 5.9. The activity was maximum at 30°C; above 40°C a rapid inactivation occurred. The Km value for glucose‐1‐phosphate (G‐1‐P) and for glycogen was 15 mM and 0.069% (w/v), respectively. NaF and ethylenediamine tetraacetic acid had no stimulative effect on the enzyme activity, though adenosine 3′,5′‐monophosphate and theophylline activated it. NaHSO3 inhibited the enzyme activity at a concentration of 1 mM. The inhibition of glucose was noncompetitive for G‐1‐P. Glycolytic intermediates and nucleotides had a minor effect on phosphorylase activity. Glycogen synthase existed in two forms, glucose‐6‐phosphate dependent and independent forms: the proportion of the latter form increased with the decrease of reserve polysaccharide levels in the ciliates. Correlations between glycolytic enzyme activities included phosphorylase and synthase activities and reserve polysaccharide contents in the ciliates were determined, and a possible regulatory mechanism of polysaccharide synthesis and degradation was discussed.
Biochemical Requirements for Intracellular Invasion by Trypanosoma cruzi: Protein Synthesis1
Authors: LIMA MARIA F. , KIERSZENBAUM FELIPE 
Published: May 2007

ABSTRACTThe effects of irreversible inhibition of protein synthesis by pactamycin in either infective forms of Trypanosoma cruzi or mammalian host cells on cellular invasion by this human pathogen were investigated. Treatment of bloodstream forms of T. cruzi with pactamycin markedly reduced their ability to bind either fibroblast‐like cells of monkey origin or myoblasts of rat origin. The number of amastigote forms that could be established intracellularly was also significantly decreased with respect to control values obtained when mock‐treated (medium alone) trypomastigotes were incubated with the cells. Pactamycin treatment also reduced the infectivity of T. cruzi trypomastigotes for mice as evidenced by both significantly reduced parasitemia levels and mortality rates when compared with those of control mice infected with mock‐treated parasites. Inhibition of protein synthesis in the host cells neither prevented cell infection by untreated trypomastigotes nor altered the percentages of infected cells or the magnitude of the infection in vitro. These results indicate that protein synthesis is a requirement for cell invasion by T. cruzi and that the parasite can establish itself and replicate within cells relying on its own protein synthesis ability.
Trypanosoma cervi from Alaskan Reindeer, Rangifer tarandus1
Authors: KINGSTON N. , MORTON JAMIE K. , DIETERICH ROBERT 
Published: May 2007

ABSTRACTTwenty‐nine (64.4%) of 45 reindeer, Rangifer tarandus, examined over a two‐year period were infected with trypanosomes. Trypomastigotes and dividing epimastigotes were found in the blood of fawns, cows, and bulls. Morphometric analysis of bloodstream trypomastigotes from reindeer and comparison of these parasites with similar stages of trypanosomes from elk, mule deer, and white‐tailed deer from the contiguous United States proved them conspecific; the trypanosomes from these members of the Cervidae are identified as Trypanosoma cervi Kingston & Morton, 1975. This is the first report of trypanosomes from reindeer. No pathogenic effects are known to be caused by these parasites.
Growth Requirements of Symbiont‐Free and Symbiont Lambda‐Bearing Paramecium octaurelia 299 for Folic Acid and Biopterin
Authors: SOLDO A. T. , GODOY G. A. , BRICKSON S. A. 
Published: May 2007

ABSTRACTWe investigated the growth requirements of symbiont‐free and symbiont lambda‐bearing Paramecium octaurelia stock 299 for folic acid and biopterin in chemically defined culture medium. Symbiont‐free P. octaurelia required both folic acid and biopterin for growth. In the absence of these substances growth of symbiont‐free P. octaurelia failed after the first transfer, whereas symbiont lambda‐bearing P. octaurelia could be maintained indefinitely in serial subculture. In the absence of folic acid and biopterin, sulfanil‐amide inhibited growth of the symbiont lambda‐beating protozoa. In the presence of folic acid and biopterin, the antiobiotic selectively inhibited growth of lambda symbionts but did not affect growth of the protozoa. In both cases, inhibition by sulfanilamide was reversed by addition of p‐aminobenzoic acid to the medium. These results support our earlier finding that folic acid is required for growth of symbiont‐free P. octaurelia 299 and that growth of the lambda‐bearing strain without exogenous folate denoted synthesis of folic acid by the symbionts. In addition, it appears that the symbionts produce sufficient biopterin to meet the needs of the host protozoon for growth.
Ultrastructural Study of the Development of Babesia ovis (Piroplasmia) in the Ovary of the Vector Tick Rhipicephalus bursa1
Authors: MOLTMANN ULRICH G. , MEHLHORN HEINZ , FRIEDHOFF KARL T. 
Published: May 2007

ABSTRACTThe reproduction of Babesia ovis inside the ovary of the vector tick Rhipicephalus bursa was studied by electron microscopy. The kinetes of B. ovis invade the ovary of the tick via hemolymph. The kinete, when situated intracellularly, is transformed into a polymorphous stage that loses all features of the invasive form. The nucleus elongates enormously and forms many folds which extend throughout the cell. Subsequently, the lobulated nucleus and the cytoplasm are divided into numerous uninuclear cytomeres by invaginations of the cell boundary and by interconnecting endoplasmic reticulum. Each cytomere, bounded by a unit‐membrane, measures ca. 4 μm in diameter and finally forms a new kinete. This proceeds as protrusion of the cytoplasm into an intracytoplasmic vacuole. An apical complex is initially visible at the tip of the protrusion that emerges steadily into the lumen of the expanding vacuole. The nucleus of each cytomere is incorporated into the newly formed kinete, which is surrounded by a coccidian pellicle the inner membranes of which are formed at the base of the intracellular protrusion. Nearly all of the cytoplasm is used for the differentiation of the kinete, which finally lies folded inside the vacuole. The kinete is apparently released by rupture of the vacuole. The description of this peculiar reproduction completes the knowledge of similar reproductive processes in other tissues of the tick. A comparison of the differentiation of the kinete in Babesia and in Theileria indicates a similar mode of development.
Genus Pleistophora Gurley, 1893: An Assemblage of at Least Three Genera1
Authors: CANNING ELIZABETH U. , HAZARD EDWIN I. 
Published: May 2007

ABSTRACTUntil recently, pansporoblastic microsporidia that produce a variable and large number of sporoblasts from a sporont have been included in a single genus, namely Pleistophora Gurley, 1893. Ultrastructural studies have been used to determine whether the resemblance of these species is fundamental or superficial. The results indicated that the multisporous pansporoblastic forms belong to at least three genera and, thus, that Pleistophora is a “composite genus.” The term pansporoblast was originally used for stages in myxosporidian development. The term sporophorous vesicle adopted from Gurley is suggested for the spore‐containing vesicle in the Microspora. Three species were studied: Pleistophora typicalis, the type‐species; Pleistophora culicis, for which a new genus Vavraia has already been proposed; and Pleistophora simulii. P. typicalis and V. culicis have isolated nuclei throughout their development, and the sporophorous vesicle wall enveloping the sporoblasts is derived from amorphous secretions laid down during merogony external to the plasmalemma. Pleistophora and Vavraia are differentiated principally in terms of the structure of the sporophorous vesicle wall and mode of division of the sporogonial plasmodium. The nuclei of young sporonts of P. simulii are in diplokaryon arrangement and undergo meiosis to give haploid nuclei in the sporoblasts. The sporophorous vesicle wall is membranoid and is laid down external to the plasmalemma at the onset of sporogony. A new genus, Polydispyrenia n. g., is suggested for this species, the affinities of which are closer to the dimorphic species of microsporidia than to Pleistophora or Vavraia. The terms “merontogenetic sporophorous vesicle” and “sporontogenetic sporophorous vesicle” are used to distinguish between the two groups.
Intraerythrocytic Development of Plasmodium knowlesi: Structure, Temperature‐ and Ca2+‐Response of the Host and Parasite Membranes1
Authors: WUNDERLICH FRANK , STÜBIG HELLA , KÖNIGK EBERHARD 
Published: May 2007

ABSTRACTThin‐sectioning and freeze‐etching electron microscopy were applied to explore the structure and the temperature‐ and Ca2+‐response of the different host and parasite membranes during intraerythrocytic development of Plasmodium knowlesi in Macacca mulatta. The plasma membrane of uninfected erythrocytes is temperature‐ and Ca2+‐responsive: chilling to 4°C and exposure to 5 mM Ca2+ induces a slight decrease in IMP‐frequency and the emergence of small IMP‐devoid patches on P‐faces. On parasite infection, the erythrocyte membrane becomes modified as indicated by an enhanced temperature‐response and the appearance of caveolae, ca. 70–90 nm in diameter. The frequency of these caveolae is increased in schizont‐infected erythrocytes. Moreover, electron dense plaques, ca. 40 nm in width, appear just beneath the erythrocyte membrane in late trophozoites and schizonts, thus indicating a further modification of the host cell membrane during parasite development. The membrane of the parasitophorous vacuole, derived from the host plasma membrane, dramatically reduces the IMP‐frequency especially on the P‐face upon parasite infection. This leads to an apparent reversal of the IMP‐distribution persisting throughout the whole infection cycle. The parasite plasma membrane forms local compaction domains with the nuclear envelope in ca. 30% of the ring‐stages and trophozoites, which disappear in late trophozoites and schizonts. Moreover, the IMP‐frequency on plasma membrane fracture faces almost doubles during parasite development. Chilling induces a decrease in the IMP‐frequency on P‐faces of the plasma membrane. Surprisingly, however, the parasite plasma membrane and the vacuolar membrane respond to externally applied Ca2+ with almost a doubling of the IMP‐frequency. The different parasite endomembranes also undergo characteristic changes during parasite development.
Analysis of Histones from the Endosymbiont Nucleus of a Binucleate Dinoflagellate1,2
Authors: RIZZO PETER J. 
Published: May 2007

ABSTRACTHistones were prepared from chromatin of the eukaryotic (endosymbiont) nucleus of Peridinium balticum (Levander) Lemmermann. The amino acid composition of whole histone was rich in lysine and similar to that of Olisthodiscus luteus and Euglena gracilis. Electropheretic analysis of these proteins in acidic‐urea disc gels revealed four major bands: one with a mobility slightly lower than that of calf thymus HI; and three others which comigrated with calf H2B, H2A, and H4, respectively. The low mobility band was soluble in 5% perchloric acid and was sensitive to FeCl3 destaining. Electrophoresis in slab gels containing 0.1% SDS revealed five major components, with approximate molecular weights of 23,000, 20,000, 15,000, 13,000, and 11,000, respectively. The 15,000 and 11,000 dalton histones had mobilities identical to those of calf H3 and H4, respectively. The two highest molecular weight components were soluble in 5% perchloric acid. No bands were found to comigrate with calf H2A or H2B but a band was present that migrated to a position intermediate between calf H2A and H4 (13,000 dalton histone). Two‐dimensional gels consisting of acidic‐urea gels in the first dimension and SDS gels in the second dimension revealed that the 20,000 dalton component and the 13,000 dalton component are not resolved in the acidic‐urea gel. As a working hypothesis, it is suggested that two of the five bands seen in SDS gels represent an H1‐like doublet, and two are analagous to H3 and H4, respectively. The remaining histone may replace H2A and H2B.
Separation of Individual Stages of Trypanosoma cruzi Grown in Cell Culture by Continuous Free‐Flow Electrophoresis
Authors: MURRAY P. KEITH , BOLTZ ROBERT C. , SCHMATZ DENNIS M. 
Published: May 2007

ABSTRACTThe separation of extracellular protozoan parasites from host cells based on a difference in surface charge has been described. However, with Trypanosoma cruzi no method exists for the isolation of pure parasite stages from heterogeneous mixtures. Studies on the electrophoresis of mixed stage populations confirm significant surface charge density differences exist among epimastigotes, trypomastigotes, and amastigotes. In ascending order of electronegativity, amastigotes have the lowest charge density, try‐pomastigotes next, followed by epimastigotes. A technique has been developed for the separation of purified populations of parasites based on these charge differences using a continuous free‐flow electrophoresis apparatus. The separated populations are morphologically intact and maintain their infectivity to mice. This separation method is applicable for preparative and analytical isolation of pure stages of T. cruzi for biochemical and immunological studies.
Radioiodination of Parasite Antigens with 1,3,4,6,‐Tetrachloro‐3α,6α‐diphenylglycoluril (IODOGEN): Studies with Zygotes of Plasmodium gallinaceum
Authors: HOWARD R. J. , KAUSHAL D. C. , CARTER R. 
Published: May 2007

ABSTRACTThe iodinating reagent 1,3,4,6,‐tetrachloro‐3α,6α‐diphenylglycoluril (IODOGEN3) was used to label antigens on zygotes of Plasmodium gallinaceum with parallel studies using lactoperoxidase‐catalyzed radioiodination for comparison. Proteins labeled by the IODOGEN method are most probably on the surface of the zygote, as the pattern of labeled proteins analyzed by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis was very similar to the pattern of lactoperoxidase‐labeled proteins. Furthermore, the labeled proteins represented only a subset of the total Coomassie Blue‐stained proteins. The radioiodinated zygote proteins were immuno‐reactive after IODOGEN or lactoperoxidase labeling. The IODOGEN method is technically much more simple than the lactoperoxidase method and does not require the addition of extraneous proteins or H2O2. The advantages of IODOGEN labeling, together with the essential equivalence of results obtained by these two, methods, make the IODOGEN method attractive for labeling parasite antigens in general.
Occurrence of 2‐Aminobutanoic Acid in the Incubation Medium of Mixed Rumen Ciliate Protozoa1
Authors: ONODERA R. , MIURA K. , FUKUDA H. 
Published: May 2007

ABSTRACTAn unknown, ninhydrin‐positive substance detected on paper chromatograms of the endogenous metabolites of mixed rumen ciliate protozoa was isolated and purified by column chromatography with ‘Dowex’ 50‐X8 resin and identified as 2‐aminobutanoic acid (α‐amino‐n‐butyric acid) on the basis of elementary analysis, mass spectrometry, paper chromatography, infrared spectrometry, and melting point.
Changes in Two Acid Hydrolase Levels During Cyst Differentiation of a Ciliate, Histriculus muscorum1
Authors: SENDO YOSHIHIRO , MATSUSAKA TADAO 
Published: May 2007

ABSTRACTCellular levels of protein and two acid hydrolases, acid phosphatase (EC 3.1.3.2) and acid proteinase, were followed during cyst differentiation, arbitrarily divided into five stages, in the ciliate Histriculus muscorum Kahl. Extracellular enzyme activities were also measured. Protein content decreased gradually during cyst differentiation. In mature cysts the protein content was ca. 60% that of stationary phase organisms. The activities of both acid hydrolases remained unchanged during stage 1 and then decreased gradually; acid proteinase decreased more rapidly. Both enzymes remained slightly active in the mature cysts. The acid proteinase activity of stage 1 was reduced by cycloheximide treatment at time zero, whereas the enzyme was no longer sensitive to the inhibitor when treated at 1.5 h (late stage 1) after the first wash with encysting medium. Acid phosphatase activity was insensitive to the inhibitor. Extracellular release of acid phosphatase increased linearly at least until stage 5, although the extracellular release of acid proteinase was not detected. Cycloheximide blocked the extracellular release of acid phosphatase after stage 1. These results suggest that de novo synthesis of acid proteinase occurs during stage 1 and that lysosomes may play an important role during early stages of cyst differentiation.
New Methods for Cultivating, Harvesting, and Purifying Mass Cultures of the Hypotrich Ciliate Euplotes aediculatus1
Authors: SCHMIDT HELMUT J. 
Published: May 2007

ABSTRACTA new method is described for mass cultivation of Euplotes aediculatus, a hypotrich ciliate containing omikron‐symbionts. The ciliate cultures, continuously aerated in Erlenmeyer flasks (5000 ml) with 4500 ml medium, yield densities of 2300 cells/ml which are four to five times higher than cell densities of cultures grown in unaerated Fernbach flasks. Harvesting such cultures involves the application of 25‐μm mesh sieves. Cells so concentrated can be purified by using columns or special chambers in which Euplotes migrates towards the cathodes in an electric field (field strength 7 V/cm).
Ellobiophrya conviva n. sp., a Commensal of Marine Ectoprocts, and a Revision of the Family Ellobiophryidae (Ciliophora, Peritricha)1
Authors: CLAMP JOHN C. 
Published: May 2007

ABSTRACTThe sessiline peritrich Ellobiophrya conviva n. sp. is described from marine ectoprocts of the genus Bugula, the first report of an ellobiophryid on bryozoan hosts. The new species is distinguished from others of its genus by its different body proportions, size, host, and structure of the clasping holdfast (for which the new name cinctum is chosen). Ellobiophrya conviva has been found only on B. neritina and B. turrita and shows a marked seasonal cycle of abundance. The family Ellobiophryidae Chatton & Lwoff is revised on the basis of new information provided by E. conviva, with the single species of the genus Clausophrya removed to Ellobiophrya as E. oblida Naidenova & Zaika n. comb. The genus Caliperia Laird remains unchanged. The two genera of the revised family are distinguished from one another by differences in the structure of the cinctum. Hypotheses are advanced to explain the morphogenesis of the cinctum and the evolution of ellobiophryids from other peritrichs.
The Spatial and Temporal Distribution of Paramecium bursaria in the Littoral Zone1
Authors: LANDIS WAYNE G. 
Published: May 2007

ABSTRACTThe spatial and seasonal distribution of Paramecium bursaria in two small Indiana ponds was studied using a sampling grid. Very small (5.0 ml) samples were taken so that the individual microhabitats could be studied. The results were evaluated in comparison to the data collected for the P. aurelia complex collected in the same manner and at the same sites. It was found that P. bursaria exist in a clumped distribution, but that the distribution was not very different from random. Paramecium bursaria also exist at the surface and at the mud‐water interface. Temperature does not seem to play a statistically significant role in determining population size. The breeding system of P. bursaria is optimized for an outbreeding population of low density. In comparison, the species of the P. aurelia complex exist in a very clumped distribution, are found only at the mud‐water interface, and are inbreeders. The evolutionary strategies of the two types of paramecia are discussed.