bluuebunny/crossref_metadata_2025 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

We 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.
The Dynamics of Micronuclear Mitosis in the Living Ciliate Spirostomum teres as Revealed by Polarization Microscopy1
Authors: JENKINS ROBERT A.
Published: May 2007

ABSTRACT. Micronuclear mitosis in living Spirostomum teres has been studied by sensitive polarization microscopy, and the dynamic aspects of micronuclear division are described. The small, spherical, interphase micronuclei lie in form‐fitting depressions in the macronuclear surface. Nuclear division begins with the rounding and slight swelling of the macronucleus and, coincidentally, the micronuclei move out of the depressions and away from the macronucleus, increase in size, and become weakly birefringent. As mitosis proceeds, the micronuclei increase in uniaxial birefringence and elongate to form irregular ovoids that convert to angular structures displaying principal axes of positive birefringence so divergent as to appear oriented at a right angle to one another. Micronuclei maintain this appearance for as long as 60 min and then abruptly change to rectangular‐shaped structures, increase in uniaxial birefringence, and begin anaphase elongation. The somewhat dumbbell‐shaped micronuclei lengthen at the constant rate of 2.0 μm/min to reach lengths >70 μm. It appears that little half‐spindle shortening occurs during spindle elongation. Accompanying the changes in micronuclear spindle length are changes in birefringence. Just before elongation begins, presumably metaphase, the micronucleus is uniformly and intensely birefringent. At the magnifications employed, a chromosome plate is not clearly visible as a region of reduced birefringence. As elongation begins, the putative half‐spindles are more birefringent than is the interzone, a condition that is maintained until the spindles have achieved ∼30% elongation, at which time a region of increased birefringence develops at the center of the interzone. This pattern persists for a very short time, then gives way to a uniform birefringence of the entire separation spindle that is maintained until elongation is completed. The rate of micronuclear spindle elongation, changes in micronuclear dimensions, and corresponding changes in birefringence are discussed with respect to possible mechanisms of mitosis.
Ultrastructural Features of Allantosoma intestinalis, a Suctorian Ciliate Isolated from the Large Intestine of the Horse1
Authors: SUNDERMANN CHRISTINE A. , PAULIN JEROME J.
Published: May 2007

ABSTRACT. Allantosoma intestinalis, a suctorian ciliate isolated from the intestine of the horse, was studied utilizing light and electron optical methods. These small sausage‐shaped organisms have a varying number of tentacles (between one and 12) located at each extremity of the body. The microtubular axoneme of each tentacle in cross‐section consists of two files of microtubules arranged in a daisy‐like configuration. Haptocysts occur in the tentacle shaft, abutted to the plasma membrane of the knob of the tentacle, and in the cell body. The haptocysts are bottle‐shaped, with prominent annular striations around their midportion. The cell is covered by three membranes, an outer plasma membrane, an outer alveolar, and an inner alveolar membrane. A thin epiplasmic layer is found beneath the inner alveolar membrane, and a single row of microtubules underlies the epiplasm. The subpellicular microtubules are arranged parallel to each other forming a corset around the cell along the long axis: such a system is not characteristic of suctorians. A field of diminutive kinetosomes (each 180 nm long, max. of 15 per field), lacking cilia, was found below the cortex. The function of these prokinetosomes is unknown. A ciliated swarmer has not been observed, only the nonciliated adult. The characteristics of Allantosoma are compared with those of other suctorian genera.
An Analysis of Specific Temperature Blocks in the Conjugation Sequence of Paramecium tetraurelia1
Authors: HINRICHSEN ROBERT D.
Published: May 2007

ABSTRACT. Temperature shifts have been used to block critical points in the conjugation sequence of Paramecium tetraurelia. Increasing temperatures above 27°C reduced ciliary agglutination, pair formation, and nuclear exchange; a complete inhibition of these stages occurred at 37°C. Temperatures below 19°C had no effect on ciliary agglutination or nuclear exchange but completely inhibited pair formation. The bases for the cells’ inability to form pairs at 19°C and 37°C were sought. Cells placed below 19°C were unable to deciliate or fuse membranes in the holdfast region; at 37°C, membrane fusion in both the holdfast and paroral regions was prevented. Time course studies on cross‐fertilization reveal that temperatures 35°C block all stages of the process up to the actual exchange of pronuclei. After the exchange has begun, the process continues despite the elevated temperature. Temperature shifts are discussed as a means of conditionally blocking critical points in the developmental program of conjugation.
An Ultrastructural Study of First‐ and Second‐Generation Merogony in the Coccidian Sarcocystis tenella1
Authors: SPEER CLARENCE A. , DUBEY J. P.
Published: May 2007

ABSTRACT. Sporocysts of the coccidian Sarcocystis tenella were originally isolated in the feces of a coyote. Sporocysts used for inoculation of lambs were obtained from experimentally infected dogs. At 14, 16, and 19 days postinoculation (DPI) of lambs with the sporocysts, various developmental stages of first‐generation meronts were found within cells located between the endothelium and internal elastic membrane of mesenteric arteries. At 19, 21, and 25 DPI, second‐generation merogony occurred in cells associated with capillaries and arterioles of kidney glomeruli and convoluted tubules. Meronts of both generations were bounded by a double pellicular membrane and were situated free in the host cell cytoplasm. Merozoites formed by endopolygeny that involved multiple intranuclear spindles of a single, large irregular nucleus. First‐generation meronts measured 22.6 × 17.1 μm (19–28.7 × 7.5–24 μm) and contained 120–240 merozoites, which measured 7.1 × 1.6 μm (4.8–7.5 × 1.3–1.8 μm). Corresponding values for second‐generation meronts were 13.2 × 9.2 μm (8.3–15 × 7–13.5 μ), 32–80, and 5.8 × 1.7 μm (5.6–6.2 × 1.4–2.2 μm).
Metabolism of α‐Glyceryl Ethers by Crithidia fasciculata. I. Study of the In Vivo Degradation of Exogenous Chimyl and Batyl Alcohols1
Authors: GABRIELIDES CHRISTINE , KAPOULAS VASSILIOS M.
Published: May 2007

ABSTRACT. [14C]chimyl and [3H]batyl alcohols were added to Crithidia fasciculata cultures during the mid‐log phase of cell growth, and the lipid extracts of the cells were analyzed for degradation products. C. fasciculata cells were able to take up exogenous glyceryl ethers, and in amounts as high as the endogenous lipid content. The glyceryl ether taken up by the cells was incorporated into lipids either prior to the ether bond cleavage or after degradation to fatty acid. The extent of degradation and the degree of incorporation of degradation products into cellular lipid were higher for chimyl than for batyl alcohol. Batyl alcohol was not metabolized efficiently, leading to the formation of large intracellular pools of free substrate. One product of glyceryl ether degradation was identified as alkyl‐dihydroxy acetone, and was detected inside and outside of the cells. The data strongly suggest that this product is the first stable intermediate in the degradation process and indicate that the extracellular formation of alkyl‐dihydroxy acetone is due to the action of exocnzyme; ecteted by the cells. The constant detection of alk I cnyl glycerol among the degradation products indicates the existence of a second mechantsm in C. fasciculata for converting the alkyl‐to alkenyl‐glycerol.
Localization of Phosphatases in Trypanosoma rhodesiense1
Authors: WILLIAMSON J. , MCLAREN DIANE J.
Published: May 2007

ABSTRACT. Phosphatase activity in Trypanosoma rhodesiense has been examined histochemically by light and electron microscopy and by enzymatic assay in homogenate fractions. Using a method with lead as capture ion, acid phosphatase was found in lysosome‐like vesicles and in the flagellar pocket. No alkaline adenosine triphosphatase (ATPase) was detectable by this method. Direct assay of p‐nitrophenylphosphatase activity in homogenate fractions showed that acid phosphatase activity was strongly membrane‐bound, but that activity at pH 9 was minimal in both soluble and particulate fractions. “Endogenous” ATPase activity was localized specifically and reproducibly in the mitochondrial membranes and under the plasma membrane of the flagellum. This nonenzymic reaction product could not be eradicated by glycerol extraction or glucose depletion. Unlike the membrane staining, which was manifest only after lead treatment, heat‐resistant electron‐dense material was found in the matrix of lysosomal vesicles in trypanosomes fixed in glutaraldehyde only and not subjected to further treatment with heavy metal reagents. X‐ray emission analysis showed the presence of calcium and phosphorus, indicating that the matrix might have a phosphate storage function.
Effect of Cell Density on Thermotaxis of Paramecium1
Authors: TSUCHIYA Y. , KAWAKUBO T.
Published: May 2007

ABSTRACT. The swiftness of thermotaxis of Paramecium caudatum has been investigated for various populations of organisms by measuring the transient spatial distribution of the gathering process of organisms that are transferred to a temperature‐gradient cell from the culture medium. The dispersion obtained from the spatial distribution for each population is found to decrease linearly with time and finally reach a steady state value. The gathering rate determined by the slope of the dispersion strongly depends on population; it increases with population.
In Vitro Cultivation of Bloodstream Forms of Trypanosoma brucei, T. rhodesiense, and T. gambiense1
Authors: BRUN R. , JENNI L. , SCHÖNENBERGER M. , SCHELL K.‐F.
Published: May 2007

ABSTRACT. A series of new in vitro systems for the cultivation of bloodstream forms of Trypanosoma (Trypanozoon) brucei brucei, T. (T.) b. rhodesiense, and T. (T.) b. gambiense was developed. The standard system consists of a feeder layer of fibroblast‐like cells derived from embryos of New Zealand White rabbits (REF) or a mountain vole, Microtus montanus (MEF), with HEPES‐buffered Minimum Essential Medium (MEM), with Earle's salts, supplemented with 15% inactivated rabbit serum. These two and other feeder layers were cross‐checked with different sera to test for growth support of bloodstream forms of the three trypanosome subspecies studied. Cultures could be initiated with bloodstream forms from mammalian hosts or from cryopreserved stabilates. Metacyclic forms from infected Glossina m. morsitans could also be used as inoculum; they transformed within 6 h to bloodstream forms. Maintenance of cultures and growth properties are described in detail. Experiments were undertaken to confirm that the cultivated bloodstream forms still possess some of the characteristic features of pleomorphic bloodstream populations. Cultivated bloodstream forms were always infective for mice, and a surface coat could be demonstrated by electron microscopy. They could also be cyclically transmitted through tsetse flies, and the metacyclic forms from these flies could be brought back into culture. In vitro cloning with single bloodstream forms and metacyclic forms could be achieved with high cloning efficiency. The consumption of glucose and the production of pyruvate and lactate were determined.
Yield Constant for Acanthamoeba polyphaga in Batch and Continuous Culture1
Authors: SINCLAIR M. J. , McCLELLAN J. F. , SINCLAIR J. L. , COLEMAN D. C.
Published: May 2007

ABSTRACT. A two‐stage chemostat modified to accommodate the growth of adhesive organisms was used to determine the yield constant, Y, of a representative soil amoeba, Acanthamoeba polyphaga, utilizing as its prey Pseudomonas paucimobilis. The first stage consisted of a glucose‐limited bacterial culture in steady state. The second stage consisted of a simplified predator‐prey system, nongrowing bacteria serving as the limiting substrate for amoebae. A refined methodology to more accurately determine Y was developed, and Y for Acanthamoeba polyphaga in batch and continuous culture was determined to be 19.1%.
Observations on Giardia of Budgerigars
Authors: BOX EDITH D.
Published: May 2007

ABSTRACT. Sick budgerigars from a local aviary were found to be infected with Giardia. The trophozoites were of the Giardia duodenalis type as defined by Filice with elongate median bodies pointed on one or both ends and more or less perpendicular to the long axis of the body. Using three fixation‐staining methods, and material from three birds, the length ranged from 10 to 18 μm and the width from 4.5 to 11 μm with a mean length to width ratio of 2. Attempts to culture the trophozoites in vitro from intestinal scrapings were unsuccessful. Also attempts to transmit the infection by fecal cysts to canaries and mice failed. It is proposed that the budgerigar form be called Giardia duodenalis, race psittaci.
Glycogen Phosphorylase and Synthase Activities of Rumen Ciliates of the Genus Entodinium
Authors: HOSHINO SADAO , WAKITA MASAAKI , IIDA AKIO
Published: May 2007

Glycogen 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

The 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

Twenty‐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

We 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

The 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

Until 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

Thin‐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

Histones 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

The 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

The 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

An 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

Cellular 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

A 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

The 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

The 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.
La Spore des Actinomyxidies: Synactinomyxon longicauda n. sp., un Nouveau Type de Groupement Sporal et Adaptations Planctoniques: Emission et Structure du Sporoplasme1
Authors: ORMIERES A. MARQUES et R.
Published: May 2007

RESUME

L'étude du caractère planctonique de différentes spores d'Actinomyxidies montre une complexité croissante dans leur adaptation au milieu aquatique. Au contact de l'eau, les trois cellules épéisporales de chaque spore se transforment en flotteurs de forme différente suivant les espèces. Ces flotteurs peuvent s'unir entre eux en un style équivelent à un quatrième flotteur ou associer diversement les huit spores issues d'un měme pansporocyste. C'est le cas dans le genre Synactinomyxon dont la diagnose est modifiée pour inclure une deuxième espèce S. Iongicauda n. sp. Un type nouveau est décrit chez lequel la preéence d'ancres à l'extrémité des cellules épisporales permet de maintenir efficacement réunies plusieurs dizaines de spores émises simultanément. Nous avons observé dans les genres Aurantiactinomyxon, Synactinomyxon, Echinactinomyxon l'emission du sporoplasme. II est libére en entier et capable de se déplacer dans l'eau pendant plus d'une heure grǎce à des mouvements amoeboïdes. Chez Aurantiactinomyxon eiseniellae les études ultrastructurales montrent que l'enveloppe du pansporocyste, d'une part, les épispores et les capsules polaires d'autre part sont réalisées à partir de cellules distinctes et profondément modifiées. Quant au sporoplasme, autrefois décrit comme un plasmode avec de nombreuses paires de noyaux, il contient, en fait, des ensembles identiques dont chacun est constitué de l'union d'un noyau satellite et d'une cellule uninucléée.

The study of the planktonic character of different Actinomyxidia spores reveals increasingly complex adaptations to an aquatic environment. On contact with water, the three episporal cells of each spore transform into floats, the forms of which differ according to species. These floats can join together so that a fourth type of float is formed, or they can unite in various ways the eight spores originating from the same pansporocyst. This is the case in the genus Synactinomyxon whose diagnosis is modified to include a second species S. Iongicauda n. sp. A new type is described in which the presence of anchors at the extremities of the episporal cells permits several dozen spores that have been emitted simultaneously to be kept together. We have observed the emission of the sporoplasm in the genera Aurantiactinomyxon, Synactinomyxon, and Echinactinomyxon. It is freed completely and for more than an hour is capable of changing its position in the water by amoeboid movements. In the case of Aurantiactinomyxon eiseniellae, ultrastructural studies show that the pansporocyst envelope on the one hand, and the epispores and polar capsules on the other hand, are formed from separate but profoundly modified cells. The sporoplasm, however, sometimes described as a plasmodium with numerous pairs of nuclei, contains, in fact, identical complexes, each consisting of a uninucleate cell united with a satellite nucleus.
Growth Cycle‐Dependent Overproduction and Accumulation of Protoporphyrin IX in Tetrahymena: Effect of Heavy Metals1
Authors: RUBEN LARRY , LAGESON JEAN , HYZY BOB , HOOPER ALAN B.
Published: May 2007

Cells of the ciliate Tetrahymena pyriformis GL overproduce and accumulate massive quantities of the heme intermediate, protoporphyrin IX. Protoporphyrin is localized intracellularly in discrete membranous compartments. The amount of porphyrin stored in the cell changes dramatically as cells progress through the growth cycle. Porphyrin overproduction is stimulated by δ‐aminolevulinic acid, but only during the mid‐stationary phase. Overproduction of protoporphyrin IX apparently results from an increase, late in the growth cycle, of activities subsequent to δ‐aminolevulinic acid synthetase. Feedback inhibition in the pathway by accumulated protoporphyrin IX does not occur. The presence of Co2+ completely inhibits accumulation of protoporphyrin IX in a manner reversed by δ‐aminolevulinic acid. Sn4+ stimulates protoporphyrin IX accumulation in the culture.
A Comparison of Growth Inhibition of Tetrahymena furgasoni by C19 and C21 Steroids
Authors: LAMONTAGNE N. S. , BROOKS J. M. , JOHNSON D. F.
Published: May 2007

The growth inhibition of Tetrahymena furgasoni (once known as “T. pyriformis W”) by C19 and C21 steroids of similar structure was measured by determining cell population at 24 h and 48 h following addition of the steroid. A cis‐fusion of the A/B rings junction, unsaturation at C‐1,2, or C‐4,5 and carbonyl substitution all enhanced inhibition, whereas the presence of two hydroxyl groups decreased inhibition. The results indicated that the transformation of C19 and C21 steroids by this protozoon may be part of a detoxication mechanism.
Phospholipid Biosynthesis in Synchronous Plasmodium falciparum Cultures1
Authors: VIAL HENRI J. , THUET MONIQUE J. , PHILIPPOT JEAN R.
Published: May 2007

The metabolism of phospholipids in synchronous Plasmodium falciparum‐infected erythrocytes was studied over one cycle of 48 h by the incorporation of labeled palmitate, serine, choline, and myo‐inositol into cellular lipids. The rates of incorporation of palmitate and serine into total phospholipids and of choline into phosphatidylcholine (PC) were linear with the maturation of the parasite, increasing by a factor of 2–5.6 according to the precursors. The rate of inositol incorporation into phosphatidylinositol was 9.6 times higher at the schizont stage than at the ring stage, with a marked increase in the second half of the cycle. A significant incorporation of palmitate into triglycerides also occurred during the schizont stage of the parasite. The incorporations of serine and palmitate into phosphatidylethanolamine (PE) and PC showed a net increase at approximately the twentieth hour of the cycle, while the radioactivities recovered in phosphatidylserine (PS) had already reached a maximum by this time. These findings indicate an instantaneous transformation of PS into PE and PC through a decarboxylation of PS into PE, then a methylation of PE into PC during the second half of the cycle. Although PS is a minor component of the Plasmodium parasite, our findings demonstrate the important role of this phospholipid as a precursor of PE and PC, which are major constituents of parasite phospholipids.
A Freeze‐Fracture Study of the Microcyst Wall, Plasma Membrane, and Intramembrane Components of Physarum polycephalum1
Authors: HOGAN JAMES C. , TURNER HENRIE M.
Published: May 2007

ABSTRACT. Freeze‐cleave replicas of encysted cells of the myxamoebae of Physarum polycephalum were examined to determine the intrawall substructure and to compare the intramembrane structural components. Cleaved areas of the cyst wall revealed a laminated substructure devoid of the macromolecular interruptions (intramembrane particles or IMP) visible in the cleaved cell membranes. The cyst wall adjacent to the cell membrane appears laminated, and a loose branching network of fibers and fibrils occurs at the wall periphery. The absence of intrawall particles is interpreted as a lack of protein or polypeptide components, thus suggesting additional support for the conclusion that polysaccharides are the major wall constituents. When cleaved cell membranes of encysted cells were examined, more intramembrane particles per unit area were observed on the extracellular membrane leaflet than on the protoplasmic membrane leaflet. In addition, homogeneous as well as aggregated particle distributions were visible on cleaved membrane leaflets. Moreover, the presence of aggregated and unaggregated particles on the same membrane leaflets similarly suggests asynchrony of the cell population. This paper examines and compares biological processes involving the cell membrane that may be related to different stages in the cell cycle or to periods of temporary stasis during the cell cycle.
The Three Cortical Membranes of the Gregarines (Parasitic Protozoa). III. Comparative Studies of the Membrane Proteins Among Different Sporozoan Species During Their Vegetative Phase1
Authors: PHILIPPE M. , VINCKIER D. , DUBREMETZ J. F. , SCHREVEL J.
Published: May 2007

ABSTRACT. The cortical membrane proteins of three gregarine and one coccidian species were compared using sodium dodecyl sulfate/polyacrylamide‐gel electrophoresis. About 30 proteins were identified in the ghosts of Gregarina blaberae and G. garnhami and 20 in G. rhyparobiae ghosts and Sarcocystis tenella pellicles. No protein with the electrophoretic mobility of muscular actin was present in the ghosts of the sporozoan species under study. Each species possessed a characteristic electrophoretic pattern; no protein was present simultaneously in the four sporozoan species and only one protein band with a similar electrophoretic mobility was found in the three gregarine species (52 Kd protein). Two G. garnhami subpopulations living in Locusta migratoria and Schistocerca gregaria exhibited the same ghost protein pattern. Thus, large differences were observed between species and not within species, and the protein electrophoretic analysis appears to be a powerful tool for taxonomic investigations in gregarines. Gregarina blaberae and G. garnhami glycoconjugates were compared after periodate/Schiff staining of the polyacrylamide gel slabs. Several glycoconjugates were reported to belong to the cytoplasmic fraction; and, in view of cytochemical and ultrastructural data, a contribution of these glycocomponents to the secretion of a mucus is discussed.
Transmission of the Trypanosomatid Flagellate Phytomonas davidi, a Symbiont of the Euphorbiaceae, by the Hemipteran Bug Pachybrachius bilobata scutellatus1
Authors: McGHEE R. BARCLAY , POSTELL FRED J.
Published: May 2007

ABSTRACT. Phytomonas davidi is found in the latex of species of the plant family Euphorbiaceae, including Chamaesyce hirta and C. hyssopifolia, to latitude 32°N in the southeastern United States. The hemipteran Pachybrachius bilobata scutellatus (family Lygaeidae) serves as an agent of transmission from plant to plant. Heavy infections of flagellates in the salivary glands were observed; trypanosomatids were less than one‐half the size seen in the plants and in the gut of the bug.
Nuclear Lethal Effect and Nucleocytoplasmic Incompatibility Induced by Endosymbionts in Amoeba proteus1
Authors: LORCH I. JOAN , JEON KWANG W.
Published: May 2007

ABSTRACT. The role of bacterial endosymbionts in the acquisition of new phenotypic characters was studied by transplanting nuclei from an uninfected strain of Amoeba proteus into the enucleated cytoplasm of a symbiont‐carrying strain. After 1–10 cell cycles, the nuclei were tested for two characters: compatibility with uninfected and infected cytoplasm, and their lethal effect against amoebae of the uninfected parent strain. A significant number of transplanted nuclei displayed both of the new phenotypic traits after a few divisions in the infected cytoplasm. Thus the influence of these endosymbionts on the nucleus of A. proteus was virtually instantaneous.
Transmission Electron Microscopy of Intracellular Sporozoites of Eimeria vermiformis (Apicomplexa, Eucoccidiida) in the Mouse1
Authors: ADAMS JOHN H. , TODD KENNETH S.
Published: May 2007

ABSTRACT. Sporozoites of Eimeria vermiformis from the mouse were first seen in the epithelial cells of villus tips and the crypts of Lieberkühn four hours after inoculation (HAI). They were always within a parasitophorous vacuole. By 12 HAI, most were in crypt epithelial cells between the basement membrane and host cell nucleus. The sporozoites in the villus tips had 26 subpellicular microtubules, two polar rings, two preconoidal rings, two refractile bodies surrounded by amylopectin‐like granules, a lamellar Golgi apparatus, numerous micronemes, and rhoptries. The sporozoites in the crypt cells had fewer amylopectin‐like granules, micronemes, and rhoptries. A nucleolus was visible, as were pieces broken off from the posterior refractile body. Later, the sporozoites folded over to become U‐shaped; the infolded membranes fused; and then the inner membranes disappeared so that spherical meronts were formed. Folding sporozoites were first seen 16 HAI and persisted until 52 HAI.
Interspecies Relationships in the Paramecium aurelia Complex: Acid Phosphatase Variation1
Authors: ALLEN SALLY LYMAN , ADAMS JULIAN , RUSHFORD CAROLINE L.
Published: May 2007

ABSTRACT. Up to five zones of acid phosphatase activity appear in gels after electrophoresis of detergent‐treated extracts from 13 of the 14 species of the Paramecium aurelia complex. The overall pattern is somewhat similar for all species: differences in intensity and mobility of individual zones permit the grouping of these sibling species into eight groups. All 14 species can be identified using the procedure of enzyme electrophoresis, although two of them are more similar than is usually the case. Problems of misclassification are discussed in terms of the nature and frequency of variants. With the judicious choice of enzymes used to screen new stocks, these problems can be circumvented. Species relationships are updated using 11 enzymes. A dendrogram constructed from the matrix of genetic distances shows four clusters of species: (i) P. biaurelia, P. triaurelia; (ii) P. primaurelia, P. pentaurelia, P. sexaurelia, P. novaurelia; (iii) P. septaurelia, P. undecaurelia, P. tredecaurelia, P. quadecaurelia; and (iv) P. tetraurelia, P. octaurelia, P. decaurelia, P. dodecaurelia. Distances between the species are large, on the order of the differences between Drosophila species. The species are characterized by an extraordinary lack of geographical differentiation and great morphological similarity, which contrasts strongly with the molecular differentiation.