bluuebunny/crossref_metadata_2025 huggingface dataset:
Local and Temporal Pattern of Con A‐Binding Site Aggregation During Conjugation in Euplotes vannus (Ciliophora, Hypotrichida)1
Authors: LUEKKEN WOLFGANG W. , BREER HEINZ , HARTKKEMEYER MARTINA
Published: May 2007

ABSTRACT. Conjugating cells of Euplotes vannus (syngens Naples and Barcarès) were investigated for Con A‐binding sites by means of fluorescence microscopy. Cells fixed with 0.4% paraformaldehyde and incubated with 15 μg/ml FITC‐Con A showed a distinct region of strong fluorescence, the size, shape and localization of which characteristically changed during the course of conjugation, first appearing at courtship stage (cells contact without forming pairs) and vanishing soon after the migration pronuclei have been exchanged, but before cells have separated. Con A binding and conjugation were blocked by cyclohexamide and α‐galactosidase. Con A‐binding was also inhibited by α‐mannosidase, α‐glucosidase and β‐galactosidase without affecting conjugation except a delay of pair formation. The results suggest an involvement of newly formed or translocated glycoconjugates in cell pairing during conjugation.
Early Developmental Stages of Sarcocystis cruzi in Calf Fed Sporocysts from Coyote Feces1
Authors: DUBEY J. P.
Published: May 2007

ABSTRACT. The development of Sarcocystis cruzi was studied in an 11‐day‐old calf killed seven days postinoculation with 5 × 108 sporocysts from feces of coyotes. Uninucleate zoites were found in arteries of mesenteric lymph nodes but not in other organs. Zoites measured 4.9 × 3.0 (3.5–7.0 × 2.1–3.5) μm. Of the 36 zoites studied, 31 were in endothelial cells, four were in macrophages in the lumen of arteries, and one was free in the lumen of an artery. Infected endothelial cells were two to three times larger than uninfected cells. Zoites appeared structurally similar to sporozoites. The occurrence of zoites in macrophages suggests that sporozoites of Sarcocystis might use such cells to reach the site of their first merogony.
Respiratory Studies on the Giant Amoeba Pelomyxa palustris1
Authors: CHAPMAN‐ANDRESEN CICILY , HAMBURGER KIRSTEN
Published: May 2007

ABSTRACT. The large fresh‐water microaerobic amoeba Pelomyxa palustris does not contain mitochondria, but three types of bacterial endosymbionts are always present. Thus, it is of interest in the discussion of the possible origin of mitochondria from primitive prokaryotes. Gas exchanges (O2, CO2) and concentration of endosymbionts were determined in individual amoebae, in which the life cycle stage was noted. Grey type (stationary phase) amoebae had a lower O2 uptake and lower endosymbiont concentration than light type (growth phase) amoebae, and highest O2 uptake was found in centrifugal pieces of light type Pelomyxa, centrifuged in vivo, which contained nearly all of the endosymbionts. In light type amoebae, the respiratory activity was independent of O2 concentration between 1 and 21%, and, when compared on the basis of dry weight and protein, of the same order as that of other free‐living protozoa. The R.Q. was slightly higher than 1, indicating that glycolysis does not play a significant role in energy metabolism. It is concluded that P. palustris is fully aerobic, and suggestions are presented as to the role of the endosymbionts in its respiratory metabolism.
Dactylosoma hannesi n. sp. (Dactylosomatidae, Piroplasmia) Found in the Blood of Grey Mullets (Mugilidae) from South Africa1
Authors: PAPERNA ILAN
Published: May 2007

ABSTRACT. A new species of Dactylosoma (Dactylosomatidae, Piroplasmia), for which the name Dactylosoma hannesi n. sp. is proposed, was discovered in blood erythrocytes of Mugil cephalus, Liza richardsoni, and L. dumerili (Mugilidae) from Swartkops estuary, located east of Port Elizabeth, South Africa. The life cycle of this species differs in some respects from that described for all other known species of Dactylosoma and Babesiosoma. Mature schizonts contain eight nuclei but undergo division only to two to four daughter cells. During cytoplasmic cleavage, schizonts assume triad, rosette, or cruciform shapes. Merozoites are finally produced through a series of binary fissions of these daughter cells which may also be involved in additional nuclear divisions.
The Surface Charge of Tritrichomonas foetus
Authors: FILHO FERNANDO COSTA E SILVA , ELIAS CEZAR ANTONIO , DE SOUZA WANDERLEY
Published: May 2007

The surface charge of Tritrichomonas foetus was evaluated by means of the binding of colloidal iron hydroxide particles at pH 1.8 and cationized ferritin particles at pH 7.2 to the cell surface, as visualized by electron microscopy and by direct measurements of the electrophoretic mobility (EPM), of cells suspended in solutions of different ionic strength and pH. At pH 7.2, T. foetus has a negative surface charge with a mean EPM of −1.03 μmμs−1μV−1μcm. At lower pH, there is a decrease in the negative surface charge with an isoelectric point at pH 1.2. At higher pH (> 9.0), there is an increase in the surface charge reaching an EPM of −2.5 μmμs−1μV−1μcm. These results indicate that the surface of T. foetus contains both negatively and positively charged dissociating groups. Binding of colloidal iron hydroxide and cationized ferritin particles throughout the cell surface of the protozoon was observed. Treatment of T. foetus with neuraminidase or trypsin reduced significantly the EPM of the cells. Enzyme‐treated cells recovered their normal EPM when incubated for 6 h in fresh culture medium by a process that is inhibited by puromycin.
Growth of Isolated Amastigotes of Trypanosoma cruzi in Cell‐Free Medium1
Authors: VILLALTA FERNANDO , KIERSZENBAUM FELIPE
Published: May 2007

Amastigotes of Trypanosoma cruzi were purified from overlays of infected Vero cell cultures by centrifugation over a discontinuous gradient of metrizamide. Pure amastigote preparations were usually recovered from the pellet under the layer of specific gravity 1.086. The isolated amastigotes grew in cell‐free ML‐15HA medium. Growth rate for the different strains of T. cruzi were in the order Y > Tulahuan > CL. The generation time of amastigotes in ML‐15HA medium was 16.8, 18.0, and 26.4 h for the Y, Tulahuen, and CL strains, respectively, in the presence of 5% CO2) and 16.8, 31.2, and 36.4 h, respectively, in the absence of CO2. Intracellular amastigotes did not differ ultrastructurally from amastigotes from either the density‐gradient fractionation or culture in cell‐free medium.
Further Studies on Haemogregarina bigemina Laveran & Mesnil, the Marine Fish Blennius pholis L., and the Isopod Gnathia maxillaris Montagu1
Authors: DAVIES ANGELA J.
Published: May 2007

Haemogregarina bigemina is redescribed from the blood of the marine fish Blennius pholis, and stages presumed to be those of the haemogregarine are recorded from the hematophagous praniza larva of the isopod Gnathia maxillaris. At College Rocks, Aberystwyth, Wales, the main study area, a high incidence of infection occurred in B. pholis. No exoerythrocytic stages were observed in these fish, nor was sexual dimorphism of the gametocyte evident. As in an earlier study, ecological evidence favored transmission by G. maxillaris rather than by leeches. Gametocytes, syzygy, oocysts, sporoblasts, and sporozoites were identified in the anterior hindgut of the isopod. The stages observed in G. maxillaris are compared with those of other haemogregarines described from the digestive tract of leeches. Mention is made of an intraleucocytic haemogregarine of another fish, Crenilabrus melops.
Development of Ox‐Coyote Cycle of Sarcocystis cruzi1
Authors: DUBEY J. P.
Published: May 2007

The ox‐coyote cycle of Sarcocystis cruzi was studied by killing 38 calves between 4 and 153 days postinoculation (DPI) with 55 × 103‐5 × 108 sporocysts from the intestines of coyotes. At 4 DPI, a zoite was found within the lumen of a mesenteric lymph node artery. At 7 DPI, zoites were found in mononuclear cells and in endothelial cells in mesenteric arteries. First generation meronts (41.0 × 17.5 μm in diameter) occurred 7–26 DPI in mesenteric lymph nodes. At 19–46 DPI, second generation meronts occurred in kidneys, muscles, and other tissues: renal meronts were 19.6 × 11.0 μm, and intramuscular meronts were 25.0 × 11.1 μm. Merozoites were found in the peripheral blood 17 DPI and later at 24–46 DPI. They divided by endodyogeny in mononuclear cells. Sarcocysts were seen first in the heart at 45 DPI and contained one or two metrocytes. At 55 DPI, sarcocysts containing only metrocytes were found in striated muscles, heart, and in smooth muscles of the urinary bladder, rumen, omasum, abomasum, and small intestine. At 67, 87, 112, and 153 DPI, sarcocysts were found only in striated muscles and in the heart. At 67 DPI, sarcocysts were up to 360 μm long. They contained only metrocytes and were not infective to the dog. At 86 DPI, sarcocysts contained mostly bradyzoites, a few metrocytes, and were infective to a coyote. The thin‐walled sarcocysts grew to a maximum length of 800 μm and contained bradyzoites that were 10.9 × 3.0 μm. At 90 DPI, two mature sarcocysts were found in 2 of 73 sections of brain and spinal cord; hundreds of sarcocysts were present in sections of tongue and heart of this calf. Gametogony occurred in the small intestine of the coyote. Macro‐and microgamonts were found in goblet cells of the small intestines of coyotes 6 h after the ingestion of infected meat. Microgamonts were few and contained 3–11 slender gametes. Oocysts were seen at 12 h and sporulation was completed 9 DPI. The prepatent period in the coyote was 8 days. The ox‐coyote cycle is compared with ox‐dog cycle.
Esterase Variants in Four Species of the Paramecium aurelia Complex1
Authors: ALLEN SALLY LYMAN , LAU ELIZABETH T. , NERAD THOMAS A. , RUSHFORD CAROLINE L.
Published: May 2007

One hundred eighty‐eight stocks of Paramecium primaurelia, P. biaurelia, P. tetraurelia, and P. octaurelia were grown axenically and tested for five esterases, visualized by starch gel electrophoresis, in a search for variant stocks. The five esterases can be distinguished on the bases of their substrate specificity, sensitivity to an inhibitor, and response to different growth conditions. This paper addresses the nature of the electrophoretic change in mobility of the variant stocks in order that species relationships can be more accurately assessed. Crosses carried out in all four species show that single genes determine the differences in mobility between variant and common subtypes. Extracts of variant stocks that gave similar patterns were run against each other, tested for their sensitivity to the inhibitor, and the pattern was compared to that found in extracts of stocks with variant and common subtypes in other species. The majority of the variants in P. primaurelia, P. tetraurelia, and P. octaurelia show an electrophoretic mobility characteristic of a common subtype, or a variant, in another species. The same proportion of variant subtypes as common subtypes have mobilities similar to esterase subtypes found in other species. Of the four species examined in this paper, P. tetraurelia and P. octaurelia appear to be most closely related on the basis of shared esterase subtypes. In P. biaurelia the mobilities of most of the variants are unique, as are the common esterase subtypes in this species. P. biaurelia stands out as having the greatest number of esterase subtypes, with very few of them homologous to subtypes found in other species. This observation supports the idea of greater diversification of stocks within P. biaurelia than for the other three species.
The Ultrastructure of Specimens of Paramecium multimicronucleatum Impregnated with Silver by the Fernández‐Galiano Method1
Authors: TELLEZ CARMEN , SMALL EUGENE B. , CORLISS JOHN O. , MAUGEL T. K.
Published: May 2007

Transmission and scanning electron microscopy of specimens of Paramecium multimicronucleatum treated with the Rio‐Hortega silver‐impregnation method as modified by Fernández‐Galiano demonstrate that considerable deposition of silver occurs around the kinetosomes, especially at the level of the basal plate and also at the proximal end of the kinetosome. In addition, silver is heavily deposited within the kinetodesmal fibers, in the fibrous matrix that surrounds the postciliary and transverse microtubules, in the connective structures observed between the two kinetosomes of a pair and between the kinetodesmal fiber and the anterior kinetosome, and in the trichocysts. Differences and similarities in sites of deposit when other methods of silver impregnation are employed are discussed and the particular value of the present technique in studies of ciliate systematics and phytogeny is stressed.
Development of Eimeria funduli in Fundulus heteroclitus1
Authors: UPTON STEVE J. , DUSZYNSKI DONALD W.
Published: May 2007

Laboratory‐reared Fundulus grandis and F. heteroclitus were experimentally infected with Eimeria funduli by being fed Palaemonetes pugio (grass shrimp) collected from endemic areas. Histological sections were made of heart, liver, hepatopancreas, spleen, gall bladder, kidney, intestine, peri‐intestinal fat, reproductive organs, and brain from F. grandis sacrificed at 1, 2, 6, 12, 18, and 24 h and from F. heteroclitus at 5, 6, 9, 14, 19, 24, 29, 34, 39, and 44 days after consuming naturally infected shrimp. We first found merogonous stages at day 9 postinfection (p.i.). No developmental stages of the parasite could be positively identified in the tissues of experimentally infected fish prior to day 9 p.i. Mature meronts were found 14 days p.i. The majority contained 8–16 (mean, 13) merozoites, but a few meronts had 18–26 (22) merozoites. Gamonts first appeared on day 14, were mature by day 19, and fertilization was completed by day 24 p.i. After sporoblast formation, sporopodia appeared during sporocyst wall formation, between days 24 and 29 p.i. Sporozoite formation was completed by day 44 p.i. in most sporocysts. Most endogenous stages occurred in hepatocytes; however, pancreatic and spleen cells were sometimes infected with gamonts.
The Life Cycle of Trypanoplasma bullocki (Zoomastigophorea: Kinetoplastida)1
Authors: BURRESON EUGENE M.
Published: May 2007

The leech Calliobdella vivida (Verrill) is the vector of Trypanoplasma bullocki. At 10°C, infective‐stage flagellates were first present in the leech's proboscis sheath five days after feeding. At 5°C, infective‐stage flagellates were not present in the leech's proboscis sheath until 10 days after feeding, but at 20°C, flagellates were located there as early as 24 h after feeding. Infected leeches retained flagellates through three subsequent feeds on uninfected fish. When flagellates were first observed in hogchoker, Trinectes maculatus (Bloch & Schneider), they were much larger than infective stages from the leech. Average flagellate length then decreased during early acute phase, but gradually increased thereafter. Peak parasitemia was greater in a hogchoker inoculated by only one leech but held at colder temperature than in a hogchoker inoculated by 45 leeches, suggesting that temperature may be more important than inoculum in determining peak parasitemia. Cell division in the fish host is described. SEM studies of fish blood flagellates revealed a pre‐oral ridge and a cytostome.
The Biology and Pathogenicity of a Recent Field Isolate of Eimeria praecox Johnson, 1930
Authors: GORE THOMAS C. , LONG PETER L.
Published: May 2007

A recent isolate of Eimeria praecox, strain G, was obtained from Georgia and purified. Studies of the life history, pathogenicity, and cross‐immunity of the isolate were conducted to verify its identity. In inoculated three‐week‐old chickens, the occurrence of merogony and gametogony was limited to the superficial epithelium of the upper intestine. Oocysts, 23 × 19.5 äm, with a shape index of 1.17 were first observed 83 h after inoculation. Mortality and morbidity were not observed in any of the experimental birds. However, there was a positive correlation between dose of oocysts, reduced weight gain, and the incidence of exudative diathesis. These studies showed that E. praecox depresses weight gains in chickens and may be of economic importance. Although complete immunity to avian coccidiosis is believed to be species specific, chickens immune to E. praecox (G) or E. acervulina had a degree of cross‐immunity to a heterologous challenge. Electrophoretic analysis of glucose phosphate isomerase and lactate dehydrogenase prepared from the European strain of E. praecox and E. praecox (G) showed no differences, confirming the identity of the isolate as E. praecox.
Serum Agglutination and Immunoglobulin Levels of Mice Infected with Naegleria fowleri1
Authors: HAGGERTY R. M. , JOHN D. T.
Published: May 2007

Agglutinins were not detected in sera from mice given one, two, or three intranasal (i.n.) inoculations or a single intravenous (i.v.) inoculation of trophozoites of Naegleria fowleri. However, agglutinins were produced following second and third i.v. inoculations. Serum immunoglobulin levels increased in both i.n.‐ and i.v.‐inoculated mice. IgG and IgM increased substantially more for i.v.‐inoculated mice. IgA levels increased more consistently for i.n.‐inoculated mice.
Electrophoretic Isoenzyme Patterns of Entamoeba histolytica and Entamoeba chattoni in a Primate Survey1
Authors: SARGEAUNT P. G. , WILLIAMS J. E. , JONES D. M.
Published: May 2007

Stocks of Entamoeba histolytica grown in a monoxenic culture system from the feces of nonhuman primates are compared with the eleven zymodemes of E. histolytica so far demonstrated from man. In a similar fashion, Entamoeba chattoni has also been grown and identified. Both E. histolytica and E. chattoni have been demonstrated in keepers of the primate collections. Comparisons have been made using the electrophoretic patterns of three enzymes: glucosephosphate isomerase [(GPI) E.C.5.3.1.9], phosphoglucomutase [(PGM) E.C.2.7.5.1], and L‐malate—NADP+ oxidoreductase (oxaloacetate‐decarboxylating) [(ME) E.C. 1.1.1.40]. Enzyme patterns of E. histolytica from the apes were found to be identical with three of those already demonstrated from man. The enzyme pattern of E. chattoni was distinctly different from that of any of the E. histolytica zymodemes. Other protozoa found in the single fecal sample examined from each subject are also listed.
A New Species of Eimeria from the Golden‐Mantled Ground Squirrel, Spermophilus lateralis, in Northern Colorado
Authors: TORBETT BRUCE E. , MARQUARDT WILLIAM C. , CAREY ANDREW C.
Published: May 2007

Oocysts of Eimeria morainensis n. sp. are described from the golden‐mantled ground squirrel, Spermophilus lateralis. in Northern Colorado. The oocysts of E. morainensis are double‐walled and subspherical, 20.3 × 19.8 (18.7–26.2 × 17.5–21.2) μm; and the sporocysts are ellipsoid, 12.1 × 6.9 (8.7–13.7 × 6.2–8.7) μm. Oocyst residuum and micropyle are absent, but a polar granule is present. Sporocyst residuum and Stieda body are present. Differences in oocyst characteristics provide the basis for recognition of this new species of Eimeria.
Distribution of Acantharia in the Western Sargasso Sea in Correspondence with “Thermal Fronts”1
Authors: BOTTAZZI ELSA MASSERA , ANDREOLI M. GABRIELLA
Published: May 2007

A study of plankton samples collected in the Western Sargasso Sea during nine cruises has shown discontinuity between samples from different latitudes as regards their percentage, abundance, and number of species of Acantharia. Limits separating zones rich in Acantharia from those poor in Acantharia were singled out. The latitude at which the difference in abundance occurs can vary. This is in accord with differences in primary production, phytoplankton, and mesopelagic fishes noted by other workers who believe that the points of these faunal changes correspond to a temperature change indicated as “thermal fronts.”
The Fine Structure of Conidophrys pitelkae Bradbury Related to its Life Cycle and Taxonomic Position in the Apostomatida1
Authors: BRADBURY PHYLLIS CLARKE , TYSON GRETA E.
Published: May 2007

Electron microscopy of the tomite of Conidophrys pitelkae confirms that Jankowski was correct in including the pilisuctorians in the Apostomatida. Like other apostome tomites, the tomite of Conidophrys possesses a rosette opening to the exterior, kinetodesmata made up of stacks of individual kinetodesmal fibrils, and canaliculi that are surrounded by dense inclusion bodies and open on the ventral surface. The fine structure of the trophont of Conidophrys, however, is quite unlike that of other apostome trophonts. The elaborate infraciliature of the tomite disappears immediately after it settles and reappears de novo on the trophont just before tomitogenesis. The cyst wall, which completely encloses the trophont and grows with it, attaches the ciliate to a seta on its, host, the shrimp Crangon crangon. The setae on which tomites settle vary greatly in size and shape, but each appears to have at its tip some digitiform cuticular projections that surmount a pore, which opens into the lumen of the seta. The trophont's only direct connection to its host is at the cytostome, a unique structure formed of delicate tubules that pass through the pore into the lumen of the seta. Ingestion is by micropinocytosis, and there are no visible food reserves.
Ultrastructure of the Peritrich Ciliate Ambiphrya ameiuri and Its Attachment to the Gills of the Catfish Ictalurus punctatus1
Authors: FITZGERALD MALINDA E. C. , SIMCO BILL A. , COONS LEWIS B.
Published: May 2007

Ambiphrya ameiuri is an ectocommensal peritrich that attaches to the gills of warm‐water fishes and filters bacteria from the water. The ultrastructure of this protozoon, its attachment to the fish gills, and its effect on the gill tissue were investigated by scanning and transmission electron microscopy. The peritrich attached to the gills by fibers extending from the scopula. A microtubular array, apparently a barren kinetosome, was present in each lobular projection, but no scopular cilia were observed. At low densities Ambiphrya had no apparent harmful effects on the fish; however, at high densities respiration may be impeded. Ultrastructural studies indicate that this organism receives no nourishment from the host tissue.
Isolation and Properties of Isolated Nuclei from the Florida Red Tide Dinoflagellate Gymnodinium breve (Davis)1
Authors: RIZZO P. J. , JONES M. , RAY S. M.
Published: May 2007

A simple and rapid method is described for the isolation of nuclei from the Florida red tide dinoflagellate Gymnodinium breve. The nuclei are free of cytoplasmic contamination and are active in endogenous RNA synthesis. The ratio of DNA: RNA: acidsoluble protein: acid‐insoluble protein is 1:0.39:0.13:0.63, respectively, and each nucleus contains ca. 113 picograms of DNA. Electrophoretic analysis of the acid‐soluble proteins reveals the presence of two histone‐like proteins with molecular weights of 12,000 and 13,000.
A Comparison of Cortical Proteins in Tetrahymena vorax Microstomes and Macrostomes1
Authors: BUHSE HOWARD E. , WILLIAMS NORMAN E.
Published: May 2007

Proteins of surface membranes and surface‐related cytoskeletons in Tetrahymena vorax microstomes and macrostomes were compared by one‐dimensional SDS polyacrylamide gel electrophoresis to see if protein differences could be detected that correlate with the transformation from one phenotype to the other. Some differences were observed. However, these alterations appear to result from the heat‐shock procedure used to synchronize the microstome‐to‐macrostome transition. The apparent lack of transformationspecific changes in cortical proteins is discussed. Similarities and differences between cytoskeletal proteins of T. pyriformis GL‐C and T. vorax are also noted and discussed.
Effect of Temperature and Osmolarity on Growth of Crithidia fasciculata, C. hutneri, C. luciliae thermophila, and Herpetomonas samuelpessoai1
Authors: SILVA JOÃO BATISTA TAVARES DA , ROITMAN ISAAC
Published: May 2007

Crithidia fasciculata (Anopheles, Culex, and Nöller strains), C. hutneri, C. luciliae thermophila, and Herpetomonas samuelpessoai were grown in a defined medium with different values of osmolarity at different temperatures. C. fasciculata (all strains) grew best between 300 to 500 mOsm; H. samuelpessoai, 400–500 mOsm; and C. hutneri and C. luciliae thermophila, 500–800 mOsm. At higher temperatures better growth was obtained at the upper osmolarities.
Scanning Electron Microscopy of Cytoskeletal Elements in the Oral Apparatus of Tetrahymena1
Authors: WILLIAMS NORMAN E. , BAKOWSKA JULITA
Published: May 2007

ABSTRACT. Extraction of the ciliated protozoon Tetrahymena with nonionic detergents produces a surface‐related cytoskeleton that consists of a basic lamina of whole‐cell dimensions together with associated microtubule and microfilament systems, including all ciliary basal bodies. The organization of the isolated cytoskeleton has been studied using scanning electron microscopy, and several new features are described in the oral region. Here the ciliary basal bodies are arranged in a very stable and highly complex pattern. This pattern was found to be identical in the four species of Tetrahymena we examined. In addition, various microtubular bundles and two separate systems of filaments were observed in scanning electron micrographs of isolated oral skeletons. The appearance of the deep fiber bundle in preparations of this type suggests that it arises, at least in part, as an extension of the ribbed wall microtubules. On the basis of its distribution within the oral skeleton, one of the filament systems described is suggested to be a contractile system responsible for pinching off food vacuoles.
A Secondary Alcohol Dehydrogenase from Tetrahymena furgasoni1
Authors: LAMONTAGNE NANCY S. , JOHNSON DAVID F. , JAKOBY WILLIAM B. , HOLMLUND CHESTER E.
Published: May 2007

ABSTRACT. Dehydrogenase activity with hydroxysteroids has been observed in Tetrahymena furgasoni (formerly T. pyriformis strain W), and the enzyme responsible has been isolated from this organism. The purified dehydrogenase is active with a variety of steroid alcohols at apparent Km values ranging from 0.2 to 4.0 mM. The C‐3 hydroxyl of ring A of the steroid nucleus is the preferred position of oxidation. However, a variety of other secondary alcohols are also substrates, with apparent Km values for 2‐butanol, 2‐pentanol, and cyclohexanol of 880, 1000. and 150 mM, respectively. With both steroidal and nonsteroidal alcohols. NAD is the preferred co‐substrate, although low activity with NADP is observed. Evidence is presented that the activity with secondary alcohols, whether steroidal or not, is the property of a single protein species.
Xanthine Phosphoribosyltransferase in Leishmania: Divalent Cation Activation1
Authors: KIDDER G. W. , NOLAN LINDA L.
Published: May 2007

ABSTRACT. Xanthine phosphoribosyltransferase (XPRTase; EC 2.4.4.22) was found in the promastigotes of four species of Leishmania (L. mexicana, L. donovani, L. braziliensis and L. tarentolae). In no case was there any transribosylation from 5‐phosphoribosyl‐1‐pyrophosphate (PRibPP), forming XMP, in dialyzed preparations, unless activated by a divalent cation. Magnesium and zinc were very low in activation efficiency in all cases, while manganese was optimally efficient. Cobalt was essentially equal to manganese for activation of the enzyme from L. mexicana and L. braziliensis but much less efficient for the enzyme from L. donovani and L. tarentolae. Gel filtration profiles of cell extracts of L. mexicana on Sephadex G‐200 indicated that the enzymes catalyzing the transribosylation from PRibPP to guanine. hypoxanthine, and xanthine were inseparable. All were eluted near the void volume. The enzyme for adenine transribosylation was clearly separate. When cell extracts of L. mexicana were applied to Sephadex G‐100 columns, the activity toward XMP formation from xanthine eluted with the void volume, together with a portion of that for the formation of GMP and IMP from guanine and hypoxanthine. A second peak of HGPRTase (EC 2.4.2.8) eluted somewhat later and was devoid of XPRTase activity. XPRTase from promastigotes of L. mexicana is heat labile, has rather a broad pH optima, and is stable to freezing when protected by nonspecific cell protein (40,000 g supernate as opposed to 100.000 g supernates).
Effects of Pinealectomy and Ocular Enucleation on Diurnal Periodicity of Leucocytozoon smithi (Haemosporina) Gametocytes in the Peripheral Blood of Domestic Turkeys1
Authors: GORE THOMAS C. , NOBLET GAYLE PITTMAN , NOBLET RAYMOND
Published: May 2007

ABSTRACT. Domestic turkeys naturally infected with Leucocytozoon smithi were blinded by bilateral ocular enucleation, pinealectomized, sham‐pinealectomized, pinealectomized plus enucleated, or maintained as controls. Groups of turkeys were acclimated to either light‐dark periods of 14L:10D or “darkness” with intermittent periods (10–20 min) of red light at irregular hours approximately every three days as required for maintenance of turkeys. Peripheral gametocyte numbers of L. smithi in all groups were determined every 2 h over a 36 h period. Under 14L: 10D photoperiod, no observable difference in the pattern of gametocyte circadian rhythmicity between pinealectomized, enucleated, pinealectomized plus enucleated, and control turkeys was noted. Although mean parasitemias differed among groups, peak gametocyte numbers occurred between 1000 and 1800 h; how parasitemias occurred between 2000 and 0400 h. However, the phase of gametocyte rhythmicity in pinealectomized plus enucleated turkey hosts did exhibit a lag with reference to other hosts when examined by least squares fits of simple harmonics. Under conditions of “darkness” with intermittent, irregular periods of red light, L. smithi gametocyte numbers of individual turkeys, pinealectomized, sham‐pinealectomized, or maintained as controls, exhibited a circadian periodicity though parasite cycles were out of phase with the natural photoperiod to which the turkeys previously had been exposed. A slight drift out of phase of L. smithi gametocyte periodicity occurred among turkeys in the sham‐pinealectomized and the control groups while a considerably more prominent drift out of phase was seen among the parasite rhythmicity patterns of the pinealectomized birds. Data indicate that the pineal gland of the turkey did not directly mediate L. smithi gametocyte circadian periodicity, although an indirect involvement in regulating the timing of parasite rhythmicity is suggested.
Effect of Temperature on the Contents of the Two Energy‐Reserve Substances, Paramylon and Wax Esters, in Euglena gracilis1
Authors: KAWABATA AKIKO , MIYATAKE KAZUTAKA , KITAOKA SHOZABURO
Published: May 2007

ABSTRACT. When a streptomycin‐bleached mutant of Euglena gracilis strain Z was cultured in the dark at 33, 26, or 15°C, the content of paramylon was higher at lower growing temperature while that of wax esters was higher at higher temperature. Transfer of the cells grown at 33°C–15°C decreased the wax ester content while increasing the paramylon content; transfer in the reverse direction caused reverse changes. On incubation with labeled acetate, the cells grown at 33°C showed more distribution of radioactivity in wax esters than the cells grown at lower temperatures. Apparently the two energy‐reserve substances have different physiological functions.
Ribosomal DNA of Leishmania brasiliensis: Number of Ribosomal Copies and Gene Isolation1
Authors: VILLALBA ELENA , RAMIREZ JOSÉ LUIS
Published: May 2007

ABSTRACT. The DNA content of the hemoflagellate Leishmania brasiliensis. strain Y, has been determined by colorimetric reactions and found to be nearly 0.226 pg/cell. When this DNA is bound to filters and hybridized with labeled rRNA from the same organism, saturation is reached at 0.47% of the DNA, corresponding to an estimated 160 ribosomal gene copies. When the DNA is sheared and centrifuged to equilibrium in CsCl gradients, two major satellites of the main band (p = 1.712 g/cm3) are observed: a heavy one (1.720 g/cm3), which hybridizes with labeled rRNA, and a light one (1.699 g/cm3) with the electron microscopic characteristics of the kinetoplast DNA network.
Characteristics of an Uptake System for α‐Aminoisobutyric Acid in Leishmania tropica Promastigotes1
Authors: LEPLEY PEGGY R. , MUKKADA ANTONY J.
Published: May 2007

ABSTRACT. Leishmania tropica promastigotes transport α‐aminoisobutyric acid (AIB), the nonmetabolizable analog of neutral amino acids, against a substantial concentration gradient. AIB is not incorporated into cellular material but accumulates within the cells in an unaltered form. Intracellular AIB exchanges with external AIB. Various energy inhibitors (amytal, HOQNO, KCN, DNP, CCCP, and arsenate) and sulfhydryl reagents (NEM, pCMB, and iodoacetate) severely inhibit uptake. The uptake system is saturable with reference to AIB‐and the Lineweaver‐Burk plots show biphasic kinetics suggesting the involvement of two transport systems. AIB shares a common transport system with alanine, cysteine, glycine, methionine, serine, and proline. Uptake is regulated by feedback inhibition and transinhibition.
The Fine Structure of the Internal Spiral of Kinetosomes in Foettingeria's Tomite, a Unique Storage Depot for Kinetosomes1
Authors: RIGSBY WILLIAM E. , BRADBURY PHYLLIS C.
Published: May 2007

ABSTRACT. The fine structure of the tomite of Foettingeria actiniarum (Claparède) was examined and compared with that of other apostome tomites. This stage in the life cycle has a unique configuration of kineties that form a spiral through the cytoplasm in the interior of the body. The structure and behavior of this internal spiral were evaluated as a mechanism for the storage of kinetosomes, an adaptation to the ciliate's two‐host life cycle. The spiral is composed of nine ribbons of laterally compressed kinetosomes that are in contact with a thin electron‐dense fibril. Paralleling the kineties of the spiral are conspicuous, swollen lamellae of the rough endoplasmic reticulum; these lamellae contain moderately electron‐dense material. The spiral is associated with the large contractile vacuole and winds about the macronucleus. The tomite of Foettingeria possesses a single, robust, caudal cilium located in a pit, along with the nozzle‐like pore of the contractile vacuole. The walls of the pit contain several trichocysts arranged radially about the caudal cilium and aimed into the pit.
Is Blepharisma hyalinum Truly Unpigmented?1
Authors: LARSEN HANS FIND , NILSSON JYTTE R.
Published: May 2007

ABSTRACT. To answer whether Blepharisma hyalinum is truly unpigmented, the organism must be established in culture as pointed out by Giese in 1973. Accordingly, the present study deals with B. hyalinum kept in culture since its isolation in 1975. The organism still remains colorless after growth in the dark; however, it contains cortical granules resembling pigment granules in colored species. A comparative study was therefore undertaken of B. hyalinum and B. steini; both species have a compact macronucleus, though of different shape. Crude pigment was extracted with acetone from organisms grown in the dark for three weeks and the maxima were measured by absorption. Purified pigment was obtained from TLC‐plate preparations and the absorption maxima were measured after removal of lipids with chloroform. No maxima characteristic of blepharismin were found in extracts of B. hyalinum, but these were present in extracts of B. steini. Electron microscopy of the cortical region revealed membrane‐bound granules in both species; these granules differed in content but not in their capacity to extrude. In B. hyalinum all granules had a homogenous electron‐dense substructure; in B. steini the granules had a net‐like granulated substructure of varying electron density. This difference corresponds to that published on “pigment” granules in albino and pigmented strains of B. undulans. Our conclusions are that B. hyalinum is unpigmented (and a valid separate species) and that the cortical granules may serve other functions than that of storing blepharismin.
A New Ciliate Genus Trichodoxa n. g. (Ciliata, Peritricha, Mobilina, Trichodinidae) with Two New Species from the Genital System of Terrestrial Pulmonates1
Authors: SIRGEL W. F.
Published: May 2007

ABSTRACT. A new ciliate genus Trichodoxa n. g. and two new species (T. genitalis n. sp., T. phalli n. sp.) are described and figured. These are only the second and third species of the family Trichodinidae to be described from the genital system of terrestrial molluscs. Only one tier of cilia surrounds the basal disc. This character, the course of the infundibular ciliature. structure of the coronal denticles, and structure of the border membrane differentiate the new genus from others in the family.
Mitochondrial Associations with Specific Components of the Cortex of Tetrahymena thermophila Nanney & McCoy, 1976: Microtubules and the Epiplasm1
Authors: AUFDERHEIDE KARL J.
Published: May 2007

Ultrastructural observations of the cortically‐located mitochondria of Tetrahymena thermophila revealed associations not only between the mitochondria and certain of the cortical microtubule bands, but also between the mitochondria and the epiplasm of the cortex. Most of the distal mitochondrial surface is close and parallel to the epiplasm; favorable views show bridge‐like structures spanning the 20–10 nm gap between the mitochondrion and the epiplasm.

Previous studies have shown that the placement of mitochondria in the cortex appears to be determined by certain of the cortical microtubule bands. This study, however, shows that mitochondrion‐microtubule interactions account for only a small proportion of the total mitochondrial area associated with the cortex; the rest is accounted for by the epiplasm. A possible analogue of the spectrin layer of erythrocyte membranes, the epiplasm may be important in helping to arrange the intricately organized components of the ciliate cortex. Its involvement in apparently helping to “moor” mitochondria to their cortical sites is the first suggestion of any role in cell patterning played by the epiplasm.
Further Observations on the Fine Structure of Acanthamoeba palestinensis (Reich, 1933). The Golgi Complex, Microbodies, and Mitochondria1
Authors: LASMAN M. , FEINSTEIN N.
Published: May 2007

The fine structure of the trophozoite of Acanthamoeba palestinensis with a special emphasis on the Golgi complex, microbodies, and mitochondria has been examined. Golgi complexes are distributed throughout the cytoplasm but are most abundant in the perinuclear region. Usually two Goigi complexes are found in the same plane on opposite sides of the nucleus. One of them appears to be in an intimate association with the nuclear membrane. The region of contact contains compact cisternae, vesicles of various sizes, as well as granular and amorphous electron‐dense material. Structural changes in the nuclear envelope are also observed in this area. A structure consisting of a Golgi complex and electron‐dense microtubule organizing center, comparable to the centrosphere of other Acanthamoeba species, has been observed. Microbodies, surrounded by a single unit membrane and containing a granular matrix and tubular inclusions, are scattered throughout the cytoplasm. These organelles, circular (∼1 μm in diameter) or ovoidal (∼1 μm in length and ∼0.5 μm in width) in section, have often an irregular outline. These microbodies are probably the morphological equivalent of peroxisomes and glyoxysomes. Most mitochondria show a typical structure including tubular cristae and intracristal inclusions. Occasionally mitochondria with two apposed double membranes running through the midline are found. Such atypical cristae have never been reported in small amoebae before.
Ultrastructure of Mucocysts in Peranema trichophorum (Euglenophyceae)1
Authors: HILENSKI LULA L. , WALNE PATRICIA L.
Published: May 2007

The “mucigenic” or “muciferous” bodies of Peranema trichophorum are further characterized here as unique extrusive organelles, the mucocysts. Intracellular and ejected mucocysts have characteristic shapes that may represent different developmental stages. Mucocysts found near the Golgi apparatus are membrane‐bounded, elongate, tubular structures with amorphous contents of low electron density. Subpellicular mucocysts are often aligned with pellicular striae and have dense contents, which are separated by an electron‐lucent zone from granular material at the tips. Ejected mucocysts are uniform in structure and consist of an inner tube with helical striations, an outer tube with a diamond‐shaped pattern, and a dense middle band. Fine fibrils, visible only after mucocyst discharge, emanate from the tips. Mucocysts may also protrude through the pellicle and discharge mucilaginous materials into the medium. Acid phosphatase activity is localized within the subpellicular mucocysts, suggesting that they may be involved in release of hydrolytic enzymes into the medium.
Presence of Amoebae in the Rhizosphere of a Beach Grass1
Authors: NAPOLITANO JOSEPH J.
Published: May 2007

The occurrence of amoebae in the rhizosphere of a beach grass (Panicum sp.) collected at the Hempstead Lake State Park, Long Island, New York, was investigated throughout the growing season of 198 1. Amoebae achieved increased population density in the root system when compared with that in the surrounding bare sand; moreover, numbers of amoebae were higher only during the period of active plant growth and up to flowering. Following flowering, the numbers of amoebae in the root system fell to the level found in bare sand. The species diversity of amoebae in this system was compared with that in the carposphere of the mushroom Laccaria trullisata which appears at the same site but at a different time of year.
Fine‐structural Alterations in Leishmania tropica within Human Macrophages Exposed to Antileishmanial Drugs in Vitro1
Authors: LANGRETH SUSAN G , BERMAN JONATHAN D. , RIORDAN G. PATRICK , LEE LINDA S.
Published: May 2007

The mechanism of action of antileishmanial compounds is poorly understood. Ultrastructural changes in Leishmania tropica within human macrophages exposed in vitro to Pentostam, pentamidine, amphotericin B, WR 6026, ketoconazole, and Formycin B were examined in these experiments. In Pentostam‐treated cultures, some organisms exhibited diminished definition of mitochondrial and other membranes, while other organisms had completely disintegrated. Pentostam‐exposed macrophages demonstrated loss of membrane definition in the absence of further alterations; it is therefore hypothesized that impaired macrophage membrane function may contribute towards the effect of this drug against macrophage‐contained organisms. Leishmania parasites in pentamidine‐treated cultures initially demonstrated swollen kinetoplasts and fragmentation of the kinetoplast DNA core. The initial observed effect of the other four drugs on the parasites was cytoplasmic condensation. These ultrastructural studies suggest that all five non‐antimonial drugs may have different mechanisms of action than antimony (Pentostam) against Leishmania.
Electrophoretic Mobility Patterns of Ribosomal Proteins as an Aid to Phenoset Classification of Amicronucleate Strains of Tetrahymena1
Authors: PETRIDOU BARBARA , CUNY MARGUERITE , HAYES FRANÇOISE
Published: May 2007

Comparison of the electrophoretic migration patterns of proteins of active 40S and 60S ribosomal subunits isolated from nine amicronucleate strains of Tetrahymena of known phenoset revealed strain dependent differences which correlated with the phenoset classification of these strains as determined by Borden, Whitt & Nanney, who compared isoenzyme patterns.
Biochemical Approaches to Mating Type Expression in Tetrahymena thermophila1
Authors: VAN BELL CRAIG T. , WILLIAMS NORMAN E.
Published: May 2007

Two‐dimensional gel electrophoresis was used to identify the patterns of protein synthesis during initiation, and the patterns of membrane protein expression following initiation, in all of the mating types of the Tetrahymena thermophila B family. In addition, one‐dimensional analysis was used to survey 125I‐Concanavalin A‐binding proteins. Although a large number of proteins was identified by each technique, no variation among the mating types was observed.
Conjugation Between G1and G2Phase Cells inParamecium tetraurelia1
Authors: MIWA ISOJI , UMEHARA NORITOSHI
Published: May 2007

Cells ofParamecium tetraurelia, stock hrd, cultured in a micro‐capillary containing 1 μl fresh culture medium, expressed mating activity through the whole cell cycle. Mating‐reactive G2phase cells can conjugate with cells of other phases. The G2phase cells, which have double (4C) the normal micronuclear DNA content, undergo pre‐meiotic DNA synthesis when conjugated with G1phase cells. The micronucleus of the progeny from the cross between a G1and a G2cell becomes triploid.
On the Organization of the Naked Filose Amoeba, Nuclearia moebiusi Frenzel, 1897 (Sarcodina, Filosea) and Its Implications1
Authors: PATTERSON DAVID J.
Published: May 2007

The ultrastructural organization of Nuclearia moebiusi is described. The organism has filose pseudopodia without supportive microtubules; it has mitochondria with flattened cristae, lacks extrusomes, microtubule‐organizing centers, and cytoplasmic microtubules. During cell division, microtubules appear only within the nucleus, and reorganization of the nuclear envelope occurs late in the nuclear division cycle. Ultrastructural studies reveal that Nuclearia spp. have a pattern of cellular organization distinct from that of other amoebae. Comparison of ultrastructural features suggests that this organism is only distantly related to other rhizopod amoebae (including other filose amoebae) and to the heliozoa.
Direct Transmission of a Hemoflagellate, Cryptobia salmositica (Kinetoplastida: Bodonina) Between Rainbow Trout Under Laboratory Conditions1
Authors: WOO PATRICK T. K. , WEHNERT SYBILLE D.
Published: May 2007

Transmission of Cryptobia salmositica occurred when infected and uninfected rainbow trout were held in the same tank. In tanks where infected and uninfected fish were allowed to mix freely, 67–80% of the uninfected fish acquired detectable infections by the 27th week. None of the control fish in another tank was infected. In another tank where the infected and uninfected fish were separated by a wire screen, 9 of 20 uninfected fish acquired detectable infections by the 22nd week. This is the first demonstration of direct transmission of a hemoflagellate via the water medium in aquatic vertebrates. Cryptobia salmositica was found in the mucus on the body surface of 9 of 10 fish examined 6 weeks after infection. These parasites were infective and some of them were morphologically similar to those in the blood or peritoneal fluid. It is suggested that the vascular species of Cryptobia were originally ectoparasitic on fishes and that these ectoparasitic species were descended from the free‐living Procryptobia.