bluuebunny/crossref_metadata_2025 huggingface dataset:
The Synthesis of the Immobilization Antigen in Paramecium aurelia: In vitro Localization of Antigen in Ribosomal Cell Fractions
Authors: SINDEN R. E.
Published: May 2007

SYNOPSIS. The distribution of a cell surface protein, the immobilization antigen, has been studied in homogenates of Paramecium aurelia stock 168, syngen 1. Two fractions, a 9,000 g supernatant fluid and a 25,000 g supernatant fluid, have been investigated for their ability to bind 125I‐labelled antibodies specific against immobilization antigen. These 2 fractions have been characterized by electron microscopy. Antigen was detected in a pure microsome fraction and in the polysome fraction. Sucrose gradient analysis of the polysome fractions indicates that antigen is associated specifically with polysomes of 228S and 311S, the latter being located primarily in the microsome fraction. These results correlate well with the structure of the immobilization antigen proposed by Steers. A possible mechanism for the synthesis of this protein is outlined.
A Photorepressible Isozyme o Malic Enzyme in Euglena gracilis Strain Z*†
Authors: KARN R. C. , HUDOCK G. A.
Published: May 2007

SYNOPSIS. Isozymes of malic enzyme in Euglena gracilis strain Z were analyzed by starch‐gel electrophoresis. Wild‐type and heat‐bleached strains were cultured in the light and the dark in the presence of various carbon sources. An isozyme detectable in heterotrophic cultures was repressed by photosynthesis. A model is proposed to explain photorepression of this isozyme.
Eurycea bislineata (Green), the Two‐Lined Salamander, a New Host of Myxidium serotinum Kudo & Sprague, 1940 (Myxosporida, Myxidiidae)
Authors: CLARK JUDITH G. , SHOEMAKER JON P.
Published: May 2007

SYNOPSIS. Myxidium serotinum was found in 51 of 58 (87.9%) specimens of the two‐lined salamander, Eurycea bislineata, from West Virginia. This constitutes a new host record. No specimens of the order Salientia, or other species of the order Caudata were infected. Eurycea bislineata appears to be the normal host of M. serotinum, which is specific for the gallbladder in a variety of amphibian hosts. Apparently, larval E. bislineata becomes infected with M. serotinum, and the parasite does not become a mature trophozoite until after the tadpoles metamorphose to the adult salamander. Certain host hormonal factors may be important to the maturation of M. serotinum.
Description de Quelques Espèces de Ciliés Hyménostomes des Genres Sathrophilus Corliss, 1960, Cyclidium O. F. Müller, 1786, Histiobalantium Stokes, 1886
Authors: GROLIERE CLAUDE‐ALAIN
Published: May 2007

RESUME. Les structures buccales de Sathrophilus vernalis Dragesco & Grolière, 1969 sont détaillées. La morphogenèse buccale de l'opisthe, semi‐autonome, avec participation du scuticus et d'une cinétie postorale droite, s'accompagne d'une re‐constitution de l'appareil buccal du proter. La morphologie buccale de Cyclidium sphagnetorumŠràmek‐Hušek, 1949 est comparée à celles de Cyclidium citrullus Cohn, 1865 et Cyclidium glaucoma O. F. Müller, 1786. La stomatogenèse Histiobalantium majus Kahl, 1933 débute par une prolifération du scuticus vers la gauche.

SYNOPSIS. Buccal structures of Sathrophilus vernalis Dragesco & Grolière, 1969 are described. The semiautonomous buccal morphogenesis of the opisthe, involving the participation of the scuticus and the right postoral kinety, is accompanied by the reconstitution of the buccal apparatus of the proter. The buccal structure of Cyclidium sphagnetorumŠràmek‐Hušek, 1949 is compared to those of Cyclidium citrullus Cohn, 1865 and Cyclidium glaucoma O. F. Müller, 1786. Stomatogenesis of Histiobalantidium majus Kahl, 1933 starts with a proliferation of the scuticus towards the left.
The Fine Structure of the Cytostome of the Apostomatous Ciliate Hyalophysa chattoni*
Authors: BRADBURY PHYLLIS CLARKE
Published: May 2007

SYNOPSIS. The fine structure of the organelles concerned with the ingestion of exuvial fluid by the trophont of the apostome ciliate, Hyalophysa chattoni, has been examined. One of the taxonomic characteristics of the order Apostomatida is that cytostomes of ciliates within the taxon are reduced and evolving toward astomy. When examined by electron microscopy the cytostome of H. chattoni appears as a small region of active pinocytosis which is continuous with a very large cortical area, the extended cytostome. The fine structure of the extended cytostome resembles that of the cytostomes of ciliates from other orders in that it is covered by a single membrane underlain with microtubular ribs. Beneath the extended cytostome are accumulations of peculiar organelles that may represent stored membrane for recycling during food vacuole formation. Associated with the site of pinocytosis is a complex fiber that may be contractile.
Effects of Glutaraldehyde and Osmium Tetroxide on Hypotrichous Ciliates, and Determination of the Most Satisfactory Fixation Methods for Electron Microscopy
Authors: SHIGENAKA Y. , WATANABE K. , KANEDA M.
Published: May 2007

SYNOPSIS. In electron microscope studies on hyppotrichous ciliates, cytolysis and/or body deformation–resulting from insufficient contact with glutaraldehyde and poor infiltration of Epon 812, particularly into the buccal cavity, usually were observed. Fixation experiments were carried out to examine the effects of some fixatives on Euplotes eurystomus, Oxytricha bifaria and Stylonychia mytilus to establish the best fixation technic applicable to all species of hypotrichous ciliates. Although the effects of fixation varied considerably with the species, 2 fully satisfactory fixation methods were developed by using OsO4 and glutaraldehyde. In one, a mixture of both fixatives was employed; in the other a very short application of OsO4 was followed by glutaraldehyde. The problem of infiltration was solved by using Spurr's low‐viscosity embedding medium in place of Epon 812.
Adoptive Transfer of Immunity to Plasmodium berghei by Spleen and Lymph Node Cells from Young and Old Mice*
Authors: KASPER LLOYD H. , ALGER NELDA E.
Published: May 2007

SYNOPSIS. Different numbers of spleen and lymph node cells of 6‐week and 6–8 month A/J mice, immune to Plasmodium berghei, were transferred into normal 4‐week old mice. Better protection was observed with 2.5 × 10s than with 107 spleen cells, and spleen cells afforded better protection than an equal number of lymph node cells. Further, spleen cells from older mice were more effective than those from young animals. Possible mechanisms of immunity transfer are discussed.
Hydroxyproline in Tetrahymena*
Authors: VAUDAUX PIERRE , DE HALLER GERARD
Published: May 2007

SYNOPSIS. Hydroxyproline (HP) can be quantified by the sensitive colorimetric procedure of Kivirikko et al. (1967). Without preliminary hydrolysis, only the free imino acid (I) can be detected. After hydrolysis in 6 N HCl at 120 C for 15 hr, also the peptide‐bound (II) and polypeptide‐bound (III) is detected. Cells grown in 2% (w/v) proteose peptone supplemented with 0.4% yeast (w/v) extract (PPY) contained 0.01 mg HP/mg cellular proteins. Over 95% was in the I or II form (soluble in cold 20% trichloro acetic acid). Cells grown in a chemically defined medium (DM), contained less than 0.34 μg/mg cellular proteins. Whereas the DM does not contain any HP, the PPY medium is rich in HP (0.032 mg/mg proteose peptone). In conclusion, the HP found in the cells grown on PPY is a “contaminant'’from this medium. No endogenous production of HP was demonstrated.
Variation in Glyoxylate Bypass Inducibility among Strains of Tetrahymena pyriformis
Authors: KEMPER DAVID L. , THOMPSON SIOE HOEY , PARSONS JOHN A.
Published: May 2007

SYNOPSIS. Seven strains of Tetrahymena pyriformis were assayed for log phase activity of the glyoxylate bypass enzymes isocitrate lyase and malate synthase. In strains 6I, 6II, 6III, and W, isocitrate lyase was induced; in HS, neither enzyme was induced by acetate. During growth in glucose‐ or acetate‐containing media, strains 6III and GL had 2 periods of increased glyoxylate bypass and isocitrate dehydrogenase enzyme activities. Enzyme activities reached a maximum at the end of log phase, declined until the middle of stationary phase, and then increased again to a maximum near the end of stationary phase.
Studies on Nuclei of Paramecium aurelia. I. Isolation and Purification by Continuous or Discontinuous Sucrose Gradient Centrifugation and Biochemical Composition.*
Authors: ISAACKS R. E. , SANTOS B. G. , MUSIL G.
Published: May 2007

SYNOPSIS. Nuclei of Paramecium aurelia were isolated and purified by a new method involving the use of continuous or discontinuous sucrose gradient centrifugation. As judged from the DNA levels or nuclear counts in the purified samples, 21–22% of the nuclei were recovered by this method. The single density of the nuclei estimated on the basis of linear sucrose gradients was between 1.35 ± 0.01 and 1.36 ± 0.01. The average picogram quantities of total protein, DNA, and RNA per nucleus were 435, 62.2, and 51.2, respectively.
Studies on Nuclei ofParamecium aurelia.II. Amino Acid Composition and Electrophoretic Properties of the Chromosomal Basic Proteins*
Authors: ISAACKS R. E. , SANTOS B. G.
Published: May 2007

SYNOPSIS.The basic proteins ofParamecium aurelianucleus were extracted from isolated nuclei and deoxyribonucleoprotein (DNP) of such nuclei. About 35–40% of the nuclear protein, predominantly a lysine‐rich histone, is acid soluble. Five major components of the histone can be distinguished by polyacrylamide gel electrophoresis. Some components ofParameciumhistone are similar to those of mammalian histones in their electrophoretic mobility, but they differ from the latter in the electrophoretic velocity and relative levels. The basic to acidic amino acid ratio of the histone from the ciliate is ∼1.1–1.5, and its amino acid composition resembles closely that of yeast histone. Through the use of Sephadex G‐200 gel filtration for purification of the histones extracted directly from isolated nuclei 2 basic proteins were resolved—component I, with an elution volume of 1.4, constitutes ∼20% and component II, with an elution volume of 1.9, ∼80%.
Morphogenesis and Polymorphism in Gastrostyla steinii
Authors: WALKER GLENN K. , GRIM J. NORMAN
Published: May 2007

SYNOPSIS

Clonal cultures of the hypotrich protozoan, Gastrostyla steinii, were protargol stained and examined by light microscopy. Morphogenetic stages were noted, as well as variations in the number and distribution of the frontal‐ventral‐transverse cirri. These cirri, for the purpose of this study only, were delineated into special topographical groups—frontal, medial, and anal. Analyses were made to evaluate possible relationships as to the number of cirri between these groups and for the total number of cirri of the organisms, and, finally, to show likely relationships between morphogenetic events and patterns of cortical variation. An interesting “extra marginal row phenomenon” also was noted and shown to have variations of its own. Cirral polymorphism is presumed to be under genic control with the ultimate individual corticotype under the influence of an underlying gradient. A “stability profile” for the organism and for each cirral group was erected and discussed with emphasis on a gradient mechanism.
Unusual Structures in the Flagellar Apparatus of a Strain of Trypanosoma cruzi*
Authors: DEANE MARIA P. , MILDER REGINA
Published: May 2007

SYNOPSIS

Certain structures, associated with the flagellum, and which had hitherto been described as appearing occasionally in some species of trypanosomes, were found very frequently in epimastigote forms of strain F of Trypanosoma cruzi: (a) a group of tubular elements in an electron‐dense mass enclosed within a swelling of the flagellar membrane as the flagellum emerges from its reservoir; (b) an expansion of the flagellar membrane at the point of the above swelling, which in cross‐sections appears as a ring; and (c) an electron dense band in the body of the organism alongside the border of the flagellar pocket.

The possible significance of these structures and the fact that so far they have been found only in one strain of T. cruzi are discussed.
Fine Structure of the Malaria Parasite Plasmodium lophurae Developing Extracellularly in vitro*
Authors: LANGRETH SUSAN G. , TRAGER WILLIAM
Published: May 2007

SYNOPSIS

Duck malaria parasites (Plasmodium lophurae), synchronized at the uninucleate trophozoite stage, were freed from their host erythrocytes by immune lysis and cultured extracellularly in duck erythrocyte extract medium. At 0 time, 1, 2, and 3 days, samples were taken for light and electron microscopy and for measurement of incorporation of [14C]‐methionine or [14C]‐proline. For 2 days the parasites developed fairly normally, progressing from large trophozoites‐early schizonts at 1 day to segmenters‐forming merozoites at 2 days. However, the 3‐day samples showed signs of deterioration: incorporation of amino acids dropped; the percentage degenerate cells rose; the progression of developmental stages slowed. At the fine structure level 2 abnormalities were observed which may indicate the limits of extracellular cultivation in vitro. Through 2 days of culture all parasites were surrounded by 2 membranes. The 3‐day samples contained some organisms with only one membrane, which may have arisen from merozoites produced extracellularly. The 2nd alteration was in the food vacuoles, which were progressively fewer, smaller, and less dense in the cultured samples and may indicate an abnormality in the extracellular parasite's feeding mechanism.
Ultrastructural and Protargol Studies of Lagenophrys callinectes* (Ciliophora: Peritrichida)
Authors: COUCH JOHN A.
Published: May 2007

SYNOPSIS

Ultrastructural and protargol studies reveal that the trophont of Lagenophrys callinectes, though highly specialized, generally conforms to the basic peritrich structural pattern.

Features described for L. callinectes trophonts which are unique for the genus are the fine structure and arrangement of the lorica and lips, the attachment organelle of the peristomial cytoplasm, its attachment to the loricastome walls, and the arrangement of the aboral kinetosomes of the trophont. Lack of a distinct scopularized region, and of a ventral lorica wall also characterize L. callinectes trophonts.

The 4‐row terminal peniculus, as revealed by protargol staining, differs from the 6‐row terminal peniculus of L. nassa suggesting that the patterns of infundibular structure, as revealed by protargol, should be useful in future taxonomic studies of Lagenophrys species.
Fine Structure of the Macronuclear Anlage of the Hypotrichous Ciliate Keronopsis rubra
Authors: RUTHMANN AUGUST
Published: May 2007

SYNOPSIS

In exconjugants of the hypotrich Keronopsis a large, highly polyploid macronuclear anlage is formed from which condensed chromatin bodies are passed into the cytoplasm where they are thought to give rise to the numerous small macronuclei of the vegetative cell. Electron microscopy shows that the chromatin bodies within the macronuclear anlage are separated from each other by sheets of low contrast lamellar material. The anlage appears therefore as a composite nucleus containing prepacked units which are extruded into the cytoplasm following condensation.
Immunogenicity and Infectivity of Sporozoites of Mammalian Malaria Isolated by Density‐Gradient Centrifugation*
Authors: KRETTLI ANTONIANA , CHEN DAVID H. , NUSSENZWEIG RUTH S.
Published: May 2007

SYNOPSIS

Sporozoites of rodent and simian malaria (Plasmodium berghei and P. cynomolgi) were purified by centrifugation on a linear Renografin/BSA gradient. This procedure made it possible to process rapidly a large number of infected mosquitoes leading to the recovery of a considerable proportion of sporozoites. Gradient‐recovered sporozoites (GRS) freed of most bacteria and mosquito tissue contaminants, retained their infectivity and immunogenicity. Mice repeatedly injected i.v. with irradiated GRS of P. berghei acquired total protection against an otherwise lethal sporozoite challenge. GRS of P. berghei and P. cynomolgi induced antisporozoite (CSP) antibody production in rats.
Isolation and Chemical Composition of Dinoflagellate Nuclei*
Authors: RIZZO P. J. , NOODÉN L. D.
Published: May 2007

SYNOPSIS

Nuclei were isolated fromPeridinium cinctum. Peridinium trochoideum, Gyrodinium cohnii(Cryptothecodinium cohnii) andGymnodinium nelsoni.The nuclei ofG. cohnii, P. trochoideumandG. nelsoniwere found to contain ∼ 6.9, 34 and 143 picograms of DNA respectively. The ratios to DNA of RNA, acid‐soluble and acid‐insoluble protein forG. cohniiwere 0.32, 0.13 and 0.99, respectively. The corresponding values forP. trochoideumwere 0.22, 0.08 and 1.22, while those forG. nelsoniwere 0.21, 0.10 and 1.09. The chemical composition of dinoflagellate nuclei is compared and contrasted with that of typical eukaryotic nuclei. The culture of these difficult organisms also is discussed.
The Sites of Action of Allopurinol in Crithidia fasciculata*
Authors: DEWEY VIRGINIA C. , KIDDER G. W.
Published: May 2007

SYNOPSIS

Reversal of the growth inhibition of Crithidia fasciculata by allopurinol requires both a purine and a pyrimidine. Hypoxanthine is the most effective purine in the reversal. Cell‐free extracts were prepared which were capable of the decarboxylation of orotidine 5′‐phosphate. Other enzyme preparations carried out the phosphoribosylation of allopurinol. By the use of [4‐14C] orotidine 5′‐phosphate (enzymatically prepared), it was shown that allopurinol ribotide (enzymatically prepared), but not the free base, inhibits orotidine 5′‐phosphate decarboxylase.
Localization of Some Enzymes of β‐oxidation of Fatty Acids in the Peroxisomes of Tetrahymena*
Authors: BLUM J. J.
Published: May 2007

SYNOPSIS

Mitochondria and peroxisomes were prepared from homogenates of Tetrahymena pyriformis by sedimentation through sucrose gradients. Catalase and isocitrate lyase served as peroxisomal markers; lactic dehydrogenase and glutamic dehydrogenase as mitochondrial markers. Acetyl‐CoA synthetase, octanoyl‐CoA synthetase, palmitoyl‐CoA synthetase, 3‐β hydroxyacyl CoA dehydrogenase, and thiolase activities were found in both the peroxisomes and the mitochondria. It is suggested that β‐oxidation of fatty acids accurs in both organelles in Tetrahymena.
Structure and Function of Kinetoplast DNA*†
Authors: SIMPSON LARRY
Published: May 2007

SYNOPSIS

Cells of the order Kinetoplastida possess a single mitochondrion which contains a large amount of a uniquely organized DNA. This kinetoplastic DNA (K‐DNA), representing 10–20% of the total cell DNA in different species, has as its major molecular component a small closed circular molecule present in large numbers. The size and thereby the amount of genetic information carried by the minicircles varies from species to species: Leishmania tarentolae and the Salivarian trypanosomes have the smallest, the Stercorarian trypanosomes Trypanosoma lewisi and Trypanosoma cruzi intermediate, and Crithidia and also Trypanosoma mega the largest minicircles. In L. tarentolae, purified minicircles, which are the size of 1 gene, have been shown by renaturation kinetics to consist of only 1 or 2 classes. L. tarentolae K‐DNA also contains another molecular species—a long molecule which may represent up to 30% of the total K‐DNA. The minicircles, nevertheless, represent a gene amplification of the order of 104. In all species that have been examined so far, the K‐DNA consists of a single sheet of interlocked closed circular molecules which can be isolated in an intact form because of its resistance to shear forces and its high molecular weight. In addition, at least in L. tarentolae, 6–9% of the K‐DNA is either free in the mitochondrion or loosely bound. The main K‐DNA structure has been termed a “network” and can be seen in the light microscope after staining in solution with acridine orange or after fixing and staining with Giemsa's, or in the electron microscope. The quaternary structure of such networks in terms of the organization of minicircles and long molecules is not understood. Controlled breakdown of networks from L. tarentolae was achieved by sonication, and the release of open and closed monomeric minicircles, catenated dimers, trimers and higher oligomers, and short linear fragments was measured. A maximum of 43% of the total network DNA was released in the form of closed monomers, dimers, and trimers, thus providing a minimal estimate for the percentage of minicircles in K‐DNA from this species. K‐DNA replicates fairly synchronously with nuclear DNA in all species that have been examined. Replication of DNA molecules in the kinetoplast networks is limited to the periphery, as seen in autoradiographs of networks isolated from cells (L. tarentolae, Crithidia fasciculata) pulsed with 3H‐thymidine. The molecular implications of this unusual replication pattern remain an open question, as does the genetic function of the K‐DNA itself.
Four New Species of Eimeria and One of Tyzzeria from the Ceylon Jungle Fowl Gallus lafayettei*
Authors: FERNANDO M. A. , REMMLER O.
Published: May 2007

SYNOPSIS

One species of Tyzzeria and 4 new species of Eimeria are described from the Ceylon jungle fowl Gallus lafayettei. The sporulated oocysts of Tyzzeria galli sp. n. are 13.8 (12–15) μ m; of Eimeria lafayettei sp. n., 19.5 (19–21) X 14.2 (13.5–15) μ m; of Eimeria indentata sp. n., 30.3 (29.5–32) X 21.4 (20–22) μ m; of Eimeria symmetrica sp. n., 35 × 28.5 μ m, and of Eimeria dissanaikei sp. n., 21 (19–23) X 14 (12–16) μ m. E. indentata, E. symmetrica, and E. dissanaikei produced patent infections in domestic fowl but T. galli and E. lafayettei did not. This is the 1st record of the genus Tyzzeria from the order Galliformes.
Phagotrophic Ingestion of a Blue‐Green Alga by Ochromonas*†
Authors: DALEY RALPH J. , MORRIS G. P. , BROWN S. R.
Published: May 2007

SYNOPSIS

Anacystis nidulans disappeared rapidly from culture in the presence of an unidentified species of Ochromonas. Disappearance was light‐independent and could be induced neither by bacteria associated with, nor by soluble products released from the flagellate. Electronmicrographs of mixed cultures revealed numerous A. nidulans cells in various stages of digestion within vacuoles of Ochromonas. Evidently the disappearance of the alga from culture resulted from phagotrophy by the chrysomonad. A 2‐stage digestive process is suggested whereby A. nidulans cells are initially sequestered in the posterior “leucosin” vacuole and then undergo the terminal stages of digestion and elimination in smaller, peripheral vacuoles.
Structure, Cytochemistry, and Locomotion of Haemogregarina sp. from Rana berlandieri
Authors: DESSER SHERWIN S. , WELLER IRIS
Published: May 2007

SYNOPSIS

Intra‐ and extracellular gametocytes of Haemogregarina sp. from Rana berlandieri were studied by light and electron microscopy. Locomotion in free gametocytes appears to be related to series of horizontal “peristaltic” waves of constriction, passing from anterior to posterior along the body. Intracellular gametocytes lie within a vacuole in the erythrocyte cytoplasm. The pellicle of the parasite consists of a trilaminar plasmalemma and an inner electron dense layer, beneath which lies a ring of 80 microtubules. The inner dense layer becomes thickened and modified in the apical region, to form a cap‐like structure. The gametocytes contain a prominent nucleus, several mitochondria, and many granular inclusions. One type of inclusion consists of elliptical, electron‐dense, profeinaceous bodies scattered throughout the cytoplasm, while other inclusions are larger and electron‐opaque, polysaccharide in nature, and occur predominantly in the pre‐ and post‐nuclear regions. In the electron microscope, pronounced pellicular folds were observed in longitudinally sectioned extracellular gametocytes. These folds are thought to represent the waves of constriction seen in motile specimens by light microscopy. The mechanism of movement of the parasite is discussed and compared with that in haemosporidian ookinetes, as well as in gregarines.
Experimental Microbial Populations Thirty‐five Years Later: The Influence of Food on the Symbiosis of Paramecium aurelia Syngen 4, 51.7
Authors: BURBANCK W. D. , MARTIN VIRGINIA L.
Published: May 2007

SYNOPSIS

Changes in the nutrition of Paramecium aurelia affect its ability to serve as host for the bacteroid parasite, kappa, and the presence or absence of kappa affects its ability to grow in axenic culture. Loss of kappa, tested by the presence or absence of killer reaction, occurred in cultures of P. aurelia growing at a reduced division rate on autoclaved Enterobacter aerogenes in suspensions of lettuce and yeast autolysate 14–17 days after they had been rendered bacteria‐free by washing. Killer Paramecium sterilized of bacteria by treatment with an antibiotic mixture of penicillin‐G and streptomycin in combination with a nonbacterial nonliving culture medium, lost the ability to kill after from 6 to 48 hours in the sterilizing medium. The ciliates from which kappa had been lost during exposure to antibiotics could be transferred immediately and maintained in axenic culture, but those washed free of bacteria could not be maintained axenically until kappa had been lost during cultivation in a medium containing killed bacteria. It is suggested that a knowledge of the nutritional requirements of symbiotic microorganisms is essential for understanding the ecological aspects of eutrophication of aquatic environments.
An Improved Method for the Isolation of Highly Polymerized Native Deoxyribonucleic Acid from Certain Protozoa*
Authors: HONIGBERG B. M. , MOHN FERN ANN
Published: May 2007

SYNOPSIS

A relatively simple phenol extraction method, with EDTA as the nuclease inhibitor, is described for the isolation of purified, highly polymerized native DNA from Trichomonas vaginalis, Trichomonas gallinae, and Tritrichomonas foetus; it is applicable also to Tetrahymena pyriformis. RNase Tl, RNase A (Worthington's R), pronase, and α‐amylase digestions constitute important steps in obtaining satisfactory yields of DNA. High degree of polymerization of the isolation product was estimated by hyperchromicity at O.D.260 after DNase treatment and by CsCl gradient analysis. The double‐stranded condition of the DNA samples was estimated by the latter method and by denaturation with NaOH, and the molecular weight by sucrose gradient analysis. Purity of the samples was determined spectrophotometrically and by chemical analyses for protein and glycogen. DNA percent recovery was estimated by the diphenylamine reaction.
Three Avenues to Ecologic Research on Parasitic Protozoa
Authors: NOBLE ELMER R.
Published: May 2007

SYNOPSIS

Our knowledge of parasitic protozoa can be greatly enhanced by increased use of the following 3 ecological approaches to the study of parasitism. A) Studies of energy flow between parasite and host. B) Systems analysis. C) Studies of nutrition through an analysis of the parasite's environment. Most of the energy in cysts and spores is never returned to the parasite‐host system. The more integrated the system the more difficult an analysis of the role of parasites in the host energy budget. A parasite‐host system can be understood only through a careful study of each part, and the relationships among these parts. A measure of the nutrient status of a body fluid should take into consideration the nutrient status of any population of parasites that may be residing in that fluid. The above considerations were applied to problems of parasitism in deepsea fishes. Small, delicate midwater fishes do not have much energy for pursuing prey. We need to know details of the effects of great pressures and low temperatures on parasites. Energy flow between parasites and deep marine fishes has never been investigated. It is possible that parasites in these fishes are more efficient in energy transformation than are their hosts. These kinds of studies may be labeled “integrative parasitology.”
Gregarines of the Genus Lecudina (Protozoa, Apicomplexa) from Pacific Ocean Polychaetes*
Authors: LEVINE NORMAN D.
Published: May 2007

SYNOPSIS

The gregarine Lecudina longissima Hoshide, 1944 is described from the intestine of the marine polychaete Lumbrineris zonata (Johnson, 1901) from Santa Catalina Island, Calif. L. catalinensis n. sp. is described from the intestine of L. inflata Moore, 1911 from the same island. L. pherusae sp. n. and L. zimmeri sp. n. are described from the intestine of the marine polychaete Pherusa capulata (Moore, 1909) off Santa Catalina Island.
On the Fine Structure of the Nucleus in Trypanosoma cruzi in Tissue Culture Forms. Spindle Fibers in the Dividing Nucleus*
Authors: DE SOUZA W. , MEYER H.
Published: May 2007

SYNOPSIS

The fine structure of the dividing nucleus in the intracellular amastigote forms of Trypanosoma cruzi from tissue cultures has been described. In the first phase of division the nucleus shows a homogenous structure owing to the dispersion of its chromatin and nucleolar material. Microtubules similar to those of a mitotic spindle in metozoan cells then appear, running from one pole to the other. They disappear when the division of the nucleus is complete and the chromatin and the nucleolar material reorganize into their former positions.
Selective Autolysis of Nuclei as a Source of DNA Precursors in Paramecium aurelia Exconjugants*
Authors: BERGER JAMES D.
Published: May 2007

SYNOPSIS

The fate of labeled DNA in macronuclear fragments of starving Paramecium aurelia exconjugants was studied by quantitative autoradiography. Labeled material originally contained in DNA of macronuclear fragments is incorporated into macronuclear anlagen. During the starvation period the mean number of macronuclear fragments per cell decreased exponentially while there was an approximately exponential increase in the volume of macronuclear anlagen. Fragments appeared to be selectively and individually autolyzed. Labeled material originally contained in fragments was largely if not completely conserved through 108 hr of starvation during which more than 90% of the fragments were lost. Soluble labeled material was detectable after autolysis of fragments began, but finally almost all labeled material was incorporated into macronuclear anlagen.
Interspecies Crosses in Paramecium aurelia (Syngen 4 by Syngen 8)*
Authors: HAGGARD BRUCE W.
Published: May 2007

SYNOPSIS

Two syngens (biologic species) of Paramecium aurelia that appear to be closely related were crossed. Parental stocks carrying different homozygous recessive marker genes were utilized to identify true hybrids (those that had undergone cross‐fertilization followed by normal nuclear processes). From these crosses of syngens 4 and 8, 32% of the conjugants survived but only 9% (27% of the survivors) were true hybrids. All 19 viable hybrids recovered were cytoplasmically descended from the syngen 8 parent; but the viable nonhybrids were cytoplasmically descended from either of the 2 parents and with equal frequency from each. Surprisingly, the hybrids could not be infected with the symbiont kappa, even though they should have carried a K gene donated by their syngen 4 parent which is necessary and sufficient to allow infection of the syngen 4 parent stocks. The hybrids required special care to cultivate and were sterile, thus indicating that they are at an evolutionary dead end. However, one type of nonhybrid clone produced by the intersyngenic conjugants was able to produce viable progeny. It is speculated that genetic elements of the cortex and in the cytoplasm (e.g. mitochondria) could be transferred intersyngenically via this type of nonhybrid clone.
The Fine Structure of the Colonial Kinetoplastid Flagellate Cephalothamnium cyclopum Stein
Authors: HITCHEN E. T.
Published: May 2007

SYNOPSIS

Cell structure, cell adhesion, and stalk formation have been examined by electron microscopy in the colonial flagellate, Cephalothamnium cyclopum. Each cell is obconical or spindle‐shaped, pointed posteriorly and truncated anteriorly. The cell membrane is underlain by epiplasm 0.1 μm thick in the posterior region, but bands of microtubules support the anterior region which is differentiated into a flagellar pocket, oral apparatus and contractile vacuole. Each of 2 flagella, joined a short way above their bases by an interflagellar connective, has a paraxial rod and mastigonemes. One flagellum is free and is important in food gathering while the other is recurrent and lies in a shallow groove on the ventral cell surface but projects posteriorly into the stalk. The basal bodies of these flagella are bipartite structures connected by a pair of striated rootlets with accessory microtubular fibers. The oral apparatus consists of a funnel‐shaped buccal cavity and cytostome. It is supported by helical and longitudinal microtubules and also has nearby striated and microtubular fibers. Possible roles of associated oral vesicles in relation to ingestion are discussed. A reticulate mitochondrion houses a massive kinetoplast which has a fibrillar substructure resembling that of dinoflagellate chromosomes. Adjacent flagellates adhere by laminate extensions of their posterior regions and attach by their recurrent flagella to a communally secreted stalk composed of finely fibrillar material. This study indicates that Cephalothamnium belongs in the order Kinetoplastida, and has many features in common with members of the family Bodonidae.
Fine Structure of Trypanosoma cyclops in Noncellular Cultures*
Authors: HEYWOOD PETER , WEINMAN DAVID , LEPMAN MURIEL
Published: May 2007

SYNOPSIS

The fine structure of the epimastigotes of Trypanosoma cyclops maintained in blood agar medium at 25 C is described. This organism was isolated from the Malaysian primates Macaca nemestrina and Macaca ira. A distinctive feature of T. cyclops is that it is pigmented when grown in the presence of hemoglobin. The pigment bodies apparently lack a substructure and are electron dense even in unstained sections. Most of the pigment is located posterior to the kinetoplast region but some is found adjacent and anterior to the kinetoplast. Cells from control cultures grown in medium lacking hemoglobin did not possess this type of pigment body. Similarly, pigment was not found in cells of an Indonesian trypanosome grown in medium containing hemoglobin.

The cytoplasm of T. cyclops is bounded by a unit membrane which is specialized where it makes contact with the flagellum. A cytostome extends from the region of the flagellar pocket. The kinetoplast and nucleus are immediately posterior to the base of the flagellum. Transverse sections in the region of the flagellar pocket and flagellar base often reveal a group of 3 microtubules which are distinct from the pellicular microtubules.
Fine Structure of Haemoproteus columbae Kruse During Macrogametogenesis and Fertilization*
Authors: GALLUCCI BETTY B.
Published: May 2007

SYNOPSIS

When blood is withdrawn from a pigeon (Columba livia) infected with gametocytes of Haemoproteus columbae, differentiation of the gametes begins immediately. This study examines the formation of the macrogamete and its fertilization. The first visible signs of differentiation are the elongation of the nucleus along with the appearance of an intranuclear spindle and atypical centrioles. Then maturation bodies, the products of nuclear reduction, form in both erythrocytic macrogametocytes and macrogametocytes free of their host cells.

Penetration of the macrogamete by the microgamete occurs rapidly. Their plasma membranes fuse, and the microgamete's nucleus, axonemes and cytoplasm enter the macrogamete. The nucleus of the microgamete expands and migrates to lie at an angle to the macrogamete nucleus. The 2 fuse across a small area.

The nuclear envelope and the plasma membrane of the zygote are a mosaic of the membranes of the 2 gametes.
Fine Structure of Haemoproteus columbae Kruse During Differentiation of the Ookinete*
Authors: GALLUCCI BETTY B.
Published: May 2007

SYNOPSIS

Ookinete differentiation begins in vitro∼1 hr after blood infected with mature gametocytes of Haemoproteus columbae is withdrawn from a pigeon. In the undifferentiated zygote, dense material accumulates at the point under the plasma membrane. The conoid and conoidal rings condense from this material. The nucleus is drawn out to a point with the intranuclear spindle (INS) at the peak. Atypical centrioles lie under the forming conoid in the cytoplasm next to the INS. Fibrous material under the inner membrane forms the polar ring from which subpellicular microtubules originate.

One hr later the centrioles have disappeared and the nucleus has returned to the center of the organism. The conoidal complex forms the tip of a growing cytoplasmic projection, the anterior end of the ookinete. During this time an elaborate pellicle is differentiating antero‐posteriorly; crystalloid formation begins with an extensive proliferation of rough endoplasmic reticulum (ER) continuous with the outer membrane of the nuclear envelope. Crystalloid particles are formed between the lamellae of the ER and collected in a sphere that is later partially surrounded by a small amount of ER.

Ookinetes, differentiated 2 hr longer than the ookinetes in vitro, were obtained from the gut of the pigeon fly, Pseudolynchia maura. The differentiated pellicle of these ookinetes consists of a plasma membrane, an inner membrane layer composed of 2 appressed membranes, and in the anterior end, an electron‐opaque lamina immediately under the inner membrane. Anterior to the polar ring, this lamina forms a canopy which, posteriorly, is drawn out into projecting ribs which diminish and disappear in the first third of the organism. Fifty to 60 subpellicular microtubules insert on the polar ring.

Ookinetes differentiated in vitro were no more than 4 hr old. They lacked micronemes and retained a pellicular cytostome and “internal cytostomes.” The differentiation of micronemes probably occurs at a later time because they are visible after 6 hr in ookinetes in the fly gut. So many degenerating organisms appeared in vitro after 5 hr that this material was discarded.
Fine Structure of Differentiating Oocysts and Mature Sporozoites of Haemoproteus metchnikovi in its Intermediate Host Chrysops callidus*
Authors: STERLING CHARLES R. , DeGIUSTI DOMINIC L.
Published: May 2007

SYNOPSIS

The fine structure of the sporogonic stages of Haemoproteus metchnikovi has been investigated by electron microscopy. Young oocysts are found beneath the basement membrane of midgut epithelial cells. These eventually protrude outward into the haemocoel space and are surrounded by a distinct oocyst capsule. Sporozoite formation begins with a subcapsular vacuolation. Evagination of the oocyst cytoplasm occurs in regions of membrane thickenings and 100–200 sporozoites are formed about a single sporoblastoid body. Remnants of the ookinete pellicle can be observed in maturing oocysts and always are found in the residual body. The fine structure of the mature sporozoite is essentially similar to that which has been described for other haemosporidia and a spherical body is described in association with the mitochondrion of the sporozoite. The sporogonic stages of H. metchnikovi have features common to the sporogonic stages of Plasmodium and Leucocytozoon that are not held in common by the latter 2 genera, including pattern of sporozoite formation and number of sporozoites formed, the presence of a cytostome and of “crystalloid” in the sporozoite.
Phototaxis by the Dinoflagellate Gymnodinium splendens Lebour*
Authors: FORWARD RICHARD B.
Published: May 2007

SYNOPSIS

A microscope‐television system was used to monitor quantitatively the behavior of Gymnodinium splendens Lebour in response to light. The predominant behavioral sequence upon stimulation is (a) an initial 2–5 sec cessation of movement (stop‐response) followed by (b) positive phototaxis. The action spectra for each response are identical, having maxima at 450 and 280 nm. Upon measuring the percent response to a range of stimulus intensities, it is apparent that a stop‐response is not a behavioral prerequisite for phototaxis. An identical circadian rhythm in photoresponsiveness is observed for phototaxis and for the stop‐response with greatest light sensitivity occurring during the first 4 hr of the entrained light period. The implication of phototactic sensitivity and the phototactic circadian rhythm in diurnal vertical migration is discussed.
Inhibition by Several Standard Antiprotozoal Drugs of Growth and O2 Uptake of Cells and Particulate Preparations of a Leptomonas*
Authors: GOLDBERG BURT , LAMBROS CHRIS , BACCHI CYRUS J. , HUTNER S. H.
Published: May 2007

SYNOPSIS

Drug sensitivities of a lower trypanosomatid, Leptomonas sp. from the hemipteran Dysdercus, to antitrypanosomatid agents were estimated by growth inhibition and inhibition of polarographically measured O2 uptake of cells and particulate fractions. Several standard trypanocides, antimalarials, and electron‐transport inhibitors were used. Acriflavine, quinacrine, primaquine, pentamidine, and ethidium, each at ∼1 mM, inhibited cellular O2 uptake by 50% after 3‐hr incubation. Suramin and melarsen were inactive. Crude particulate fractions oxidized L‐α‐glycerophosphate at 80% the rate of succinate oxidation and L‐proline at 55% the succinate rate, leading to choice of succinate as standard respiratory substrate. Concentrations for 50% inhibition of growth were (μg/ml): ethidium bromide 0.009, acriflavine HCl 0.12, Antrycide 0.83, pentamidine diisethionate 1.5, and stilbamidine isethionate 1.1. Possible use of this trypanosomatid as model organism for screening antitrypanosomatid agents, and use of ethidium and acriflavine as initial model compounds are discussed.
Specificity of Amino Acid Transport in Trypanosoma equiperdum*
Authors: RUFF MICHAEL D. , READ CLARK P.
Published: May 2007

SYNOPSIS

Uptake of [14C] alanine, arginine, glutamic acid and phenylalanine by Trypanosoma equiperdum occurred by both a mediated mechanism and diffusion. Twenty amino acids were studied as inhibitors of absorption of the above amino acids. Results suggested that at least 4 distinct transport loci are involved in amino acid transport. These 4 loci have overlapping affinities for amino acids and seem to be involved, respectively, in the absorption of (a) arginine and phenylalanine; (b) arginine; (c) alanine, phenylalanine, and glutamic acid; (d) glutamic acid. The data also showed that multiple sites for substrate binding occur on each of 2 transport systems.
Stentor tartari sp. n. from India
Authors: MURTHY K. V. NARAYANA , BAI A. R. KASTURI
Published: May 2007

SYNOPSIS

A species of Stenior isolated from freshwater ponds and tanks in and around Bangalore, India, showed striking differences from those that have been described so far. The ciliate is red in color and has 2 spherical macronuclei and 2 small micronuclei. On the basis of the nuclear apparatus and pigmentation of the body, it is believed to be a new species, named in honor of Professor Vance Tartar as Stentor tartari. n. sp.
Simple Nutrition of Crithidia deanei, a Reduviid Trypanosomatid with an Endosymbiont*
Authors: MUNDIM MARIA HERMELINDA , ROITMAN ISAAC , HERMANS MARIA A. , KITAJIMA ELLIOT W.
Published: May 2007

SYNOPSIS

Crithidia deanei from the reduviid hemipteron, Zelus leucogrammus, unlike most lower trypanosomatids cultivated in defined medium, required only 2 amino acids, methionine and tyrosine; only 4 vitamins, folic acid, thiamine, biotin, and nicotinamide; and neither hemin nor a purine source. Electron microscopy reveals an endosymbiont, probably bacterial, which presumably provides the other basic trypanosomatid essential nutrients.
Spore Dimorphism in a Microsporidan Isolate*
Authors: FOWLER JERRY L. , REEVES ELDON L.
Published: May 2007

SYNOPSIS

A microsporidan isolate currently considered to represent a mixed infection of Nosema necatrix Kramer, 1965 and Thelohania diazoma Kramer, 1965 was subjected to cultivation in hosts held at various temperatures. The ratio of the Nosema (monospore) to the Thelohania (octospore) forms at these temperatures was found to vary from 1:1 at 16 C to 1:0 at 32 C. Isolation technics using mechanical, temperature and temporal methods separated monosporous from octosporous forms for inoculation purposes. However, microscopic examination of hosts receiving these inocula revealed the presence of both monospores and octospores. Electrophoretic analysis of monospores and monospore‐octospore mixtures indicated equivalent hydrophobic protein spectra. These observations suggest that this isolate has the ability to produce either single spores or spores in groups of eight. This microsporidan was not considered a member of the genus Stempellia since spores in groups of 2 or 4 were not observed. Retention of the name Nosema necatrix Kramer is suggested.
Automatic Cell Counting in Continuous Flow Cultures of Tetrahymena pyriformis*
Authors: RASMUSSEN LEIF , COHR KARL‐HEINZ , BUHSE H. E. , ZEUTHEN ERIK
Published: May 2007

SYNOPSIS

This report describes an electronic cell counter constructed for determining cell number in cultures of the ciliate, Tetrahymena pyriformis. The culture chamber has been equipped with a device which determines the number of cells per unit volume and records the number automatically. As cell multiplication is unaffected by the counting procedure the cells are returned to the culture. Furthermore, keeping the culture volume constant we have arranged a continuous flow of fresh nutrient medium through the culture chamber and thus established conditions under which cell multiplication has continued for months while determinations of cell concentrations have been recorded every 10 min. Since the culture volume has been small, ∼25 ml, growth studies utilizing this method require less than one liter of fresh medium per week in spite of the fast multiplication (9 generations per 24 hr) occurring in cultures of Tetrahymena pyriformis under optimal conditions.
Growth of the Peritrich Opercularia coarctata in Axenic Culture*
Authors: McLAUGHLIN DAVID , JOHNSON GLEN R. , BRADLEY CAROLE J.
Published: May 2007

SYNOPSIS

A synthetic medium for Opercularia coarctata was developed that contains 20 amino acids, 10 vitamins, an 8‐component balanced salt solution, Fe2(SO4)3·(NH4)2SO4·24H2O, Tween 80, stigmasterol, a 7‐component nucleic acid mixture, phenol red as an indicator, and 2,500 U.S.P. units/ml penicillin to maintain sterility. This medium supported axenic survival for 96 hr. Multiple supplements of thioctic acid, niacin, niacinamide, inositol, PABA, oleic acid, and Fe(NO3)2·9H2O instead of Fe2(SO4)3·(NH4)2SO4·24H2O coverted the survival medium into a growth medium, which permitted 36–45 days continuous cultivation of populations in excess of 4 × 103 cells/3.0 ml final volume. Five generations were produced during the 48 hr logarithmic growth period. Serial transfers at 72 hr and during periods of greatest cell density produced a maximum of 8 generations 96 hr after initiation but the medium failed to sustain growth through more than 6 serial transfers. Extension of this investigation to formulating a minimal axenic medium is discussed.
A Fluid System for the Cultivation, Light Microscope Examination and Manipulation of Obligate Anaerobes*
Authors: RITTER HOPE
Published: May 2007

SYNOPSIS

A chamber in tandem with oxygen‐free gas supply and gas‐collecting reservoirs constitutes a system capable of anaerobic maintenance within the range of 0.8–20 μM at 13 C. Cultures contained within the chamber portion of this system are examined through exposed oculars of a microscope otherwise sealed from room atmosphere. Materials are interchanged between the 2 atmospheres through an air lock. Shoulder‐length gloves enable all manipulations common to aerobic cultivation procedures without undue restraint.