bluuebunny/crossref_metadata_2025 huggingface dataset:
The Conversion of Phenylalanine to Tyrosine in Tetrahymena pyriformis*
Authors: MAVRIDES C. , WHITLOW KAREN J. , D'IORIO A.
Published: May 2007

SYNOPSIS. Phenylalanine hydroxylase could not be assayed in extracts of Tetrahymena pyriformis strain W in a system by which the enzyme could be assayed in rat liver extracts. Isotopically labelled phenylalanine, however, was converted to tyrosine by growing or washed cells. Growth conditions which allowed limited synthesis of unconjugated tetrahydropteridine severely reduced the ability of the cells to synthesize tyrosine from phenylalanine. The presence of glucose and acetate in the growth medium resulted in elevated free tyrosine pools and an increased capacity of washed cell suspensions to convert phenylalanine to tyrosine. It would appear that the putative phenylalanine hydroxylation system is not subject to the repressive effects of glucose and acetate which apply to the enzymes of tyrosine catabolism. The significance of this distinction is discussed.
Isonema papillatum sp. n., a New Colorless Marine Flagellate: A Light‐ and Electronmicroscopic Study
Authors: PORTER DAVID
Published: May 2007

SYNOPSIS. Isonema papillatum sp. n. is described from observations with the light and electron microscope. It has 2 short emergent subapical flagella without appendages, a specialized ingestion apparatus, and a nonrigid naked cell body capable of pronounced changes in shape similar to euglenoid movements. It lacks a stigma and flagellar swelling and does not form paramylon granules. The nucleolus persists throughout nuclear division.
Coccidia of Brazilian Snakes: Isospora decipiens, Eimeria micruri, E. liophi and E. leimadophi spp. n., with Redescriptions of Caryospora brasiliensis Carini, 1932 and Eimeria poecilogyri Carini, 1933*
Authors: LAINSON RALPH , SHAW JEFFREY J.
Published: May 2007

SYNOPSIS. Caryospora brasiliensis Carini, 1932 is redescribed in the snake Philodryas olfersi, from Barcarena, Pará State, north Brazil, with some additional observations on the endogenous stages. Isospora decipiens sp. n., is described from the same snake: it develops to maturity in the subepithelial tissues of the small intestine. The oocyst wall is extremely delicate, and only free sporocysts could be found in the feces. Diagnosis depended on histologic sections. Oocysts are estimated at ∼18 × 9 μm: there is no micropyle, oocyst residuum, or polar bodies. The sporocysts are oval and average 10.03 × 8.25 μm; they have no Stieda body, and the residuum is formed of only a few granules. It is suggested that some previous reports of Cryptosporidium in reptiles may have been based on the separated sporocysts of Isospora species, and that histologic confirmation is required to establish their identity. Eimeria micruri sp. n. was found in the coral snake, Micrurus filiformis, from Belém, Pará. Oocysts are of an asymmetrical egg‐shape, average 20.20 × 14.90 μm, and have a very thin, colorless wall of 1 layer. There is no micropyle, oocyst residuum, or polar bodies. Sporocysts are ellipsoid with a small Stieda body, and average 12.80 × 6.60 μn; there is a small sporocyst residuum. Eimeria liophi sp. n. is recorded in the colubrid snake Liophis cobella, also from Belém. The oocysts are spherical to subspherical, averaging 14.53 × 13.83 μm; there is no micropyle, oocyst residuum or polar bodies. Sporocysts are ellipsoid and average 10.20 × 5.50 μm. They have a delicate Stieda body and the sporocyst residuum is composed of fine scattered granules. A redescription is made of Eimeria poecilogyri Carini, 1933 from the snake Leimadophis poecilogyrus from Serra dos Carajás, Pará. An additional new species, Eimeria leimadophi, also is reported from the same snake. Oocysts are spherical to subspherical, averaging 17.09 × 16.64 μm, with a colorless wall of a single layer ∼0.5 μm thick. There is no micropyle, and the oocyst has a large, spherical residuum. Sporocysts are pear‐shaped, with a prominent Stieda body, and average 12.10 × 5.20 μm; the sporocyst residuum is composed of a few small granules.
Blood Parasites of Pekin Robins (Liothrix luteus)*
Authors: MANWELL REGINALD D. , SESSLER GLORIA J.
Published: May 2007

SYNOPSIS. The Pekin Robin (Liothrix luteus) is a species of babbler (Timaliidae) native to Southeast Asia. Except for Plasmodium tenue, a malaria parasite of the subgenus Novyella and much like P. vaughani, with which they are very commonly infected, these birds seem remarkably free of blood parasites. Of 152 birds examined, 4 harbored Leucocytozoon; no infections with Haemoproteus, trypanosomes, Atoxoplasma, or microfilariae were observed. Blood inoculation from 50 Pekin Robins into canaries revealed 3 P. relictum infections. Experimental inoculation of Pekin Robins with no evidence of prior malarial infection, with 6 species of Plasmodium, P. cathemerium, P. circumflexum, P. elongatum, P. octamerium, P. paranucleophilum, and P. vaughani, gave negative results; evidently the birds have a very unusual resistance to malaria (other than P. tenue). Their insusceptibility to P. vaughani is additional evidence of the validity of P. tenue as a species.
Zschokkella floridanae sp. n. (Myxosporidea) from the Goldspotted Killifish, Floridichthys carpio (Günther)*
Authors: RAPACZ ELEANOR , IVERSEN E. S. , FEIGENBAUM DAVID
Published: May 2007

SYNOPSIS. Zschokkella floridanae sp. n. (Myxosporidea) is described from the gall bladder of the goldspotted killifish, Floridichthys carpio, collected in south Florida. The fresh spore is circular to ovoid in front view and irregularly oblong in sutural view. It averages 14.5 in length × 13.3 μm in width. The polar filament, wound 6–8 times, is 55.3 μm when extended.
Effects of High Hydrostatic Pressure on Morphogenesis in Naegleria gruberi (Schardinger)*
Authors: TODD S. R. , KITCHING J. A.
Published: May 2007

SYNOPSIS. The ameboid phase of Naegleria gruberi can be activated to transform to the flagellate phase, and cysts to excyst and transform to the flagellate phase, by a limited treatment with high hydrostatic pressure followed by release. The most effective treatment at 21 G is 45 min at 3500 psi (238 atm), which leads to almost 100% transformation. Following this dose of high pressure, 50% of amebae transform within 55–70 min after release of pressure, and nearly all within 75–120 min. Nearly all cysts hatch and transform within 200–240 min after release. Pressures of 4000 psi (272 atm) and above, and of 1000 psi (68 atm) and below, were ineffective at any duration of treatment.
Leishmania in the Chick Embryo. II. Effects of Inoculum Size, Strain Origin, and Stage Injected and Infectivity of Embryo‐Derived Parasites for Hamsters*
Authors: HOLBROOK THOMAS W. , STAUBER LESLIE A.
Published: May 2007

SYNOPSIS. Amastigotes of Leishmani donovani strains 2S, 3S, 3K, Hm, Gm, and Et were inoculated intravenously into 14‐day chick embryos. The course of infection was followed by examinations of liver impression smears. With strain 33 at 33 C incubation, there was a 29‐fold increase at 6 days postinfection when the inoculum contained ∼4 × 106 amastigotes, but only a ∼6.3‐fold increase when ∼64 × 106 parasites were injected. Infection courses of several geographic strains were compared at 30, 33, and 35 C incubation. Although the results were variable, Sudan strains 2S and 3S appeared to be separate isolations of a single strain. The Burma (Et), Kenya (3K), and Mediterranean (Hm, Gm) strains appeared to be distinct, but confirming evidence of their distinctness should be sought using serologic, epidemiologic, clinical, and biochemical criteria. Strains 2S and 3S multiplied best at 33 C or below, but the embryos usually failed to survive at 28 or 30 C. Multiplication was inhibited partially at 35 C and completely at 37 C.

Inoculation of strain 3S promastigotes into chick embryos resulted in a loss of parasites in 1 hr to 2 days postinfection. Only amastigotes were seen in embryos incubated at 28 and 33 C for 4 days.

Hamsters infected with parasites passaged once in chick embryos died at median postinoculation times that were closely comparable to those noted among hosts infected with amastigotes from hamster spleen.
Experimental Transmission of Trypanosoma numidae Wenyon to Guinea Fowl and Chickens in Tanzania
Authors: FALLIS A. M. , JACOBSON R. L. , RAYBOULD J. N.
Published: May 2007

SYNOPSIS. Trypanosoma numidae Wenyon, 1909 from the peripheral blood of Numida mitrata (guinea fowl) and Gallus domesticus (domestic chicken) underwent change and multiplication in the ornithophilic simuliids, Simulium adersi and a species of the Simulium impukane group, and in the mammalophilic species, Simulium vorax and Simulium nyasalandicum. Trypanosomes appeared in the peripheral blood of guinea fowl and chickens following the experimental transfer of flagellates from these flies.
The Polychlorinated Biphenyls, Aroclors 1248 and 1260: Effect on and Accumulation by Tetrahymena pyriformis*
Authors: COOLEY NELSON R. , KELTNER JAMES M. , FORESTER JERROLD
Published: May 2007

SYNOPSIS. Effects of 2 polychlorinated biphenyls, Aroclor 1248 and 1260, on axenic Tetrahymena pyriformis strain W were investigated and compared with published data on Aroclor 1254. Aroclors 1248 and 1260 at 1 mg/liter in the presence of 0.1% (v/v) polyethylene glycol 200 reduced significantly (P < 0.005) growth rates and 96‐hr populations of T. pyriformis grown at 26 C. Both toxicants were ∼ 0.001 as toxic as Aroclor 1254. Ciliates were exposed for 7 days to concentrated Aroclors 1248 40X, 1254 60X, and 1260 79X over initial concentrations in the media. Accumulation of Aroclors increased with increased chlorination. It is suggested that if levels in the environment reached those used in these studies, the chief ecologic effect of Aroclor 1254 would be reduction of availability of the ciliates as food and as nutrient regenerators, but with Aroclors 1248 and 1260, this effect would be secondary to accumulation of the toxicants by the ciliates. Accumulation of polychlorinated biphenyls by ciliates would permit the toxicants to enter aquatic food chains. Thus the compounds could exert toxic effects at higher trophic levels.
Role of Riboflavin and Certain Amino Acids in the Excystment of Schizopyrenus russelli*
Authors: RASTOGI A. K. , SAGAR P. , AGARWALA S. C.
Published: May 2007

SYNOPSIS. A simple medium, consisting of riboflavin and a mixture of L‐glutamic acid, L‐tryptophan, L‐isoleucine, L‐serine, and L‐proline has been shown to induce rapid and mass scale excystment in Schizopyrenus russelli. Whereas percentage excystment was found to depend on the concentration of riboflavin and amino acids, more than 80% of cysts were found to excyst within 4 hr, when adequate amounts of these were supplied. Several individual amino acids, particularly L‐glutamic acid, L‐tryptophan, and L‐proline, also supported considerable excystment, but riboflavin was always indispensable.
Oxidation of NADH in a Coupled Oxidase‐Peroxidase Reaction and its Significance for the Fermentation in Rumen Protozoa of the Genus Isotricha
Authors: PRINS R. A. , PRAST E. R.
Published: May 2007

SYNOPSIS. Cell‐free extracts of the anaerobic rumen ciliate Isotricha prostoma possess a strong NADH oxidase activity. Evidence for H2O2 as an intermediary product during oxidation of NADH has been obtained. Gatalase activity could not be demonstrated but hydrogen peroxide is removed by a rate limiting NAD peroxidase.

In addition to oxygen several other compounds such as ferricyanide, cytochrome c, menadione and certain dyes may function as electron acceptors during oxidation of NADH. The ferricyanide reductase activity in the Isotricha extracts strongly resembles that of the mitochondrial enzyme from mammalian sources in a number of characteristics.

Partial inhibition of NADH oxidase activity was obtained with the following chelating agents: hydroxylamine, diethyl dithiocarbamate, 2,9‐dimethyl‐1,10‐phenanthroline (DMPH), and 2‐thenoyl trifluoroacetone, whereas citrate, tartrate, pyrophosphate, salicylaldoxime, EDTA and 8‐hydroxyquinoline had no effect. The peroxidase was blocked completely by 0.42 mM DMPH and this inhibitor was used to block the enzyme in whole cells in experiments on oxygen toxicity. The oxidase was largely insensitive to azide, KCN, and uncouplers. Antimycin A and rotenone caused a partial inhibition of the oxidase when added in very high concentrations. ATP formation occurred during oxidation of NADH, and P/O ratios were 0.1–0.35. Addition of small amounts of oxygen to intact ciliates led to a decrease in the production of hydrogen and butyrate, while the production of acetate was increased and no change in the lactate formation was seen. This shift in fermentation end‐products possibly is caused by a competition of oxygen for NADH.
Cochleomeritus emersoni sp. n. (Protozoa, Apicomplexa), a Lecudinid Gregarine from the Pacific Ocean Polychaete Diopatra ornata Moore, 1911*
Authors: LEVINE NORMAN D.
Published: May 2007

SYNOPSIS

The gregarine Cochleomeritus emersoni sp. n. is described from the intestine of the marine polychaete Diopatra ornata from the Pacific Ocean off Point Hueneme, California.
Grellia gen. n. for Eucoccidium of Grell (1953) Preoccupied*
Authors: LEVINE NORMAN D.
Published: May 2007

SYNOPSIS

Grellia
gen. n. is established for the genus Eucoccidium of Grell (1953) preoccupied, and the classification of the apicomplexan order Protococcidiorida Kheisin, 1956 is reviewed, giving diagnoses, type species and a list of species. Grelliidae fam. n. is established for the genera Grellia, Coelotropha, Myriosporides and Defretinella.
Development of Hepatozoon griseisciuri in Cultured Squirrel Cells*
Authors: HENDRICKS LARRY D. , FAYER RONALD
Published: May 2007

SYNOPSIS

Sporocysts of Hepatozoon griseisciuri obtained from laboratory‐reared spiny rat mites (Echinolaelaps echidninus) and laboratory‐reared squirrel mites (Haemogamasus reidi) were made bacteria‐free and incubated in trypsin‐bile for 30 min at 37 C to release sporozoites. Hepatozoon griseisciuri sporozoites were inoculated into monolayer cultures of primary adult squirrel kidney (PSK) cells and cell line cultures of neonatal squirrel kidney (SK), heart (SH), and spleen (SS) cells. Extracellular sporozoites underwent flexing, gliding, and pivoting movements similar to other coccidian sporozoites. Sporozoites entered cells in all the cultures used and were found intracellularly as early as 1 hr and as late as 10 days after inoculation. In SK, SH, and SS cells, development proceeded only to the trophozoite stage. In PSK cells, immature schizonts and mature schizonts containing 12–40 merozoites were present from 5 through 10 days after inoculation. The finding of pairs of intracellular organisms within a single parasitophorous vacuole in PSK cells suggested that endodyogeny or limited schizogony had occurred.
Tracheloraphis haloetes sp. n. (Ciliophora, Gymnostomatida): Description and a Key to Species of the Genus Tracheloraphis
Authors: BORROR ARTHUR C.
Published: May 2007

SYNOPSIS

Tracheloraphis haloetes sp. n. occurred in a water sample from a Bahama industrial salt works (S = 82 ppt). Its measurement, shape, ciliation (pericytostomal, locomotory, and nonmotile), internal structure, and behavior are described. A simple binary key is used to indicate its similarities to and differences from its congeners. The key is based on characteristics of nuclear configuration, glabrous zone morphology, body shape, and patterns of ciliation.
An Electron Microscope‐Cytochemical Method for Differentiating Membranes of Host Red Cells and Malaria Parasites*
Authors: SEED THOMAS M. , AIKAWA MASAMICHI , STERLING CHARLES R.
Published: May 2007

SYNOPSIS

Limiting membranes of malaria parasites and host red cells stain differently when exposed to positively charged iron colloid. Negatively charged red cell membranes avidly bind colloid, whereas parasite membranes do not. This selectivity in colloidal iron uptake by the 2 types of membranes can be utilized as an aid in discerning the amounts of contaminating host cell membranes in “free” malaria parasite preparations and in related cell‐free membrane extracts.
Ultrastructural Architecture and Organization of the Spore Envelope during Development in Thelohania bracteata (Strickland, 1913) after Freeze‐Etching*
Authors: LIU T. P. , DAVIES D. M.
Published: May 2007

SYNOPSIS

An ultrastructural study was made of the spore envelope during development in the microsporidan, Thelohania bracteata. The frozen‐etched outer (convex) face of the relatively thin spore coat in the earliest immature stage of development has a granular structure in regular array. The inner (concave) face bears particles as well as depressions arranged in a net‐like pattern. The mature spore coat has a substructure of numerous microfibers, ∼8 nm in diameter, arranged in a matrix and forming thin layers which run parallel to the spore surface. The mature spore coat possesses both outer and inner limiting layers. The outer (convex) face of the outer limiting layer is granular. The convex face of inner limiting layer bears many particles as well as many long, narrow depressions. The concave face of the inner limiting layer carries many stud‐like projections, ∼40 nm long and 30 nm high, which are complementary to the depressions observed on the convex face. In addition, the concave face has subunits ∼15 nm in diameter, apparently arranged in a hexagonal pattern with a center to center distance of ∼18 nm. The change in size of these projections, depressions, and subunits presumably is related to spore maturation.
DNA and RNA Syntheses by Intraerythrocytic Stages of Plasmodium knowlesi*
Authors: CONKLIN K. A. , CHOU S. C. , SIDDIQUI W. A. , SCHNELL J. V.
Published: May 2007

SYNOPSIS

Incorporation of the nucleic acid precursors, orotic acid, adenosine, thymidine, and uridine, was studied in various stages of intraerythrocytic Plasmodium knowlesi from infected rhesus monkeys. Incubation of the parasitized erythrocytes with the precursors was for 3 hr periods using a plasma‐free culture medium. The samples containing primarily rings, early trophozoites, or late trophozoites incorporated orotic acid, adenosine, and uridine into RNA; however, these stages exhibited negligible or very low levels of incorporation of any of the precursors into DNA. The sample containing late trophozoite and schizont stages incorporated orotic acid, adenosine, and uridine into RNA, and orotic acid, adenosine, and very low levels of thymidine into DNA. These results indicate that DNA synthesis (the S phase of the cell cycle) occurs very close to the time of nuclear division, and that either the G1 or G2 phase is very short in P. knowlesi.

It was also observed that adenosine and orotic acid, 2 precursors which are incorporated into both DNA and RNA, are utilized differently by the intraerythrocytic parasites. Incorporation of orotic acid into RNA and DNA and adenosine incorporation into DNA were continuous for the entire incubation period, whereas incorporation of adenosine into RNA was very low during the last 2 hr of each period. It was further demonstrated that the parasites utilized exogenous uridine for synthesis of RNA, and that the older parasite stages incorporated thymidine into DNA.
Observations sur des Nyctothères des genres Sicuophora de Puytorac & Grain, Metasicuophora gen. n. et Parasicuophora Albaret, Ciliés parasites de Batraciens Anoures
Authors: ALBARET JEAN‐LOUIS
Published: May 2007

RESUME

L'ampoule rectale de quelques Batraciens Anoures d'Afrique et d'Asie héberge 4 espèces de Nyctothères caractèrisèes par la prèsence d'une ventouse sur toute la face infèrieure et une topographie ciliaire presque identique. L'observation des formations squelettiques polysaccharidiques montre que ces èlèments constituent un critère taxonomique complèmentaire ayant une signification phylogènètique, Chez Sicuophora macropharyngea (Bezzenberger 1904) comb. n. et S. xenopi de Puytorac & Grain, 1968, les plaques de la ventouse forment un pavage. Les plaques marginales sont acuminèes. Metasicuophora petteri gen. n., sp. n. est une espèce de grande taille, très aplatie. Les plaques marginales de la ventouse sont èlargies à leur extrèmitè et l'armature squelettique de la face supèrieure est très dèveloppèe. Chez Parasicuophora xavierae sp. n., les èlèments squelettiques de la ventouse sont constituès par des filaments identiques à ceux observès chez P. mantellae Albaret, 1968.

SYNOPSIS

The rectum of several African and Asian anuran amphibians harbors 4 species of nyctotherid ciliates characterized by the presence of a sucker on the entire lower surface, and a nearly identical ciliary distribution. Observations of the skeletal structures made up of polysaccharides indicate that these elements constitute a complementary taxonomic criterion with a phylogenetic significance. In Sicuophora macropharyngea (Bezzenberger 1904) comb. n. and S. xenopi de Puytorac & Grain, 1968, the plaques of the sucker have a pavement‐like arrangement and the marginal plaques are pointed. Metasicuophora petteri gen. n., sp. n. is a large, very flattened species. The marginal plaques of the sucker have terminal enlargements and the skeleton of the upper surface is well developed. In Parasicuophora xavierae sp. n., the skeletal elements of the sucker consist of filaments identical to those observed in P. mantellae Albaret, 1968.
Crystalloid Inclusions in Species of Leucocytozoon, Parahaemoproteus, and Plasmodium*†
Authors: TREFIAK WILLIAM D. , DESSER SHERWIN S.
Published: May 2007

SYNOPSIS

Cytoplasmic vacuoles seen in methanol‐fixed, Giemsa's‐stained ookinetes of Leucocytozoon simondi, Parahaemoproteus fringillae and Plasmodium gallinaceum, when studied with the electron microscope, were found to correspond with crystalloid inclusions of similar structure, particle size, and arrangement. Cytochemical examination of these “crystalloids” revealed their lipid‐protein nature. Morphologically similar inclusions were found also in ookinetes of Leucocytozoon ziemanni and Parahaemoproteus velans. In L. simondi, crystalloid is formed rapidly after fertilization, from amorphous electron dense material seen in mature macrogametocytes. The arrangement and distribution of crystalloids in the zygote, ookinete, oocyst, and sporozoite are described. On the basis of differences in structure and particle size, it is proposed that the crystalloid inclusions in Haemosporina be divided into 2 types. Type I—lipid‐protein in nature, characterized by electron dense irregularly spherical particles, 25–40 nm in diameter, with individual particles not invested by membrane. Type II—probably virus, characterized by electron dense, irregularly spherical, membrane‐bounded particles, with a diameter usually greater than 40 nm.
A Comparative Study of Gametocyte Ultrastructure in Avian Haemosporidia*
Authors: STERLING CHARLES R. , AIKAWA MASAMICHI
Published: May 2007

SYNOPSIS

The fine structure of gametocytes of 3 avian haemosporidian parasites Plasmodium gallinaceum, Haemoproteus columbae, and Leucocytozoon simondi has been studied and compared by electron microscopy. The gametocytes of all 3 species are bounded by a 3‐layered limiting membrane system, possess a cytostome during some portion of their residence within host cells, and their sex can be distinguished by both nuclear and cytoplasmic characteristics. L. simondi differs most significantly from P. gallinaceum and H. columbae in possessing large intranuclear granules, mitochondria associated with pocket infoldings of the nuclear envelope near the atypical centriole complex and compartmentalization of the cytoplasm by segments of closely aligned unit membranes. Further, the cytostome of L. simondi does not appear to be a persistent structure as in the other 2 species and pigment is not present within food vacuoles. L. simondi also is capable of infecting a wider variety of host cells and within leukocytes produces striations of the host nucleus and an apparent spiral banding of the host cell surface. The comparison of P. gallinaceum, H. columbae, and L. simondi gametocytes by electron microscopy leads to the conclusion that Plasmodium and Haemoproteus are more closely related to each other than either of them is on Leucocytozoon.

The terminology used to describe certain organelles within the gametocyte's cytoplasm has been reexamined and the relationship of the nucleolus to parasite maturation also is described.
Differentiation During Encystment and Excystment in Oxytricha fallax*
Authors: GRIMES GARY W.
Published: May 2007

SYNOPSIS

During encystment of Oxytricha fallax, a wall composed of 4 distinct layers, each derived from a different kind of endoplasmic vesicle, is formed between the 2 unit membranes that cover the vegetative cell. Numerous autophagic vacuoles arise in the endoplasm and later (during excystment undergo internal changes comparable to those characteristic of food vacuoles. Mitochondria aggregate into a band. The 2 macronuclei fuse and their nucleoli become homogeneous. Except for the 2 cell membranes, all visible cortical structures, including cilia, kinetosomes, and microtubules, disappear. Despite the absence of visible ciliature in the mature cyst, the various primordia of the normal vegetative ciliature arise during excystment in the same positional relations to one another as is characteristic of developments during cell division.
Incorporation of Radioactive Pyrimidine Nucleosides into DNA and RNA of Eimeria tenella (Coccidia) Cultured In Vitro*
Authors: OUELLETTE CAROL A. , STROUT RICHARD G. , McDOUGALD LARRY R.
Published: May 2007

SYNOPSIS

Autoradiographic methods were used to study the incorporation of tritiated cytidine, thymidine, and uridine into asexual stages of Eimeria tenella cultured in embryonic chick kidney cells. Developing parasites did not incorporate 3H‐thymidine either when host cells were labeled prior to infection or when the cultures were labeled for 30 min, 48–72 hr after infection. Continuous exposure of infected cultures to 3H‐thymidine for up to 18 hr resulted in light labeling of cell cytoplasm and schizonts. 3H‐cytidine and 3H‐uridine were incorporated into parasites developing in cultures that were labeled before infection. When the cultures were labeled for 30 min, 48–72 hr postinfection and fixed immediately, schizonts were labeled lightly with 3H‐cytidine but contained dense accumulations of 3H‐uridine.
Competition of Ethionine and Methionine for Aminoacyl‐tRNA Formation in an In Vitro System from Ochromonas danica*
Authors: ZIV E. , HOCHBERG A. , DEGROOT N. , RAHAT M.
Published: May 2007

SYNOPSIS

Aminoacyl‐tRNA synthetase and tRNA were isolated from the chrysomonad Ochromonas danica. The mutual effect of methionine and ethionine, and the effect of other amino acids on methionyl‐ and ethionyl‐tRNA formation, were tested in an in vitro system.

The tRNAMet had a similar accepting capacity for either methionine or ethionine. Ethionine and methionine, but none of the other amino acids tested, competed for the same aminoacyl‐tRNA synthetase. The Km of methionine was 0.88 × 10–5 M, and that of ethionine 5 × 10–4 M. Ethionine inhibited methionine binding; Ki 3.4 × 10–4 M. The respective values in a similar system isolated from E. coli were 2.2 × 10–5, 1.95 × 10–3, and 1.95 × 10–3.
Selenidium fauchaldi sp. n. and S. telepsavi (Stuart) comb. nov. (Protozoa, Apicomplexa), Gregarines from Polychaetes*
Authors: LEVINE NORMAN D.
Published: May 2007

SYNOPSIS

Gregarine Selenidium fauchaldi sp. n. is described from the intestinal lumen of the polychaete Phragmatopoma californica (Fewkes, 1889) in the intertidal zone of the Pacific Ocean on Santa Catalina Island, California. In addition, the new combination Selenidium telepsavi (Stuart, 1871) comb. nov. is introduced for the gregarine originally described as Monocystis telepsavi from the polychaete Telepsavus castarum in the Black Sea.
Microsporidian Parasites of Trematode Larvae from Aquatic Snails in West Malaysia
Authors: CANNING ELIZABETH U. , FOON LAI PENG , JOE LIE KIAN
Published: May 2007

SYNOPSIS

In a survey of microsporidian parasites of trematode larvae of Malaysian fresh‐water snails, species of Nose‐matidae were found 7 times in rediae from 425 Lymnaea rubiginosa, 6 times in rediae from 97 Indoplanorbis exustus and not at all in other snails. There were 3 species of Microsporida in all: one, found in Echinoparyphium dunni, Echinostoma hystricosum and Echinostoma malayanum was identified as Nosema eurytremae Canning; another, which was found in E. dunni and Echinostoma audyi, had paired nuclei (diplokaryon form) in sporogony only and was named a new species, Nosema vasicola sp.n.; the 3rd, from E. hystricosum, lacked diplokaryon nuclei throughout development, was considered to belong to a new genus and was named Unikaryon piriformis gen.n., sp.n. Nosema eurytremae was transmitted experimentally to Fasciola hepatica rediae in Lymnaea truncatula.
Khawkinea quartana, a Colorless Euglenoid Flagellate. I. Ultrastructure
Authors: SCHUSTER FREDERICK L. , HERSHENOV BETTY
Published: May 2007

SYNOPSIS

Khawkinea quartana, a naturally occurring colorless homologue of Euglena, was examined with the electron microscope. The organism is biflagellate though only one of the 2 flagella emerges from the anterior reservoir. The pellicular strips covering the body of the organism are supported by microtubules which are continuous in part with microtubules bordering the reservoir. Additional rows of microtubules are found associated with the kinetosomes. An eyespot is located in the wall of the reservoir and, adjacent to it, the contractile vacuole.

The nucleus, mitochondria, and Golgi complexes are similar to those described in other euglenoid flagellates. The food reserve is paramylon.

The study supports the phylogenetic origin of Khawkinea from pigmented Euglena through the loss of chloroplasts.
The Differentiation of Herpetomonas megaseliae: Ultrastructural Observations*
Authors: JANOVY J. , LEE K. W. , BRUMBAUGH J. A.
Published: May 2007

SYNOPSIS

Ultrastructure of both undifferentiated (promastigote and paramastigote) and differentiated (opisthomastigote) forms of Herpetomonas megaseliae is described. There is a posterior migration of the kinetoplast at the end of the exponential growth phase. The posterior extension of the flagellar pocket precedes migration of the kinetoplast. Opisthomastigotes have an electron‐translucent mitochondrial matrix in comparison with undifferentiated forms. The Golgi body changes from a stack of flattened sacs to an aggregation of vesicles. Several structures previously reported from Trypanosomatidae, e.g. subpellicular organelles, pellicular microtubules, membrane whorls, stored metabolic products, surface blebs, and an intraflagellar body are also present in H. megaseliae.
Ultrastructure et Evolution Nucléaire des Trophozoïtes d'une Grégarine d'Ephéméroptère: Enterocystis fungoides M. Codreanu
Authors: DESPORTES ISABELLE
Published: May 2007

RESUME

La structure fine du trophozoïte d'Enterocystis fungoides est voisine de celle décrite chez d'autres Grégarines (Gregarinidae, Stylocephalidae): l'épicyte, la structure fibrillaire de l'ectocyte, les organites cellulaires et les enclaves (amylopectine, mucopolysaccharides) leur sont comparables.

Les caractères plus spécifiques sont: (A) l'involution de l'épicyte entre les trophozoïtes associés, due, semble‐t‐il, à l'appariement très précoce de ces trophozoïtes. (B) les évaginations de l'enveloppe nucléaire. Ce bourgeonnement nucléaire semble en rapport avec l'anabolisme de la jeune Grégarine, cellule en croissance semblable à l'ovocyte par maints caractères: augmentation considérable des dimensions du noyau et du nucléole, accumulation de ribosomes et de substances de réserve dans le cytoplasme.

SYNOPSIS

The fine structure of the trophont of Enterocystis fungoides does not differ widely from the ultrastructural organization described in other Gregarines (Gregarinidae, Stylocephalidae). The epicyte, the fibrillar structure of the ectocyte, the cell organelles and inclusions (paraglycogen = amylopectin, mucopolysaccharides) are similar.

Its specific peculiar features are the following: (A) The involution of the epicyte between the biassociative trophonts, due to their early pairing. (B) The evaginations of the nuclear envelope. It seems advisable to connect this nuclear budding with the anabolic activity of the young gregarine, a developing cell similar in many features to an ovocyte: increasing of the size of nucleus and nucleolus, accumulation of ribosomes and reserve substances in the cytoplasm.
Galvanic Stimulation of Volvox globator I. Electroosmotic Patterns Associated with the Ion Exchange Properties.
Authors: WIRT NATHANIEL S.
Published: May 2007

SYNOPSIS

Application of direct electric potentials across immobilized Volvox globator colonies produced patterns in the ambient solution that were observable by dark field microscopy by the use of polystyrene spheres in the medium. Two large elliptical swirls occurred immediately adjacent to the colony nearest the anode. A clear area developed outwards from the cathodal side of the colony. Since similar patterns were obtained with live, dead, and deflagellated colonies, it was assumed that the phenomena were purely physical. The electric potential induced an electroosmosis in the glass stimulation chamber. Live or dead colonies, immobilized by being secured with a glass coverslip, experienced an anodal movement of water and associated polystyrene spheres. The electroosmosis gave rise to solution patterns which were shown not to be the result of hydrostatic pressure (turbulence) or thermal convection currents. When anion‐exchange beads were substituted for colonies in the stimulation chamber, application of the electric potential produced a smooth laminar flow around the positively charged beads. Cation‐exchange beads, on the other hand, produced 2 large anodal swirl patterns. Clearly, the colony surface behaved like a weakly charged cation exchanger. Other investigators have determined that the cell walls of pond water plants and algae are negatively charged and have ion‐exchange abilities. The negatively charged Volvox cell wall caused an electroosmosis in the colony, in the cathodal direction. Previous explanations for the galvanotaxis of Volvox are not adequate because they do not take into account the negatively charged cell wall.
Galvanic Stimulation of Volvox globator II. Mechanism of Galvanic Response, an Effect of Calcium Displacement
Authors: WIRT NATHANIEL S.
Published: May 2007

SYNOPSIS

Slight increases or decreases in calcium ions in solutions which supported the growth of Volvox globator colonies caused the colonies to fall to the bottoms of their containers. High speed cinematography (600 frames/sec) showed that the flagella beat normally (21/sec) in balanced electrolyte solutions which have calcium concentrations between 0.5 and 1.0 mM. When colonies were placed in 10.0 or 0.0 mM CaCl2 solutions, flagellar beating disappeared within 1 hr. The cessation of flagellar beating was reversible when colonies were replaced in the balanced solution.

The Volvox cell wall has been shown to be a fairly good cation‐exchanger with calcium ions acting as the counterion to the fixed negative change. Colonies that were photopositive and gave a cathodal galvanotaxis responded to DC electrical potentials by producing solution patterns that were indicators of colony electronegativity. Colony resistance to electroosmotic flow was compared in potassium and calcium solutions. When colonies were placed in darkness for 24 hr and stimulated by DC electrical potentials, their cation‐exchange properties became reduced and the cell walls appeared thinner. Application of a high DC electrical potential to dark‐adapted colonies caused the colonies to shrink on their anode sides (anodal contraction).

Other workers have found that the flagella on the anodal sides of dark‐adapted colonies ceased beating during DC electrical stimulation. It is hypothesized that the electric current caused an increase of calcium ions on the anodal side of the colony that inhibited the flagellar mechanism of beating on that side.

It is also hypothesized that the galvanotaxis associated with light‐adapted (photopositive) colonies was due to calcium displacements in the colony cell walls that affected the flagellar beating on both sides of the colony.
Analysis of the Antigenic Relationships Among Trichomonas, Histomonas, Dientamoeba and Entamoeba III. Immunoelectrophoresis Technics*
Authors: DWYER DENNIS M.
Published: May 2007

SYNOPSIS

Antigens prepared from Trichomonas gallinae, Histomonas meleagridis, Dientamoeba fragilis, Entamoeba invodens and Entamoeba histolytica were separated by electrophoresis in agar gels and reacted with antisera prepared in rabbits against each of the 5 species. The most numerous and strongest precipitin lines were obtained from reactions between the homologous antigens and antisera. Direct and cross‐absorption reaction methods were employed with each antiserum and the various antigens to ascertain quantitatively the immunologic relationships among the several organisms. Trichomonas shared many common antigens with Histomonas, fewer with Dientamoeba and none with either species of Entamoeba. Histomonas was more closely related antigenically to Dientamoeba than to Trichomonas. The histomonad had only a few weakly cross‐reacting antigens in common with the 2 Entamoeba species. Dientamoeba shared the most common antigens with Histomonas, fewer with Trichomonas and the fewest with Entamoeba. Somewhat stronger cross‐reactivity was obtained with anti‐Dientamoeba serum and E. invadens than between this immune serum and E. histolytica. The 2 species of Entamoeba shared the largest number of common antigens with each other, and to a much lesser extent both species cross reacted with Dientamoeba. Anti‐Entamoeba sera had only a few weak cross‐reacting precipitins with Histomonas. No antigenic relationship was found between either species of Entamoeba and Trichomonas.
Biosynthesis of Choline and Ethanolamine Phospholipids in Crithidia fasciculata*
Authors: PALMER F. B. ST. C.
Published: May 2007

SYNOPSIS

The incorporation of radioactivity from [1,2‐34C]choline, [1,2‐34C]ethanolamine, [3‐14C]serine and [methyl‐14C]methionine into lipids was studied in growing cultures of Crithidia fasciculata. Lecithin was formed both from choline and by the methylation of phosphatidylethanolamine. Mono‐ and dimethylphosphatidylethanolamines were present in no more than trace amounts. Growth of the protozoa in media containing choline (1 mM) did not decrease synthesis by the methylation pathway. Phosphatidylethanolamine was formed from ethanolamine. Radioactivity from serine also was present in both phosphatidylethanolamine and lecithin; however, the presumed intermediate, phosphatidylserine, could not be detected.
The Mitochondria of Pre‐Erythrocytic Plasmodium berghei
Authors: TERZAKIS J. A. , VANDERBERG J. P. , HUTTER R. M.
Published: May 2007

SYNOPSIS

Considerable sectioning was required to demonstrate the mitochondrial cristae of pre‐erythrocytic Plasmodium berghei in rat liver. The cristae vary from thin, budding tubules to dilated cisternae and most are obliquely and tangentially sectioned. These factors give the impression of an unusually small number of cristae. Numerous variations of fixation protocols failed to alter significantly the appearance of pre‐erythrocytic parasite membranes. The data confirm previous suppositions that certain cytoplasmic bodies noted in pre‐erythrocytic mammalian malarial parasites are indeed mitochondria. The term “acristate mitochondria” should be used with great caution in that it raises a serious semantic problem.
The Structure and Origin of Mastigonemes in Ochromonas minute and Monas sp.*
Authors: HILL F. G. , OUTKA D. E.
Published: May 2007

SYNOPSIS

Structure, function, and development of mastigonemes (flagellar hairs) of 2 chrysophycean flagellates were examined with light and electron microscopy in whole mount and sectioned preparations. Mastigonemes of both organisms are identical, consisting of a tapered base 0.25–0.3 μm long, maximum width of 0.03 μm; a hollow shaft 0.85 μm × 23 nm; and 2 types of laterally projecting filaments. Two rows of mastigonemes are attached to the long flagellum, one on each side in the same plane as the central pair of microtubules. One row is composed of single mastigonemes while the other bears them in “tufts.” The primary mastigonemal attachment is on the flagellar membrane. Developmental sequences as supported by electron micrographs and kinetic studies demonstrate the intracellular location of promastigonemes during reflagellation, colchicine‐inhibited reflagellation, and release from inhibition. The promastigonemes first appear in the peri‐nuclear space in association with the outer nuclear membrane and several dozen may accumulate there. These may pinch off as bundles and move into the cytoplasm, or if mastigonemes are being utilized rapidly by the cell, the promastigonemes are channeled a few at a time from the perinuclear space into the Golgi apparatus where some structural modifications are made. The mastigonemes are then transported in Golgi‐derived secretory‐type vesicles to the cell surface near the base of the growing flagellum where the vesicle membrane fuses with the plasma membrane and the mastigonemes become extracellular, although the membrane association is retained. The origin of the asymmetric arrangement of mastigonemes on the flagellum is discussed.
An Infectious Agent Associated with Amebas of the Genus Naegleria*
Authors: DUNNEBACKE T. H. , SCHUSTER F. L.
Published: May 2007

SYNOPSIS

A study of amebas of the genera Naegleria, Acanthamoeba, Polysphondylium, and Didymium shows that a cytopathogenic agent that is filterable and passageable is present only in the strains of the Naegleria whether they are obtained free‐living from soil samples (N. gruberi) or as pathogens from humans (N. fowleri). The agents obtained from the different Naegleria strains are similar in amount and in their cytopathogenic interaction with chick cultures. The agent has characteristics that distinguish it from the known viruses.
Phosphorus Regeneration in Fresh‐Water Paramecia*
Authors: BUECHLER D. G. , DILLON R. D.
Published: May 2007

SYNOPSIS

Turnover rates of soluble phosphorus (P) by Paramecium multimicronucleatum were compared under 3 temperature regimes. Phosphorus uptake by this heterotroph was almost completely dependent on consumption of bacteria rather than direct uptake of soluble 32PO4. Phosphorus uptake rates by P. bursaria when in its autotrophic state (a symbiotic relationship with zoochlorellae) and when in its heterotrophic (bacteria feeding) state were also compared. Paramecium bursaria showed a much higher uptake of P when large numbers of labeled bacteria were present than when they were absent. Phosphorus turnover rates by P. bursaria were determined and compared with those of P. multimicronucleatum. These ciliates showed remarkably rapid turnover rates for soluble P. In each case turnover rates were universely related to biomass. Ciliates, although small, have very high metabolic rates and therefore may be important for nutrient regeneration in our fresh‐water lakes, streams, and ponds.
Induction of Temperature Sensitivity in Paramecium aurelia by Nitrosoguanidine*
Authors: HIPKE HUBERTUS , HANSON EARL D.
Published: May 2007

SYNOPSIS

Paramecium aurelia cells were exposed to N‐methyl‐N‐nitroso‐N′‐nitroguanidine for periods of 15–30 min. The lethality in homozygous clones derived from treated cells depends on the time of treatment within the cell cycle. Exposures at interfission ages 0.04, 0.40, and 0.80 were tested yielding lethalities of 12.5, 44 and 2%, respectively. These results correlate with the period of DNA synthesis in the micronuclei. A temperature sensitive mutant has been found which cannot live at 31 C but divides at ∼1 fission per day at 19 and 25 C. The rise in temperature from 19–25 C does not significantly change the fission rate whereas in normal cells it would be doubled. Genetic analysis shows that this mutation is caused by a single recessive gene.
Mutations Affecting the Trichocysts in Paramecium aurelia. I. Morphology and Description of the Mutants*
Authors: POLLACK SIDNEY
Published: May 2007

SYNOPSIS

Six types of genic mutants have been isolated. Their phenotypes range from animals with no trichocysts (trichless), to animals with morphologically abnormal trichocysts (football, stubby, pointless, screwy‐cigar), to animals which are incapable of extruding otherwise normal looking trichocysts (nondischarge). The football mutant possesses football‐shaped trichocysts, which, unlike wild‐type trichocysts, do not attach at the cortex. The stubby mutant possesses shorter trichocysts which have a very highly variable morphology. The screwy‐cigar animals have thinner and usually longer trichocysts than those found in wild‐type cells. The trichocysts of the pointless mutant have all the components of the wild‐type organelles but not in their proper relationship. Electron microscopic studies of the mutants have demonstrated that although the morphology of the various mutant trichocysts may differ, their ultrastructure and early developmental stages are comparable to those of trichocysts found in wild type. The mutations are usually pleiotropic, affecting other systems besides trichocysts. The existence of these mutants, particularly trichless, poses some interesting questions regarding the function of trichocysts, and also gives insight into the development of trichocysts.
The Molecular Biology of Euglena gracilis IX. Amino Acid Pool Composition
Authors: KEMPNER E. S. , MILLER J. H.
Published: May 2007

SYNOPSIS

The amino acid composition of the acid soluble fraction of Euglena gracilis was determined from cells grown in 4 different culture media. Glutamic acid is the major free amino acid. Hydrolysis of this fraction increases the amount of free amino groups, the major amino acids found are then glutamic acid, aspartic acid, glycine and arginine. The pattern of amino acid distribution is similar in all 4 culture media.

L‐arginyl‐L‐glutamine was isolated and identified in extracts from all 4 culture conditions. It was shown to be a metabolic intermediate by radioactivity chase experiments.
Thymidylic Acid Synthesis in Eimeria tenella (Coccidia) Cultured In Vitro*
Authors: OUELLETTE CAROL A. , STROUT RICHARD G. , McDOUGALD LARRY R.
Published: May 2007

SYNOPSIS

The source of thymidylic acid for DNA synthesis in 1st generation stages of Eimeria tenella cultured in vitro was investigated using 5‐bromo‐2′‐deoxyuridine, a thymidine analog, and 5‐fluoro‐2′‐deoxyuridine, an inhibitor of de novo thymidylic acid synthesis. Results show that the parasite is unable to utilize either exogenous thymidine or 5‐bromo‐2′‐deoxyuridine but is dependent upon the methylation of deoxyuridylic acid via the thymidylate synthetase reaction to supply thymidine for DNA synthesis.
Dihydrofolate Reductase in Plasmodium lophurae and Duckling Erythrocytes*
Authors: PLATZER EDWARD G.
Published: May 2007

SYNOPSIS

Dihydrofolate reductase activity in duckling erythrocytes was found to be low, while activity in erythrocytes heavily infected with small uninucleate trophozoites was like that of uninfected erythrocytes. Activity of the enzyme in erythrocytes infected with large multinucleate parasites, however, was greatly increased. This activity was 5 times higher in erythrocyte‐free large trophozoites than in small ones. The dihydrofolate reductase of P. lophurae differed from the host enzyme in: greater molecular weight; higher sensitivity to pyrimethamine inhibition; pH optimum; substrate and cofactor specificity; and stimulation by salts. The parasite enzyme was partially purified by ammonium sulfate precipitation.