bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemotaxis and Sexual Behavior in Chlamydomonas*
Authors: TSUBO YOSHIHIRO 
Published: May 2007

Intraspecific chemotaxis between gametes was demonstrated in Chlamydomonas moewusii Gerloff var. rotunda nov. var. which was previously used as C. sp. 24 (Tsubo Y. 1957). a heterothallic isogamous species from Japan. The reaction is unidirectional; the “+” gametes are attracted by the “—” gametes or cell‐free supernatant of medium in which the :“‐” gametes were suspended. In a study with 4 other isogamous heterothallic Chlamydomonas — C. moewusii Gerloff, C. eugametos Moewus, C. reinhardi Dangeard, and C. morewusii Gerloff var. tenuichloris nov. var. — none of them revealed any intraspecific chemotactic behavior. However, as with the “—” gametes of C. moewusii var. rotunda, both mating types of C. moewusii, C. eugametos, and C. moewusii var. tenuichloris were interspecifically attracted by the supernatant of the “—” culture of C. moewusii var. rotunda. Only C. rein‐ hardi showed no chemotactic behavior in intra‐ or interspecific combinations.Although chemotaxis occurred in the above‐mentioaed combinations, neither agglutination nor pairing ner zygete formation followed at all in the same combinations. The“;–” cells of C. moewusii var. rotunda killed by osmium vaper and then washed no longer produced the chemotactic agent, but did agglutinate with living “+” cells. Therefore, evidently, chemo‐taxis is a separate step from agglutination and zygote‐for‐mation yet does not seem necessary in the mating of isoga‐mous Chlamydomonas. Nonetheless, since this activity appears not in the vegetative but in the gametic stage, it seems to concern the sexual activity of the cells. In preliminary studies the chemotactic agent produced by C. moewusii var. rotunda was shown to be volatile.
A Comparison of Synchronized Cell Division in Protozoa*
Authors: SCHERBAUM OTTO H. 
Published: May 2007

SYNOPSIS. From an equation derived for measuring synchrony in microbial systems, a synchronization index (SI) may be computed, which depends on 3 parameters: (1) fraction of the population undergoing synchronous division; (2) time during which this synchrony of division occurs, and (3) generation time during normal exponential multiplication.Synchronization indices were computed and tabulated for 14 microbial cultures in which cell division was synchronized by different methods. The SI's range from 0.20 to 0.80. In the ideal situation—instantaneous doubling of the cell number in the mass culture—the SI is 1.00.
Glucose Metabolism of Euglena gracilis var. bacillaris; Growth and Enzymatic Studies*
Authors: HURLBERT RONALD E. , RITTENBERG SYDNEY C. 
Published: May 2007

SYNOPSIS. A number of small molecules including CO2, certain Krebs cycle acids and certain amino acids stimulated growth and glucose utilization of a colorless strain of Euglena gracilis in a phthalate‐buffered mineral salts medium. Their major effect was to shorten markedly the lag period; some compounds also gave small increases in maximum growth rate and total cell yield. The stimulatory substances were effective in small (sparking) amounts. It is suggested that all the stimulatory substances acted similarly, by keeping the internal concentration of oxaloacetate at a sufficiently high level to allow effective operation of the terminal respiratory cycle.Glucose utilization was initiated within a pH range of 3.0 to 5.0. This range could be extended by the addition of glycine to the growth medium. Cells cultured at pH 4.5 could be adapted to growth at pH 7.0 in a phosphate‐buffered mineral salts medium containing a small amount of citrate. Neither adaptation nor growth occurred at pH 7.0 in the absence of citrate. Since no evidence of citrate utilization was obtained and since EDTA replaced citrate, it is concluded that citrate was acting as a chelator.The major enzymes of the Embden‐Meyerhof‐Parnas and pentose phosphate pathways were demonstrated in cell‐free extracts. The data presented indicate that glucose metabolism in Euglena is similar to that found in a wide variety of other cells. Indirect evidence was also obtained for the operation of a uridine linked pathway in hexose metabolism.With the exception of hexokinase, for which results were inconsistent, all the enzymes demonstrated were routinely found in the supernatant fraction of the cell‐free extracts. The pH optima of a number of the enzymes were found to be between pH 7.5 and 8.6, although the cells from which the enzymes were obtained were grown in acid medium.
Effect of Type of Carbohydrate on Growth and Protein Synthesis by Tetrahymena pyriformis
Authors: REYNOLDS HOWARD , WRAGG JUNE B. 
Published: May 2007

SYNOPSIS. In chemically defined media at carbohydrate concentrations ≧ 0.5% (w/v) Tetrahymena pyriformis W multiplied more rapidly, developed larger cells, and achieved greater growth as measured by optical density when carbohydrate was provided as dextrin rather than glucose. In media containing 0.3 mg/ml of amino acid nitrogen, growth increased with glucose concentration from 0.1 to 1%, did not change significantly to 3%, and was sharply inhibited at higher glucose levels. With dextrin, maximum growth paralleled carbohydrate concentration from 0.1 to 3%. At higher N levels the inhibitory concentration of glucose was lowered, but growth in dextrin media was not affected except at N concentrations that were inhibitory independent of carbohydrate source. At 1% carbohydrate levels, total cell protein per ml of culture was 60% greater, protein per cell approximately 50% greater, and cells were 1.5 to 2 times larger in media with dextrin than with glucose. Comparable differences in protein synthesis were observed at 2% carbohydrate levels and efficiency of conversion of substrate‐N to protein‐N was greater in the medium with dextrin than glucose.Growth as measured by optical density in media with 0.3 mg/ml of N and 1 or 2% (w/v) of dextrin was not significantly reduced by the simultaneous presence of 1 or 2% glucose. This observation appeared to negate osmotic pressure as an explanation of reduced growth in the presence of glucose. At higher osmolar concentrations osmotic pressure appeared to be a major determinant of overall growth but not of cell size.
Disc Testing of Drugs Against Plated Trichomonas vaginalis*
Authors: SAMUELS ROBERT , STOUDER DONALD J. 
Published: May 2007

SYNOPSIS. Inhibitory activity of a series of drugs has been tested against Trichomonas vaginalis pour‐plated in agar. Drugs were applied in impregnated paper discs on the surface of the agar and activities determined by the presence of surrounding zones without growth. Control discs without drug showed no inhibition of the flagellate's growth.Some relationships of structure to activity were found in a group of substituted nitroimidazoles and nitrothiazoles. Diamidines, except for one with a triazene nucleus, produced little or no effect. Antibiotics varied from very high activity to none; a group of miscellaneous compounds, not quite so widely. Among the antibiotics, thiolutin merits further study as a possible biotin antagonist. Three closely related drugs, one of them known to inhibit cholesterol synthesis in mammals and Protozoa, restricted growth of T. vaginalis.Suggestions are made as to further uses of disc or strip tests with plated trichomonads for studies of nutrition, metabolism, and genetics.
Taxonomic‐Nomenclatural Practices in Protozoology and the New International Code of Zoological Nomenclature*
Authors: CORLISS JOHN O. 
Published: May 2007

SYNOPSIS.All zoologists are affected by provisions in the very recently published International Code of Zoological Nomenclature, the first revised edition of these important rules to appear in over 50 years. Common nomenclatural practices, often malpractices, of protozoologists and parasitologists who work primarily in taxonomic fields are revealed and discussed in light of recommendations and mandatory regulations to be found in the new Code. Some errors have been due solely to carelessness; others have involved misinterpretations of various directives; still others have involved cases not adequately covered by the old Règles. Certain mistakes of the past cannot be changed; but others are to be rectified upon discovery, according to mandates in articles of the new Code. Practical applications of the rules of nomenclature are stressed, and examples are taken from actual situations found to exist throughout all major taxa of the phylum Protozoa.Because of the value of such discussion in both new and revisory work in protozoan systematics, the following major topics are given special consideration: matters of orthography, the original spelling of names and their justified or unjustified emendation; authorships and dates of names, who is responsible and when, and how such data are properly cited; mandatory dates in the new Code, and their effect on both already established names and names not yet proposed; the principles of priority and conservation or continuity, and how the rules attempt to satisfy proponents of both of these diametrically opposed “laws”; the concepts of synonymy and homonymy, and proper methods of treating names which have become involved in such situations; family‐group names, and the several special nomenclatural problems they present to protozoan taxonomists; the major problem of types, and the peculiar position of protozoologists with regard to the type concept, especially type‐specimens for categories in the species‐group; miscellaneous considerations, several unrelated but significant topics not appropriate for inclusion in preceding sections of the paper.
A Mensural Study of Division in Trypanosoma simiae and Trypanosoma congolense
Authors: STEPHEN L. E. 
Published: May 2007

SYNOPSIS. Dividing forms of Trypanosoma simiae and T. congolense in stained thin blood films taken from pigs infected by wild Glossina morsitans submorsitans were measured employing a technique which took account of the distance between the divided kinetoplasts, the positions of the nucleus or nuclei and the lengths of the original and developing flagella.Analysis of these measurements showed that binary fission in these trypanosomes consisted of a gradual increase in the distance between the divided kinetoplasts along the long axis of the body; progressive outgrowth of a daughter flagellum from the blepharoplast associated with the posteriorly placed kinetoplast; migration of the nucleus toward the posterior end of the body; separation of the divided nuclei in the direction of the long axis of the body; and fission of the cytoplasm in an antero‐posterior direction and finally separation into two individuals by a stepped, sliding motion.No evidence to support syngamy or other type of germ cell reproduction was observed.
Experimental Infection of the Hemipteron Oncopeltus fasciatus with Trypanosomatidae Isolated from other Hosts*
Authors: HANSON WILLIAM L. , McGHEE R. BARCLAY 
Published: May 2007

SYNOPSIS. In an effort to determine the degree of host specificity and morphology of the insect trypanosomatids in a presumably foreign host, individuals of a laboratory colony of the hemipteron Oncopeltus fasciatus were given intra‐rectal injections with various species of axenically cultured parasites. Crithidia isolated from the hemipterons Acanthocephala femorata, Euryophthalmus davisi, and Arilus cristatus, as well as those from the dipterons Phaenicia sericata and Culex pipiens, and Crithidia (Strigomonas) oncopelti presumably isolated from O. fasciatus or Asclepias syriaca, demonstrated extensive multiplication whereas a leptomonad from the hemipteron Leptoglossus phyllopus and a blastocrithidian from the hemipteron Euschistus servus underwent little reproduction and disappeared after 8 and 25 days respectively. Another blastocrithidian taken from the hemipteron Melanolestes picipos flourished and has been transferred through 7 generations of O. fasciatus. None of the crithidia were transmitted although numerous flagellates and leishmaniform bodies were observed in the feces of bugs injected with all species.The crithidia in the gut of O. fasciatus were somewhat more elongated than culture forms and this appeared to be particularly marked in the dipteron group. In bugs injected with C. acanthocephali and C. oncopelti a few specimens were seen with the kinetoplast posterior to the nucleus. Leptomonas leptoglossi enlarged markedly when injected into the gut of O. fasciatus and in many organisms the nucleus was displaced to the posterior half of the body. There was no apparent change in the morphology of the two blastocrithidia in this host.Although some minor morphological changes were observed, this work in general supports the view of Wallace that Crithidia is a distinct genus and probably does not represent a stage in the life cycle of other organisms.
Free Amino Acids in Tetrahymenidae
Authors: LOEFER JOHN B. , SCHERBAUM OTTO H. 
Published: May 2007

SYNOPSIS. Free amino acids in extracts of a number of tetrahymenid genera, species and strains of Tetrahymena pyriformis were separated by a combination of paper electrophoresis at pH 1.9 and descending paper chromatography with lutidine as solvent. Ethanol extracts of ciliates cultured at temperatures of either 15°, 25° or 35°C were used. Relative evaluation of ninhydrin spot intensity was made for T. pyriformis strains WH52, UM226, hybrids No. 25, No. 76, PR, HS and N. Extracts from 15° and 25°C cultures of T. limacis, T. setifera HZ1, T. vorax V2, Glaucoma chattoni A and Colpidium campylum C were analyzed in the same way.Seventeen spots were usually found on all chromatograms indicating the presence of the substances alanine, arginine, aspartic acid/asparagine, cysteine/cystine, glutamic acid/glutamine, glycine, histidine, leucine, lysine, methionine, phenylalanine, proline, serine, taurine, threonine, tyrosine and valine. No cysteic acid was demonstrable. Cysteine/cystine, histidine, phenylalanine and taurine generally occur in relatively low concentrations or appear to be absent. Those ranked as generally abundant include aspartic acid/asparagine, arginine, serine and threonine. Spot intensities for the remainder of those listed above indicate they were very abundant in most samples.FAA analyses have now been made by us, including those in a previous report, on tetrahymenid ciliates belonging to 3 genera (Colpidium, Glaucoma and Tetrahymena), on 4 species of Tetrahymena (limacis, setifera, vorax and pyriformis) and on 11 strains of T. pyriformis. Although extracts have been compared from ciliates grown at temperatures of 10°, 15°, 25° and 35°C, no striking differences in the qualitative or quantitative composition of the known amino acids in these patterns were observed. It was not possible to establish correlations with serotypes, and no features that might serve as useful taxonomic criteria were observed.
Fine Structure of the Oral Area of Tetrahymena patula
Authors: MILLER O. L. , STONE G. E. 
Published: May 2007

SYNOPSIS. In axenic culture, the polymorphic ciliate, Tetrahymena patula, consists of two cell types, a small mouthed form (microstome) and a larger carnivorous macrostome both of which possess the tetrahymenal‐type buccal apparatus. With the exception of over‐all size, only minor differences were found in the structure of the oral area of the two cell types.Each of the membranelles, which lie on the left wall of the buccal cavity, consists of three long rows of kinetosomes with attached cilia. A series of parallel fibers originating at the base of the inner row of kinetosomes in each membranelle runs toward the adjacent, lower membranelle or in the case of the third membranelle toward the junction of the left and right walls of the buccal cavity. After a short distance, a portion of each fiber rises and subdivides to form a periodic array of fine fibrils which lie immediately under the pellicle and run parallel with the long axes of the membranelles. The remaining portion of these kinetosomal fibers continues through the cytoplasm to connect with the kinetosomes of the next membranelle.The undulating membrane, which borders the right wall of the buccal overture, consists of a single row of cilia. Examinations of thin sections show, however, that there are actually two rows of kinetosomes in the membrane base. The outer row is ciliated while the inner row of kinetosomes, which are alternately spaced relative to those in the outer row, lies deeper in the cytoplasm and has no cilia. Fibers project straight down from the base of kinetosomes in both rows and join to form a tangled network which underlies the entire length of the membrane.The oral ribs begin near the base of the undulating membrane and descend in decreasing number to the cytopharynx. There is a connection between the fiber system of the undulating membrane and the tips of the oral ribs. The ribs appear in cross section as raised, thickened ridges of the inner pellicular layer with the outer layer adhering only at the top of the ridges. Immediately underlying the oral rib area is a relatively thick differentiated layer composed of fine fibers within a ground substance.
Serological Investigations of Trichomonads. I. Comparisons of “Natural” and Immune Antibodies
Authors: Samuels Robert , Chun‐Hoon Harry 
Published: May 2007

SYNOPSIS. Active, normal sera or other body fluids from many vertebrate species were found to cytolyze Tritrichomonas augusta; heat inactivated sera agglutinated the organisms. Techniques were devised for quantitative determination of “natural” agglutinating and lytic activity against a number of trichomonads. Amphibian, avian, mammalian, and reptilian sera all possessed activity, as did chicken egg yolk, or yolk sac contents, human ascitic fluid, and cow's milk. For individuals of a given species, levels of “natural” agglutinin did not vary significantly. Among donor species, there were wide and consistent differences. The serum of any one individual, tested against 6 strains of T. augusta, showed constant activity. Agglutinating activity was relatively unaffected by changes of physical factors in the reaction milieu. Lytic activity was restored to heat‐inactivated serum by addition of guinea pig serum as a source of complement. When serum was fractionated, agglutinating activity was found primarily in the γ globulins and on into the β. On the basis of these reactions and the activity of specific serum fractions, an antibody mechanism has been postulated.By means of reciprocal agglutination tests with absorbed sera, both “natural” and immune agglutinins have been shown to be specific for Tritrichomonas augusta, T. foetus, and T. suis (?), as well as for Trickomonas gallinarum and Trichomonas vaginalis. Absorption with one species does not remove activity against others. Among strains of T. augusta, absorption with any one removes some antibody against others, but not necessarily all. On the basis of reciprocal absorption and test of 6 strains, 3 antigenic groups have been established: 2 groups are well‐separated; the 3rd intermediate between the others and cross‐reacting with both.Lack of agglutinin absorption by 2 common enterobacteria, a yeast, and Forssman antigen (sheep erythrocytes) showed that these, at least, were not involved as sources of heterophil stimulation for “natural” antibody. Whether “natural” antibody results from heterophil stimulation, however, or is genetically determined, has not been answered. Direct stimulation of “natural” antibody production by occult infection with trichomonads could not have occurred in the case of trichomonad‐free, laboratory reared chicks, or mammalian sera active against T. augusta.
The Riboflavin Requirement and the Effects of Acriflavin on the Fine Structure of the Kinetoplast of Leishmania tarentolae*
Authors: Trager William , Rudzinska Maria A. 
Published: May 2007

SYNOPSIS. Leishmania tarentolae requires at least 10 mμg riboflavin per ml for optimal growth on successive subculture in a denned medium. At this level many organisms are aflagellate or with a short flagellum; higher concentrations of riboflavin did not increase the yield of leptomonads but did increase the proportion with a flagellum at least as long as the body. At limiting levels of riboflavin, acriflavin markedly inhibited growth without producing akinetoplastic forms. With riboflavin at 20 mμ/ml or higher, acriflavin at around 500 mμg/ml permitted an approximately 10‐fold multiplication. Seventy % of the leptomonads formed were akinetoplastic and they could not give rise to subcultures.In electron micrographs of acriflavin‐treated organisms the nucleus was unaffected but the cytoplasmic organelles, notably the kinetoplast and mitochondria, were altered. The mitochondria appeared swollen with their cristae replaced by circular profiles. In the kinetoplast the dense fibrillar material (probably DNA) lost its structure, became diffuse, and eventually disappeared. The observed changes again indicate close relationship between the kinetoplast and the mitochondria of hemoflagellates.
Plistophora myotrophica spec, nov., Causing High Mortality in the Common Toad Bufo bufo L., with Notes on the Maintenance of Bufo and Xenopus in the Laboratory
Authors: CANNING E. U. , ELKAN E. , TRIGG P. I. 
Published: May 2007

SYNOPSIS. Colonies of Bufo bufo kept for pregnancy diagnostic purposes were found infected with a new species of microsporidian, Plistophora myotrophica, causing atrophy of the striated muscles. Lysis of myofibrils by the parasite leads to the formation of fusiform spaces in the fibers packed with microsporidian spores. A cyst wall is not formed. Toads become emaciated and suffer heavy mortality.In experimental infections the sporoplasm hatches in the gut. Fusiform granular bodies, not identifiable as blood cells, are found in the muscle capillaries at 18 days and possibly represent early stages of the parasite. Between 18 and 23 days division of the parasite occurs in the muscle fibers, first by binary fission, then multiple fission and finally by plasmotomy culminating in the formation of sporonts with 16 to 100 nuclei. Separation into sporoblasts precedes spore formation.In old infections phagocytes, which are probably monocytes, infiltrate between the groups of spores and ingest them. Ingested spores which stain differently from their free counterparts, are dead. Muscle regeneration is initiated by the toad, with the formation of long chains of sarcoblasts, sometimes 30 or more in a chain, responsible for the regeneration and redifferentiation of myofibrils.Tadpoles are refractory to infection. As toads normally lead a solitary life the high local incidence in the area from which the toads were collected is explained only if the toads acquire the infection from spore‐contaminated ground in the breeding season.
The Taxonomy of Pyxidiella curvicaula (Penard)
Authors: CURDS COLIN R. 
Published: May 2007

SYNOPSIS. The peritrich Pyxidiella curvicaula (Penard) was observed in the activated sludge of an English sewage works and was successfully cultured in the laboratory.A number of observations were made upon clonal cultures of P. curvicaula which indicated that this species is colonial at one stage in the asexual life cycle. The branching of the colonial adult is more complex than originally described, and a maximum of 17 individuals has been observed upon one stalk.Since P. curvicaula is in reality a colonial peritrich, it should therefore be transferred to the genus Opercularia Stein, with the name of the species changed to Opercularia curvicaula.