DOCSLIB.ORG

Control of Flagellum Number in Naegleria Temperature Shock Induction of Multiflagellate Cells

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Control of Flagellum Number in Naegleria Temperature Shock Induction of Multiflagellate Cells jf. Cell Sci. 7) 463-481 (1970) 463 Printed in Great Britain CONTROL OF FLAGELLUM NUMBER IN NAEGLERIA TEMPERATURE SHOCK INDUCTION OF MULTIFLAGELLATE CELLS A. D. DINGLE Department of Biology, McMaster University, Hamilton, Ontario, Canada SUMMARY This paper describes the production of supernumerary flagella by flagellates of Naegleria gniberi exposed to sublethal temperature shocks during the amoeba-to-flagellate transforma- tion. When transformed at any constant temperature below 34 CC, cells of N. gniberi strain NB-i may develop from 1 to 4 flagella, but biflagellate cells predominate and the average number of flagella per cell in these populations is approximately 22. Populations exposed to a 38 °C temperature shock during transformation develop about twice as many flagella as controls (average number of flagella per cell is approximately 4's). The individual response of cells is extremely heterogeneous: some develop no more than the normal 2 flagella, whereas others develop as many as 18. At least half the cells produce 5 or more flagella, as opposed to fewer than 1 % with 5 or more flagella in control populations. Multiflagellate cells and popula- tions are normal in appearance, apart from the excess flagella and resulting disorientation of the normal swimming pattern. The supernumerary flagella, their basal bodies and the rhizoplast (which is also occasionally doubled) are indistinguishable from those of normal cells. Maximal production of flagella occurs over the narrow temperature range from 37-5 to 385 °C and is related to the duration of exposure to a given temperature: optimal flagellum induction is ob- tained following a 45-50 min exposure to a 38-2 °C temperature shock. After approximately 1 h the flagellates revert to amoebae, losing both normal and supernumerary flagella. Populations of these amoebae followed through 2 more cycles of retransformation and reversion developed the normal number of flagella (22). Clones isolated from multiflagellate populations were identical to normal populations, developing approximately 2-1 flagella per flagellate at normal temper- atures and 45 flagella per flagellate when temperature shocked again. INTRODUCTION Both the number and the distribution of cilia and flagella on eucaryotic cells are subject to enormous variation. For example, flagella are often found singly as on many protistan cells, on virtually all sperm cells and on the retinal rods of photoreceptors. They are frequently paired, as on other protistan cells, on epithelio-muscular cells of coelenterate gastroderm, and on cells of the rat adenohypophysis. Several or even thousands of flagella may be present on a single cell, as in the case of polymastigote flagellates, ciliates, sperms of ferns and cycads, and in the ciliated epithelia of both vertebrates and invertebrates. This extreme variability in the number and distribution of flagella raises intriguing questions about cellular differentiation and regulation at the organelle level. One such question concerns the nature of the controls which direct the development 464 A. D. Dingle of precisely one flagellum on mammalian spermatozoa (Fawcett, 1958), two flagella on cells of mammalian adenohypophysis (Wheatley, 1967), and hundreds of cilia on the ciliated epithelium of mammalian trachea (Dirksen & Crocker, 1966) or lung (Sorokin, 1968). In multicellular organisms these are developmental controls in which each different length, function and distribution is expressed against a constant genetic background. In the case of many unicellular organisms, so precise is the genetic control of flagellum number and distribution that these parameters often constitute important criteria for taxonomic characterization. Many examples come to mind, such as Monas and Polytoma with 1 flagellum, Chlamydomonas and Bodo with 2 and Tetramitus, Hexamitus and Octamitus with 4, 6 and 8 flagella respectively. Consider also the following comment on the classification of chrysomonad flagellates (Hall, 1953): 'on the basis of flagellar equipment, four families have been created: Chromulinidae, with one flagellum; Syncriptidae, with two equal flagella; Ochromonididae, with one long and one short flagellum; and Prymnesiidae, with three flagella.' Despite many such examples of rigorous controls over flagellum number, there have been repeated observations of cells with unusual numbers of flagella, for example mammalian sperm tails with double axonemes (Fawcett, 1961), and the atypical multiflagellated sperms of the snail Viviparus (Gall, 1961). Furthermore, the cells of many species routinely have variable numbers of flagella: newly flagellated swarm cells of the myxomycete Didymium nigripes possess only one flagellum but after several hours may develop a second (Kerr, i960). More impressive is the transition in which virtually all cells of mammalian foetal lung—whether fibroblast, chondrocyte, myo- cyte, mesothelial cell or epithelial cell—initially develop single 'primary' or (9 + 0) cilia. Later, only those cells of the maturing lung which differentiate into the epithelial border develop 250-300 basal bodies and cilia (9 + 2) apiece (Sorokin, 1968). The flagellates of Naegleriagniberi have been described as possessing predominantly 2 (Alexieff, 1912; Wilson, 1916) or predominantly 4 flagella (Willmer, 1956). Normal flagellate populations of the NB-i strain are composed of cells bearing from 1 to 4 flagella and, very rarely, exceptional cells are seen with 5 or more (Fulton & Dingle, 1967; reviewed in Fulton, 1969). During an investigation of temperature effects on the rate of Naegleria transformation it was noticed that among the reduced numbers of cells which developed flagella at sublethal temperatures (approximately 40 °C), there was a significant increase in the proportion of cells which produced 3, 4 or more flagella. At that time it was realized that the amoeba-to-flagellate transformation of Naegleria presented a near unique system with which to study the development of the centriole-like basal bodies in cells which have no visible centriole precursor. This is a particularly intriguing possibility in the light of the commonly accepted generaliza- tion that centrioles and basal bodies develop only in association with pre-existing centriole-like templates. However, because of their small size and limited number, centrioles are not easily visualized in cells, either by light or electron microscopy. Some means of either enhancing the resolution or increasing the number of centrioles and basal bodies is therefore a prerequisite for the elucidation of the developmental sequence by which these organelles arise. This paper presents such a method, based on a sublethal temperature shock, which Control of flagellum number in Naegleria 465 induces the development of approximately double the normal complement of basal bodies and flagella in transforming populations of Naegleria. The appearance and behaviour of the multiflagellate cells and their flagellar apparatuses are compared with those of normal biflagellate cells, and the longevity and heredity of the excess flagella and basal bodies are discussed in the light of the supposed continuity of centrioles and basal bodies from one cell generation to the next. Subsequent reports (A. D. Dingle, in preparation; C. Fulton & A. D. Dingle, in preparation) will describe the effects of environmental variables on the induction of excess flagella, and the use of these 'hairy' populations in studies of the development and continuity of basal bodies in Naegleria. A preliminary report of this work has been published (Dingle, 1967). MATERIALS AND METHODS Petri-dish cultures of Naegleria gruberi strain NB-i were grown at 34 °C on nutrient agar (NM) in association with the bacterium Aerobacter aerogenes, as described by Fulton & Dingle (1967). Cells from early stationary-phase cultures were suspended in 0-002 M tris (hydroxy- methyl) aminomethane (tris) buffer, pH 74, washed free of bacteria by differential centrifuga- tion using the method C described by Fulton (1969), and resuspended in tris at final cell densities of 5-10 x io5/ml. Aliquots of 15-20 ml of these suspensions were dispensed into unstoppered 125-ml Erlenmeyer flasks and shaken at 100 2-5-cm strokes per min under various temperature regimens as described in the Results section. Particular care was taken to control water baths to within ±o-i °C of any reported experimental temperature. Cell densities were determined by diluting aliquots of the suspension into a large volume of electrolyte (04% NaCl), agitating vigorously and counting in a Model F Coulter counter at threshold 20 (attenuation 2; aperture current 64). Mean cell volumes were likewise determined by threshold sizing with the Coulter counter which had been previously calibrated in cubic micrometres per threshold division (Sheldon & Parsons, 1967) against direct measurements made on 1000 NB-l cyst diameters using a Nikon filar micrometer eyepiece. At intervals, samples of transforming cells were fixed and stained in Lugol's iodine at a ratio of 4 drops cell suspension to 1 drop fixative. Using phase-contrast optics at 500 x magnification, the percentage of flagellated cells (%F) was determined for samples of 100 cells, and counts of the average number of flagella per cell (f/F) were made on samples of at least 300 flagellates. Light-microscope photomicrographs of iodine-fixed flagellates were taken using phase- contrast optics and Ilford FP-4 film in a Nikon EFM semi-automatic camera attachment. For electron microscopy, cell suspensions
Load more

Recommended publications
  • The Intestinal Protozoa
    The Intestinal Protozoa A. Introduction 1. The Phylum Protozoa is classified into four major subdivisions according to the methods of locomotion and reproduction. a. The amoebae (Superclass Sarcodina, Class Rhizopodea move by means of pseudopodia and reproduce exclusively by asexual binary division. b. The flagellates (Superclass Mastigophora, Class Zoomasitgophorea) typically move by long, whiplike flagella and reproduce by binary fission. c. The ciliates (Subphylum Ciliophora, Class Ciliata) are propelled by rows of cilia that beat with a synchronized wavelike motion. d. The sporozoans (Subphylum Sporozoa) lack specialized organelles of motility but have a unique type of life cycle, alternating between sexual and asexual reproductive cycles (alternation of generations). e. Number of species - there are about 45,000 protozoan species; around 8000 are parasitic, and around 25 species are important to humans. 2. Diagnosis - must learn to differentiate between the harmless and the medically important. This is most often based upon the morphology of respective organisms. 3. Transmission - mostly person-to-person, via fecal-oral route; fecally contaminated food or water important (organisms remain viable for around 30 days in cool moist environment with few bacteria; other means of transmission include sexual, insects, animals (zoonoses). B. Structures 1. trophozoite - the motile vegetative stage; multiplies via binary fission; colonizes host. 2. cyst - the inactive, non-motile, infective stage; survives the environment due to the presence of a cyst wall. 3. nuclear structure - important in the identification of organisms and species differentiation. 4. diagnostic features a. size - helpful in identifying organisms; must have calibrated objectives on the microscope in order to measure accurately.
    [Show full text]
  • That of a Typical Flagellate. the Flagella May Equally Well Be Called Cilia
    ZOOLOGY; KOFOID AND SWEZY 9 FLAGELLATE AFFINITIES OF TRICHONYMPHA BY CHARLES ATWOOD KOFOID AND OLIVE SWEZY ZOOLOGICAL LABORATORY, UNIVERSITY OF CALIFORNIA Communicated by W. M. Wheeler, November 13, 1918 The methods of division among the Protozoa are of fundamental signifi- cance from an evolutionary standpoint. Unlike the Metazoa which present, as a whole, only minor variations in this process in the different taxonomic groups and in the many different types of cells in the body, the Protozoa have evolved many and widely diverse types of mitotic phenomena, which are Fharacteristic of the groups into which the phylum is divided. Some strik- ing confirmation of the value of this as a clue to relationships has been found in recent work along these lines. The genus Trichonympha has, since its discovery in 1877 by Leidy,1 been placed, on the one hand, in the ciliates and, on the other, in the flagellates, and of late in an intermediate position between these two classes, by different investigators. Certain points in its structure would seem to justify each of these assignments. A more critical study of its morphology and especially of its methods of division, however, definitely place it in the flagellates near the Polymastigina. At first glance Trichonympha would undoubtedly be called a ciliate. The body is covered for about two-thirds of its surface with a thick coating of cilia or flagella of varying lengths, which stream out behind the body. It also has a thick, highly differentiated ectoplasm which contains an alveolar layer as well as a complex system of myonemes.
    [Show full text]
  • Release of Dissolved Amino Acids by Flagellates and Ciliates Grazing on Bacteria
    OCEANOLOGICA ACTA - VOL. 21 - No3 J Release of dissolved amino acids by flagellates and ciliates grazing on bacteria Christine FERRIE:R-PAGlb a, Markus KARNER b, Fereidoun RASSOULZADEGAN ’ a Observatoire Oceanologique Europeen, Centre Scientifique de Monaco, avenue Saint-Martin, MC-98000 Monaco, Principaute de Monaco bUniversity of Hawaii, SOEST Dept. Oceanography, 1000 Pope Road, Honolulu, Hawaii 96822, USA ‘Observatoire OcCa.nologique, URA-CNRS 716, Station Zoologique, BP 28,06230 Villefranche-sur-Mer, France (Received 25/01/97, revised 21/08/97, accepted 29108197) Abstract - Release of amino acids was examined in the laboratory in the form of dissolved primary amine (DPA) by two marine planktonic protozoa (the oligotrichous ciliate, Strombidium sulcatum and the aplastidic flagellate Pseudobodo sp.) grazing on bacteria. DPA release rates were high (19-25 x 1O-6 and 1.8-2.3 x 10m6pmol DPA cell-’ h-l for flagellates and ciliates, respectively) during the exponential phase, when the ingestion rates were maximum. Release rates were lower during the other growth phases. The release of DPA accounted for 10 % (flagellates) and 16 % (ciliates) of the total nitro- gen ingested. Our data suggest that the release of DPA by protozoa could play an important role in supporting bacterial and ‘consequently autotrophic pica- and nanoplankton growth, especially in oligotrophic waters, where the release of phyto- planktonic dissolved organic matter is low. 0 Elsevier, Paris amino acids / protozoa / excretion rates I dissolved organic matter RCsumC - ExcrCtion d’acides amin& par des ciliCs et des flagell&s. Les taux d’excretion d’acides amines par deux pro- tozoaires planctoniques marins (un cilie oligotriche, Strombidium sulcatum, et un flagelle heterotrophe, Pseudobodo sp.), nourris avec des batteries inactivees (par choc de temperature) ont etC quantifies exptrimentalement.
    [Show full text]
  • Classification and Nomenclature of Human Parasites Lynne S
    C H A P T E R 2 0 8 Classification and Nomenclature of Human Parasites Lynne S. Garcia Although common names frequently are used to describe morphologic forms according to age, host, or nutrition, parasitic organisms, these names may represent different which often results in several names being given to the parasites in different parts of the world. To eliminate same organism. An additional problem involves alterna- these problems, a binomial system of nomenclature in tion of parasitic and free-living phases in the life cycle. which the scientific name consists of the genus and These organisms may be very different and difficult to species is used.1-3,8,12,14,17 These names generally are of recognize as belonging to the same species. Despite these Greek or Latin origin. In certain publications, the scien- difficulties, newer, more sophisticated molecular methods tific name often is followed by the name of the individual of grouping organisms often have confirmed taxonomic who originally named the parasite. The date of naming conclusions reached hundreds of years earlier by experi- also may be provided. If the name of the individual is in enced taxonomists. parentheses, it means that the person used a generic name As investigations continue in parasitic genetics, immu- no longer considered to be correct. nology, and biochemistry, the species designation will be On the basis of life histories and morphologic charac- defined more clearly. Originally, these species designa- teristics, systems of classification have been developed to tions were determined primarily by morphologic dif- indicate the relationship among the various parasite ferences, resulting in a phenotypic approach.
    [Show full text]
  • How Chlamydomonas Keeps Track of the Light Once It Has Reached the Right Phototactic Orientation
    1562 Biophysical Journal Volume 73 September 1997 1562-1562 How Chiamydomonas Keeps Track of the Light Once It Has Reached the Right Phototactic Orientation Klaus Schaller, Ruth David, and Rainer Uhl Abteilung Physikalische Biologie der Ludwig Maximilians Universitat, D-80638 Munchen, Germany ABSTRACT By using a real-time assay that allows measurement of the phototactic orientation of the unicellular alga Chlamydomonas with millisecond time resolution, it can be shown that single photons not only induce transient direction changes but that fluence rates as low as 1 photon cell-1 s-1 can already lead to a persistent orientation. Orientation is a binary variable, i.e., in a partially oriented population some organisms are fully oriented while the rest are still at random. Action spectra reveal that the response to a pulsed stimulus follows the Dartnall-nomogram for a rhodopsin while the response to a persistent stimulus falls off more rapidly toward the red end of the spectrum. Thus light of 540 nm, for which ch/amy-rhodopsin is equally sensitive as for 440-nm light, induces no measurable persistent orientation while 440-nm light does. A model is presented which explains not only this behavior, but also how Chlamydomonas can track the light direction and switches between a positive and negative phototaxis. According to the model the ability to detect the direction of light, to make the right turn and to stay oriented, is a direct consequence of the helical path of the organism, the orientation of its eyespot relative to the helix-axis, and the special shielding properties of eyespot and cell body.
    [Show full text]
  • Influence of Zwitterionic Buffer Effects with Thermal Modification
    insects Article Influence of Zwitterionic Buffer Effects with Thermal Modification Treatments of Wood on Symbiotic Protists in Reticulitermes grassei Clément Sónia Duarte 1,* , Lina Nunes 2,3 , Davor Kržišnik 4 , Miha Humar 4 and Dennis Jones 5,6 1 LEAF (Linking Landscape, Environment, Agriculture and Food) Research Centre, Instituto Superior de Agronomia, Universidade de Lisboa. Tapada da Ajuda, 1349-017 Lisboa, Portugal 2 LNEC, National Laboratory for Civil Engineering, Structures Department, Av. do Brasil, 101, 1700-066 Lisbon, Portugal; [email protected] 3 cE3c, Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, University of the Azores, 9700–042 Angra do Heroísmo, Portugal 4 Biotechnical Faculty, University of Ljubljana, SI-1000 Ljubljana, Slovenia; [email protected] (D.K.); [email protected] (M.H.) 5 Department Wood Science and Engineering, Luleå University of Technology, Forskargatan 1, S-93197 Skellefteå, Sweden; [email protected] 6 Department of Wood Processing and Biomaterials, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 1176, 16521 Praha 6–Suchdol, Czech Republic * Correspondence: [email protected] Simple Summary: Over the past thirty years, the thermal modification of wood has become a universally recognised and commercialised wood modification process. Thermal modifications may Citation: Duarte, S.; Nunes, L.; affect wood properties, either positively (dimensional stability and decay resistance) or negatively Kržišnik, D.; Humar, M.; Jones, D. (mechanical properties). The combination of the impregnation of specific reagents with thermal Influence of Zwitterionic Buffer modification may help to overcome the negative effects on wood properties. In this study, we evaluate Effects with Thermal Modification the effect of a combination of two zwitterionic buffers, bicine and tricine, and thermal modification Treatments of Wood on Symbiotic of two wood species (beech and spruce) against subterranean termites and their symbiotic fauna.
    [Show full text]
  • Flagellate and Ciliate Distribution in Sediments of a Lowland River: Relationships with Environmental Gradients and Bacteria
    Scientific Paper: Aquatic Microbial Ecology 31, 67-76, 2003 Flagellate and ciliate distribution in sediments of a lowland river: relationships with environmental gradients and bacteria Björn Gücker*, Helmut Fischer Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Department of Limnology of Lowland Rivers and Shallow Lakes, Müggelseedamm 301, 12587 Berlin, Germany Abstract: It is generally assumed that protozoa are important predators of bacteria in the microbial food web, but limited data are available on protozoan abundance in streambed sediments. We investigated flagellate and ciliate abundance, community structure and spatial distribution in the shifting and stratified sandy sediments of a 6th order lowland river (River Spree, Germany) in relation to environmental gradients and bacteria. Flagellates and ciliates were quantified and identified using live observation and quantitative protargol staining techniques. Abundances (median and interquartile range) were 1900 cells cm–3 of benthic sediment (938 to 3363, n = 104) in flagellates and 148 cells cm–3 (29 to 363) in ciliates. Bodonids, colorless euglenids and hypotrich ciliates, predominantly Aspidisca cicada Müller, dominated the protistan community. Protistan abundance declined with increasing sediment depth in stratified sediments. A microaerophilic to anaerobic community occurred in deeper layers of these sediments. Aerobic bacterivorous protozoa prevailed in shifting sands. The prostistan community seemed to be structured by an interplay of factors, such as dissolved oxygen, light penetration, bacteria and sediment composition. Estimates using published grazing rates indicated that flagellate and ciliate densities were too small to control bacterial densities in these lowland river sediments. Key-words: Protists, protozoa, Flagellates, Ciliates, Spatial distribution, Sediments, Lowland river, Microbial loop, Microbial food web, Microbial ecology .
    [Show full text]
  • Spatial Distribution Pattern of Ciliated Protozoa in a Mediterranean Interstitial Environment
    l AQUATIC MICROBIAL ECOLOGY Vol. 9: 47-54, 1995 Published April 28 Aquat microb Ecol 1 l Spatial distribution pattern of ciliated protozoa in a Mediterranean interstitial environment G. Santangelo, P. Lucchesi Dipartimento Scienze Ambiente e Territorio, via Volta 4.1-56100 Pisa. Italy ABSTRACT. The spatial distribution of ciliates in a Mediterranean interstitial comrnunlty was analysed. During spring and summer ciliates tend to form patches and to stratify reaching their maximal density 3 to 6 cm below the surface. These patches are a few centimeters wide and deep and, in many cases, show the codominance of several taxa. Together with the distribution of ciliates, that of flagellates and culturable aerobic-heterotrophic bacteria was examined; these microorganisms too show wide varia- tions in their distribution. A close, positive correlation was found between ciliate and flagellate abun- dance, together with a frequent overlap of their patches. These findings suggest that they interact or respond to the same environmental factors. The scarcity of bacterivorous ciliate species in the area could account for the lack of correlation between ciliates and aerobic-heterotrophic bacteria. Differ- ences in the spatial distribution of interstitial oxygen content and porosity, over small distances, were also found. Some species seem to be sensitive to these factors, but an influence on overall ciliate abun- dance was not identified. Variations were found in ciliate taxonomic composition between neighbour- ing samples; they may be explained by local, undetermined, microenvironmental factors or by differ- ent recolonization phases in each sample. KEY WORDS: Sandy shore . Distribution pattern . Interstitial environment - Ciliates - Mediterranean Sea INTRODUCTION nity composition of marine interstitial ciliates from an exposed Mediterranean beach and their spatial distri- Marine-bottom sediments should be considered a bution.
    [Show full text]
  • The Protists
    The Protists (160,000 living & extinct species; estimates to 200,000 actual species) mostly single-celled, eukaryotes restricted to aquatic, or moist environments: oceans, ponds, lakes, rivers, damp soil, tree bark, snow, etc.; some species are colonial or multicellular; autotrophs & heterotrophs; with or without cell walls; most motile. Genetic analyses have dramatically changed the classification scheme if this group of organisms. In this course we will discuss examples of three main types of protists; algae, protozoa and slime & water molds. Algae [Plant-Like Protists] (22,000 living species) diverse group of mostly unicellular protists, some colonial or multicellular; restricted to aquatic or moist environments: oceans, ponds, lakes, rivers, soil, bark, snow, etc.; photosynthetic with chloroplasts containing chlorophyll and other pigments, most motile; most with cell wall; cell walls of cellulose, proteins,, silica or other materials classified according to their kinds of photosynthetic pigments and composition of cell wall Fire Algae (Dinoflagellates; Phylum Pyrrhophyta, 2100 species) unicellular, many symbiotic as zooxanthellae; some produce cell walls of armored plates, blooms produce toxic red tides, bioluminescent Diatoms (Glass Algae; Phylum Chrysophyta, 28000 living & extinct species) most abundant group of algae; unicellular, radial symmetry, cell walls contain silica; common in freshwater and oceans; source of diatomaceous earth; gliding movement, Euglenas (Phylum Euglenophyta, 1000 species) unicellular, only algae without
    [Show full text]
  • Dinoflagellate Life-Cycle Complexities
    J. Phycol. 38, 417–419 (2002) DINOFLAGELLATE LIFE-CYCLE COMPLEXITIES The dinoflagellates are a group of predominately pseudopodial network illustrated by Hofender (1930) marine, alveolate protists whose structural organiza- as an anastomosing feeding structure of Ceratium hi- tion, morphological diversity, and novel behaviors have rundinella is likely an artifact of cell trauma, while the captured the imaginations of phycologists and proto- juxtaposition of a small Protoperidinium within the sul- zoologists for 250 years. The 2000 or so extant species cus of Ceratium lunula, interpreted by Norris (1969) as that comprise the dinoflagellates sort almost equally evidence of feeding, may represent spurious, post- as phototrophs and heterotrophs; however, a growing mortem placement of specimens (Jacobson 1999). awareness that many species are really mixotrophic, Successful cultivation of dinoflagellates was not engaging in some combination of phototrophy and achieved until early in the twentieth century when phagotrophy, is eroding the conventional view of di- Crypthecodinium cohii was first grown on rotting pieces noflagellate nutrition (Stoecker 1999). The intricate of the brown algae Fucus (Taylor 1987). Since then, jigsaw puzzles formed by the thecal plates of armored only a small percentage of dinoflagellate species have species (Fensome et al. 1993, Steidinger and Tangen been successfully brought into culture. Most of these 1996), the complex light-sensing organelles of the War- are neritic, photosynthetic species whose growth re- nowiacids
    [Show full text]
  • GENERAL BACTERIOLOGY 1. Bacterial Cell (Morphology, Staining
    GENERAL BACTERIOLOGY 1. Bacterial cell (morphology, staining reactions, classification of bacteria) The protoplast is bounded peripherally has a very thin, elastic and semi-permeable cytoplasmic membrane (a conventional phospholipid bilayer). Outside, and closely covering this, lies the rigid, supporting cell wall, which is porous and relatively permeable. The structures associated with the cell wall and the cytoplasmic membrane (collectively the cell envelope) combine to produce the cell morphology and characteristic patterns of cell arrangement. Bacterial cells may have two basic shapes: spherical (coccus) or rod-shaped (bacillus); the rod-shaped bacteria show variants that are common-shaped (vibrio), spiral (spirillium and spirochetes) or filamentous. The cytoplasm, or main part of the protoplasm, is a predominantly aqueous environment packed with ribosomes and numerous other protein and nucleotide-protein complexes. Some larger structures such as pores or inclusion granules of storage products occur in some species under specific growth conditions. Outside the cell wall there may be a protective gelatinous covering layer called a capsule. Some bacteria bear, protruding outwards from the cell wall, one or more kinds of filamentous appendages: flagella, which are organs of locomotion, fimbriae, which appear to be organs of adhesion, and pili, which are involved in the transfer of genetic material. Because they are exposed to contact and interaction with the cells and humoral substances of the body of the host, the surface structures of bacteria are the structures most likely to have special roles in the processes of infection. Shape: this can be of 3 main types: round (cocci) - regular (staphylococci) - flattened (meningococci) - lancet shaped (pneumococci) elongated (rods) - straight (majority of them are like this; e.g.
    [Show full text]
  • When a Ciliate Meets a Flagellate: a Rare Case of Colpoda Spp. and Colpodella Spp
    biology Case Report When a Ciliate Meets a Flagellate: A Rare Case of Colpoda spp. and Colpodella spp. Isolated from the Urine of a Human Patient. Case Report and Brief Review of Literature Vlad S. Neculicioiu 1,†, Ioana A. Colosi 1,†, Dan A. Toc 1,*, Andrei Lesan 2 and Carmen Costache 1 1 Department of Microbiology, Iuliu Hat, ieganu University of Medicine and Pharmacy, 400349 Cluj-Napoca, Romania; [email protected] (V.S.N.); [email protected] (I.A.C.); [email protected] (C.C.) 2 Pneumology Department, Iuliu Hat, ieganu University of Medicine and Pharmacy, 400332 Cluj-Napoca, Romania; [email protected] * Correspondence: [email protected] † Authors with equal contribution. Simple Summary: In the era of new emerging diseases, particularly seen in patients with impaired immunity, it is of outmost importance to recognize unusual etiologic agents and to provide solutions regarding their treatment and prophylaxis. Our paper presents the first recorded evidence of the parasites Colpoda spp. and Colpodella spp. isolated together from the urine of a human patient. Although the patient did not experience any urinary symptoms and we discovered the parasites purely incidental, their disappearance was noticed after a combined therapy with two antibiotic Citation: Neculicioiu, V.S.; Colosi, drugs. In order to better understand the involvement of these two parasites in human pathology, I.A.; Toc, D.A.; Lesan, A.; Costache, C. we performed a brief review of the existing medical literature. Isolation of these parasites was When a Ciliate Meets a Flagellate: A recorded in different areas of the globe; however, we encountered a discrepancy in the diagnostic Rare Case of Colpoda spp.
    [Show full text]