Behavior of a Virus in a Symbiotic System, Paramecium bursaria—Zoochlorella

SYNOPSIS In a culture system of Paramecium bursaria , virus particles were found in large number. The particle was able to infect and multiply in certain cells of the zoochlorella, an intracellular symbiotic alga of P. bursaria. The infective particle, designated as zoochlorella cell virus (ZCV), was icosahedral and 120–180 nm in edge to edge diameter. The ZCV particle was found to differ from any of the already established viruses attacking the green and the blue-green algae. Within the system where P. bursaria cells were growing, ZCV particles were detected in the depression of the pellicle, among the cilia growing in the cytopharynx, and in the food vacuole of P. bursaria. ZCV particles were infective only for the zoochlorella cells which were recently released from the cytoplasm of P. bursaria. The multiplication process of ZCV comprised the adsorption of the particle to the cell wall of the zoochlorella, the penetration of nucleic acid into the host cell interior, the replication of viral constituents, the maturation of viral particles and their final release by the burst of the zoochlorella cell. ZCV particles appeared only in the cytoplasmic region of the zoochlorella cell in which many ribosomes were distributed. A possible ecosystem among the 3 members consisting of P. bursaria , zoochlorella and ZCV is discussed.     

Morphogenèse de Régénération chez le CiliéCondylostoma magnum (Spiegel): Etude ultrastructurale

SYNOPSIS Cortical events occurring in the course of regeneration in Condylostoma magnum (Spiegel) were studied by electron microscopy. The zone of regeneration is very rich in vacuoles and small vesicles formed from the plasma membrane. Multiplication of kinetosomes starts on the left side of kineties in the V-shaped left ventral area, normally implicated in stomatogenesis, at the level of the anterior kinetosomes of the somatic pairs. The proliferation proceeds by the appearance of young kinetosomes most often orthogonal to the old ones. This process of multiplication is very rapid and terminates in the formation of an “anarchic field” in which one observes that: (a) the newly formed kinetosomes do not possess all the associated postciliary fibers; and (b) when these fibers are detected, the kinetosomes are not in the same orientation. Differentiation of the adoral organelles takes place in the left part of the field (left primordium) by an alignment of the kinetosomes into 2 rows for each organelle (oriented perpendicularly to the antero-posterior axis of the ciliate), of which only one has the postciliary fibers. Ciliatogenesis occurs in numerous kinetosomes of the anarchic field; in certain kinetosomes it is achieved at the onset of their arrangement into organelles and is concomitant with growth of the nematodesmata. The 3rd (anterior) row of the organelles, the interkinetosomal desmata, and connections among neighboring organelles appear only secondarily. Differentiation of the paroral cilia occurs later. It takes place in the interior of the primordium, whose organization is primarily anarchic, and is accompanied by a progressive resorption of the major part of the newly formed kineties. Numerous kinetosomes of the right field have the associated postciliary fibers, which are not found at the level of the regenerated “polystichomonad” (paroral organization characteristic of C. magnum). Finally, the formation of new kinetosomes within a somatic kinety at the time of its elongation is described.     

Description de Quelques Espèces de Ciliés Hyménostomes des Genres Sathrophilus Corliss, 1960, Cyclidium O. F. Müller, 1786, Histiobalantium Stokes, 1886

RESUME. Les structures buccales de Sathrophilus vernalis Dragesco & Grolière, 1969 sont détaillées. La morphogenèse buccale de l'opisthe, semi-autonome, avec participation du scuticus et d'une cinétie postorale droite, s'accompagne d'une re-constitution de l'appareil buccal du proter. La morphologie buccale de Cyclidium sphagnetorum Šràmek-Hušek, 1949 est comparée à celles de Cyclidium citrullus Cohn, 1865 et Cyclidium glaucoma O. F. Müller, 1786. La stomatogenèse Histiobalantium majus Kahl, 1933 débute par une prolifération du scuticus vers la gauche.
SYNOPSIS. Buccal structures of Sathrophilus vernalis Dragesco & Grolière, 1969 are described. The semiautonomous buccal morphogenesis of the opisthe, involving the participation of the scuticus and the right postoral kinety, is accompanied by the reconstitution of the buccal apparatus of the proter. The buccal structure of Cyclidium sphagnetorum Šràmek-Hušek, 1949 is compared to those of Cyclidium citrullus Cohn, 1865 and Cyclidium glaucoma O. F. Müller, 1786. Stomatogenesis of Histiobalantidium majus Kahl, 1933 starts with a proliferation of the scuticus towards the left.     

Mutations Affecting the Trichocysts in Paramecium aurelia. I. Morphology and Description of the Mutants*

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.     

How Camillo Golgi became “the Golgi”

On April 1898 Camillo Golgi communicated to the Medical-Surgical Society of Pavia, the discovery of the “internal reticular apparatus”, a novel intracellular organelle which he observed in nerve cells with the silver impregnation he had introduced for the staining of the nervous system. Soon after the discovery it became evident that this cellular component, which was also named the “Golgi apparatus”, was a ubiquitous structure in eukaryotic cells. However the reality of the organelle was questioned for years and many cytologists considered the internal reticular apparatus as an artefact due to the fixation and/or metallic impregnation procedure. The controversy was finally solved in the mid-1950s by electron microscopy when the Golgi apparatus definitely acquired its dignity of being a genuine cell organelle. The designation of “Golgi complex” entered officially in the literature in 1956. Both the terms Golgi apparatus and Golgi complex are currently interchangeable. However a quick “the Golgi” and the introduction of Golgi in adjectival form are now prevalent in the blooming scientific literature on the organelle. Thus Camillo Golgi underwent his final transformation and, becoming the eponym of the organelle he had discovered, he found a way to immortality.     

Caractéristiques Ultrastructurales du Cortex et des Membranelles du CiliéEspejoia mucicola (Oligohymenophora, Hymenostomata, Tetrahymenina)

RESUME. L' étude détaillée du cortex et des organelles buccaux adoraux d' Espejoia montre que ce Cilié possède une organisation ultrastructurale comparable à celle des Tétrahyméniens. Tout en restant conforme au plan général d'organisation de ces derniers, des variations spécifiques décelées tant au niveau du cortex d'une part, que des membranelles, d'autre part, font ressortir des affinités trés marquées pour le genre Glaucoma et autres Ciliés voisins. En conséquence, en nous appuyant en outre sur les données récentes de la morphogenèse, nous confirmons la position d' E. mucicola parmi les Tetrahymenina, dans la famille des Glaucomidae.     

Some Ultrastructural and Functional Aspects of the Golgi Apparatus of Thelohania sp. (Microsporida) in the Shrimp Pandalus jordani Rathbun

SYNOPSIS. Electron microscope observations on Thelohania sp. in the shrimp Pandalus jordani support the view that the Golgi complex in Microsporida is a "classical" one, composed of vesicular, vacuolar, and cisternal components. During development of the sporoblast, a portion of the Golgi complex is seen as an electron-dense reticulum enmeshing the core of the polar filament. Associated with the reticulum are electron-dense bodies. The reticulum and "dense bodies," reported in several previous publications, have not been well understood and have been given a variety of names. The evidence favors the view that these structures have secretory activity in which the reticulum concentrates or synthesizes material, some of which takes the form of membrane-bounded granules. It is suggested that the most appropriate name for the reticulum is "reticulum golgien," and that the correct name for the "dense bodies" is the standard cytologic term, "secretion granules." The secretion granules apparently remain in the posterior part of the spore, and may be stored there for some as yet undetermined use.     

Caractéristiques De La Stomatogenèse Et Des Ultrastructures Corticale Et Buccale Du Cilié Colpodidea Bursaria Truncatella O. F. Müller, 1773

RESUME. Chacun des 45–80 organelles adoraux de Bursaria truncatella O. F. Müller est constitué de 3 rangées de cinétosomes et l'aire buccale droite est couverte de nombreuses doubles rangées de cinétosomes. La stomatogenèse débute par la désorganisation et la résorption des organelles buccaux postérieurs. Puis, il y a désorganisation des rangées parorales de cinétosomes et multiplication des cinétosomes sur l'aire orale droite, en měme temps que sont rompues, selon une ligne oblique, un certain nombre de cinéties somatiques. La prolifération des cinétosomes aux extrémités des cinéties. de part et d'autre de la ligne de rupture, aboutit, d'une part, à la formation d'un champ anarchique qui est le primordium oral droit de l'opisthe, d'autre part, à la formation de nombreux doublets qui constituent chacun le primordium de chaque organelle adoral. Après la séparation des tomites, les cinétosomes de l'aire droite s'ordonnent en doubles rangées et les organelles adoraux se complètent par addition d'une 3ème rangée de cinétosomes. Les cinétosomes somatiques sont jumelés, reliés par 2 desmoses. Les fibres transverses postérieures et les fibres postciliaires forment de longs rubans de microtubules dirigés vers l'arrière et juxtaposés dans les crětes intercinétiennes. Les doubles rangées droites de cinétosomes buccaux sont assimilables à des stichodyades. Les organelles des cinétosomes adoraux portent des rideaux de fibres postciliaires convergents ou divergents. La rangée postérieure de chaque organelle est non ciliée. Par son type de stomatogenèse, par sa structure corticale, par l'ultrastructure des organelles adoraux, Bursaria appartient aux Colpodidea, ce qui suggère des remarques de plusieurs types. SYNOPSIS. In Bursaria truncatella O. F. Müller, each of the 45–80 adoral organelles is composed of 3 rows of kinetosomes, and the right buccal area is covered by many double rows of kinetosomes. Stomatogenesis begins by disorganization and disappearance of the posterior buccal organelles. Next, there is disorganization of the paroral rows of kinetosomes and multiplication of kinetosomes in the right oral area; at the same time, some somatic kineties are disrupted along an oblique line. Multiplication of kinetosomes at the extremities of the kineties, on both sides of the disruption, leads to the formation of an anarchic field which is the right oral primordium of the opisthe and the formation of doublets each of which constitutes an adoral organelle. After the separation of the tomites. the kinetosomes in the right buccal area position themselves, and the adoral organelles are completed by the addition of a 3rd row of kinetosomes. Somatic kineties are formed by successive pairs of ciliated kinetosomes united by 2 desmoses. the long posterior transverse ribbons and the postciliary ribbons extend posteriad, overlapping in the pellicular ridges. Oral rows of kinetosomes on the right can be compared with stichodyads. the adoral kinetosomes have convergent or divergent postciliary ribbons. the posterior row of kinetosomes in each organelle is not ciliated. By the type of stomatogenesis, the cortical ultrastructure, the ultrastructure adoral of its organelles, Bursaria belongs to the Colpodidea.     

La Genèse des Mérozoïtes chez la Coccidie Eimeria necatrix. Etude Ultrastructurale*

RESUME. Les schizontes de 2 ème génération d'Eimeria necatrix ont étéétudiés au microscope électronique. La différenciation des mérozoïtes est associée à la dernière mitose, qui ne semble pas différer essentiellement des précédentes. Les mérozoïtes se développent à la périphérie du schizonte. Le conoide et 22 microtubules sous pelliculaires, probablement induits par les centrioles, et le complexe membranaire interne ainsi que les précurseurs des rhoptries, qui semblent issus de l'appareil de Golgi, apparaissent auprès de chaque pôle nucléaire, sous la membrane du schizonte. Ces organites sont les premiers inclus dans les ébauches de mérozoïtes. Puis, le noyau, le dictyosome et les vésicules multimembranaires pénètrent dans les futurs mérozoïtes. Les micronèmes, probablement formés par l'appareil de Golgi, et les grains d'amylopectine sont produits plus tard, quand les mérozoïtes se séparent du reliquat cytoplasmique. Le mode de genèse de ces divers organites et les relations entre le dernière mitose et la différenciation sont discutés. SYNOPSIS. Second generation schizonts of Eimeria necatrix were studied with the aid of the electron microscope. Differentiation of daughter merozoites is associated with the last mitosis, which is not significantly different from the earlier ones. The merozoites develop at the periphery of the schizont. The conoid and 22 subpellicular microtubules, probably induced by centrioles, and the inner membranes complex and the rhoptry anlagen which seem to be produced by the Golgi apparatus, appear close to each nuclear pole, just near the schizont membrane. These organelles are the first to appear in the merozoite anlagen. Then, nucleus, dictyosome and multimembranous vesicles enter the budding merozoites. Micronemes, probably originating from Golgi apparatus, and amylopectin granules are produced later, when daughter merozoites separate from the residuum. The genesis of these various organelles and the relation between the last mitosis and differentiation are discussed.     

Ultrastructure of Prorodon (Ciliophora, Prostomatida) I. Somatic Cortex and Some Implications Concerning Kinetid Evolution In Prostomatid and Colpodid Ciliates

ABSTRACT. This study describes the ultrastructure of the somatic cortex of Prorodon aklitolophon and Prorodon teres. the meridionally arranged somatic kineties of both species can be separated into two parts: a short anterior part, which consists of a few somatic dikinetids (in which both kinetosomes are ciliated), and a longer posterior consisting of monokinetids. the somatic monokinetids are associated with a convergent postciliary microtubular ribbon, a transverse microtubular ribbon flatly inserted in front of the kinetosome, a short and steeply extending kinetodesmal fibre attached to kinetosomal triplet 5 and 7, and a desmose anterior to triplet 3. From this desmose, two to five prekinetosomal microtubules originate and extend anteriorly. the posterior kinetosome of the somatic dikinetids is associated with the same microfibrillar and microtubular structures as the somatic monokinetid, except that no prekinetosomal microtubules originate from the desmose. the anterior kinetosome has a single postciliary microtubule and a tangentially oriented transverse microtubular ribbon. the permanent collecting canals of the unique contractile vacuole system extend parallel and adjacent to the somatic kinetics of Prorodon . the collecting canals are supported by the prekinetosomal microtubules. A similarly organized contractile vacuole system is not yet known from any other ciliate group. One of the most surprising results of this investigation was finding a significant similarity between the somatic dikinetid pattern of Prorodon and the colpodid dikinetid pattern. A hypothesis is presented to illustrate the evolution of the somatic kinetid patterns in colpodid and prostomatid ciliates.     

Ultrastructure de Quelques Stades de la Microsporidie Octosporea muscaedomesticae Flu, Parasite de Ceratitis capitata (Wiedemann) (Diptère, Trypetidae)

La présence de diplocaryons à tous les stades de la sporulation d'Octosporea muscaedomesticae Flu, 1911 est mise en évidence ainsi qu'une membrane pansporoblastique autour des sporoblastes en développement et des spores. Le problème présenté par ces 2 faits est discuté. Une évolution étrange des ribosomes périnucléaires et démontrée. Une telle étude ultrastructurale est nécessaire et intéressante car O. muscaedomesticae est l'espèce-type du genre Octosporea.     

Etude Ultrastructurale du Genre Enteromonas da Fonseca (Zoomastigophorea) et Révision de l'Ordre des Diplomonadida Wenyon

RESUME. Deux espèces d'Enteromonas sont observées, provenant, l'une de l'intestin de Triton, l'autre des crottes du Lapin domestique. La cellule piriforme porte un noyau antérieur et 4 flagelles insérts près du pôle ventral du noyau. Le flagelle récurrent (R) est logé dans une dépression ventrale ou cytostome. Les cinétosomes, disposés en une paire antérieure (#1, #2) et une paire postérieure (#3, R), sont liés entre eux par des microfibrilles. Une fibre microtubulaire située au-dessus du noyau est reliée au cinétosome #1. Une autre fibre microtubulaire sous-nucléaire est homologue de la fibre microtubulaire croisée qui existe chez les cellules de Diplozoaires. Le cytostome est bordé par 2 lèvres: la gauche proéminente et armée par plusieurs rangées de microtubules, la droite contenant seulement une mince fibre microtubulaire associée à des microfibrilles. Le cytostome occupe les 2/3 de la face ventrale. Le flagelle récurrent pénètre dans le cytostome puis dépasse l'extrémite de la cellule. Les Bactéries sont phagocytées au fond du cytostome, entre les 2 lèvres distendues. Elles sont digérées dans les nombreuses vacuoles et les corps résiduels sont évacués par rupture de la membrane cellulaire. L'ergastoplasme est concentré près de la périphérie de la cellule. Il n'y a pas de mitochondrie ni d'appareil de Golgi. Dans les kystes observés la cellule plurinucléée est enfermée dans une enveloppe kystique microfibrillaire, les axonèmes sont libres dans le cytoplasme. Les formes diplomonades sont nombreuses et ressemblent aux cellules d'Hexamita, excepté par le cytostome qui est différent. Dans ces formes, les 2 monades sont souvent disposées selon une symétrie axiale binaire mais quelquefois elles sont associées de façon plus anarchique. La cinétide d'Enteromonas est organisée comme celle d'un zoïde de Diplozoaire. Il est possible que le genre Enteromonas soit à l'origine des Diplomonadida et que l'état diplomonadien transitoire chez Enteromonas se soit stabilisé ensuite chez les Diplomonadida. Enteromonas apparaît plus primitif que les autres genres de Diplomonadida aussi nous proposons de créer 2 sous-ordres: celui des Enteromonadina avec le genre Enteromonas et celui des Diplomonadina avec les genres Trepomonas, Trigonomonas, Hexamita, Spironucleus, Octomitus, Giardia. La disposition des cinétosomes et l'existence du cytostome sont les principaux caractères communs entre Enteromonas et les Retortamonadida, cependant les fibres annexes ne sont pas homologues. Une étude plus complète de la division nucléaire et cellulaire de ces 2 ordres de Zooflagellés est nécessaire pour donner un meilleur schéma évolutif. SYNOPSIS. Fine structure of 2 species of Enteromonas, one from the intestine of the salamander, Triturus vulgaris, and another from the feces of domestic rabbit, Oryctolagus cuniculi, is described. The pyriform cell has an anteriorly located nucleus. The 4 flagella originate from an area near the anterior end of the nucleus. The recurrent flagellum (R) is lodged in a ventral depression or cytostome. The kinetosomes, arranged into 2 pairs, anterior (#1, #2) and posterior (#3, R), are interconnected by microfibrils. One microtubular fiber, connected to kinetosome #1, is situated near the anterior surface of the nucleus. Another, subnuclear, microtubular fiber is homologous to the “crossed'’fiber found in Diplozoa. The cytostome is bordered by 2 lips: the preeminent left lip is equipped with several rows of microtubules, while the right lip contains only a thin microtubular fiber associated with microfibrils. The cytostome occupies 2/3 of the ventral surface. The recurrent flagellum passes over the anterior surface of the cell and then comes to lie in the cytostome. The bacteria are phagocytosed in the bottom part of the cytostome between the 2 distended lips. They are digested in numerous vacuoles. The undigested residual bodies are evacuated by a rupture of the cell membrane. The ergastoplasm is concentrated near the cell periphery. Mitochondria and the Golgi apparatus are absent. In the cyst stage, the multinucleate cell is enclosed in a microfibrillar membrane; the axonemes lie free in the cytoplasm. Diplomonad forms of Enteromonas resembling Hexamita are numerous, except that the cytostome is different in these 2 genera. In such forms, the arrangement of the 2 individuals often has binary axial symmetry, but on occasion they are associated in a more anarchic fashion. The mastigont of Enteromonas is organized like that of a single zooid of a diplozoon. It is possible that the genus Enteromonas is ancestral to Diplomonadida and that the diplomonad state, transitory in Enteromonas, became permanently established in Diplomonadida. Enteromonas appears to be more primitive than the other genera of Diplomonadida. Thus we propose 2 suborders: Enteromonadina, subord. nov. with the genus Enteromonas, and Diplomonadina Wenyon, emend., with the genera Trepomonas, Trigonomonas, Hexamita, Spironucleus, Octomitus, Giardia. The arrangement of the kinetosomes and the existence of a cytostome are the principal characters common to Enteromonas and Retortamonadida, while their “accessory'’fibers are not homologous. A more complete study of division of the 2 zooflagellate orders is necessary for the presentation of a more detailed evolutionary scheme of these groups.     

Raster-Elektronenmikroskopie von Spermien des Hausschafs (Ovis ammon aries,L.)

Zusammenfassung Bei der Präparation von Schafspermien für die Beobachtung im Raster-Elektronenmikroskop wurden beigemengte Schleimstoffe durch zahlreiche Waschvorgänge mit schonender Zentrifugation und Behandlung mit Hyaluronidase weitgehend entfernt.Der Kopf des Spermium wird durch zwei bogenförmige Linien in drei Zonen unterteilt. In der vorderen Zone erhebt sich direkt hinter einem schmalen Randwulst symmetrisch die (dem apikalen Akrosomsegment entsprechende) apikale Sichel. Die äquatoriale Zone ist meist geringfügig über das Niveau der vorderen Zone erhaben; in ihrem medialen hinteren Bereich zeichnet sich ein lunulaähnlicher Bezirk mit granulierter Oberfläche ab. Die der hinteren Zone zugrundeliegende postnukleäre Scheide greift mit zahlreichen schmalen Fortsätzen in das äquatoriale Segment des Akrosoms; dazwischen gelegene Einsenkungen geben der Grenze beider Zonen ein sägezahnartiges Aussehen. Die Oberfläche der hinteren Zone weist viele grübchenförmige Einsenkungen auf. Caudal drückt sich der basale Gürtel in einem glatten bandförmigen Bereich aus. An der Kopfbasis umzieht der Ansatzwulst in ovalem Verlauf die Ansatzhöhle sowie die beiden hinteren Knöpfe.Am Schwanz des Spermium sind im Verbindungsstück zwei stärkere laterale Stranggruppen und zwischen ihnen zwei bzw. drei mediale gebänderte Stränge zu erkennen, die in der Tiefe der Ansatzhöhle aus dem Kapitulum entspringen. Das Mittelstück besitzt eine regelmäßige Schrägbänderung als Ausdruck seiner linksgewundenen mitochondrialen Tripelhelix; es schließt mit einem quergestellten Schlußring ab. Am Hauptstück sind neben einer queren Rippung drei längsverlaufende Wülste festzustellen, deren Stärke sich im Verlauf ändert. Das Endstück verjüngt sich in seinem Anfangsteil etwas; sein Durchmesser bleibt dann aber bis zum abgerundeten Schwanzende gleich.

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Scanning electron microscopy of spermatozoa of the domestic sheep (Ovis ammon aries, L.)

Summary This investigation is concerned with the scanning electron microscopic appearance of sheep spermatozoa in comparison with details gained with the transmission electron microscope by earlier authors.The head of the spermatozoon is subdivided into three zones by two curved lines. In the anterior zone the apical sickle protrudes symmetrically behind a narrow marginal roll; the apical sickle corresponds to the apical segment of the acrosome. The equatorial zone is generally slightly elevated above the level of the anterior zone. In the medial posterior part of the equatorial zone a lunulalike area with granular surface is found. The posterior zone shows numerous small pitches; it corresponds to the post-nuclear sheath, which sends small processes into the equatorial segment of the acrosome. The surface view of this border between equatorial and posterior zone exhibits a saw-toothed appearance. A smooth tape-like area corresponds to the basal belt. At the base of the head an inserting-roll surrounds both posterior knobs and the implantation fossa.The connecting-piece of the sperm-tail consists of two lateral, and two or three, respectively, banded medial cords. These cords originate from the capitellum, which lies inside the implantation fossa. The middle-piece shows a periodical oblique pattern, which corresponds to the left-winded mitochondrial tripel-helix inside. The middle-piece reaches to a transverse terminal ring-like structure (annulus). The principal-piece shows periodically arranged transversal ribs as well as three longitudinal elevations. The latter are modified in the course of the principal-piece. The diameter of the end-piece decreases slightly in the anterior part; then it remains constant to the rounded tip.

Die Untersuchung wurde mit Unterstützung durch den Sonderforschungsbereich 51 (Medizinische Molekularbiologie und Biochemie) der Deutschen Forschungsgemeinschaft durchgeführt. — Für die Bereitstellung der Spermien danken wir Herrn Dr. E. Metzger (Abteilung für Andrologie und künstliche Besamung der tierärztlichen Fakultät der Universität München), für technische Hilfe Frau H. Asam und Herrn Ch. Grosse.     

Localisation of thiamine pyrophosphatase within the cytoplasmic fine structure of trophozoites of Entamoeba histolytica and E. invadens

McCaul T.F. and Bird R.G. 1978. Localisation of thiamine pyrophosphatase within the cytoplasmic fine structure of trophozoites of Entamoeba histolytica and E. invadens. International Journal for Parasitology8: 501–506. The distribution of thiamine pyrophosphatase (TPPase) activity was studied in both formaldehyde and glutaraldehyde fixed trophozoites of Entamoeba histolytica and E. invadens. The activity was localised within certain vacuoles. No dense deposits for TPPase activity were seen in the small vesicles, elongated smooth-walled lacunae equated with endoplasmic reticulum, or the nucleus. The demonstration of small vesicles surrounding the larger vacuoles indicated that the Golgi-like vacuoles might be involved in the production of cell coat materials and primary lysosomes.