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1

Cercomer theory: Significance of sperm morphology, oncosphere metamorphosis, polarity reversal, and the cercomer to evolutionary relationships of Monogenea to Cestoidea

100%
Mackiewicz J. S.
Acta Parasitologica Polonica
|
1984
|
tom 29
|
nr 1-8
2
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A brief summary of the North American Caryophyllaeidae (Cestoidea) and their vertebrate hosts

100%
Mackiewicz J. S.
Wiadomości Parazytologiczne
|
1961
|
tom 07
|
nr 4-6
3

Caryophyllidea [Cestoidea]: molecules, morphology and evolution

100%
Mackiewicz J. S.
Acta Parasitologica
|
2003
|
tom 48
|
nr 3
Recent literature on the evolution and interrelationships of the Caryophyllidea based on molecular and morphological criteria is reviewed. Molecular analyses with SSU rDNA, LSU rDNA and ef-1 alpha reaffirms the basal or near basal position of these nonozoic cestodes. Major emphasis is on an evaluation of the scoring in morphological character matrices used in cladistic studies. Suggested changes to present scoring are: uterus is dorsal; scolex is afossate, fossate or difossate with little support for monofossate; ciliated coracidium is absent; vitellaria are circum-cortical and circum-medullary; testes are cortical and medullary; metacercoid stage is absent; and the spermatozoan lacks a crested body, flagellar rotation and proximodistal fusion. Of the 41 recognized genera of the Caryophyllidea, 59% have an afossate scolex and the remainders are fossate. The use of a new character, “nuclear vacuole” in the nucleus of mature vitellocytes, is suggested. To aid in identifying cestode body types in an evolutionary context, they are designated as monopleuroid, polypleuroid and strobila. Tabulated differences between the monozoic Caryophyllidea and polyzoic eucestodes suggest that the two groups may warrant separate taxonomic status. The question of whether or not the monozoic state is primary or secondarily derived is not resolved. Using the life cycle characterstics of the Pseudophyllidea and of Archigetes as models, it is hypothesized that progenesis may have played a major role in the evolution of the Caryophyllidea. If the role of progenesis can be substantiated through total evidence incorporating cytohistological data, then the monozoic condition becomes coincidental and the hypothesis is not supported that the Caryophyllidea are ancestral and preceded polyzoic eucestodes.
4

Professor Zbigniew (Bob) Kabata (1924-2014)

63%
Mackiewicz J. S., Swiderski Z.
Acta Parasitologica
|
2014
|
tom 59
|
nr 4
5

Ultrastructure of spermatogenesis and spermatozoa of the caryophyllidean cestode Glaridacris catostomi Cooper, 1920

63%
Swiderski Z., Mackiewicz J. S.
Acta Parasitologica
|
2002
|
tom 47
|
nr 2
Spermatogenesis of Glaridacris catostomi from Catostomus commersoni (Catostomidae) from Albany, New York (USA) was studied by means of TEM, SEM and squashes. Mature testes of G. catostomi contain all consecutive stages of spermatogenesis; primary spermatogonia are usually situated at the periphery and mature spermatozoa in the centre of testes. The primary spermatogonium divides mitotically, but the two daughter cells, secondary spermatogonia, remain connected with each other by a cytoplasmic bridge. Spermatogenesis in G. catostomi is of a rosette type. Six incomplete, synchronic cytokineses, five mitotic and meiotic divisions occur simultaneously, resulting in a cluster of four tertiary spermatogonia, then eight quaternary spermatogonia, and subsequently sixteen primary spermatocytes are formed. These enlarge, their nuclei move to the periphery and the cluster of cells takes on the form of rosette. After the first meiotic division, a rosette of thirty-two secondary spermatocytes is formed. The haploid nuclei of these are smaller and the cell membranes near the centre of the rosette become indistinct as the displacement of nuclei toward the periphery continues. The second maturation division results in sixty-four spermatids. During spermiogenesis, their nuclei subsequently elongate, migrate, and are transformed into electron-dense, filiform nuclei of spermatozoa. Each spermatid forms at the surface a so-called "zone of differentiation". From this conical zone arise initially three elongating processes: cytoplasmic extension and two lateral flagella. The spermiogenesis type observed in G. catostomi is characterised by an early abortion of the second axoneme. The remaining single axoneme, forming the sperm flagellum, elongates in parallel with cytoplasmic process accommodating the sperm nucleus; the two parts are initially separated. The migration of the sperm nucleus induces their lateral fusion, which is, however, very superficial; the flagellar axoneme and sperm nucleus are never incorporated completely into a common sperm body as observed in pseudophyllideans or cyclophyllideans. The spermatozoon of G. catostomi consists of two elongate parts: nucleated sperm body with a row of cortical microtubules and flagellum connected by a narrow, longitudinal bridge throughout nearly the entire length. The flagellum consists of a single axoneme of the 9 + '1' Platyhelminthes type. The value of spermiogenesis type and sperm ultrastructure as taxonomie tools in platyhelminth phylogeny is discussed.
6

Scolex development, morphology and mode of attachment of Wenyonia virilis Woodland, 1923 [Cestoidea, Caryophyllidea]

63%
Ibraheem M. H., Mackiewicz J. S.
Acta Parasitologica
|
2006
|
tom 51
|
nr 1
Development and morphology of the scolex and mode of attachment of Wenyonia virilis Woodland, 1923, a caryophyllaeid cestode from the silurid Nile fish Synodontis schall (Bloch et Schneider, 1801), were studied by means of light and scanning electron microscopy (SEM). Scolex and genital primordia changes through four stages of juvenile development are described. Longitudinal ridges do not appear on the scolex until the cestode has well defined genital primordia. This is in stark contrast to other caryophyllidean genera in which the basic morphology of the adult scolex becomes evident at the procercoid stage in the oligochaete intermediate host. The scolex of the adult has 13 to 19 prominent longitudinal ridges and deep furrows that come together at the apex to form an apical ring, a protrusible terminal introvert within the apical ring that forms a deep apical pouch when fully retracted, and a central group of Faserzellen. The scolex of W. virilis appears similar to the rugomonobothriate scolex of another African caryophyllid, Monobothrioides chalmersius (Woodland, 1924). Comparisons are made with other caryophyllideans having a scolex with a terminal structure: Monobothrium Diesing, 1863, Djombangia Bovien, 1926 and Caryoaustralus Mackiewicz et Blair, 1980. The terminal introvert may be responsible for attachment in early juvenile stages, but may be supplemented by the longitudinal ridges and furrows later in development. Host tissue appears to be drawn into these furrows that function as weak organs of attachment. We could not determine how the introvert of adult worms functions in attachment. At the site of attachment, the mucosa showed necrosis and degeneration and the submucosa exhibited vacuolization and infiltration with lymphocytes and leucocytes.
7

Ultrastructural studies on the cellular organisation of the coracidium of the cestode Bothriocephalus clavibothrium Ariola, 1899 [Pseudophyllidea, Bothriocephalidae]

63%
Swiderski Z., Mackiewicz J. S.
Acta Parasitologica
|
2004
|
tom 49
|
nr 2
The unhatched, newly hatched and free-swimming coracidia of Bothriocephalus clavibothrium Ariola, 1899 an intestinal parasite of the teleostean fish Arnoglossus laterna (Walbaum, 1792) (Pleuronectidae) from the Mediterranean Sea near Séte, France were examined by means of transmission electron microscopy (TEM) and cytochemistry methods. Each unhatched and hatched coracidium of B. clavibothrium is composed of a hexacanth larva, oncosphere, about 28 µm in diameter, surrounded by a 5-7 µm thick ciliated envelope containing about 16 mesomere nuclei and a large amount of nutritive reserves (α- and ß-glycogen and lipids). Several cell types were distinguished within the oncosphere: (1) binucleated subtegumental cell; (2) two flame cells; (3) binucleated penetration gland; (4) two nerve cells; (5) about 100 intermediate, somatic cells which represent perikarya of both somatic and hook musculature; (6) about 50 small embryonic cells, some of them with pycnotic nuclei containing very dense chromatin and showing evident signs of regression and degeneration; and (7) about 10 to 12 germinative cells with prominent nucleoli in large lobate nuclei, surrounded by a thin layer of compact, granular cytoplasm rich in RNA. Apoptosis of numerous micromeres and of outer-envelope and ciliated-envelope material was frequently observed. The total number of oncospheral cells is about 160, the highest number reported from various orders and families of cestodes. This number, along with our own data from different cestode orders and families, supports our hypothesis that the progressive reduction in oncosphere cell numbers is correlated with a simplification of the infective larval stages and is a general trend in cestode evolution. This correlation represents an interesting ontogenic adaptation to the parasitic way of life.
8

Ultrastructural and cytochemical studies of GER-bodies in the intrauterine eggs of Wenyonia virilis Woodland, 1923 (Cestoda, Caryophyllidea)

51%
Mlocicki D., Swiderski Z., Mackiewicz J. S., Ibraheem M. H.
Acta Parasitologica
|
2011
|
tom 56
|
nr 1
Ultrastructural and cytochemical characteristics of GER-bodies observed in the vitellocyte cytoplasm of the intrauterine eggs of the caryophyllidean cestode Wenyonia virilis are described. In this species GER-bodies were observed only in the cytoplasm of vitellocytes, surrounded by a newly formed egg-shell. They are composed of spherical areas of condensed, electron-dense cytoplasm which contains concentrically arranged parallel lamellae of granular endoplasmic reticulum (GER), forming characteristic balls of different sizes. Each GER-body is surrounded by numerous free ribosomes, polyribosomes, α-glycogen rosettes and large mitochondria. Results of cytochemical analysis by means of PATSC-SP test for polysaccharides indicated that glycogen is absent within the GER-bodies, however, a strongly positive reaction was observed only in large aggregations of α-glycogen rosettes and β-glycogen particles, localised usually near GER-bodies.
9

Spermatological characteristics of the enigmatic monogenean Dictyocotyle coeliaca Nybelin, 1941 (Monopisthocotylea: Monocotylidae) reveal possible adaptation to endoparasitism

51%
Brunanska M., Mackiewicz J. S., Poddubnaya L. G.
Acta Parasitologica
|
2017
|
tom 62
|
nr 1
10

Ultrastructure of intrauterine eggs: Evidence of early ovoviviparity in the caryophyllidean cestode Wenyonia virilis Woodland, 1923

51%
Mlocicki D., Swiderski Z., Mackiewicz J. S., Ibraheem M. H.
Acta Parasitologica
|
2010
|
tom 55
|
nr 4
349-358
Ultrastructural evidence for early intraurerine embryonic development of Wenyonia virilis is presented. At the initial stage of egg formation, the fertilized oocyte or ovum is surrounded by numerous vitellocytes and newly formed eggshell. Individual vitellocytes undergo progressive fusion into a vitelline syncytium. During cleavage divisions, three types of blastomeres are formed: macromeres, mesomeres and micromeres. Two large macromeres contain a large nucleus with spherical nucleolus and numerous small heterochromatin islands dispersed in moderately electron-dense nucleoplasm. The granular cytoplasm shows a few large mitochondria. Medium-sized mesomeres contain a spherical nucleus with numerous heterochromatin islands, adjacent to the nuclear envelope, and a prominent electron-dense nucleolus. Their nuclei are embedded in granular cytoplasm with a few large and numerous small mitochondria and Golgi complexes. The small micromeres are characterized by presence of spherical nucleoli with large areas of highly condensed heterochromatin and a few islands of granular electron-lucent nucleoplasm. Their granular cytoplasm shows a few small lipid droplets and several spherical mitochondria. Majority of micromeres give rise to the hexacanth but many of them also undergo degeneration or apoptosis. Both mesomeres and macromeres are engaged in the formation of the oncospheral envelopes. The outer envelope is formed by a fusion of two macromeres whereas the inner envelope originates from a fusion of mesomeres. The intrauterine eggs of W. virilis usually contain an embryo at the early preoncopheral phase of development and possesses three primary envelopes: (1) thick eggshell; (2) thin cytoplasmic layer of the outer envelope and (3) inner envelope. Based on embryonic development, egg type and life-cycle characteristics, caryophyllideans tend to show closer affinities to spathebothriideans than to the former pseudophyllideans.
11

Ultrastructural and cytochemical study on vitellogenesis in the diphyllidean cestode Echinobothrium euterpes (Echinobothriidae) and its phylogenetical implications

51%
Swiderski Z., Mackiewicz J. S., Eira C., Miquel J.
Acta Parasitologica
|
2011
|
tom 56
|
nr 2
The first description of vitellogenesis in the Diphyllidea is presented in this paper. Though the type of vitellogenesis and mature vitellocyte in Echinobothrium euterpes appear to be unique among the Eucestoda, however, they somewhat resemble that observed in the two orders of the lower cestodes, Tetraphyllidea and Proteocephalidea. Vitellocyte maturation is characterized by: (1) an increase in cell volume; (2) extensive development of short, parallel, frequently concentric cisternae of GER that produce dense proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) progressive formation of saturated lipid droplets; their continuous enlargement and fusion; (5) formation of small accumulations of glycogen particles scattered between and among lipid droplets in the cytoplasm of maturing vitellocytes; (6) concentration of dense proteinaceous granules in the peripheral layer of cytoplasm, around the cell plasma membrane; and (7) vacuolization of cytoplasm of mature vitellocytes accompanied by a rapid increase in its volume. A new, unreported type of dense proteinaceous granules, situated around the limiting plasma membranes of mature vitellocytes, is described. Vitellogenesis evidently differs from that with typical shell-globules and shell-globule clusters previously reported in other taxa of lower cestodes. Cytochemical staining with periodic acidthiosemicarbazide-silver proteinate for glycogen indicates a strongly positive reaction for glycogen particles between and around large unsaturated lipid droplets of the maturing and mature vitellocytes. Some hypotheses concerning the interrelationship between this pattern of vitellogenesis, possible mode of egg formation, embryonic development and diphyllidean life cycle, and their phylogenetic implications are drawn and discussed.
12

Ultrastructural and cytochemical studies on vitellogenesis in the trypanorhynch cestode Parachristianella trygonis Dollfus, 1946 [Eutetrarhynchidae]

51%
Swiderski Z., Miquel J., Neifar L., Mackiewicz J. S.
Acta Parasitologica
|
2007
|
tom 52
|
nr 2
During vitellogenesis in Parachristianella trygonis Trypanorhyncha, Eutetrarhynchidae) we distinguished four stages: (1) gonial or stem cell stage; (2) early differentiation stage concentrated on protein synthetic activity and shell-globule formation; (3) advanced differentiation stage with main cell activity concentrated on carbohydrate synthesis (glycogenesis) and massive glycogen storage in the form of α-glycogen rosettes and β-glycogen particles; and finally (4) mature vitellocyte stage. Early vitellocyte maturation is characterised by: (1) an increase in cell volume; (2) extensive development of large, parallel cisternae of GER that produce proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) continuous enlargement of proteinaceous granules within vacuoles and their transformation into shell-globule clusters composed of heterogeneous material. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for polysaccharides indicated a strongly positive reaction for the presence of α-glycogen rosettes and β-glycogen particles in the advanced stage of vitellocyte maturation. Both protein synthesis for shell-globule formation and carbohydrate synthesis or glycogenesis, important storage of nutritive reserves for the developing embryos, observed during cytodifferentiation of P. trygonis vitellocytes overlap in time to some extent. Mature vitelline cells are very rich in three types of cell inclusions accumulated in large amounts in their cytoplasm: (1) shell-globule clusters, playing an important role in egg-shell formation; (2) numerous large lipid droplets, as well as a high accumulation of lipid and α-glycogen rosettes and β-glycogen particles that undoubtedly represent important nutritive reserves for the developing embryos. Despite the fact that the type of vitellogenesis and ultrastructure of the mature vitellocyte in P. trygonis appears to differ to some extent from those of three other trypanorhynch species, its general pattern and ultrastructure greatly resembles those observed in other lower cestodes. Factors that may have contributed to the qualitative and quantitative variation in lipids during vitellogenesis among the four species of Trypanorhyncha, are identified and discussed.
13

Ultrastructural studies on the reproductive system of progenetic Diplocotyle olrikii [Cestoda, Spathebothriidea]: Ovarian tissue

51%
Poddubnaya L. G., Mackiewicz J. S., Brunanska M., Scholz T.
Acta Parasitologica
|
2005
|
tom 50
|
nr 3
The ultrastructure of the ovary and oogenesis are described from the immature and sexually mature female reproductive system of the progenetic spathebothriidean tapeworm, Diplocotyle olrikii from the body cavity of Gammarus oceanicus. Two types of cells are described: germinal (oogonia, oocytes) and interstitial. A comparison is made of the fine structure of oogonia, early and advanced maturing oocytes and mature oocytes. Two types of inclusions, cortical granules and lipid droplets, are produced by maturing oocytes, and remain in the cytoplasm of mature oocytes within the ovovitelline duct lumen while only lipid droplets are evident in the oocyte cytoplasm of intrauterine eggs. The fate and possible functions of both inclusions are discussed. The interstitial component of the ovary is a syncytium. The maturing oocyte surface is prolonged into lamellae, forming a lamellar mesh with adjacent germ cells and close association of interstitial mitochondria. Deep invaginations of the ovarian basement layer between numerous folds of ovarian lobules facilitate close contact of the interstitium and sarcoplasmic glycogen-rich processes with maturing oocytes. Synchronism in maturity among all of the oocytes in the ovary is shown at different stages of oogenesis. Such a pattern of oogenesis results in the production of many eggs at the same stage of development and is considered an adaptation for the dissemination of fertilized eggs that occurs only at the death of the gammarid host.
14

Cytochemical and ultrastructural study on vitellogenesis in caryophyllidean cestode Khawia armeniaca [Cholodkovski, 1915]

51%
Swiderski Z., Brunanska M., Poddubnaya L. G., Mackiewicz J. S.
Acta Parasitologica
|
2004
|
tom 49
|
nr 1
Vitellogenesis in Khaxvia armeniaca was examined by means of transmission electron microscopy (TEM) and cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) for specific detection of glycogen at the ultrastructural level. Mature vitelline follicles consist of cells in various stages of development, progressing from immature cells of gonial type near the periphery to mature vitellocytes towards the centre. Maturation of vitelline cells is characterized by: (1) increase in cell volume; (2) increase in nuclear surface area restoring the N/C ratio; (3) nucleolar transformation; (4) extensive development of large parallel cisternae of GER, the shell-protein producing units; (5) development of Golgi complexes engaged in shell-granule/shell-globule vitelline material formation and package; (6) formation and storage of glycogen in the cytoplasm; (7) simultaneous, independent formation and storage of intranuclear glycogen; (8) continuous fusion of small shell-granules into larger shell-globules that fuse into large shell-globule clusters with a progressive increase in the number and size of the latter; and (9) degeneration of GER in the medial layer of vitellocyte cytoplasm with degenerative changes and accumulation of glycogen and shell-globule clusters within the cytoplasm, associated with a massive accumulation of glycogen in the nucleus. The functional significance of the large amount of nuclear and cytoplasmic glycogen and numerous shell-globule clusters is analysed. The ultrastructural aspect of vitellogenesis is compared with that in other monozoic and polyzoic cestodes. Conclusions concerning the interrelationships of vitellogenesis patterns and ultrastructural cytochemistry of mature vitellocytes to the various types of embryogenesis, are drawn and discussed.
15

Ultrastructure of spermiogenesis in the caryophyllidean cestode Wenyonia virilis Woodland, 1923, with re-assessment of flagellar rotation in Glaridacris catostomi Cooper, 1920

51%
Miquel J., Swiderski Z., Mackiewicz J. S., Ibraheem M. H.
Acta Parasitologica
|
2008
|
tom 53
|
nr 1
The ultrastructure of spermiogenesis in Wenyonia virilis Woodland, 1923, a caryophyllaeid cestode from the silurid Nile fish Synodontis schall (Bloch et Schneider, 1801), is described by means of transmission electron microscopy (TEM) for the first time. Spermiogenesis follows the characteristic caryophyllidean type and is initiated by the formation of a differentiation zone. This area, delimited at its base by a ring of arching membranes and bordered by cortical microtubules, contains two centrioles associated with typical striated rootlets with a reduced intercentriolar body between them. The apical area of the differentiation zone exhibits electron-dense material that is present only during the early stages of spermiogenesis. Only one of the centrioles develops into a free flagellum that grows at an angle of >90° in relation to the cytoplasmic extension. Spermiogenesis is also characterized by a flagellar rotation and a proximodistal fusion of the flagellum with the cytoplasmic extension. The most interesting features observed in W virilis are the presence of a reduced, very narrow intercentriolar body and the unique type of flagellar rotation >90°. Results are compared with those described in two caryophyllideans, Glaridacris catostomi Cooper, 1920 and Khawia armeniaca (Cholodkovski, 1915). Contrary to the original report of Świderski and Mackiewicz (2002), that flagellar rotation has never been observed in spermiogenesis of G. catostomi, re-assessment of their description and illustrations leads us to conclude that flagellar rotation must logically occur in that species. The value of various morphological features of sperm in phylogenetic inference is discussed.
16

Fine structure of egg-forming complex ducts, eggshell formation and supporting neuronal plexus in progenetic Diplocotyle olrikii [Cestoda, Spathebothriidea]

45%
Poddubnaya L. G., Mackiewicz J. S., Swiderski Z., Brunanska M., Scholz T.
Acta Parasitologica
|
2005
|
tom 50
|
nr 4
Ultrastructural descriptions of the oviduct, fertilization canal, seminal receptacle, ovovitelline duct, vitelline reservoir, ootype, Mehlis' gland, proximal uterus, and neurosecretory elements associated with egg-forming ducts are given for the progenetic spathebothriidean tapeworm, Diplocotyle olrikii from the body cavity of Gammarus oceanicus. The functional significance of cortical granules of the oocyte, as necessary elements for joining vitelline material to an oocyte in the ovovitelline duct, is established. The proximal ootype has a vesicular epithelium and is the site of initial, nascent eggshell formation. Precursors of nascent eggshell are vesicles, synthesized in both the proximal ootype wall and vitelline cytoplasm that become associated with the newly formed shell. Major shell structure comes from subsequent deposition of shell globules from a disintegration of vitelline clusters. Mehlis' gland has a single secretory cell type. Secretory granules from Mehlis' gland become associated with the developing egg that passes through to the distal ootype and proximal uterus where egg-formation is completed. It is not known, however, whether Mehlis' gland secretion promotes breakdown of free vitelline cells, liberation of shell globules, confluence of shell globules on the developing eggshell or provides further structural components for the shell. Despite some differences in ootype morphology, the basic process of eggshell formation in D. olrikii may share much in common with the Pseudophyllidea and Caryophyllidea. Small vesicles and dense-core vesicles are in nerve terminals near duct musculature. Nerve terminals with large dense vesicles are described near, in, and within the seminal receptacle, fertilization canal and distal ootype. The possible physiological effects of exocrine neurosecretions are discussed.
17

Ultrastructure and cytochemistry of vitellogenesis in Wenyonia virilis Woodland, 1923 [Cestoda, Caryophyllidea]

39%
Swiderski Z., Mlocicki D., Mackiewicz J. S., Miquel J., Ibraheem M. H., Brunanska M.
Acta Parasitologica
|
2009
|
tom 54
|
nr 2
131-142
Vitellogenesis in Wenyonia virilis was examined by transmission electron microscopy (TEM), including the cytochemical detection of glycogen at the ultrastructural level with the periodic acid-thiosemicarbazide-silver proteinate (PA-TSC-SP) technique. Mature vitelline follicles have cells in various stages of development, progressing from immature cells of gonial type near the periphery of the follicle to maturing and mature vitellocytes towards the centre. Maturation is characterized by: (1) increase in cell volume; (2) increase in nuclear surface area restoring the N/C (nucleo-cytoplasmic) ratio; (3) nucleolar transformation; (4) extensive development of parallel cisternae of GER, the shell-protein producing units; (5) development of Golgi complexes, engaged in shell-granule/shell-globule formation and packaging; (6) synthesis and storage of glycogen in the cytoplasm; (7) simultaneous, independent formation and storage of intranuclear glycogen; (8) continuous fusion of small shell-granules into larger shell-globules and fusion of these into large shell-globule clusters with a progressive increase in the number and size of the latter; and (9) disintegration of GER in the medial layer of vitellocyte cytoplasm, degenerative changes and accumulation of glycogen and shell-globule clusters within the cytoplasm. The functional significance of numerous shell-globule clusters and the relatively small amount of nuclear and cytoplasmic glycogen is analysed. Unlike vitellogenesis of other caryophyllids, the nuclear glycogen of mature vitellocytes in W. virilis is randomly dispersed in the nucleoplasm and never forms a high central accumulation, the so-called “nuclear vacuole”. The nutritive function of vitellocytes appears greatly reduced in W. virilis, a fact perhaps related to the intrauterine development of the early embryos. The ultrastructure of vitellogenesis in W. virilis is compared with that in other lower cestodes, both monozoic and polyzoic. Conclusions concerning interrelationships of the vitellogenesis pattern of the ultrastructural cytochemistry of mature vitellocytes of W. virilis to intrauterine embryonation, absence of uterine glands and an extensive uterus characteristic for this species, are drawn and discussed.
18

Ultrastructure of vitellocytes in the cestode Progrillotia pastinacae Dollfus, 1946 [Trypanorhyncha, Progrillotiidae]

39%
Swiderski Z., Miquel J., Mlocicki D., Neifar L., Grytner-Ziecina B., Mackiewicz J. S.
Acta Parasitologica
|
2006
|
tom 51
|
nr 3
The present study describes the ultrastructure of mature vitellocytes of the trypanorhynch cestode Progrillotia pastinacae Dollfus, 1946 (Progrillotiidae), a parasite of the common stingray Dasyatis pastinaca (Linnaeus, 1758) (Dasyatidae). The vitelline cells of this species measure about 24 μm in length and about 20 μm in width. They have small, elongated, slightly lobulated nuclei, about 4–5 μm in length, with large dense elongated nucleoli and numerous irregularly-shaped dense clumps of heterochromatin. The extensive cytoplasm is rich in numerous cell organelles and cell inclusions. While the perinuclear cytoplasm contains numerous long parallel cisternae of GER, ribo-and polyribosomes, several Golgi complexes and mitochondria, the peripheral cytoplasm contains predominantly three types of cell inclusions: a great number of large lipid droplets, several shell globule clusters, and a very small amount of glycogen-like particles. The most characteristic features of vitellocytes in P. pastinacae are having almost no traces of glycogen and the great number of large, highly osmiophobic lipid droplets representing saturated fatty acids. The presence of large amounts of lipids also in two other trypanorhynchs, Grillotia erinaceus (Beneden, 1858) Guiart, 1927 and Dollfusiella spinulifera (Beveridge et Jones, 2000) Beveridge, Neifar et Euzet, 2004, is in strong contrast to the condition in the most evolved cestodes, Cyclophyllidea, that usually show no trace of lipids.
19

Vitellogenesis in Mosgovoyia ctenoides [Railliet, 1890] Beveridge, 1978 [Cyclophyllidea, Anoplocephalidae]

39%
Swiderski Z., Mlocicki D., Eira C., Miquel J., Grytner-Ziecina B., Mackiewicz J. S.
Acta Parasitologica
|
2005
|
tom 50
|
nr 4
Vitellogenesis in Mosgovoyia ctenoides was examined by means of transmission electron microscopy. Mature vitelline follicles consist of cells in various stages of development, progressing from immature cells of gonial type near the periphery to mature vitellocytes towards the centre. Maturation is characterized by: (1) increase in cell volume; (2) extensive development of large parallel cisternae of granular endoplasmic reticulum (GER), the vitelline material producing units; (3) development of Golgi complexes engaged in vitelline material package; (4) continuous fusion of small vesicles into larger vitelline vesicles and fusion of these into a single very large vesicle, which is characteristic for mature vitellocytes of this tapeworm. Vitellogenesis in M ctenoides is compared with that in other cestodes. Some conclusions concerning the interrelationship between the vitellogenesis pattern and the type of embryogenesis are drawn and discussed.
20

Ultrastructural and cytochemical studies on vitellogenesis in trypanorhynch cestode Dollfusiella spinulifera Beveridge, Neifar et Euzet, 2004 [Eutetrarhynchidae]

39%
Swiderski Z., Miquel J., Mlocicki D., Neifar L., Grytner-Ziecina B., Mackiewicz J. S.
Acta Parasitologica
|
2006
|
tom 51
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nr 3
The first description of vitellogenesis in the Trypanorhyncha is presented in this paper. Though the type of vitellogenesis and mature vitellocyte in Dollfusiella spinulifera appear to be unique among the Eucestoda, to some extent they resemble that observed in the lower cestodes, namely the Tetraphyllidea and Pseudophyllidea. Maturation is characterized by: (1) an increase in cell volume; (2) extensive development of large, parallel, frequently concentric cisternae of GER that produce proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) continuous enlargement of proteinaceous granules within vesicles and their transformation into shell globule clusters; and (5) progressive fusion of all vesicles, with flocculent material containing the proteinaceous granules and shell globule clusters, into a single very large vesicle that characterises mature vitellocytes of this tapeworm. Cell inclusions in and around the large vesicle consist of flocculent material of a very low density, a few shell globule clusters, moderately dense proteinaceous granules and numerous large droplets of unsaturated lipids. A new previously unreported mode of transformation of proteinaceous granules into shell globule clusters, that evidently differs from that of pseudophyllideans and tetraphyllideans, is described. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for polysaccharides indicates a strongly positive reaction for membrane-bound glycoproteins in all membranous structures such as GER, mitochondria, Golgi complexes, nuclear and cell plasma membranes. Similar staining revealed β-glycogen particles scattered in the cytoplasm of maturing vitellocytes. Typical cytoplasmic β-glycogen particles appear mainly during early vitellocyte maturation but it is characteristic for this species that they are only seldom visible in mature cells. Some working hypotheses concerning the interrelationship between this particular pattern of vitellogensis, possible mode of egg formation in D. spinulifera, its embryonic development and trypanorhynchean life cycle, are drawn and discussed.
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