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Tomáš Scholz - One of the best experts on this subject based on the ideXlab platform.
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spermatozoa of tapeworms platyhelminthes Eucestoda advances in ultrastructural and phylogenetic studies
Biological Reviews, 2009Co-Authors: Celine Levron, Mikuláš Oros, Jordi Miquel, Tomáš ScholzAbstract:: New data on spermiogenesis and the ultrastructure of spermatozoa of 'true' tapeworms (Eucestoda) are summarized. Since 2001, more than 50 species belonging to most orders of the Eucestoda have been studied or reinvestigated, particularly members of the Caryophyllidea, Spathebothriidea, Diphyllobothriidea, Bothriocephalidea, Trypanorhyncha, Tetraphyllidea, Proteocephalidea, and Cyclophyllidea. A new classification of spermatozoa of eucestodes into seven basic types is proposed and a key to their identification is given. For the first time, a phylogenetic tree inferred from spermatological characters is provided. New information obtained in the last decade has made it possible to fill numerous gaps in the character data matrix, enabling us to carry out a more reliable analysis of the evolution of ultrastructural characters of sperm and spermiogenesis in eucestodes. The tree is broadly congruent with those based on morphological and molecular data, indicating that convergent evolution of sperm characters in cestodes may not be as common as in other invertebrate taxa. The main gaps in the current knowledge of spermatological characters are mapped and topics for future research are outlined, with special emphasis on those characters that might provide additional information about the evolution of tapeworms and their spermatozoa. Future studies should be focused on representatives of those major groups (families and orders) in which molecular data indicate paraphyly or polyphyly (e.g. 'Tetraphyllidea' and Trypanorhyncha) and on those that have a key phylogenetic position among eucestodes (e.g. Diphyllidea, 'Tetraphyllidea', Lecanicephalidea, Nippotaeniidea).
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Revision of the order Bothriocephalidea Kuchta, Scholz, Brabec & Bray, 2008 (Eucestoda) with amended generic diagnoses and keys to families and genera
Systematic Parasitology, 2008Co-Authors: Roman Kuchta, Tomáš Scholz, Rodney A BrayAbstract:The tapeworm order Bothriocephalidea Kuchta, Scholz, Brabec & Bray, 2008 (Platyhelminthes: Eucestoda), which has until recently formed part of the suppressed order Pseudophyllidea, is revised. Four new genera, namely Andycestus n. g. [type- and only species A. abyssmus (Thomas, 1953 ) n. comb.], Plicocestus n. g. [type- and only species P. janickii (Markowski, 1971 ) n. comb.] (both Bothriocephalidae), Mesoechinophallus n. g. [type-species M. hyperogliphe (Tkachev, 1979) n. comb.; other species M. major (Takao, 1986 ) n. comb. (Echinophallidae)] and Kimocestus n. g. [type- and only species K. ceratias (Tkachev, 1979) n. comb.] (Triaenophoridae) are proposed. Parabothriocephaloides Yamaguti, 1934 , Penetrocephalus Rao, 1960 and Tetracampos Wedl, 1861 are resurrected as valid genera, whereas Alloptychobothrium Yamaguti, 1968 (newly synonymised with Plicatobothrium Cable & Michaelis, 1967 ), Capooria Malhotra, 1985 and Coelobothrium Dollfus, 1970 (syns of Bothriocephalus Rudolphi 1808), Fissurobothrium Roitman, 1965 (syn. of Bathybothrium Lühe, 1902 ), Paratelemerus Gulyaev, Korotaeva & Kurochkin, 1989 (syn. of Parabothriocephaloides Yamaguti, 1934 ) and Tetrapapillocephalus Protasova & Mordvinova, 1986 (syn. of Oncodiscus Yamaguti, 1934 ) are considered to be invalid. A recently erected genus, Dactylobothrium Srivastav, Khare & Jadhav, 2006, and its type- and only species, D. choprai Srivastav, Khare & Jadhav, 2006, are considered to be unrecognisable, because their descriptions contain a number of obvious errors and also indicate that a mixture of several taxa, probably of at least two cestode orders, were studied. Parabothriocephaloides wangi nom. nov. is proposed for Parabothriocephalus psenopsis Wang, Liu & Yang, 2004 from Psenopsis anomala in China in order to avoid a secondary homonymy. All 46 genera considered to be valid are revised, with their generic diagnoses amended on the basis of a critical examination of extensive museum and newly collected specimens. Despite apparent paraphyly or polyphyly of some bothriocephalidean families, especially the Triaenophoridae, the current classification restricted to four families, proposed by Bray et al. ( 1994 ), namely the Bothriocephalidae, Echinophallidae, Philobythiidae and Triaenophoridae, is provisionally retained with slight modifications until more molecular data on most genera are available. Keys to families and genera are provided.
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revision of the order bothriocephalidea kuchta scholz brabec bray 2008 Eucestoda with amended generic diagnoses and keys to families and genera
Systematic Parasitology, 2008Co-Authors: Roman Kuchta, Tomáš Scholz, Rodney A BrayAbstract:The tapeworm order Bothriocephalidea Kuchta, Scholz, Brabec & Bray, 2008 (Platyhelminthes: Eucestoda), which has until recently formed part of the suppressed order Pseudophyllidea, is revised. Four new genera, namely Andycestus n. g. [type- and only species A. abyssmus (Thomas, 1953) n. comb.], Plicocestus n. g. [type- and only species P. janickii (Markowski, 1971) n. comb.] (both Bothriocephalidae), Mesoechinophallus n. g. [type-species M. hyperogliphe (Tkachev, 1979) n. comb.; other species M. major (Takao, 1986) n. comb. (Echinophallidae)] and Kimocestus n. g. [type- and only species K. ceratias (Tkachev, 1979) n. comb.] (Triaenophoridae) are proposed. Parabothriocephaloides Yamaguti, 1934, Penetrocephalus Rao, 1960 and Tetracampos Wedl, 1861 are resurrected as valid genera, whereas Alloptychobothrium Yamaguti, 1968 (newly synonymised with Plicatobothrium Cable & Michaelis, 1967), Capooria Malhotra, 1985 and Coelobothrium Dollfus, 1970 (syns of Bothriocephalus Rudolphi 1808), Fissurobothrium Roitman, 1965 (syn. of Bathybothrium Luhe, 1902), Paratelemerus Gulyaev, Korotaeva & Kurochkin, 1989 (syn. of Parabothriocephaloides Yamaguti, 1934) and Tetrapapillocephalus Protasova & Mordvinova, 1986 (syn. of Oncodiscus Yamaguti, 1934) are considered to be invalid. A recently erected genus, Dactylobothrium Srivastav, Khare & Jadhav, 2006, and its type- and only species, D. choprai Srivastav, Khare & Jadhav, 2006, are considered to be unrecognisable, because their descriptions contain a number of obvious errors and also indicate that a mixture of several taxa, probably of at least two cestode orders, were studied. Parabothriocephaloides wangi nom. nov. is proposed for Parabothriocephalus psenopsis Wang, Liu & Yang, 2004 from Psenopsis anomala in China in order to avoid a secondary homonymy. All 46 genera considered to be valid are revised, with their generic diagnoses amended on the basis of a critical examination of extensive museum and newly collected specimens. Despite apparent paraphyly or polyphyly of some bothriocephalidean families, especially the Triaenophoridae, the current classification restricted to four families, proposed by Bray et al. (1994), namely the Bothriocephalidae, Echinophallidae, Philobythiidae and Triaenophoridae, is provisionally retained with slight modifications until more molecular data on most genera are available. Keys to families and genera are provided.
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Phylogenetic relationships of the monozoic tapeworms (Eucestoda: Caryophyllidea) inferred from morphological characters
Systematic Parasitology, 2008Co-Authors: Mikuláš Oros, Vladimíra Hanzelová, Tomáš Scholz, John S. MackiewiczAbstract:Phylogenetic relationships of all genera of the order Caryophyllidea, possibly the earliest branching group of true tapeworms (Platyhelminthes: Eucestoda) and the only one that is monozoic, have been assessed for the first time. Results of this cladistic analysis, inferred from 30 unweighted morphological characters, are only partly congruent with the existing classification, which consists of four families based on the position of the inner longitudinal muscles in relation to the internal genital organs. Whereas all but five genera of the Caryophyllaeidae form a monophyletic clade, members of the Capingentidae are split, occurring within six unrelated groups. The Lytocestidae is also paraphyletic, as some genera appear in four unrelated clades. Archigetes appears in a derived clade, indicating that its direct (monoxenous) life-cycle involving only tubificid oligochaetes is secondarily derived and not plesiomorphic among the Eucestoda, as postulated by some authors.
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suppression of the tapeworm order pseudophyllidea platyhelminthes Eucestoda and the proposal of two new orders bothriocephalidea and diphyllobothriidea
International Journal for Parasitology, 2008Co-Authors: Roman Kuchta, Tomáš Scholz, Jan Brabec, Rodney A BrayAbstract:Abstract Pseudophyllidea van Beneden in Carus, 1863, a well recognised order of tapeworms (Platyhelminthes: Eucestoda), is suppressed because it is composed of two phylogenetically unrelated groups, for which the new names Bothriocephalidea and Diphyllobothriidea are proposed. The new orders differ from each other in the following characters: (i) position of the genital pore: on the dorsal, dorso-lateral or lateral aspects and posterior to the ventral uterine pore in the Bothriocephalidea versus on the ventral aspect of segments and anterior to the uterine pore in the Diphyllobothriidea; (ii) the presence of a muscular external seminal vesicle in the Diphyllobothriidea, which is absent in the Bothriocephalidea; (iii) the presence of a uterine sac in the Bothriocephalidea, which is absent in the Diphyllobothriidea; and (iv) the spectrum of definitive hosts: mainly teleost fishes, never homoiothermic vertebrates in the Bothriocephalidea, versus tetrapods, most frequently mammals, in the Diphyllobothriidea, with species of Diphyllobothrium, Spirometra and Diplogonoporus parasitic in humans. The Diphyllobothriidea, which includes 17 genera in four families (Digramma is synonymised with Ligula), is associated with cestode groups that have a range of plesiomorphic characters (Haplobothriidea and Caryophyllidea), whereas the Bothriocephalidea, consisting of 41 genera grouped in four families, is the sister-group to the ‘acetabulate’ or ‘tetrafossate’ cestodes, which are generally regarded as having derived characters.
Mikuláš Oros - One of the best experts on this subject based on the ideXlab platform.
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spermatozoa of tapeworms platyhelminthes Eucestoda advances in ultrastructural and phylogenetic studies
Biological Reviews, 2009Co-Authors: Celine Levron, Mikuláš Oros, Jordi Miquel, Tomáš ScholzAbstract:: New data on spermiogenesis and the ultrastructure of spermatozoa of 'true' tapeworms (Eucestoda) are summarized. Since 2001, more than 50 species belonging to most orders of the Eucestoda have been studied or reinvestigated, particularly members of the Caryophyllidea, Spathebothriidea, Diphyllobothriidea, Bothriocephalidea, Trypanorhyncha, Tetraphyllidea, Proteocephalidea, and Cyclophyllidea. A new classification of spermatozoa of eucestodes into seven basic types is proposed and a key to their identification is given. For the first time, a phylogenetic tree inferred from spermatological characters is provided. New information obtained in the last decade has made it possible to fill numerous gaps in the character data matrix, enabling us to carry out a more reliable analysis of the evolution of ultrastructural characters of sperm and spermiogenesis in eucestodes. The tree is broadly congruent with those based on morphological and molecular data, indicating that convergent evolution of sperm characters in cestodes may not be as common as in other invertebrate taxa. The main gaps in the current knowledge of spermatological characters are mapped and topics for future research are outlined, with special emphasis on those characters that might provide additional information about the evolution of tapeworms and their spermatozoa. Future studies should be focused on representatives of those major groups (families and orders) in which molecular data indicate paraphyly or polyphyly (e.g. 'Tetraphyllidea' and Trypanorhyncha) and on those that have a key phylogenetic position among eucestodes (e.g. Diphyllidea, 'Tetraphyllidea', Lecanicephalidea, Nippotaeniidea).
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Vitellogenesis in the cestode Atractolytocestus huronensis Anthony, 1958 (Caryophyllidea: Lytocestidae)
Parasitology Research, 2009Co-Authors: Magdaléna Bruňanská, Petra Drobníková, Mikuláš OrosAbstract:Vitellogenesis in the parthenogenetic caryophyllidean tapeworm Atractolytocestus huronensis Anthony, 1958, parasitizing the carp Cyprinus carpio L., has been examined using light (LM) and transmission electron microscopy and cytochemical staining with periodic acid–thiosemicarbazide–silver proteinate for glycogen. It was found that formation of vitellocytes shares the same basic patterns in lower tapeworms with parthenogenetic and normal reproduction. Each vitelline follicle of A . huronensis consists of vitellocytes at various stages of development and an interstitial tissue. Projections of the interstitial tissue surround each vitellocyte and extend as a cytoplasmic sheath on the follicular periphery. In contrary to other Eucestoda, interstitial tissue of A . huronensis includes numerous electron-dense vesicles of various sizes. Maturing and mature vitellocytes contain vitelline material in the form of single small shell globules, which may gradually fuse and give rise to the large shell globule clusters. Shell globule clusters are of two types in A . huronensis . Additional vitelline material is represented by single “lamellar” granules and glycogen in the cytoplasm of mature vitellocytes. The ultrastructural features of vitellogenesis and/or vitellocyte in A. huronensis are compared with that in other caryophyllideans and/or Neodermata.
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Phylogenetic relationships of the monozoic tapeworms (Eucestoda: Caryophyllidea) inferred from morphological characters
Systematic Parasitology, 2008Co-Authors: Mikuláš Oros, Vladimíra Hanzelová, Tomáš Scholz, John S. MackiewiczAbstract:Phylogenetic relationships of all genera of the order Caryophyllidea, possibly the earliest branching group of true tapeworms (Platyhelminthes: Eucestoda) and the only one that is monozoic, have been assessed for the first time. Results of this cladistic analysis, inferred from 30 unweighted morphological characters, are only partly congruent with the existing classification, which consists of four families based on the position of the inner longitudinal muscles in relation to the internal genital organs. Whereas all but five genera of the Caryophyllaeidae form a monophyletic clade, members of the Capingentidae are split, occurring within six unrelated groups. The Lytocestidae is also paraphyletic, as some genera appear in four unrelated clades. Archigetes appears in a derived clade, indicating that its direct (monoxenous) life-cycle involving only tubificid oligochaetes is secondarily derived and not plesiomorphic among the Eucestoda, as postulated by some authors.
Daniel R. Brooks - One of the best experts on this subject based on the ideXlab platform.
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ophiotaenia bonneti sp n Eucestoda proteocephalidea a parasite of rana vaillanti anura ranidae in costa rica
Folia Parasitologica, 2006Co-Authors: Alain De Chambrier, Sandrine Claire Coquille, Daniel R. BrooksAbstract:Ophiotaenia bonneti sp. n. is described from the intestine of the frog Rana vaillanti Brocchi, 1877 (Anura: Ranidae) from San Gerardo, Guanacaste, Costa Rica. The new species is characterized by the testes 100-177 in number, the genital pores situated anteriorly, the osmoregulatory canals overlapping the testis field, the cirrus pouch length as 15-24% of proglottis width, and the uterus with 18-32 ramified diverticula on each side. It differs from the 23 known species of the genus Ophiotaenia La Rue, 1911, parasitic in amphibians, by one to several morphological characters. It differs from O. gracilis Jones, Cheng et Gillespie, 1958, the most morphologically similar species, in the sucker diameter in % of scolex diameter and in the morphology of the eggs - funnel-like depression and embryophore closely investing the oncosphere in O. gracilis. We generally observe a very low mean prevalence of the Proteocephalidea in Neotropical amphibians (about 0.41%-3%), but in the case of some host species, the prevalence can reach up to 25%. We conclude that these cestodes exhibit a strict host specificity of the oioxene type. Ophiotaenia junglensis Srivastava et Capoor, 1980 is considered a species inquirenda. Batrachotaenia hernandezi (Flores-Barroeta, 1955) becomes Ophiotaenia hernandezi (Flores-Barroeta, 1955) comb. n., B. tigrina (Woodland, 1925) becomes O. tigrina (Woodland, 1925) comb. n. and B. ceratophryos (Parodi et Widakowich, 1916) becomes O. ceratophryos (Parodi et Widakowich, 1916) comb. n.
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taxonomic revision of rhinebothroides Eucestoda tetraphyllidea phyllobothriidae parasites of neotropical freshwater stingrays rajiformes myliobatoidei potamotrygonidae
Journal of Parasitology, 2003Co-Authors: Fernando P L Marques, Daniel R. BrooksAbstract:Extensive new collections of specimens of Rhinebothroides spp. from a wide range of Neotropical freshwater potamotrygonid stingrays in numerous localities permitted critical evaluation of the validity of the 7 nominal species in the genus. Some qualitative characters previously used in the taxonomy of this group are highly variable within and among populations, and most morphometric and meristic characters thought to have taxonomic value for this group overlapped among several previously defined nominal species. Characters that were consistent throughout populations and that clearly define morphotypes supported recognition of 4 species: R. freitasi (syn. R. circularisi and R. venezuelensis), R. glandularis (syn. R. mclennanae), R. moralarai, and R. scorzai. We provide a taxonomic review of the genus, 8 additional host records, 7 new localities, and an identification key.
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calliobothrium spp Eucestoda tetraphyllidea onchobothriidae in mustelus schmitti chondrichthyes carcharhiniformes from argentina and uruguay
Journal of Parasitology, 2002Co-Authors: Veronica A Ivanov, Daniel R. BrooksAbstract:Three species of Calliobothrium inhabit the spiral intestine of Mustelus schmitti in Argentina and Uruguay. Calliobothrium verticillatum australis is redescribed and its taxonomic status modified to species as C. australis. Calliobothrium barbarae n. sp. can be distinguished from all other species of Calliobothrium, which are small bodied, nonlaciniate, and without accessory piece between the bases of axial hook, by worm length, number of segments, cocoon morphology, and hooks shape. Calliobothrium lunae n. sp. is different from other Calliobothrium spp., which are small bodied, nonlaciniate, and have an accessory piece, by the number of segments and testes, hook shape, cocoon morphology, and the presence of ciliumlike projections on the distal surface of muscular pads. Calliobothrium australis is clearly distinguished from other large-bodied, laciniate species of the genus by worm length, number of testes, ovary shape, cocoon morphology, hook shape, and in being hyperapolytic. The oioxenous specificity i...
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anindobothrium n gen Eucestoda tetraphyllidea inhabiting marine and freshwater potamotrygonid stingrays
Journal of Parasitology, 2001Co-Authors: Fernando P L Marques, Daniel R. Brooks, Carlos A LassoAbstract:Anindobothrium n. gen. is proposed to accommodate Caulobothrium anacolum inhabiting Himantura schmardae from Colombia, and 2 new species, one inhabiting Potamotrygon orbigny in Brazil and the other inhabiting Paratrygon aereiba in Venezuela. Members of the new genus resemble members of Pararhinebothroides, Rhinebothroides, and Anthocephalum by having bothridia with poorly differentiated apical suckers and vasa deferentia expanded into external seminal vesicles. It further resembles Pararhinebothroides, Rhinebothroides, and Anthocephalum cairae by having vas deferens inserted near the poral rather than aporal end of the cirrus sac. The 3 species assigned to the new genus form an apparent monophyletic group, based on the possession of 3 putative synapomorphies: (1) genital pores in the anterior ¼ of the proglottid, a trait that is unusual, but not unique, among phyllobothriids; (2) anteroventral ovarian lobes converging to the center of the proglottid, a character not previously reported for phyllobothriids...
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two new species of oochoristica luhe 1898 Eucestoda cyclophyllidea anoplocephalidae linstowiinae parasitic in ctenosaura spp iguanidae from costa rica and mexico
Journal of Parasitology, 1999Co-Authors: Daniel R. Brooks, Perezponce G De Leon, Luis GarciaprietoAbstract:: Five species of Oochoristica, Oochoristica osheroffi, Oochoristica gracewileyae, Oochoristica whitentoni, and 2 new species described herein have strobilae longer than 200 mm, many secondary ovarian lobes, and testes extending anteriorly to midovarian level. A combination of 3 characters distinguishes the 5 species from each other. Oochoristica osheroffi has an average of 68 testes per proglottid, ovarian lobes wider than long, and osmoregulatory canals not forming an anastomosing plexus; O. gracewileyae has an average of 113 testes per proglottid, ovarian lobes longer than wide, and osmoregulatory canals not forming an anastomosing plexus; O. whitentoni has an average of 125 testes per proglottid, ovarian lobes wider than long, and osmoregulatory canals forming an anastomosing plexus; a new species in Ctenosaura similis from Costa Rica has an average of 62 testes per proglottid, ovarian lobes longer than wide, and osmoregulatory canals forming an anastomosing plexus; and a new species in Ctenosaura pectinata from Mexico has an average of 122 testes per progottid, ovarian lobes longer than wide, and osmoregulatory canals forming an anastomosing plexus. Oochoristica gracewileyae differs from the other 4 species by having genital pores 10-15% rather than 25-35% of proglottid length from the anterior end and by having convoluted rather than straight or sinuous transverse osmoregulatory canals. The new species from Mexico differs from the other 4 species and apparently from all described species of Oochoristica thus far by possessing darkly staining granules throughout the parenchyma of the scolex.
Jordi Miquel - One of the best experts on this subject based on the ideXlab platform.
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spermatozoa of tapeworms platyhelminthes Eucestoda advances in ultrastructural and phylogenetic studies
Biological Reviews, 2009Co-Authors: Celine Levron, Mikuláš Oros, Jordi Miquel, Tomáš ScholzAbstract:: New data on spermiogenesis and the ultrastructure of spermatozoa of 'true' tapeworms (Eucestoda) are summarized. Since 2001, more than 50 species belonging to most orders of the Eucestoda have been studied or reinvestigated, particularly members of the Caryophyllidea, Spathebothriidea, Diphyllobothriidea, Bothriocephalidea, Trypanorhyncha, Tetraphyllidea, Proteocephalidea, and Cyclophyllidea. A new classification of spermatozoa of eucestodes into seven basic types is proposed and a key to their identification is given. For the first time, a phylogenetic tree inferred from spermatological characters is provided. New information obtained in the last decade has made it possible to fill numerous gaps in the character data matrix, enabling us to carry out a more reliable analysis of the evolution of ultrastructural characters of sperm and spermiogenesis in eucestodes. The tree is broadly congruent with those based on morphological and molecular data, indicating that convergent evolution of sperm characters in cestodes may not be as common as in other invertebrate taxa. The main gaps in the current knowledge of spermatological characters are mapped and topics for future research are outlined, with special emphasis on those characters that might provide additional information about the evolution of tapeworms and their spermatozoa. Future studies should be focused on representatives of those major groups (families and orders) in which molecular data indicate paraphyly or polyphyly (e.g. 'Tetraphyllidea' and Trypanorhyncha) and on those that have a key phylogenetic position among eucestodes (e.g. Diphyllidea, 'Tetraphyllidea', Lecanicephalidea, Nippotaeniidea).
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Ultrastructural and cytochemical studies on vitellogenesis in trypanorhynch cestode Dollfusiella spinulifera Beveridge, Neifar et Euzet, 2004 (Eutetrarhynchidae)
Acta Parasitologica, 2006Co-Authors: Zdzisław Świderski, Jordi Miquel, Daniel Młocicki, Lassad Neifar, Barbara Grytner-zięcina, John S. MackiewiczAbstract: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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Ultrastructure of the spermatozoon of Dollfusiella spinulifera (Beveridge and Jones, 2000) Beveridge, Neifar and Euzet, 2004 (Trypanorhyncha, Eutetrarhynchidae)
Parasitology Research, 2006Co-Authors: Jordi Miquel, Zdzisław ŚwiderskiAbstract:The ultrastructural organization of the mature spermatozoon of the trypanorhynch cestode Dollfusiella spinulifera is described. The spermatozoon is a long filiform cell, tapered at both ends, which lacks mitochondria. Its cytoplasm contains (1) two axonemes of different lengths of the 9+‘1’ pattern of trepaxonematan Platyhelminthes, (2) two rows of parallel cortical microtubules, each of which is adjacent to the opposite sides of the plasma membrane, (3) the nucleus, and (4) glycogen in the form of both α-glycogen rosettes and β-glycogen particles. Unlike the majority of cestode spermatozoa, the spematozoon of D. spinulifera lacks crested bodies and periaxonemal sheath. In view of the present results, the postulated synapomorphic value of crested bodies for the Eucestoda is questioned.
Celine Levron - One of the best experts on this subject based on the ideXlab platform.
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spermatozoa of tapeworms platyhelminthes Eucestoda advances in ultrastructural and phylogenetic studies
Biological Reviews, 2009Co-Authors: Celine Levron, Mikuláš Oros, Jordi Miquel, Tomáš ScholzAbstract:: New data on spermiogenesis and the ultrastructure of spermatozoa of 'true' tapeworms (Eucestoda) are summarized. Since 2001, more than 50 species belonging to most orders of the Eucestoda have been studied or reinvestigated, particularly members of the Caryophyllidea, Spathebothriidea, Diphyllobothriidea, Bothriocephalidea, Trypanorhyncha, Tetraphyllidea, Proteocephalidea, and Cyclophyllidea. A new classification of spermatozoa of eucestodes into seven basic types is proposed and a key to their identification is given. For the first time, a phylogenetic tree inferred from spermatological characters is provided. New information obtained in the last decade has made it possible to fill numerous gaps in the character data matrix, enabling us to carry out a more reliable analysis of the evolution of ultrastructural characters of sperm and spermiogenesis in eucestodes. The tree is broadly congruent with those based on morphological and molecular data, indicating that convergent evolution of sperm characters in cestodes may not be as common as in other invertebrate taxa. The main gaps in the current knowledge of spermatological characters are mapped and topics for future research are outlined, with special emphasis on those characters that might provide additional information about the evolution of tapeworms and their spermatozoa. Future studies should be focused on representatives of those major groups (families and orders) in which molecular data indicate paraphyly or polyphyly (e.g. 'Tetraphyllidea' and Trypanorhyncha) and on those that have a key phylogenetic position among eucestodes (e.g. Diphyllidea, 'Tetraphyllidea', Lecanicephalidea, Nippotaeniidea).