Spermiogenesis

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Bernard Marchand - One of the best experts on this subject based on the ideXlab platform.

  • Ultrastructure of Spermiogenesis and the spermatozoon of Macracanthorhynchus hirudinaceus (Pallas, 1781) (Acanthocephala: Archiacanthocephala), a parasite of the wild boar Sus scrofa.
    The Journal of Parasitology, 2005
    Co-Authors: Josephine Foata, Julia-laurence Culioli, Bernard Marchand
    Abstract:

    The present paper describes the ultrastructure of Spermiogenesis and the spermatozoon of Macracanthorhynchus hirudinaceus, an acanthocephalan parasite of the wild boar Sus scrofa. At the beginning of spermatogenesis, spermatocytes exhibit synaptonemal complexes and 2 centrioles. In the spermatid, only 1 centriole remains, generating a flagellum with a 9+2 pattern. Another ultrastructural feature observed during the Spermiogenesis of M. hirudinaceus is the condensation of the chromatin, forming a "honeycomb" structure in the old spermatid and a homogeneous, electron-dense structure in the spermatozoon. The mature spermatozoon of M. hirudinaceus presents a reversed anatomy, as has been described previously in other species of the Acanthocephala. The spermatozoon is divided into 2 parts: an axoneme, and a nucleocytoplasmic derivative. The spermatozoon flagellum exhibits a 9+2 or 9+0 pattern. The process of Spermiogenesis and the ultrastructural organization of the spermatozoon of M. hirudinaceus are compared with available data regarding other acanthocephalan species.

  • ultrastructure of Spermiogenesis and spermatozoon of leptorhynchoides plagicephalus acanthocephala palaeacanthocephala a parasite of the sturgeon acipenser naccarii osteichthyes acipenseriformes
    Parasitology Research, 2004
    Co-Authors: Josephine Foata, B S Dezfuli, Barbara Pinelli, Bernard Marchand
    Abstract:

    This paper describes the ultrastructure of Spermiogenesis and the spermatozoon of Leptorhynchoides plagicephalus, an acanthocephalan parasite of the sturgeon Acipenser naccarii, a species which is under the threat of extinction. At the beginning, Spermiogenesis in L. plagicephalus is characterized by the presence of a single centriole in the early spermatid. This centriole generates a flagellum with a 9+0 pattern. Another ultrastructural feature observed during the Spermiogenesis of L. plagicephalus is the condensation of chromatin to form an “intranuclear wall”. The mature spermatozoon of L. plagicephalus presents a reversed anatomy, as observed in other species of the Acanthocephala. The spermatozoon is divided into two parts: an axoneme and a nucleocytoplasmic derivative. The pattern of Spermiogenesis and the ultrastructural organization of the spermatozoon of L. plagicephalus are compared with information available on other acanthocephalan species. The appearance of an “intranuclear wall” observed during the present study represents the first record within the Acanthocephala and is unknown from other animal taxa.

  • Spermiogenesis and ultrastructure of the spermatozoon of the liver fluke fasciola gigantica cobbold 1856 digenea fasciolidae a parasite of cattle in senegal
    Journal of Parasitology, 2004
    Co-Authors: Papa Ibnou Ndiaye, Cheikh Tidiane Ba, Jordi Miquel, Bernard Marchand
    Abstract:

    The present paper describes the Spermiogenesis and the ultrastructure of the spermatozoon of Fasciola gigantica, as revealed by transmission electron microscopy. Spermiogenesis in F. gigantica begins with the formation of a differentiation zone containing 2 centrioles with associated striated roots and an intercentriolar body between them. Each centriole develops a flagellum. Proximodistal fusion of these flagella with the median cytoplasmic extension gives rise to the spermatozoon. Spermiogenesis in F. gigantica is characterized by the formation of a dorsolateral cytoplasmic expansion, an external ornamentation of the cell membrane, and spinelike bodies. These 3 structures were also observed in the anterior part of the spermatozoon. Our study describes for the first time the simultaneous presence of dorsolateral cytoplasmic expansion, external ornamentation of the plasma membrane, and spinelike bodies in the spermatozoon of a trematode.

  • Ultrastructure of Spermiogenesis and the spermatozoon in the genus Joyeuxiella Fuhrmann, 1935 (Cestoda, Cyclophyllidea, Dipylidiidae): comparative analysis of J. echinorhynchoides (Sonsino, 1889) and J. pasqualei (Diamare, 1893)
    Parasitology Research, 2003
    Co-Authors: Papa Ibnou Ndiaye, Jordi Miquel, Sylvia Agostini, Bernard Marchand
    Abstract:

    This paper describes the ultrastructure of Spermiogenesis and the mature spermatozoon of two Dipylidiidae cestodes, Joyeuxiella echinorhynchoides and J. pasqualei . In both species, Spermiogenesis follows the type III described by Bâ and Marchand for the cyclophyllideans. Nevertheless, it is interesting to note the presence of striated roots associated with the centrioles. The spermatozoon presents the same ultrastructural features in J. echinorhynchoides and J. pasqualei . The apical cone in the anterior extremity of the sperm is more than 2.0 μm long in both J. echinorhynchoides and J. pasqualei . Both species present a single crest-like body, 150 nm thick in J. echinorhynchoides and 75 nm thick in J. pasqualei . The cortical microtubules are spiralled at an angle of 40–45° to the spermatozoon axis in both Joyeuxiella species. A periaxonemal sheath and glycogen granules are also described in the mature sperm. We also describe, for the first time, the disposition of glycogen granules in two opposed and spiralled cords in cestodes and the formation of the periaxonemal sheath in the final stage of Spermiogenesis.

  • Ultrastructure of Spermiogenesis and the spermatozoon in the genus Joyeuxiella Fuhrmann, 1935 (Cestoda, Cyclophyllidea, Dipylidiidae): comparative analysis of J. echinorhynchoides (Sonsino, 1889) and J. pasqualei (Diamare, 1893).
    Parasitology Research, 2003
    Co-Authors: Papa Ibnou Ndiaye, Jordi Miquel, Sylvia Agostini, Bernard Marchand
    Abstract:

    This paper describes the ultrastructure of Spermiogenesis and the mature spermatozoon of two Dipylidiidae cestodes, Joyeuxiella echinorhynchoides and J. pasqualei. In both species, Spermiogenesis follows the type III described by B?nd Marchand for the cyclophyllideans. Nevertheless, it is interesting to note the presence of striated roots associated with the centrioles. The spermatozoon presents the same ultrastructural features in J. echinorhynchoides and J. pasqualei. The apical cone in the anterior extremity of the sperm is more than 2.0 microm long in both J. echinorhynchoides and J. pasqualei. Both species present a single crest-like body, 150 nm thick in J. echinorhynchoides and 75 nm thick in J. pasqualei. The cortical microtubules are spiralled at an angle of 40-45 degrees to the spermatozoon axis in both Joyeuxiella species. A periaxonemal sheath and glycogen granules are also described in the mature sperm. We also describe, for the first time, the disposition of glycogen granules in two opposed and spiralled cords in cestodes and the formation of the periaxonemal sheath in the final stage of Spermiogenesis.

Aneta Yoneva - One of the best experts on this subject based on the ideXlab platform.

  • spermatological characters in the diphyllobothriidean schistocephalus solidus cestoda
    Acta Zoologica, 2013
    Co-Authors: Céline Levron, Aneta Yoneva, Martin Kalbe
    Abstract:

    Levron, C., Yoneva, A. and Kalbe, M. 2011. Spermatological characters in the diphyllobothriidean Schistocephalus solidus (Cestoda). —Acta Zoologica (Stockholm) 00: 1–8. The Spermiogenesis and the mature spermatozoon of Schistocephalus solidus (Cestoda: Diphyllobothriidea) are described using transmission electron microscopy. Spermiogenesis in S. solidus begins with the formation in the spermatid of a differentiation zone surrounded by cortical microtubules and delimited by arching membranes. This conical area presents two centrioles associated with striated rootlets and a median cytoplasmic extension between them. The centrioles are separated by an intercentriolar body composed of three electron-dense plates dividing four electron-lucent plates. The centrioles give rise to two flagella that undergo a rotation and later fuse proximodistally with the median cytoplasmic expansion. The presence of an electron-dense material in the distal part of the differentiation zone is observed in the early stage of Spermiogenesis. This pattern corresponds to Type I Spermiogenesis according to the classification proposed by Bâ and Marchand (Memoires du Museum National d’Histoire Naturelle 1995; 166: 87). The mature spermatozoon of S. solidus presents the Type I pattern defined by Levron et al. (Biological Reviews 2010; 85: 523). It consists of five regions that exhibit two axonemes, parallel cortical microtubules, nucleus and electron-dense zones. The anterior tip of the spermatozoon possesses only a few singlets. The axonemes are of a 9 + ’1’ trepaxonematan pattern and do not reach the posterior extremity of the mature spermatozoon.

  • spermatological characters of monozoic tapeworms cestoda caryophyllidea including first data on a species from the indomalayan catfish
    Journal of Parasitology, 2012
    Co-Authors: Aneta Yoneva, Céline Levron, Tomáš Scholz
    Abstract:

    Abstract: The ultrastructure of Spermiogenesis and mature spermatozoon in Lytocestus indicus (Cestoda: Lytocestidae) is described; this is the first representative of this group of monozoic, presumably most basal, tapeworms (Eucestoda) from the Indomalayan region to be documented in this manner. Similarly, as in other caryophyllideans, its Spermiogenesis involves the formation of a conical differentiation zone with 2 centrioles associated with striated roots and an intercentriolar body. In the course of the process, 1 of the centrioles develops a free flagellum, which fuses with a cytoplasmic protrusion, whereas the other remains oriented in a cytoplasmic bud. Spermiogenesis is also characterized by the presence of electron-dense material in the early stages of Spermiogenesis and a slight rotation of the flagellar bud. The mature spermatozoon of L. indicus is a filiform cell tapered at both extremities that lacks mitochondria; its nucleus has parallel disposition to the axoneme and does not reach up to th...

  • Spermiogenesis and spermatozoon ultrastructure of the paruterinid cestode Notopentorchis sp. (Cyclophyllidea)
    Parasitology Research, 2012
    Co-Authors: Aneta Yoneva, Pavel N. Nikolov, Yana Mizinska, Céline Levron, Jean Mariaux, Boyko B. Georgiev
    Abstract:

    Ultrastructural characters of the Spermiogenesis and mature spermatozoon of Notopentorchis sp. (Cestoda, Cyclophyllidea, Paruterinidae), a parasite from Apus affinis (Aves, Apodiformes, Apodidae) from Gabon, are described by means of transmission electron microscopy. Cytochemical analysis for detection of glycogen was applied. Vestigial striated roots associated with the two centrioles are present in the zone of differentiation. The Spermiogenesis is characterized by an external growth of free flagellum followed by a proximodistal fusion of the latter with cytoplasmic protrusion, thus, corresponding to the cestode Spermiogenesis of the type III pattern described by Bâ and Marchand (Mem. Mus. Natl. Hist. Nat. 166:87–95, 1995). In the final stage of Spermiogenesis, a single crested body appears at the base of the forming spermatozoon. The mature spermatozoon of Notopentorchis sp. is filiform and tapering at both extremities. It consists of five regions differing in their ultrastructural characteristics. The anterior extremity of the mature spermatozoon is characterized by the presence of an apical cone and a single crested body. The cytoplasm contains one axoneme of 9 + “1” type of the trepaxonematan Platyhelminthes, a periaxonemal sheath, a layer of twisted cortical microtubules, transverse intracytoplasmic walls, and granules of glycogen. The nucleus is coiled in spiral around the axoneme. The posterior extremity of the spermatozoon is characterized by the presence of electron-dense material. This structural organization corresponds to the morphology of cestode spermatozoon of type VII as defined by Levron et al. (Biol Rev 85: 523-543, 2010). The comparison of the results with those of the two previous studies on paruterinids suggests that several characters of the Spermiogenesis and the mature spermatozoon are invariable, i.e. the type III Spermiogenesis and the presence of vestigial striated roots, a single crested body, a periaxonemal sheath, and intracytoplasmic walls. The main differences of the sperm cells among members of this family are the lack of dense granules (as in Triaenorhina rectangula) and the presence of electron-dense material in the posterior extremity of the spermatozoon (as in Notopentorchis sp.).

  • Spermatological characters in the diphyllobothriidean Schistocephalus solidus (Cestoda)
    Acta Zoologica, 2011
    Co-Authors: Céline Levron, Aneta Yoneva, Martin Kalbe
    Abstract:

    The Spermiogenesis and the mature spermatozoon of Schistocephalus solidus (Cestoda: Diphyllobothriidea) are described using transmission electron microscopy. Spermiogenesis in S. solidus begins with the formation in the spermatid of a differentiation zone surrounded by cortical microtubules and delimited by arching membranes. This conical area presents two centrioles associated with striated rootlets and a median cytoplasmic extension between them. The centrioles are separated by an intercentriolar body composed of three electron-dense plates dividing four electron-lucent plates. The centrioles give rise to two flagella that undergo a rotation and later fuse proximodistally with the median cytoplasmic expansion. The presence of an electron-dense material in the distal part of the differentiation zone is observed in the early stage of Spermiogenesis. This pattern corresponds to Type I Spermiogenesis according to the classification proposed by Baˆ and Marchand (Me´moires du Muse´um National d’Histoire Naturelle 1995; 166: 87). The mature spermatozoon of S. solidus presents the Type I pattern defined by Levron et al. (Biological Reviews 2010; 85: 523). It consists of five regions that exhibit two axonemes, parallel cortical microtubules, nucleus and electron-dense zones. The anterior tip of the spermatozoon possesses only a few singlets. The axonemes are of a 9 + ’1’ trepaxonematan pattern and do not reach the posterior extremity of the mature spermatozoon

  • ultrastructure of Spermiogenesis and mature spermatozoon of breviscolex orientalis cestoda caryophyllidea
    Parasitology Research, 2011
    Co-Authors: Aneta Yoneva, Céline Levron, Mikulas Oros, Martina Orosova, Tomáš Scholz
    Abstract:

    Spermiogenesis and spermatozoon ultrastructure of the caryophyllidean cestode Breviscolex orientalis Kulakovskaya, 1962, first member of the family Capingentidae studied, a parasite of cyprinid fish Abbottina rivularis, are described using transmission electron microscopy. Spermiogenesis in B. orientalis follows the Type II pattern described by Bâ and Marchand (Mem Mus Natl Hist Nat 166:87–95, 1995) for cestodes. It begins with the formation of a zone of differentiation containing a large nucleus and a pair of centrioles. The centrioles are separated from one another by an intercentriolar body composed of three electron-dense layers. Each centriole is associated with typical striated roots. At the beginning of the Spermiogenesis, an electron-dense material is observed in the apical region of the differentiation zone. During the initial stage of Spermiogenesis, one of the centrioles gives rise to a free flagellum, which then rotates and undergoes proximodistal fusion with the cytoplasmic protrusion of the differentiation zone. The mature spermatozoon of B. orientalis corresponds to the Type III pattern described by Levron et al. (Biol Rev 85:523–543, 2010). It is characterized by the absence of mitochondrion and crested body. Five regions of the mature spermatozoon are differentiated. The main ultrastructural characteristics are: one axoneme of 9 + “1” trepaxonematan pattern, cortical microtubules and nucleus. The comparison of the Spermiogenesis of B. orientalis with those of the other caryophyllidean species demonstrates some variation within the order relative to the presence and morphology of the intercentriolar body, the presence of slight rotation of the flagellar bud and a complete proximodistal fusion of the free flagellum with a cytoplasmic protrusion.

Boyko B. Georgiev - One of the best experts on this subject based on the ideXlab platform.

  • Spermiogenesis and spermatozoon ultrastructure of the paruterinid cestode Notopentorchis sp. (Cyclophyllidea)
    Parasitology Research, 2012
    Co-Authors: Aneta Yoneva, Pavel N. Nikolov, Yana Mizinska, Céline Levron, Jean Mariaux, Boyko B. Georgiev
    Abstract:

    Ultrastructural characters of the Spermiogenesis and mature spermatozoon of Notopentorchis sp. (Cestoda, Cyclophyllidea, Paruterinidae), a parasite from Apus affinis (Aves, Apodiformes, Apodidae) from Gabon, are described by means of transmission electron microscopy. Cytochemical analysis for detection of glycogen was applied. Vestigial striated roots associated with the two centrioles are present in the zone of differentiation. The Spermiogenesis is characterized by an external growth of free flagellum followed by a proximodistal fusion of the latter with cytoplasmic protrusion, thus, corresponding to the cestode Spermiogenesis of the type III pattern described by Bâ and Marchand (Mem. Mus. Natl. Hist. Nat. 166:87–95, 1995). In the final stage of Spermiogenesis, a single crested body appears at the base of the forming spermatozoon. The mature spermatozoon of Notopentorchis sp. is filiform and tapering at both extremities. It consists of five regions differing in their ultrastructural characteristics. The anterior extremity of the mature spermatozoon is characterized by the presence of an apical cone and a single crested body. The cytoplasm contains one axoneme of 9 + “1” type of the trepaxonematan Platyhelminthes, a periaxonemal sheath, a layer of twisted cortical microtubules, transverse intracytoplasmic walls, and granules of glycogen. The nucleus is coiled in spiral around the axoneme. The posterior extremity of the spermatozoon is characterized by the presence of electron-dense material. This structural organization corresponds to the morphology of cestode spermatozoon of type VII as defined by Levron et al. (Biol Rev 85: 523-543, 2010). The comparison of the results with those of the two previous studies on paruterinids suggests that several characters of the Spermiogenesis and the mature spermatozoon are invariable, i.e. the type III Spermiogenesis and the presence of vestigial striated roots, a single crested body, a periaxonemal sheath, and intracytoplasmic walls. The main differences of the sperm cells among members of this family are the lack of dense granules (as in Triaenorhina rectangula) and the presence of electron-dense material in the posterior extremity of the spermatozoon (as in Notopentorchis sp.).

  • Ultrastructure of Spermiogenesis and mature spermatozoon of Anonchotaenia globata (von Linstow, 1879) (Cestoda, Cyclophyllidea, Paruterinidae).
    Acta Zoologica, 2010
    Co-Authors: Aneta Yoneva, Katia Georgieva, Pavel N. Nikolov, Yana Mizinska, Boyko B. Georgiev, Stoyanka Stoitsova
    Abstract:

    Yoneva, A., Georgieva, K., Mizinska, Y., Nikolov, P. N., Georgiev, B. B. and Stoitsova, S. R. 2010. Ultrastructure of Spermiogenesis and mature spermatozoon of Anonchotaenia globata (von Linstow, 1879) (Cestoda, Cyclophyllidea, Paruterinidae). — Acta Zoologica (Stockholm) 91: 184–192 The ultrastructure of Spermiogenesis and of the spermatozoon of a species of the family Paruterinidae is described for the first time. The Spermiogenesis of Anonchotaenia globata starts with the formation of a differentiation zone with two centrioles associated with thin striated roots. One of the centrioles gives rise to a free flagellum followed by a slight flagellar rotation and a proximodistal fusion of the flagellum with the cytoplasmic protrusion. This pattern corresponds to Type III Spermiogenesis in cestodes. The spermatozoon consists of five distinct regions. The anterior extremity possesses an apical cone and a single helically coiled crested body. The cortical microtubules are spirally arranged. The axoneme is surrounded by a periaxonemal sheath and a thin layer of cytoplasm filled with electron-dense granules in Regions I–V. The periaxonemal sheath is connected with the peripheral microtubules by transverse intracytoplasmic walls in Regions III and IV. The nucleus is spirally coiled around the axoneme. Anonchotaenia globata differs from Dilepididae (where paruterinids have previously been classified) in the type of Spermiogenesis, the lack of glycogen inclusions and the presence of intracytoplasmic walls. The pattern of Spermiogenesis is similar to that in Metadilepididae and Taeniidae, which are considered phylogenetically close to Paruterinidae.

  • Ultrastructure of Spermiogenesis and mature spermatozoon of Triaenorhina rectangula (Cestoda: Cyclophyllidea: Paruterinidae).
    Folia Parasitologica, 2009
    Co-Authors: Aneta Yoneva, Katia Georgieva, Pavel N. Nikolov, Yana Mizinska, Boyko B. Georgiev, Stoyanka Stoitsova
    Abstract:

    Ultrastructural characters of Spermiogenesis and mature spermatozoon of Triaenorhina rectangula (Fuhrmann, 1908) are examined by transmission electron microscopy. Spermiogenesis follows the Bâ and Marchand's Type III Spermiogenesis of cestodes. The process begins with the formation of a differentiation zone containing two centrioles and a cytoplasmic protrusion. The centrioles are associated with vestigial striated roots. One of the centrioles develops a free flagellum externally to the cytoplasmic protrusion. After a slight rotation, the free flagellum fuses with the cytoplasmic protrusion. In the final stage of Spermiogenesis, a single crested body appears in the anterior part of the differentiating spermatozoon. The anterior extremity of the mature spermatozoon is characterised by an apical cone and a single crested body. The axoneme is of the 9+"1" trepaxonematan type. A periaxonemal sheath and electron-dense rods are described in some parts of the mature spermatozoon. The nucleus is electron-dense and spirally coiled around the axoneme. The cortical microtubules are spirally arranged at an angle of about 40° to the spermatozoon axis. The present results show that the ultrastructural characters of Spermiogenesis and mature spermatozoon of T. rectangula resemble most closely those in taeniids and metadilepidids. The comparison of these results with the only previous spermiological description of a paruterinid species reveals differences relative to the occurrence of filamentous rods of electron-dense material versus intracytoplasmic walls in the mature spermatozoon that may reflect the polyphyletic character of the Paruterinidae.

  • ultrastructure of Spermiogenesis and mature spermatozoon of triaenorhina rectangula cestoda cyclophyllidea paruterinidae
    Folia Parasitologica, 2009
    Co-Authors: Aneta Yoneva, Katia Georgieva, Pavel N. Nikolov, Yana Mizinska, Boyko B. Georgiev, Stoyanka Stoitsova
    Abstract:

    Ultrastructural characters of Spermiogenesis and mature spermatozoon of Triaenorhina rectangula (Fuhrmann, 1908) are examined by transmission electron microscopy. Spermiogenesis follows the Bâ and Marchand's Type III Spermiogenesis of cestodes. The process begins with the formation of a differentiation zone containing two centrioles and a cytoplasmic protrusion. The centrioles are associated with vestigial striated roots. One of the centrioles develops a free flagellum externally to the cytoplasmic protrusion. After a slight rotation, the free flagellum fuses with the cytoplasmic protrusion. In the final stage of Spermiogenesis, a single crested body appears in the anterior part of the differentiating spermatozoon. The anterior extremity of the mature spermatozoon is characterised by an apical cone and a single crested body. The axoneme is of the 9+"1" trepaxonematan type. A periaxonemal sheath and electron-dense rods are described in some parts of the mature spermatozoon. The nucleus is electron-dense and spirally coiled around the axoneme. The cortical microtubules are spirally arranged at an angle of about 40 degrees to the spermatozoon axis. The present results show that the ultrastructural characters of Spermiogenesis and mature spermatozoon of T. rectangula resemble most closely those in taeniids and metadilepidids. The comparison of these results with the only previous spermiological description of a paruterinid species reveals differences relative to the occurrence of filamentous rods of electron-dense material versus intracytoplasmic walls in the mature spermatozoon that may reflect the polyphyletic character of the Paruterinidae.

  • Spermiogenesis and sperm ultrastructure of valipora mutabilis linton 1927 cestoda cyclophyllidea gryporhynchidae
    Parasitology Research, 2008
    Co-Authors: Aneta Yoneva, Katia Georgieva, Pavel N. Nikolov, Yana Mizinska, Boyko B. Georgiev, Zdzislaw świderski
    Abstract:

    This is the first ultrastructural study of the Spermiogenesis and the mature spermatozoon of a cyclophyllidean cestode of the family Gryporhynchidae. The Spermiogenesis of Valipora mutabilis begins with the formation of a differentiation zone delimited by arching membranes and containing two centrioles. One of the centrioles develops an axoneme that grows directly into the cytoplasmic protrusion. The other centriole remains situated in a cytoplasmic bud and is subsequently aborted (type IV of cestode Spermiogenesis). The mature spermatozoon of V. mutabilis is a filiform cell, tapered at both extremities and lacks mitochondria. The anterior extremity is characterised by the presence of an apical cone and a single helicoidal crested body. The axoneme is of 9 + ‘1’ trepaxonematan pattern, with a periaxonemal sheath. The cortical microtubules are twisted at an angle of about 45° to the spermatozoon axis. The nucleus is electron dense and spirally coiled around the axoneme. The cytoplasm is electron lucent and contains numerous granules of electron-dense material. In contrast to a recent opinion for close phylogenetic relationships, these ultrastructural data demonstrate the distant position between gryporhynchids and the family Taeniidae. The most similar pattern in the ultrastructure of the Spermiogenesis and the mature spermatozoon has been described for dilepidids, some hymenolepidids and some anoplocephalids.

Jordi Miquel - One of the best experts on this subject based on the ideXlab platform.

  • brachycoelium salamandrae frolich 1789 digenea brachycoeliidae ultrastructural study of Spermiogenesis and the mature spermatozoon
    Zoologischer Anzeiger – A Journal of Comparative Zoology, 2013
    Co-Authors: Abdoulaye J. S. Bakhoum, Cheikh Tidiane Ba, Catarina Eira, Alexis Ribas, Jordi Miquel
    Abstract:

    Abstract Ultrastructural characters of Spermiogenesis and the mature spermatozoon of Brachycoelium salamandrae are described by means of transmission electron microscopy. Spermiogenesis begins with the formation of a differentiation zone containing a nucleus, several mitochondria, and two centrioles associated with striated rootlets and with an intercentriolar body between them. The two centrioles originate two free flagella that grow orthogonally to the median cytoplasmic process before fusing with it. The final stage of Spermiogenesis is characterized by a constriction of the ring of arched membranes and the liberation of the young spermatozoon. In this final stage a pear shaped electron-dense material appears at the level of centrioles. Spermatozoon of B. salamandrae exhibits two axonemes of different length with the 9+‘1’ trepaxonematan pattern, a nucleus, two mitochondria, two bundles of parallel cortical microtubules and granules of glycogen. Additionally, the spermatozoon of B. salamandrae shows external ornamentations of the plasma membrane and spinelike bodies. The most relevant spermatozoon characters of B. salamandrae are discussed and compared with those of other species belonging to the superfamily Gorgoderoidea.

  • Spermiogenesis and spermatozoon ultrastructure of the diphyllidean cestode Echinobothrium euterpes (Neifar, Tyler and Euzet 2001) Tyler 2006, a parasite of the common guitarfish Rhinobatos rhinobatos
    Parasitology research, 2011
    Co-Authors: Adji Mama Marigo, Catarina Eira, Jordi Miquel
    Abstract:

    Spermiogenesis and the ultrastructural characters of the spermatozoon of Echinobothrium euterpes are described by means of transmission electron microscopy, including cytochemical analysis for glycogen. Materials were obtained from a common guitarfish Rhinobatos rhinobatos caught in the Gulf of Gabes (Tunisia). Spermiogenesis in E. euterpes is characterized by the orthogonal development of two unequal flagella followed by the flagellar rotation and the proximodistal fusion of these flagella with the median cytoplasmic process. The most interesting pattern characterizing the diphyllidean cestodes is the presence of a triangular body constituted by fines and dense granules without visible striation and assimilated at the striated rootlets. This pattern, only related in the Diphyllidea cestodes may be a synapomorphy of this order. Spermiogenesis is also characterized by the presence of a very short flagellum (around 1 μm long), observed in all the stages of Spermiogenesis. This type of flagellum has never been commented in the diphyllidean cestodes and should be considered as an evolved character in this group. In the latest stage of Spermiogenesis, this short axoneme probably degenerates. Thus, the mature spermatozoon of E. euterpes possesses only one axoneme of 9 + “1” trepaxonematan pattern. It also exhibits a single helical electron-dense crested body, a spiraled nucleus, few parallel cortical microtubules, and α-glycogen granules. Similitudes and differences between spermatozoa of diphyllideans are discussed.

  • Ultrastructure of Spermiogenesis in the caryophyllidean cestode Wenyonia virilis Woodland, 1923, with re-assessment of flagellar rotation in Glaridacris catostomi Cooper, 1920
    Acta Parasitologica, 2008
    Co-Authors: Jordi Miquel, John S Mackiewicz, Zdzisław Świderski, Mohammed H. Ibraheem
    Abstract:

    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.

  • Ultrastructure of Spermiogenesis and mature spermatozoon of Angularella beema (Clerc, 1906) (Cestoda, Cyclophyllidea, Dilepididae)
    Acta Parasitologica, 2006
    Co-Authors: Aneta Yoneva, Zdzisław Świderski, Katia Georgieva, Yana Mizinska, Jordi Miquel, Boyko B. Georgiev
    Abstract:

    The ultrastructure of the Spermiogenesis of a dilepidid cestode species is described for the first time. The Spermiogenesis of Angularella beema is characterised by absence of both flagellar rotation and proximodistal fusion. The differentiation zone is surrounded by cortical microtubules and is delimited by a ring of arching membranes. It contains two centrioles, one of which develops the axoneme that grows directly into the elongating cytoplasmic protrusion. This pattern of Spermiogenesis was described as the Type IV Spermiogenesis of cestodes. Among cestodes, similar pattern of Spermiogenesis is known in the family Hymenolepididae and in some representatives of the family Anoplocephalidae. The mature spermatozoon of A. beema consists of five regions differing in their ultrastructural characteristics. It is characterised by the presence of cortical microtubules (spirally arranged at angle of 30–40° to the spermatozoon axis) and a single crested body. There is a periaxonemal sheath in certain parts of the spermatozoon as well as glycogen-like granules between the periaxonemal sheath and the cortical microtubules. The comparisons of the mature spermatozoon of A. beema with those of other two dilepidid species ( Dilepis undula and Molluscotaenia crassiscolex ) demonstrate some variation within the family: presence of periaxonemal sheath in A. beema and D. undula and its absence in M. crassiscolex ; presence of electron-dense rods in D. undula and their absence in A. beema .

  • Spermiogenesis and spermatozoon ultrastructure of the cestode mosgovoyia ctenoides cyclophyllidea anoplocephalidae an intestinal parasite of oryctolagus cuniculus lagomorpha leporidae
    Journal of Parasitology, 2006
    Co-Authors: Catarina Eira, José Vingada, Jordi Miquel, Jordi Torres
    Abstract:

    Ultrastructural characters in Spermiogenesis and spermatozoa are considered important tools to elucidate the phylogenetic relationships within the Platyhelminthes. In the Anoplocephalidae, ultrastructural data refer to the spermatozoon of 14 species, whereas data on Spermiogenesis refer to only 7 species. The present study focused on the Spermiogenesis and spermatozoon of the anoplocephalid cestode Mosgovoyia ctenoides, as revealed by transmission electron microscopy. Type IV Spermiogenesis was detected, beginning with the formation of a differentiation zone containing 2 centrioles, with a centriolar adjunct and vestigial striated rootlets. Different forms of the latter character have been described in other anoplocephalids. This study supports Spermiogenesis of type IV as the most frequent in the Anoplocephalidae and confirms the presence of a centriolar adjunct in yet another type IV Spermiogenesis species. The spermatozoon of M. ctenoides possesses 1 axoneme of the 9+‘1’ trepaxonematan type, 2 crestlik...

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  • spermatological characters in the diphyllobothriidean schistocephalus solidus cestoda
    Acta Zoologica, 2013
    Co-Authors: Céline Levron, Aneta Yoneva, Martin Kalbe
    Abstract:

    Levron, C., Yoneva, A. and Kalbe, M. 2011. Spermatological characters in the diphyllobothriidean Schistocephalus solidus (Cestoda). —Acta Zoologica (Stockholm) 00: 1–8. The Spermiogenesis and the mature spermatozoon of Schistocephalus solidus (Cestoda: Diphyllobothriidea) are described using transmission electron microscopy. Spermiogenesis in S. solidus begins with the formation in the spermatid of a differentiation zone surrounded by cortical microtubules and delimited by arching membranes. This conical area presents two centrioles associated with striated rootlets and a median cytoplasmic extension between them. The centrioles are separated by an intercentriolar body composed of three electron-dense plates dividing four electron-lucent plates. The centrioles give rise to two flagella that undergo a rotation and later fuse proximodistally with the median cytoplasmic expansion. The presence of an electron-dense material in the distal part of the differentiation zone is observed in the early stage of Spermiogenesis. This pattern corresponds to Type I Spermiogenesis according to the classification proposed by Bâ and Marchand (Memoires du Museum National d’Histoire Naturelle 1995; 166: 87). The mature spermatozoon of S. solidus presents the Type I pattern defined by Levron et al. (Biological Reviews 2010; 85: 523). It consists of five regions that exhibit two axonemes, parallel cortical microtubules, nucleus and electron-dense zones. The anterior tip of the spermatozoon possesses only a few singlets. The axonemes are of a 9 + ’1’ trepaxonematan pattern and do not reach the posterior extremity of the mature spermatozoon.

  • spermatological characters of monozoic tapeworms cestoda caryophyllidea including first data on a species from the indomalayan catfish
    Journal of Parasitology, 2012
    Co-Authors: Aneta Yoneva, Céline Levron, Tomáš Scholz
    Abstract:

    Abstract: The ultrastructure of Spermiogenesis and mature spermatozoon in Lytocestus indicus (Cestoda: Lytocestidae) is described; this is the first representative of this group of monozoic, presumably most basal, tapeworms (Eucestoda) from the Indomalayan region to be documented in this manner. Similarly, as in other caryophyllideans, its Spermiogenesis involves the formation of a conical differentiation zone with 2 centrioles associated with striated roots and an intercentriolar body. In the course of the process, 1 of the centrioles develops a free flagellum, which fuses with a cytoplasmic protrusion, whereas the other remains oriented in a cytoplasmic bud. Spermiogenesis is also characterized by the presence of electron-dense material in the early stages of Spermiogenesis and a slight rotation of the flagellar bud. The mature spermatozoon of L. indicus is a filiform cell tapered at both extremities that lacks mitochondria; its nucleus has parallel disposition to the axoneme and does not reach up to th...

  • Spermiogenesis and spermatozoon ultrastructure of the paruterinid cestode Notopentorchis sp. (Cyclophyllidea)
    Parasitology Research, 2012
    Co-Authors: Aneta Yoneva, Pavel N. Nikolov, Yana Mizinska, Céline Levron, Jean Mariaux, Boyko B. Georgiev
    Abstract:

    Ultrastructural characters of the Spermiogenesis and mature spermatozoon of Notopentorchis sp. (Cestoda, Cyclophyllidea, Paruterinidae), a parasite from Apus affinis (Aves, Apodiformes, Apodidae) from Gabon, are described by means of transmission electron microscopy. Cytochemical analysis for detection of glycogen was applied. Vestigial striated roots associated with the two centrioles are present in the zone of differentiation. The Spermiogenesis is characterized by an external growth of free flagellum followed by a proximodistal fusion of the latter with cytoplasmic protrusion, thus, corresponding to the cestode Spermiogenesis of the type III pattern described by Bâ and Marchand (Mem. Mus. Natl. Hist. Nat. 166:87–95, 1995). In the final stage of Spermiogenesis, a single crested body appears at the base of the forming spermatozoon. The mature spermatozoon of Notopentorchis sp. is filiform and tapering at both extremities. It consists of five regions differing in their ultrastructural characteristics. The anterior extremity of the mature spermatozoon is characterized by the presence of an apical cone and a single crested body. The cytoplasm contains one axoneme of 9 + “1” type of the trepaxonematan Platyhelminthes, a periaxonemal sheath, a layer of twisted cortical microtubules, transverse intracytoplasmic walls, and granules of glycogen. The nucleus is coiled in spiral around the axoneme. The posterior extremity of the spermatozoon is characterized by the presence of electron-dense material. This structural organization corresponds to the morphology of cestode spermatozoon of type VII as defined by Levron et al. (Biol Rev 85: 523-543, 2010). The comparison of the results with those of the two previous studies on paruterinids suggests that several characters of the Spermiogenesis and the mature spermatozoon are invariable, i.e. the type III Spermiogenesis and the presence of vestigial striated roots, a single crested body, a periaxonemal sheath, and intracytoplasmic walls. The main differences of the sperm cells among members of this family are the lack of dense granules (as in Triaenorhina rectangula) and the presence of electron-dense material in the posterior extremity of the spermatozoon (as in Notopentorchis sp.).

  • Spermatological characters in the diphyllobothriidean Schistocephalus solidus (Cestoda)
    Acta Zoologica, 2011
    Co-Authors: Céline Levron, Aneta Yoneva, Martin Kalbe
    Abstract:

    The Spermiogenesis and the mature spermatozoon of Schistocephalus solidus (Cestoda: Diphyllobothriidea) are described using transmission electron microscopy. Spermiogenesis in S. solidus begins with the formation in the spermatid of a differentiation zone surrounded by cortical microtubules and delimited by arching membranes. This conical area presents two centrioles associated with striated rootlets and a median cytoplasmic extension between them. The centrioles are separated by an intercentriolar body composed of three electron-dense plates dividing four electron-lucent plates. The centrioles give rise to two flagella that undergo a rotation and later fuse proximodistally with the median cytoplasmic expansion. The presence of an electron-dense material in the distal part of the differentiation zone is observed in the early stage of Spermiogenesis. This pattern corresponds to Type I Spermiogenesis according to the classification proposed by Baˆ and Marchand (Me´moires du Muse´um National d’Histoire Naturelle 1995; 166: 87). The mature spermatozoon of S. solidus presents the Type I pattern defined by Levron et al. (Biological Reviews 2010; 85: 523). It consists of five regions that exhibit two axonemes, parallel cortical microtubules, nucleus and electron-dense zones. The anterior tip of the spermatozoon possesses only a few singlets. The axonemes are of a 9 + ’1’ trepaxonematan pattern and do not reach the posterior extremity of the mature spermatozoon

  • Spermatological characters of bothriocephalideans (Cestoda) inferred from an ultrastructural study on Oncodiscus sauridae and Senga sp.
    Parasitology Research, 2011
    Co-Authors: Lenka Šípková, Céline Levron, Mikulas Oros, Jean-lou Justine
    Abstract:

    Spermiogenesis and ultrastructure of the spermatozoon of two bothriocephalidean cestodes, Oncodiscus sauridae from the lizardfish Saurida nebulosa Valenciennes, 1850 and Senga sp. from the eel Mastacembelus armatus (Lacepède, 1800), have been studied using transmission electron microscopy. Spermiogenesis included the formation of a zone of differentiation, where two centrioles associated with the striated rootlets occur. An intercentriolar body composed of one thick central electron-dense plate and two thinner plates on each side appears between two centrioles. Two flagella of unequal length grow and undergo a vertical rotation and proximodistal fusion with the median cytoplasmic process. Subsequently, the nucleus penetrates into the median cytoplasmic extension. The electron-dense material in the early stages of Spermiogenesis is characteristic for the apical region of the differentiation zone. This electron-dense material is typical for basal tapeworms, e.g., Bothriocephalidea, Caryophyllidea, Diphyllobothriidea, and Spathebothriidea. The mature spermatozoon of O. sauridae and Senga sp. is filiform and possesses two axonemes of the 9 + “1” trepaxonematan pattern, a nucleus, cortical microtubules, and electron-dense granules. The anterior part of the gamete contains a single electron-dense crested body. The most interesting character found is the presence of a ring of cortical microtubules encircling the axoneme in the anterior part of the spermatozoon. This feature has been detected only for species of the order Bothriocephalidea and may represent a synapomorphy of these tapeworms. A classical pattern for spermatological characters (Spermiogenesis of type I with dense material in early stages and sperm of type II with a characteristic ring of cortical microtubules in the anterior part) in Bothriocephalidea is discussed.

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