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Bernard Marchand - One of the best experts on this subject based on the ideXlab platform.
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advances in spermatological characters in the Digenea review and proposal of spermatozoa models and their phylogenetic importance
Advances in Parasitology, 2017Co-Authors: Abdoulaye J. S. Bakhoum, Bernard Marchand, Jean-lou Justine, Jordi Miquel, Papa Ndiaye, Alessandra Falchi, Yann QuilichiniAbstract:Abstract The wide biodiversity and economic importance of Digeneans have motivated a great deal of research in the last decade, focussing on their phylogenetic positions. Molecular research was instrumental for our understanding of phylogeny in the Digenea, but spermatological studies have also provided many results, which are potentially useful for phylogeny; however, the complete spermatological data set has never been reviewed in a whole phylogenetic perspective. Spermatological data are now available for more than 100 species, belonging to 15 superfamilies and 46 families. In this paper, we try to summarize the current knowledge about sperm structure in the Digeneans and propose a classification of Digenean spermatozoa into five basic models. The main ultrastructural characters used are (1) the type of axoneme, (2) the lateral expansion, (3) the association ‘external ornamentation of the plasma membrane + cortical microtubules’, (4) the field of cortical microtubules and its number, (5) the location of the external ornamentation, (6) the location of the maximum number of cortical microtubules and (7) the number of mitochondria. We also outline the most interesting features for phylogenetic inference and their possible value in the context of Digenean systematics, phylogeny and evolution. Associations between sperm models and superfamilies were found as follows: Type 1 in the Schistosomatoidea; Type 2 in the Hemiuroidea; Type 3 in the Opecoeloidea, Lepocreadioidea, Haploporoidea and Opisthorchioidea; Type 4 in the Gorgoderoidea, Microphalloidea, Plagiorchioidea and Gymnophalloidea; Type 5 in the Echinostomatoidea, Microscaphidioidea, Paramphistomoidea, Pronocephaloidea and Brachylaimoidea.
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First spermatological study in the Atractotrematidae (Digenea, Haploporoidea): the case of Atractotrema sigani, intestinal parasite of Siganus lineatus
Parasite, 2015Co-Authors: Abdoulaye J. S. Bakhoum, Yann Quilichini, Jean-lou Justine, Jordi Miquel, Rodney A Bray, Carlos Feliu, Bernard MarchandAbstract:The ultrastructural organization of the mature spermatozoon of the Digenean Atractotrema sigani (from Siganus lineatus off New Caledonia) was investigated by transmission electron microscopy. The male gamete of A. sigani exhibits the general morphology described in Digeneans with the presence of two axonemes of different lengths showing the 9 + “1” pattern of the Trepaxonemata, a nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation, spine-like bodies and granules of glycogen. However, the mature spermatozoon of A. sigani has some specific characters such as the morphology of its anterior region and the submembranous electron-dense material. Although similar structures have been reported in some Digenean species, the presence of a submembranous electron-dense material describing a complete ring is reported here for the first time in the mature spermatozoon of A. sigani. In addition, sperm characteristics are compared between the Haploporoidea and their supposed close superfamilies, and possible phylogenetic implications of these findings for the Digenea are discussed.
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Vitellogenesis of the Digenean Plagiorchis elegans (Rudolphi, 1802) (Plagiorchioidea, Plagiorchiidae).
Parasitology International, 2014Co-Authors: Samuel Greani, Yann Quilichini, Stephen E Greiman, Josephine Foata, Papa Ibnou Ndiaye, Vasyl V Tkach, Bernard MarchandAbstract:The ultrastructural organization of vitellogenesis of Plagiorchis elegans (Rudolphi, 1802), experimentally obtained from the golden hamster Mesocricetus auratus (Linnaeus, 1758), is described using transmission electron microscopy. This study is the first ultrastructural study of vitellogenesis in a member of the superfamily Plagiorchioidea. The four stages usually observed during vitellogenesis are described: stage I, cytoplasm of the vitellocytes mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active synthesis of the shell globule clusters; stage IV, vitellocytes are filled with shell globule clusters and contain several lipid droplets, and glycogen granules are grouped around clusters and droplets. Vitellogenesis in P. elegans is compared with that of other Digenea. The differences among P. elegans and previously studied Digeneans include, but are not limited to the occurrence of dense coiled endoplasmic reticulum saccules and the concentration of glycogen in the mesenchyme, which may be considered as a fifth stage of maturation of the vitelline glands. This peculiarity was not observed in all trematodes, which clearly indicates differences in the vitellogenesis in various Digenean lineages at different stages of maturation of their vitelline cells.
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ultrastructure of the spermatozoon of the Digenean plagiorchis elegans rudolphi 1802 plagiorchioidea plagiorchiidae
Journal of Morphology, 2013Co-Authors: P Ndiaye, Cheikh Tidiane Ba, Yann Quilichini, Stephen E Greiman, Volodymyr V Tkach, Bernard MarchandAbstract:The ultrastructure of the mature spermatozoon of the type genus of the Plagiorchiidae Plagiorchis elegans (Rudolphi, 1802), a parasite of the Golden hamster, Mesocricetus auratus is described. This study is the first ultrastructural study of the spermatozoon of a Plagiorchis, the second of a plagiorchiid species and only the third in the Plagiorchioidea. Previously data on spermatozoon ultrastructure existed only for the plagiorchiid Enodiotrema reductum and the omphalometrid Rubenstrema exasperatum. The mature spermatozoon of P. elegans exhibited the general pattern described in most Digenean species, namely two axonemes of the 9 + "1" Trepaxonemata pattern, nucleus, mitochondria, external ornamentation of the plasma membrane, spine-like bodies, and glycogen granules. However, the rather typical expansion of the plasma membrane is not found in P. elegans. Another peculiarity of the spermatozoon of P. elegans is the presence of a structure called thin cytoplasm termination. Spermatozoon ultrastructure of P. elegans is compared with that of E. reductum and R. exasperatum. Spermatozoon of P. elegans conforms to the general pattern described in E. reductum. Thus, this study further expands our knowledge on the spermatozoon ultrastructure among the members of the Plagiorchioidea, one of the most phylogenetically derived groups of the Digenea.
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ultrastructural study of the spermatozoon of heterolebes maculosus Digenea opistholebetidae a parasite of the porcupinefish diodon hystrix pisces teleostei
Parasitology International, 2010Co-Authors: Yann Quilichini, Josephine Foata, Jean-lou Justine, Rodney A Bray, Bernard MarchandAbstract:This paper describes the ultrastructure of the mature spermatozoon of Heterolebes maculosus. It is the first study of this kind concerning the Opistholebetidae (Platyhelminthes, Digenea). The ultrastructural elements observed in the spermatozoon are: two axonemes with 9+"1" pattern of Trepaxonemata and their attachment zones, two mitochondria, a nucleus, cortical microtubules, external ornamentation of the plasma membrane and spine-like bodies. The number and the disposition of cortical microtubules, the organisation of 11 cortical microtubules disposed in semi-circle around the first mitochondrion in the external ornamentation region and the organisation of the posterior part of the spermatozoon are discussed. Three principal types of posterior part of Digenean spermatozoa are proposed. The similarity between the spermatozoon of the Opistholebetidae H. maculosus and Opecoelidae enables us to confirm that these two families are closely related.
Jordi Miquel - One of the best experts on this subject based on the ideXlab platform.
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Sperm characteristics in the Digenean Diplodiscus amphichrus (Paramphistomoidea, Diplodiscidae), a parasite of the Chinese edible frog Hoplobatrachus rugulosus
Zoomorphology, 2020Co-Authors: Papa Mbagnick Diagne, Alexis Ribas, Srisupaph Poonlaphdecha, Jordi MiquelAbstract:The ultrastructural characteristics of the mature spermatozoon of Diplodiscus amphichrus (Digenea, Paramphistomoidea, Diplodiscidae) and their ultrastructural organisation were examined by means of transmission electron microscopy. Live Digeneans were collected from the Chinese edible frog Hoplobatrachus rugulosus in Thailand. The male gamete of D. amphichrus is a filiform cell with two axonemes of the 9 + ’1’ trepaxonematan pattern, nucleus, one mitochondrion, parallel cortical microtubules, a well-developed lateral expansion, external ornamentation of the plasma membrane, spine-like bodies, and granules of glycogen. These ultrastructural characteristics have already been described in other paramphistomoids studied so far except for the cladorchiids, which present some differences. Two characteristics of the male gamete of D. amphichrus were found for the first time in a Digenean: (i) the appearance of the initial part of the lateral expansion before the axonemes in the anterior extremity and (ii) the separation between the second axoneme and the nucleus in the posterior tip. Our results are compared with the available data in the Digenea and particularly with other paramphistomoids.
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Spermatological characteristics of Siphoderina aloysiae (Digenea, Cryptogonimidae), an intestinal parasite of Sciaena umbra (Teleostei, Sciaenidae)
Zoomorphology, 2019Co-Authors: Hichem Kacem, Jordi MiquelAbstract:The ultrastructural organisation of the spermatozoon of Siphoderina aloysiae (Digenea, Cryptogonimidae) is described based upon examination by transmission electron microscopy. Live Digeneans were collected from the digestive tract of the Brown meagre Sciaena umbra (Teleostei: Sciaenidae), caught off the Gulf of Gabès in La Chebba (Tunisia). The male gamete of S. aloysiae is a filiform cell, tapered at both extremities, and exhibits typical characteristics of Digenean sperm such as two axonemes showing the 9 + ‘1’ trepaxonematan pattern with different lengths. The first axoneme is disorganised and disappears near the anterior nuclear extremity. However, the second axoneme reaches the posterior extremity of the spermatozoon. The latter also contains a nucleus, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. Cortical microtubules are absent in the anterior extremity of the spermatozoon and appear after the disappearance of the electron-dense material. In addition, the male gamete of S. aloysiae has two mitochondria. The first mitochondrion is associated with the external ornamentation of the plasma membrane and spine-like bodies. The second is more posteriorly located at the nuclear region after the disappearance of the first axoneme. The present study provides new data on the mature male gamete of S. aloysiae that may be useful for the understanding of Digenean relationships and phylogenetic studies.
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ultrastructural organisation of the spermatozoon of allopodocotyle tunisiensis derbel and neifar 2009 Digenea opecoelidae an intestinal parasite of solea aegyptiaca chabanaud 1927 teleostei soleidae
Tissue & Cell, 2019Co-Authors: Hichem Kacem, Papa Mbagnick Diagne, Jordi MiquelAbstract:Abstract The ultrastructure of the spermatozoon of Allopodocotyle tunisiensis (Digenea, Opecoelidae), an intestinal parasite of Solea aegyptiaca (Teleostei, Soleidae), is described by transmission electron microscopy (TEM). The mature spermatozoon is a filiform cell that exhibits two axonemes of different length with the 9+'1' pattern of trepaxonematan Platyhelminthes. In the anterior spermatozoon extremity, cortical microtubules are absent. They appear after the disappearance of an anterior electron-dense material, being initially in a continuous and submembranous layer. They surround only partially the sperm cell. Later, these cortical microtubules are distributed into two bundles. Additionally, the spermatozoon of A. tunisiensis shows two mitochondria, a nucleus, an external ornamentation of the plasma membrane, spine-like bodies, and a large amount of glycogen granules. According to the location of the external ornamentation, A. tunisiensis presents a Quilichini et al.'s type 2 spermatozoon. With respect to the posterior extremity, the sperm cell of A. tunisiensis corresponds to the Quilichini et al.'s opecoelid type. The morphology of the first mitochondrion with a U-shaped posterior extremity is described for the first time in a Digenean spermatozoon.
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Spermatological characteristics of Siphoderina aloysiae (Digenea, Cryptogonimidae), an intestinal parasite of Sciaena umbra (Teleostei, Sciaenidae)
Zoomorphology, 2019Co-Authors: Hichem Kacem, Jordi MiquelAbstract:The ultrastructural organisation of the spermatozoon of Siphoderina aloysiae (Digenea, Cryptogonimidae) is described based upon examination by transmission electron microscopy. Live Digeneans were collected from the digestive tract of the Brown meagre Sciaena umbra (Teleostei: Sciaenidae), caught off the Gulf of Gabes in La Chebba (Tunisia). The male gamete of S. aloysiae is a filiform cell, tapered at both extremities, and exhibits typical characteristics of Digenean sperm such as two axonemes showing the 9 + ‘1’ trepaxonematan pattern with different lengths. The first axoneme is disorganised and disappears near the anterior nuclear extremity. However, the second axoneme reaches the posterior extremity of the spermatozoon. The latter also contains a nucleus, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. Cortical microtubules are absent in the anterior extremity of the spermatozoon and appear after the disappearance of the electron-dense material. In addition, the male gamete of S. aloysiae has two mitochondria. The first mitochondrion is associated with the external ornamentation of the plasma membrane and spine-like bodies. The second is more posteriorly located at the nuclear region after the disappearance of the first axoneme. The present study provides new data on the mature male gamete of S. aloysiae that may be useful for the understanding of Digenean relationships and phylogenetic studies.
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advances in spermatological characters in the Digenea review and proposal of spermatozoa models and their phylogenetic importance
Advances in Parasitology, 2017Co-Authors: Abdoulaye J. S. Bakhoum, Bernard Marchand, Jean-lou Justine, Jordi Miquel, Papa Ndiaye, Alessandra Falchi, Yann QuilichiniAbstract:Abstract The wide biodiversity and economic importance of Digeneans have motivated a great deal of research in the last decade, focussing on their phylogenetic positions. Molecular research was instrumental for our understanding of phylogeny in the Digenea, but spermatological studies have also provided many results, which are potentially useful for phylogeny; however, the complete spermatological data set has never been reviewed in a whole phylogenetic perspective. Spermatological data are now available for more than 100 species, belonging to 15 superfamilies and 46 families. In this paper, we try to summarize the current knowledge about sperm structure in the Digeneans and propose a classification of Digenean spermatozoa into five basic models. The main ultrastructural characters used are (1) the type of axoneme, (2) the lateral expansion, (3) the association ‘external ornamentation of the plasma membrane + cortical microtubules’, (4) the field of cortical microtubules and its number, (5) the location of the external ornamentation, (6) the location of the maximum number of cortical microtubules and (7) the number of mitochondria. We also outline the most interesting features for phylogenetic inference and their possible value in the context of Digenean systematics, phylogeny and evolution. Associations between sperm models and superfamilies were found as follows: Type 1 in the Schistosomatoidea; Type 2 in the Hemiuroidea; Type 3 in the Opecoeloidea, Lepocreadioidea, Haploporoidea and Opisthorchioidea; Type 4 in the Gorgoderoidea, Microphalloidea, Plagiorchioidea and Gymnophalloidea; Type 5 in the Echinostomatoidea, Microscaphidioidea, Paramphistomoidea, Pronocephaloidea and Brachylaimoidea.
Yann Quilichini - One of the best experts on this subject based on the ideXlab platform.
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advances in spermatological characters in the Digenea review and proposal of spermatozoa models and their phylogenetic importance
Advances in Parasitology, 2017Co-Authors: Abdoulaye J. S. Bakhoum, Bernard Marchand, Jean-lou Justine, Jordi Miquel, Papa Ndiaye, Alessandra Falchi, Yann QuilichiniAbstract:Abstract The wide biodiversity and economic importance of Digeneans have motivated a great deal of research in the last decade, focussing on their phylogenetic positions. Molecular research was instrumental for our understanding of phylogeny in the Digenea, but spermatological studies have also provided many results, which are potentially useful for phylogeny; however, the complete spermatological data set has never been reviewed in a whole phylogenetic perspective. Spermatological data are now available for more than 100 species, belonging to 15 superfamilies and 46 families. In this paper, we try to summarize the current knowledge about sperm structure in the Digeneans and propose a classification of Digenean spermatozoa into five basic models. The main ultrastructural characters used are (1) the type of axoneme, (2) the lateral expansion, (3) the association ‘external ornamentation of the plasma membrane + cortical microtubules’, (4) the field of cortical microtubules and its number, (5) the location of the external ornamentation, (6) the location of the maximum number of cortical microtubules and (7) the number of mitochondria. We also outline the most interesting features for phylogenetic inference and their possible value in the context of Digenean systematics, phylogeny and evolution. Associations between sperm models and superfamilies were found as follows: Type 1 in the Schistosomatoidea; Type 2 in the Hemiuroidea; Type 3 in the Opecoeloidea, Lepocreadioidea, Haploporoidea and Opisthorchioidea; Type 4 in the Gorgoderoidea, Microphalloidea, Plagiorchioidea and Gymnophalloidea; Type 5 in the Echinostomatoidea, Microscaphidioidea, Paramphistomoidea, Pronocephaloidea and Brachylaimoidea.
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First spermatological study in the Atractotrematidae (Digenea, Haploporoidea): the case of Atractotrema sigani, intestinal parasite of Siganus lineatus
Parasite, 2015Co-Authors: Abdoulaye J. S. Bakhoum, Yann Quilichini, Jean-lou Justine, Jordi Miquel, Rodney A Bray, Carlos Feliu, Bernard MarchandAbstract:The ultrastructural organization of the mature spermatozoon of the Digenean Atractotrema sigani (from Siganus lineatus off New Caledonia) was investigated by transmission electron microscopy. The male gamete of A. sigani exhibits the general morphology described in Digeneans with the presence of two axonemes of different lengths showing the 9 + “1” pattern of the Trepaxonemata, a nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation, spine-like bodies and granules of glycogen. However, the mature spermatozoon of A. sigani has some specific characters such as the morphology of its anterior region and the submembranous electron-dense material. Although similar structures have been reported in some Digenean species, the presence of a submembranous electron-dense material describing a complete ring is reported here for the first time in the mature spermatozoon of A. sigani. In addition, sperm characteristics are compared between the Haploporoidea and their supposed close superfamilies, and possible phylogenetic implications of these findings for the Digenea are discussed.
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Vitellogenesis of the Digenean Plagiorchis elegans (Rudolphi, 1802) (Plagiorchioidea, Plagiorchiidae).
Parasitology International, 2014Co-Authors: Samuel Greani, Yann Quilichini, Stephen E Greiman, Josephine Foata, Papa Ibnou Ndiaye, Vasyl V Tkach, Bernard MarchandAbstract:The ultrastructural organization of vitellogenesis of Plagiorchis elegans (Rudolphi, 1802), experimentally obtained from the golden hamster Mesocricetus auratus (Linnaeus, 1758), is described using transmission electron microscopy. This study is the first ultrastructural study of vitellogenesis in a member of the superfamily Plagiorchioidea. The four stages usually observed during vitellogenesis are described: stage I, cytoplasm of the vitellocytes mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active synthesis of the shell globule clusters; stage IV, vitellocytes are filled with shell globule clusters and contain several lipid droplets, and glycogen granules are grouped around clusters and droplets. Vitellogenesis in P. elegans is compared with that of other Digenea. The differences among P. elegans and previously studied Digeneans include, but are not limited to the occurrence of dense coiled endoplasmic reticulum saccules and the concentration of glycogen in the mesenchyme, which may be considered as a fifth stage of maturation of the vitelline glands. This peculiarity was not observed in all trematodes, which clearly indicates differences in the vitellogenesis in various Digenean lineages at different stages of maturation of their vitelline cells.
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ultrastructure of the spermatozoon of the Digenean plagiorchis elegans rudolphi 1802 plagiorchioidea plagiorchiidae
Journal of Morphology, 2013Co-Authors: P Ndiaye, Cheikh Tidiane Ba, Yann Quilichini, Stephen E Greiman, Volodymyr V Tkach, Bernard MarchandAbstract:The ultrastructure of the mature spermatozoon of the type genus of the Plagiorchiidae Plagiorchis elegans (Rudolphi, 1802), a parasite of the Golden hamster, Mesocricetus auratus is described. This study is the first ultrastructural study of the spermatozoon of a Plagiorchis, the second of a plagiorchiid species and only the third in the Plagiorchioidea. Previously data on spermatozoon ultrastructure existed only for the plagiorchiid Enodiotrema reductum and the omphalometrid Rubenstrema exasperatum. The mature spermatozoon of P. elegans exhibited the general pattern described in most Digenean species, namely two axonemes of the 9 + "1" Trepaxonemata pattern, nucleus, mitochondria, external ornamentation of the plasma membrane, spine-like bodies, and glycogen granules. However, the rather typical expansion of the plasma membrane is not found in P. elegans. Another peculiarity of the spermatozoon of P. elegans is the presence of a structure called thin cytoplasm termination. Spermatozoon ultrastructure of P. elegans is compared with that of E. reductum and R. exasperatum. Spermatozoon of P. elegans conforms to the general pattern described in E. reductum. Thus, this study further expands our knowledge on the spermatozoon ultrastructure among the members of the Plagiorchioidea, one of the most phylogenetically derived groups of the Digenea.
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ultrastructural study of the spermatozoon of heterolebes maculosus Digenea opistholebetidae a parasite of the porcupinefish diodon hystrix pisces teleostei
Parasitology International, 2010Co-Authors: Yann Quilichini, Josephine Foata, Jean-lou Justine, Rodney A Bray, Bernard MarchandAbstract:This paper describes the ultrastructure of the mature spermatozoon of Heterolebes maculosus. It is the first study of this kind concerning the Opistholebetidae (Platyhelminthes, Digenea). The ultrastructural elements observed in the spermatozoon are: two axonemes with 9+"1" pattern of Trepaxonemata and their attachment zones, two mitochondria, a nucleus, cortical microtubules, external ornamentation of the plasma membrane and spine-like bodies. The number and the disposition of cortical microtubules, the organisation of 11 cortical microtubules disposed in semi-circle around the first mitochondrion in the external ornamentation region and the organisation of the posterior part of the spermatozoon are discussed. Three principal types of posterior part of Digenean spermatozoa are proposed. The similarity between the spermatozoon of the Opistholebetidae H. maculosus and Opecoelidae enables us to confirm that these two families are closely related.
Josephine Foata - One of the best experts on this subject based on the ideXlab platform.
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Vitellogenesis of the Digenean Plagiorchis elegans (Rudolphi, 1802) (Plagiorchioidea, Plagiorchiidae).
Parasitology International, 2014Co-Authors: Samuel Greani, Yann Quilichini, Stephen E Greiman, Josephine Foata, Papa Ibnou Ndiaye, Vasyl V Tkach, Bernard MarchandAbstract:The ultrastructural organization of vitellogenesis of Plagiorchis elegans (Rudolphi, 1802), experimentally obtained from the golden hamster Mesocricetus auratus (Linnaeus, 1758), is described using transmission electron microscopy. This study is the first ultrastructural study of vitellogenesis in a member of the superfamily Plagiorchioidea. The four stages usually observed during vitellogenesis are described: stage I, cytoplasm of the vitellocytes mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active synthesis of the shell globule clusters; stage IV, vitellocytes are filled with shell globule clusters and contain several lipid droplets, and glycogen granules are grouped around clusters and droplets. Vitellogenesis in P. elegans is compared with that of other Digenea. The differences among P. elegans and previously studied Digeneans include, but are not limited to the occurrence of dense coiled endoplasmic reticulum saccules and the concentration of glycogen in the mesenchyme, which may be considered as a fifth stage of maturation of the vitelline glands. This peculiarity was not observed in all trematodes, which clearly indicates differences in the vitellogenesis in various Digenean lineages at different stages of maturation of their vitelline cells.
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ultrastructural study of the spermatozoon of heterolebes maculosus Digenea opistholebetidae a parasite of the porcupinefish diodon hystrix pisces teleostei
Parasitology International, 2010Co-Authors: Yann Quilichini, Josephine Foata, Jean-lou Justine, Rodney A Bray, Bernard MarchandAbstract:This paper describes the ultrastructure of the mature spermatozoon of Heterolebes maculosus. It is the first study of this kind concerning the Opistholebetidae (Platyhelminthes, Digenea). The ultrastructural elements observed in the spermatozoon are: two axonemes with 9+"1" pattern of Trepaxonemata and their attachment zones, two mitochondria, a nucleus, cortical microtubules, external ornamentation of the plasma membrane and spine-like bodies. The number and the disposition of cortical microtubules, the organisation of 11 cortical microtubules disposed in semi-circle around the first mitochondrion in the external ornamentation region and the organisation of the posterior part of the spermatozoon are discussed. Three principal types of posterior part of Digenean spermatozoa are proposed. The similarity between the spermatozoon of the Opistholebetidae H. maculosus and Opecoelidae enables us to confirm that these two families are closely related.
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Spermiogenesis and sperm ultrastructure of Deropristis Inflata Molin, 1859 (Digenea, Deropristidae), a parasite of Anguilla anguilla
Parasitology Research, 2007Co-Authors: Josephine Foata, Yann Quilichini, Bernard MarchandAbstract:To our knowledge, this paper describes the first ultrastructural results on spermiogenesis and the spermatozoon of a Digenea belonging to the family Deropristidae, Deropristis inflata . Spermiogenesis follows the usual pattern found in the Digeneans, but a single noteworthy characteristic concerns the centriole, which presents a “prominent pear-shaped electron-dense region.” Spermiogenesis in D. inflata begins with the formation of a differentiation zone. The two centrioles give rise to flagella. These two flagella undergo a rotation of 90° and fuse with the median cytoplasmic process. The proximo-distal fusion occurs at the level of attachment zones. The mature spermatozoon of D. inflata possesses five regions and presents all the features found in the Digenean gamete. However, several characteristics allow us to distinguish the spermatozoon of D. inflata from other digenetic trematoda, namely the external ornamentations of the plasmic membrane, the anterior and posterior extremities. Furthermore, the distal part of the nucleus in front of those of the mitochondria appears such a distinctive criterion in the spermatozoon of this species. Our ultrastructural investigations produce new data on the reproduction of D. inflata , which may be useful for the understanding of the phylogenetic relationships in the Deropristidae family.
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Spermiogenesis and sperm ultrastructure of Deropristis Inflata Molin, 1859 (Digenea, Deropristidae), a parasite of Anguilla anguilla.
Parasitology Research, 2007Co-Authors: Josephine Foata, Yann Quilichini, Bernard MarchandAbstract:To our knowledge, this paper describes the first ultrastructural results on spermiogenesis and the spermatozoon of a Digenea belonging to the family Deropristidae, Deropristis inflata. Spermiogenesis follows the usual pattern found in the Digeneans, but a single noteworthy characteristic concerns the centriole, which presents a "prominent pear-shaped electron-dense region." Spermiogenesis in D. inflata begins with the formation of a differentiation zone. The two centrioles give rise to flagella. These two flagella undergo a rotation of 90 degrees and fuse with the median cytoplasmic process. The proximo-distal fusion occurs at the level of attachment zones. The mature spermatozoon of D. inflata possesses five regions and presents all the features found in the Digenean gamete. However, several characteristics allow us to distinguish the spermatozoon of D. inflata from other digenetic trematoda, namely the external ornamentations of the plasmic membrane, the anterior and posterior extremities. Furthermore, the distal part of the nucleus in front of those of the mitochondria appears such a distinctive criterion in the spermatozoon of this species. Our ultrastructural investigations produce new data on the reproduction of D. inflata, which may be useful for the understanding of the phylogenetic relationships in the Deropristidae family.
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ultrastructural study of the spermatozoon of pronoprymna ventricosa Digenea baccigerinae parasite of the twaite shad alosa fallax lacepede pisces teleostei
Parasitology Research, 2007Co-Authors: Yann Quilichini, Josephine Foata, Bernard MarchandAbstract:In this paper, we describe the ultrastructural organisation of the spermatozoon of a Digenea Baccigerinae Pronoprymna ventricosa. This spermatozoon possesses the elements found in the others Digeneans: two axonemes with 9 + “1” pattern, a mitochondrion, a nucleus, cortical microtubules and external ornamentations. However, this spermatozoon presents two particularities. The first is the presence of a single field of cortical microtubules disposed in the ventral side (mitochondrion side) of the spermatozoon. In the other Digeneans, two fields of cortical microtubules are observed between the two axonemes. The second is the presence of external ornamentations not associated with cortical microtubules. These two points have, to our knowledge, never been described in another Digenean. Moreover, a separation in two groups of the Digenean spermatozoa is proposed in relation to the localisation of the external ornamentations. We propose to distinguish a first group exhibiting these elements in the proximal part of the spermatozoon and a second one with external ornamentations in a second part of the gamete.
Vasyl V Tkach - One of the best experts on this subject based on the ideXlab platform.
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Phylogeny and systematics of the Proterodiplostomidae Dubois, 1936 (Digenea: Diplostomoidea) reflect the complex evolutionary history of the ancient Digenean group
Systematic Parasitology, 2020Co-Authors: Vasyl V Tkach, Scott D. Snyder, Tyler J. Achatz, Eric E. Pulis, Kerstin Junker, Jeffrey A. Bell, Ali Halajian, Francisco Tiago Vasconcelos MeloAbstract:The Proterodiplostomidae Dubois, 1936 is a relatively small family of diplostomoidean Digeneans parasitising the intestines of reptilian hosts associated with freshwater environments in tropical and subtropical regions. The greatest diversity of proterodiplostomids is found in crocodilians, although some parasitise snakes and turtles. According to the most recent revision, the Proterodiplostomidae included 17 genera within 5 subfamilies. Despite the complex taxonomic structure of the family, availability of testable morphology-based phylogenetic hypotheses and ancient hosts, molecular phylogenetic analyses of the group were practically lacking. Herein, we use novel DNA sequence data of the nuclear lsrRNA gene and mitochondrial cox 1 gene from a broad range of proterodiplostomid taxa obtained from crocodilian, fish, and snake hosts on four continents to test the monophyly of the family and evaluate the present morphology-based classification system of the Proterodiplostomidae in comparison with the molecular phylogeny. This first detailed phylogeny for the Proterodiplostomidae challenges the current systematic framework. Combination of molecular phylogenetic data with examination of freshly collected quality specimens and re-evaluation of morphological criteria resulted in a number of systematic and nomenclatural changes along with a new phylogeny-based classification of the Proterodiplostomidae. As the result of our molecular and morphological analyses: (i) the current subfamily structure of the Proterodiplostomidae is abolished; (ii) three new genera, Paraproterodiplostomum n. g., Neocrocodilicola n. g. and Proteroduboisia n. g., are described and Pseudoneodiplostomoides Yamaguti, 1954 is restored and elevated from subgenus to genus level; (iii) two new species, Paraproterodiplostomum currani n. g., n. sp. and Archaeodiplostomum overstreeti n. sp., are described from the American alligator in Mississippi, USA. Comparison of the structure of terminal ducts of the reproductive system in all proterodiplostomid genera did not support the use of these structures for differentiation among subfamilies (or major clades) within the family, although they proved to be useful for distinguishing among genera and species. Our study includes the first report of proterodiplostomids from Australia and the first evidence of a snake acting as a paratenic host for a proterodiplostomid. A key to proterodiplostomid genera is provided. Questions of proterodiplostomid-host associations parasitic in crocodilians are discussed in connection with their historical biogeography. Our molecular phylogeny of the Proterodiplostomidae closely matches the current molecular phylogeny of crocodilians. Directions for future studies of the Proterodiplostomidae are outlined.
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characterization of the complete mitochondrial genome of plagiorchis maculosus Digenea plagiorchiidae representative of a taxonomically complex Digenean family
Parasitology International, 2019Co-Authors: Mian Sayed Khan, Vasyl V Tkach, Nehaz Muhammad, Dong Zhang, Xingquan ZhuAbstract:Despite the highly divergent morphology, pathogenicity and worldwide distribution of Digenean parasites belonging to one of the largest families, the Plagiorchiidae, there are no complete mitochondrial (mt) genomes published to date for plagiorchiids. In this study, we obtained nuclear ribosomal DNA (ITS region and 28S rDNA) sequences and the complete mt genome sequences of Plagiorchis maculosus (Rudolphi 1802) Braun, 1902, and assessed its phylogenetic relationship with other xiphidiates, based on the mtDNA sequences. The obtained ITS and 28S rDNA sequences were identical to the corresponding sequences of P. maculosus available in GenBank. The complete mitochondrial genome of P. maculosus (14,124 bp) contained 36 genes (atp8 is absent) and a long non-coding region (NCR) with two sets of repeated sequences of 283 nucleotides each. The phylogenetic tree resulting from Bayesian inference (BI) analyses based on concatenated nucleotide sequences of all 36 genes of P. maculosus and other xiphidiates mitochondrial genomes, indicated that P. maculosus (and the Plagiorchiidae) is phylogenetically closest to the Brachycladiidae and Paragonimidae. The present study describes the first mitochondrial genome from the type genus of the family Plagiorchiidae. The overall gene arrangement, nucleotide composition, A + T contents, AT and GC skew and codon usage with relative synonymous codon usage (RSCU) for 12 PCGs are described. Characterization of mitochondrial genomes from additional plagiorchiid taxa is necessary to make further progress in phylogenetic and epidemiological studies of these Digeneans as well as accurate diagnostics of these parasites including those parasitic in humans.
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Paradeuterobaris victoriae n. sp. (Digenea: Microscaphidiidae) and Buckarootrema minuta n. sp. (Digenea: Pronocephalidae) from the Victoria River Red-Faced Turtle, Emydura victoriae (Pleurodira: Chelidae) in Australia
Comparative Parasitology, 2015Co-Authors: Scott D. Snyder, Vasyl V TkachAbstract:Abstract Paradeuterobaris victoriae n. sp. (Digenea: Microscaphidiidae) and Buckarootrema minuta n. sp. (Digenea: Pronocephalidae) are described from the Victoria River red-faced turtle, Emydura victoriae (Pleurodira: Chelidae), from the Victoria River, Northern Territory, Australia. Each of the new species is the second known member of a previously monotypic genus. Paradeuterobaris victoriae n. sp. differs from Paradeuterobaris novaguineae in the extent of the vitellarium and ventral glands, the position of the testes, and the presence of numerous uterine loops between the anterior testis and seminal vesicle, among other characters. Buckarootrema minuta n. sp. differs from Buckarootrema goodmani in the relative length of the ceca, the relative position of the gonads and testes, the position of uterine loops, the number of eggs, and overall body size. This work is the first report of any parasite from the Victoria River red-faced turtle and the first report of endohelminths from turtles of Northern Territory.
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Vitellogenesis of the Digenean Plagiorchis elegans (Rudolphi, 1802) (Plagiorchioidea, Plagiorchiidae).
Parasitology International, 2014Co-Authors: Samuel Greani, Yann Quilichini, Stephen E Greiman, Josephine Foata, Papa Ibnou Ndiaye, Vasyl V Tkach, Bernard MarchandAbstract:The ultrastructural organization of vitellogenesis of Plagiorchis elegans (Rudolphi, 1802), experimentally obtained from the golden hamster Mesocricetus auratus (Linnaeus, 1758), is described using transmission electron microscopy. This study is the first ultrastructural study of vitellogenesis in a member of the superfamily Plagiorchioidea. The four stages usually observed during vitellogenesis are described: stage I, cytoplasm of the vitellocytes mainly filled with ribosomes and few mitochondria; stage II, beginning of the synthetic activity; stage III, active synthesis of the shell globule clusters; stage IV, vitellocytes are filled with shell globule clusters and contain several lipid droplets, and glycogen granules are grouped around clusters and droplets. Vitellogenesis in P. elegans is compared with that of other Digenea. The differences among P. elegans and previously studied Digeneans include, but are not limited to the occurrence of dense coiled endoplasmic reticulum saccules and the concentration of glycogen in the mesenchyme, which may be considered as a fifth stage of maturation of the vitelline glands. This peculiarity was not observed in all trematodes, which clearly indicates differences in the vitellogenesis in various Digenean lineages at different stages of maturation of their vitelline cells.
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Transmission rates of the bacterial endosymbiont, Neorickettsia risticii, during the asexual reproduction phase of its Digenean host, Plagiorchis elegans, within naturally infected lymnaeid snails
Parasites & Vectors, 2013Co-Authors: Stephen E Greiman, Vasyl V Tkach, Jefferson A VaughanAbstract:Background Neorickettsia are obligate intracellular bacterial endosymbionts of Digenean parasites present in all lifestages of Digeneans. Quantitative information on the transmission of neorickettsial endosymbionts throughout the complex life cycles of Digeneans is lacking. This study quantified the transmission of Neorickettsia during the asexual reproductive phase of a Digenean parasite, Plagiorchis elegans , developing within naturally parasitized lymnaeid pond snails. Methods Lymnaea stagnalis snails were collected from 3 ponds in Nelson County, North Dakota and screened for the presence of Digenean cercariae. Cercariae were identified to species by PCR and sequencing of the 28S rRNA gene. Neorickettsia infections were initially detected using nested PCR and sequencing of a partial 16S rRNA gene of pooled cercariae shed from each parasitized snail. Fifty to 100 single cercariae or sporocysts were isolated from each of six parasitized snails and tested for the presence of Neorickettsia using nested PCR to estimate the efficiency at which Neorickettsia were transmitted to cercariae during asexual development of the Digenean. Results A total of 616 L. stagnalis were collected and 240 (39%) shed Digenean cercariae. Of these, 18 (8%) were Neorickettsia -positive. Six Neorickettsia infections were selected to determine the transmission efficiency of Neorickettsia from mother to daughter sporocyst and from daughter sporocyst to cercaria. The prevalence of neorickettsiae in cercariae varied from 11 to 91%. The prevalence of neorickettsiae in sporocysts from one snail was 100%. Conclusion Prevalence of Neorickettsia infection in cercariae of Plagiorchis elegans was variable and never reached 100%. Reasons for this are speculative, however, the low prevalence of Neorickettsia observed in some of our samples (11 to 52%) differs from the high prevalence of other, related bacterial endosymbionts, e.g. Wolbachia in Wolbachia -dependent filariid nematodes, where the prevalence among progeny is universally 100%. This suggests that, unlike the Wolbachia -filaria relationship, the Neorickettsia -Digenean relationship is not obligatory mutualism. Our study represents the first quantitative estimate of the Neorickettsia transmission through the asexual phase of the Digenean life cycle.