Abdoulaye J . S . Bakhoum (original) (raw)
Papers by Abdoulaye J . S . Bakhoum
Advances in parasitology, 2017
The wide biodiversity and economic importance of digeneans have motivated a great deal of researc... more 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 numb...
Zoologischer Anzeiger - A Journal of Comparative Zoology
PeerJ, 2016
Spermatological characteristics of species from two monorchiid genera, Opisthomonorchis and Param... more Spermatological characteristics of species from two monorchiid genera, Opisthomonorchis and Paramonorcheides, have been investigated, for the first time, by means of transmission electron microscopy. The ultrastructural study reveals that the mature spermatozoon of Opisthomonorchis dinema and Paramonorcheides selaris share several characters such as 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 of the plasma membrane, spine-like bodies, granules of glycogen and similar morphologies of the anterior and posterior extremities. The slight differences between the male gamete of O. dinema and P. selaris are the length of the first axoneme and the position of the second mitochondrion. This study also elucidates the general morphology of the spermatozoon in all monorchiid species described so far, which corresponds to a unique sperm...
Contribution à la connaissance de l'ultrastructure de la spermiogenèse et du spermatozoïde des Di... more Contribution à la connaissance de l'ultrastructure de la spermiogenèse et du spermatozoïde des Digènes Abdoulaye Jacque Sacodou Bakhoum ADVERTIMENT. La consulta d'aquesta tesi queda condicionada a l'acceptació de les següents condicions d'ús: La difusió d'aquesta tesi per mitjà del servei TDX (www.tdx.cat) ha estat autoritzada pels titulars dels drets de propietat intel•lectual únicament per a usos privats emmarcats en activitats d'investigació i docència. No s'autoritza la seva reproducció amb finalitats de lucre ni la seva difusió i posada a disposició des d'un lloc aliè al servei TDX. No s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant al resum de presentació de la tesi com als seus continguts. En la utilització o cita de parts de la tesi és obligat indicar el nom de la persona autora. ADVERTENCIA. La consulta de esta tesis queda condicionada a la aceptación de las siguientes condiciones de uso: La difusión de esta tesis por medio del servicio TDR (www.tdx.cat) ha sido autorizada por los titulares de los derechos de propiedad intelectual únicamente para usos privados enmarcados en actividades de investigación y docencia. No se autoriza su reproducción con finalidades de lucro ni su difusión y puesta a disposición desde un sitio ajeno al servicio TDR. No se autoriza la presentación de su contenido en una ventana o marco ajeno a TDR (framing). Esta reserva de derechos afecta tanto al resumen de presentación de la tesis como a sus contenidos. En la utilización o cita de partes de la tesis es obligado indicar el nombre de la persona autora. WARNING. On having consulted this thesis you're accepting the following use conditions: Spreading this thesis by the TDX (www.tdx.cat) service has been authorized by the titular of the intellectual property rights only for private uses placed in investigation and teaching activities. Reproduction with lucrative aims is not authorized neither its spreading and
Parasite, 2015
The ultrastructural organization of the mature spermatozoon of the digenean Atractotrema sigani (... more 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.
Zoologischer Anzeiger - A Journal of Comparative Zoology, 2015
ABSTRACT The male gametes of Brachylecithum eliomydis (Digenea, Dicrocoeliidae) a parasite of Eli... more ABSTRACT The male gametes of Brachylecithum eliomydis (Digenea, Dicrocoeliidae) a parasite of Eliomys quercinus “the garden dormouse” caught in France were described by micrographs of transmission electron microscopy (TEM). The mature spermatozoon of B. eliomydis presents classical characteristics early described in digenean species such as the two axonemes of different lengths with the 9 + “1” pattern of the trepaxonematan platyhelminthes, two bundles of parallel cortical microtubules, two mitochondria, a nucleus and granules of glycogen. Moreover, several characteristics, described in the spermatozoon of B. eliomydis, vary within digenean taxa. Those are (1) the morphology of anterior and posterior spermatozoon extremities, (2) the external ornamentation of the plasma membrane and its association or not with cortical microtubules, (3) the presence or absence of spine-like bodies and (4) the number of cortical microtubules and their organisation into one or two parallel bundles. Using these four criteria, the morphology of the mature spermatozoon of B. eliomydis was compared to that of the other dicrocoellids, brachycoeliids, paragonimids and troglotrematids species described so far. The general morphology of the spermatozoon described in B. eliomydis, could characterize the family Dicrocoeliidae.
PeerJ, 2015
The mature spermatozoa of Stephanostomum murielae and Stephanostomoides tenuis are described by t... more The mature spermatozoa of Stephanostomum murielae and Stephanostomoides tenuis are described by transmission electron microscopy. They present several ultrastructural features previously reported in other digeneans. Their spermatozoa possess two axonemes of different length showing the 9 + '1' trepaxonematan pattern, four attachment zones, two mitochondria (with an anterior moniliform one in S. murielae), a nucleus, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. The main differences between the mature spermatozoon of S. murielae and S. tenuis are the maximum number of cortical microtubules, the morphology of the anterior spermatozoon extremity and the anterior mitochondrion. This study is the first concerning members of the family Acanthocolpidae. The main ultrastructural characteristics discussed are the morphology of the anterior and posterior spermatozoon extremities, antero-lateral electron dense material, external ornamentations, spine-like bodies and number and morphology of mitochondria. In addition, the phylogenetic significance of all these ultrastructural features is discussed and compared to molecular results in order to highlight the complex relationships in the Digenea.
Cell biology international, Jan 24, 2015
Spermatological characteristics are described for the first time in the genus Neomultitestis Mach... more Spermatological characteristics are described for the first time in the genus Neomultitestis Machida, 1982, belonging to the family Lepocreadiidae Odhner, 1905. Adult Neomultitestis aspidogastriformis were collected from the digestive tract of Platax teira, caught off New Caledonia. The mature spermatozoon of N. aspidogastriformis is described by transmission electron microscopy (TEM). It includes two axonemes with 9 + "1" pattern of Trepaxonemata, an antero-lateral electron-dense material, attachment zones, two mitochondria, a nucleus, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies, and granules of glycogen. Certain ultrastructural characteristics of the spermatozoon, especially the antero-lateral electron-dense material, are shared by N. aspidogastriformis and all species of the superfamily Lepocreadioidea studied so far. The antero-lateral electron-dense material, present in different families of lepocread...
Parasite, 2014
The spermatological characteristics of Collyricloides massanae (Digenea: Collyriclidae), a parasi... more The spermatological characteristics of Collyricloides massanae (Digenea: Collyriclidae), a parasite of Apodemus sylvaticus caught in France, were studied by means of transmission electron microscopy. The mature sperm of C. massanae presents two axonemes of different lengths with the 9 + ''1'' pattern of the Trepaxonemata, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies, one mitochondrion, a nucleus and granules of glycogen. An analysis of spermatological organisation emphasised some differences between the mature spermatozoon of C. massanae and those reported in the Gorgoderoidea species studied to date, specially belonging to the families Dicrocoeliidae, Paragonimidae and Troglotrematidae. The ultrastructural criteria described in C. massanae such as the morphology of both anterior and posterior spermatozoon extremities, the association ''external ornamentation + cortical microtubules'', the type 2 of external ornamentation and the spine-like bodies would allow us to bring closer the Collyriclidae to Microphalloidea. However, further ultrastructural and molecular studies are needed particularly in the unexplored taxa in order to fully resolve the phylogenetic position of the Collyriclidae.
Zoologischer Anzeiger - A Journal of Comparative Zoology, 2013
The mature spermatozoon of Parahemiurus merus (Digenea: Hemiuroidea: Hemiuridae) is filiform, tap... more The mature spermatozoon of Parahemiurus merus (Digenea: Hemiuroidea: Hemiuridae) is filiform, tapered in both ends and exhibits the general pattern described in most digeneans so far: two axonemes of the 9+'1' pattern of trepaxonematan Platyhelminthes, nucleus, mitochondrion, external ornamentation of the plasma membrane and parallel cortical microtubules. However, the spermatozoon of P. merus presents some peculiarities. The presence of an external ornamentation of the plasma membrane not associated with cortical microtubules in the anterior part of the spermatozoon is described for a second genus in the family Hemiuridae. Cortical microtubules are disposed in only one side of the spermatozoon as described in other species of Hemiuroidea but, in P. merus, the number of cortical microtubules is much lower. The results obtained are compared with the available data on Hemiuroidea in order to improve the understanding of phylogenetic relationships of hemiuroids. Similarities found between spermatozoa of hemiurids and lecithasterids are in accordance with molecular evidence that group these two families in a same clade.
Zoologischer Anzeiger - A Journal of Comparative Zoology, 2013
Ultrastructural characters of spermiogenesis and the mature spermatozoon of Brachycoelium salaman... more 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.
Tissue and Cell, 2013
The Mesometridae includes only five genera and eight species. The available data on the ultrastru... more The Mesometridae includes only five genera and eight species. The available data on the ultrastructure of sperm cells of mesometrid species referred to two species only, Elstia stossichianum and Wardula capitellata. The present study revealed the ultrastructure of the spermatozoon of a third genus and third species of Mesometridae, Centroderma spinosissima. The mature spermatozoon of C. spinosissima presents two axonemes with different lengths of the Ehlers' 9 + '1' trepaxonematan pattern, a nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, a lateral expansion, spine-like bodies, cytoplasmic ornamented buttons and granules of glycogen. The spermatozoon of C. spinosissima is similar to those of the previously studied mesometrids. However, some peculiarities such as the presence of two mitochondria, the disposition of the external ornamentation of the plasma membrane and the morphology of the posterior spermatozoon extremity, characterize the male gamete of C. spinosissima. Moreover, the presence of cytoplasmic ornamented buttons is a characteristic found only in the mature spermatozoon of mesometrids and it probably represents an autapomorphy for this family.
Parasitology Research, 2011
During vitellogenesis in the microphallid trematode Maritrema feliui, we distinguished four stage... more During vitellogenesis in the microphallid trematode Maritrema feliui, we distinguished four stages: (I) a stem cell stage of the gonial type; (II) an early differentiation stage with the main cell activity concentrated on the initiation of protein synthetic activity and the beginning of shell globule formation; (III) an advanced differentiation stage concentrated on a rapid intensification of protein synthetic activity, the progressive fusion of individual shell globules into large shell globule clusters and the formation of saturated lipid droplets and a small amount of β-glycogen particles in the peripheral cytoplasm, considered as a store of nutritive reserves for the developing embryos; and (IV) the mature vitellocyte. Early vitellocyte maturation is characterised by: (1) an increase in cell volume; (2) extensive development of large, labyrinth-like cisternae of GER that produce proteinaceous granules; (3) the development of Golgi complexes engaged in packaging this material; and (4) a continuous enlargement of proteinaceous granules within vacuoles and their transformation into shell globule clusters composed of the heterogeneous material observed during vitellocyte cytodifferentiation. Mature vitelline cells are very rich in two types of cell inclusions accumulated in large amounts in their cytoplasm: (1) shell globule clusters, which play an important role in eggshell formation; and (2) a few osmiophobic lipid droplets of a saturated nature that undoubtedly represent nutritive reserves for the developing embryos. In addition, there are small numbers of β-glycogen particles in the peripheral cytoplasm of mature vitellocytes of this species. The general pattern and ultrastructure of vitellogenesis in M. feliui greatly resembles those observed in another microphallid trematode, Maritrema linguilla, in other digeneans and in some lower cestodes. Quantitative and qualitative variations in lipids (saturated and unsaturated) and glycogen (α-glycogen rosettes and β-glycogen particles) during platyhelminth vitellogenesis between the different species of trematodes and some lower cestodes are identified and discussed.
Parasitology Research, 2011
We present the first ultrastructural description of spermiogenesis and of the spermatozoon of Rub... more We present the first ultrastructural description of spermiogenesis and of the spermatozoon of Rubenstrema exasperatum (Omphalometridae), an intestinal parasite of Sorex araneus (Soricidae). Spermiogenesis begins with the formation of the differentiation zone delimited at the base by the ring of the arched membranes and bordered by cortical microtubules. This area contains two centrioles associated with striated rootlets and with an intercentriolar body. It also contains the nucleus and numerous mitochondria. The intercentriolar body is made up of seven electron-dense layers. The two centrioles give rise to two free flagella that grow orthogonally to the median cytoplasmic process. Additionally, flagellar rotation is followed by the proximodistal fusion of the flagella with the median cytoplasmic process, while the nucleus and mitochondria migrate along the spermatid. The constriction of the ring of arched membranes gives rise to the young spermatozoon. The mature spermatozoon of R. exasperatum shows several ultrastructural characters found in digenean spermatozoa such as two axonemes, mitochondrion, two bundles of parallel cortical microtubules, nucleus, and granules of glycogen. External ornamentation of the plasma membrane and spinelike bodies are also present in the spermatozoon of this species. In the present study, we produced additional spermatological data concerning a previously unexplored family, and we also compare our data to the existent ultrastructural descriptions within the Digenea in order to assess the use of several characters proposed as phylogenetic tools.
Journal of Helminthology, 2013
The current study was designed to increase the spermatological ultrastructural database on Digene... more The current study was designed to increase the spermatological ultrastructural database on Digenea, thus contributing to the future establishment of phylogenetic relationships within this group based on ultrastructural characteristics of both spermiogenesis and spermatozoa. Spermiogenesis in Elstia stossichianum begins with the formation of a differentiation zone containing two centrioles, two striated rootlets, a nucleus, several mitochondria and an intercentriolar body constituted by seven electron-dense layers. Each centriole develops into a free flagellum growing orthogonally to the median cytoplasmic process. Proximo-distal fusion of the flagella with the median cytoplasmic process occurs after flagellar rotation. Both nucleus and mitochondria migrate before the complete proximo-distal fusion of both flagella with the median cytoplasmic process. Finally, the constriction of the ring of arched membranes gives rise to the young spermatozoon. The mature spermatozoon of E. stossich...
Folia Parasitologica, 2013
the genus Mediogonimus Woodhead et Malewitz, 1936 includes liver parasites of arvicoline and muri... more the genus Mediogonimus Woodhead et Malewitz, 1936 includes liver parasites of arvicoline and murine rodents from North America and Europe (see Jones 2008). to date, this genus includes only two species, namely Mediogonimus ovilacus Woodhead et Malewitz, 1936 and Mediogonimus jourdanei Mas-coma et rocamora, 1978. the genus Mediogonimus was initially placed in the subfamily Prosthogoniminae lühe, 1909 in the family Prosthogonimidae lühe, 1909. later, other authors included this subfamily in the family Plagiorchiidae lühe, 1901 or lepodermatidae odhner, 1910 (now synonymized with Plagiorchiidae). The classification and taxonomic status of Prosthogonimidae have varied considerably according to authors. the Prosthogonimidae have been considered a family closely related to the cephalogonimidae looss, 1899, both families included in the superfamily Plagiorchioidea lühe, 1901, due to morphoanatomical aspects (see Jones 2008). Brooks et al. (1989), who accept the latter family status, propose placing it in the superfamily Microphalloidea Ward, 1901, although it is unclear how they reached this conclusion based on their morphological phylogenetic analysis (see cribb et al. 2001). recently, the relationship between cephalogonimids and prosthogonimids was not corroborated by molecular analysis (olson et al. 2003). According to the latter authors, they represent different clades and prosthogonimids are the sister group of the microphalloidean family Pleurogenidae travassos, 1921. these results are in agreement with Jones (2008) who considers that the family Prosthogonimidae should belong to the superfamily Microphalloidea. the controversies concerning this family are common to most digenean taxa, being recurrent problems to the establishment of relationships within the Platyhelminthes. in order to help clarifying such relationships in the Platy
Advances in parasitology, 2017
The wide biodiversity and economic importance of digeneans have motivated a great deal of researc... more 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 numb...
Zoologischer Anzeiger - A Journal of Comparative Zoology
PeerJ, 2016
Spermatological characteristics of species from two monorchiid genera, Opisthomonorchis and Param... more Spermatological characteristics of species from two monorchiid genera, Opisthomonorchis and Paramonorcheides, have been investigated, for the first time, by means of transmission electron microscopy. The ultrastructural study reveals that the mature spermatozoon of Opisthomonorchis dinema and Paramonorcheides selaris share several characters such as 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 of the plasma membrane, spine-like bodies, granules of glycogen and similar morphologies of the anterior and posterior extremities. The slight differences between the male gamete of O. dinema and P. selaris are the length of the first axoneme and the position of the second mitochondrion. This study also elucidates the general morphology of the spermatozoon in all monorchiid species described so far, which corresponds to a unique sperm...
Contribution à la connaissance de l'ultrastructure de la spermiogenèse et du spermatozoïde des Di... more Contribution à la connaissance de l'ultrastructure de la spermiogenèse et du spermatozoïde des Digènes Abdoulaye Jacque Sacodou Bakhoum ADVERTIMENT. La consulta d'aquesta tesi queda condicionada a l'acceptació de les següents condicions d'ús: La difusió d'aquesta tesi per mitjà del servei TDX (www.tdx.cat) ha estat autoritzada pels titulars dels drets de propietat intel•lectual únicament per a usos privats emmarcats en activitats d'investigació i docència. No s'autoritza la seva reproducció amb finalitats de lucre ni la seva difusió i posada a disposició des d'un lloc aliè al servei TDX. No s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant al resum de presentació de la tesi com als seus continguts. En la utilització o cita de parts de la tesi és obligat indicar el nom de la persona autora. ADVERTENCIA. La consulta de esta tesis queda condicionada a la aceptación de las siguientes condiciones de uso: La difusión de esta tesis por medio del servicio TDR (www.tdx.cat) ha sido autorizada por los titulares de los derechos de propiedad intelectual únicamente para usos privados enmarcados en actividades de investigación y docencia. No se autoriza su reproducción con finalidades de lucro ni su difusión y puesta a disposición desde un sitio ajeno al servicio TDR. No se autoriza la presentación de su contenido en una ventana o marco ajeno a TDR (framing). Esta reserva de derechos afecta tanto al resumen de presentación de la tesis como a sus contenidos. En la utilización o cita de partes de la tesis es obligado indicar el nombre de la persona autora. WARNING. On having consulted this thesis you're accepting the following use conditions: Spreading this thesis by the TDX (www.tdx.cat) service has been authorized by the titular of the intellectual property rights only for private uses placed in investigation and teaching activities. Reproduction with lucrative aims is not authorized neither its spreading and
Parasite, 2015
The ultrastructural organization of the mature spermatozoon of the digenean Atractotrema sigani (... more 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.
Zoologischer Anzeiger - A Journal of Comparative Zoology, 2015
ABSTRACT The male gametes of Brachylecithum eliomydis (Digenea, Dicrocoeliidae) a parasite of Eli... more ABSTRACT The male gametes of Brachylecithum eliomydis (Digenea, Dicrocoeliidae) a parasite of Eliomys quercinus “the garden dormouse” caught in France were described by micrographs of transmission electron microscopy (TEM). The mature spermatozoon of B. eliomydis presents classical characteristics early described in digenean species such as the two axonemes of different lengths with the 9 + “1” pattern of the trepaxonematan platyhelminthes, two bundles of parallel cortical microtubules, two mitochondria, a nucleus and granules of glycogen. Moreover, several characteristics, described in the spermatozoon of B. eliomydis, vary within digenean taxa. Those are (1) the morphology of anterior and posterior spermatozoon extremities, (2) the external ornamentation of the plasma membrane and its association or not with cortical microtubules, (3) the presence or absence of spine-like bodies and (4) the number of cortical microtubules and their organisation into one or two parallel bundles. Using these four criteria, the morphology of the mature spermatozoon of B. eliomydis was compared to that of the other dicrocoellids, brachycoeliids, paragonimids and troglotrematids species described so far. The general morphology of the spermatozoon described in B. eliomydis, could characterize the family Dicrocoeliidae.
PeerJ, 2015
The mature spermatozoa of Stephanostomum murielae and Stephanostomoides tenuis are described by t... more The mature spermatozoa of Stephanostomum murielae and Stephanostomoides tenuis are described by transmission electron microscopy. They present several ultrastructural features previously reported in other digeneans. Their spermatozoa possess two axonemes of different length showing the 9 + '1' trepaxonematan pattern, four attachment zones, two mitochondria (with an anterior moniliform one in S. murielae), a nucleus, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. The main differences between the mature spermatozoon of S. murielae and S. tenuis are the maximum number of cortical microtubules, the morphology of the anterior spermatozoon extremity and the anterior mitochondrion. This study is the first concerning members of the family Acanthocolpidae. The main ultrastructural characteristics discussed are the morphology of the anterior and posterior spermatozoon extremities, antero-lateral electron dense material, external ornamentations, spine-like bodies and number and morphology of mitochondria. In addition, the phylogenetic significance of all these ultrastructural features is discussed and compared to molecular results in order to highlight the complex relationships in the Digenea.
Cell biology international, Jan 24, 2015
Spermatological characteristics are described for the first time in the genus Neomultitestis Mach... more Spermatological characteristics are described for the first time in the genus Neomultitestis Machida, 1982, belonging to the family Lepocreadiidae Odhner, 1905. Adult Neomultitestis aspidogastriformis were collected from the digestive tract of Platax teira, caught off New Caledonia. The mature spermatozoon of N. aspidogastriformis is described by transmission electron microscopy (TEM). It includes two axonemes with 9 + "1" pattern of Trepaxonemata, an antero-lateral electron-dense material, attachment zones, two mitochondria, a nucleus, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies, and granules of glycogen. Certain ultrastructural characteristics of the spermatozoon, especially the antero-lateral electron-dense material, are shared by N. aspidogastriformis and all species of the superfamily Lepocreadioidea studied so far. The antero-lateral electron-dense material, present in different families of lepocread...
Parasite, 2014
The spermatological characteristics of Collyricloides massanae (Digenea: Collyriclidae), a parasi... more The spermatological characteristics of Collyricloides massanae (Digenea: Collyriclidae), a parasite of Apodemus sylvaticus caught in France, were studied by means of transmission electron microscopy. The mature sperm of C. massanae presents two axonemes of different lengths with the 9 + ''1'' pattern of the Trepaxonemata, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, spine-like bodies, one mitochondrion, a nucleus and granules of glycogen. An analysis of spermatological organisation emphasised some differences between the mature spermatozoon of C. massanae and those reported in the Gorgoderoidea species studied to date, specially belonging to the families Dicrocoeliidae, Paragonimidae and Troglotrematidae. The ultrastructural criteria described in C. massanae such as the morphology of both anterior and posterior spermatozoon extremities, the association ''external ornamentation + cortical microtubules'', the type 2 of external ornamentation and the spine-like bodies would allow us to bring closer the Collyriclidae to Microphalloidea. However, further ultrastructural and molecular studies are needed particularly in the unexplored taxa in order to fully resolve the phylogenetic position of the Collyriclidae.
Zoologischer Anzeiger - A Journal of Comparative Zoology, 2013
The mature spermatozoon of Parahemiurus merus (Digenea: Hemiuroidea: Hemiuridae) is filiform, tap... more The mature spermatozoon of Parahemiurus merus (Digenea: Hemiuroidea: Hemiuridae) is filiform, tapered in both ends and exhibits the general pattern described in most digeneans so far: two axonemes of the 9+'1' pattern of trepaxonematan Platyhelminthes, nucleus, mitochondrion, external ornamentation of the plasma membrane and parallel cortical microtubules. However, the spermatozoon of P. merus presents some peculiarities. The presence of an external ornamentation of the plasma membrane not associated with cortical microtubules in the anterior part of the spermatozoon is described for a second genus in the family Hemiuridae. Cortical microtubules are disposed in only one side of the spermatozoon as described in other species of Hemiuroidea but, in P. merus, the number of cortical microtubules is much lower. The results obtained are compared with the available data on Hemiuroidea in order to improve the understanding of phylogenetic relationships of hemiuroids. Similarities found between spermatozoa of hemiurids and lecithasterids are in accordance with molecular evidence that group these two families in a same clade.
Zoologischer Anzeiger - A Journal of Comparative Zoology, 2013
Ultrastructural characters of spermiogenesis and the mature spermatozoon of Brachycoelium salaman... more 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.
Tissue and Cell, 2013
The Mesometridae includes only five genera and eight species. The available data on the ultrastru... more The Mesometridae includes only five genera and eight species. The available data on the ultrastructure of sperm cells of mesometrid species referred to two species only, Elstia stossichianum and Wardula capitellata. The present study revealed the ultrastructure of the spermatozoon of a third genus and third species of Mesometridae, Centroderma spinosissima. The mature spermatozoon of C. spinosissima presents two axonemes with different lengths of the Ehlers' 9 + '1' trepaxonematan pattern, a nucleus, two mitochondria, two bundles of parallel cortical microtubules, external ornamentation of the plasma membrane, a lateral expansion, spine-like bodies, cytoplasmic ornamented buttons and granules of glycogen. The spermatozoon of C. spinosissima is similar to those of the previously studied mesometrids. However, some peculiarities such as the presence of two mitochondria, the disposition of the external ornamentation of the plasma membrane and the morphology of the posterior spermatozoon extremity, characterize the male gamete of C. spinosissima. Moreover, the presence of cytoplasmic ornamented buttons is a characteristic found only in the mature spermatozoon of mesometrids and it probably represents an autapomorphy for this family.
Parasitology Research, 2011
During vitellogenesis in the microphallid trematode Maritrema feliui, we distinguished four stage... more During vitellogenesis in the microphallid trematode Maritrema feliui, we distinguished four stages: (I) a stem cell stage of the gonial type; (II) an early differentiation stage with the main cell activity concentrated on the initiation of protein synthetic activity and the beginning of shell globule formation; (III) an advanced differentiation stage concentrated on a rapid intensification of protein synthetic activity, the progressive fusion of individual shell globules into large shell globule clusters and the formation of saturated lipid droplets and a small amount of β-glycogen particles in the peripheral cytoplasm, considered as a store of nutritive reserves for the developing embryos; and (IV) the mature vitellocyte. Early vitellocyte maturation is characterised by: (1) an increase in cell volume; (2) extensive development of large, labyrinth-like cisternae of GER that produce proteinaceous granules; (3) the development of Golgi complexes engaged in packaging this material; and (4) a continuous enlargement of proteinaceous granules within vacuoles and their transformation into shell globule clusters composed of the heterogeneous material observed during vitellocyte cytodifferentiation. Mature vitelline cells are very rich in two types of cell inclusions accumulated in large amounts in their cytoplasm: (1) shell globule clusters, which play an important role in eggshell formation; and (2) a few osmiophobic lipid droplets of a saturated nature that undoubtedly represent nutritive reserves for the developing embryos. In addition, there are small numbers of β-glycogen particles in the peripheral cytoplasm of mature vitellocytes of this species. The general pattern and ultrastructure of vitellogenesis in M. feliui greatly resembles those observed in another microphallid trematode, Maritrema linguilla, in other digeneans and in some lower cestodes. Quantitative and qualitative variations in lipids (saturated and unsaturated) and glycogen (α-glycogen rosettes and β-glycogen particles) during platyhelminth vitellogenesis between the different species of trematodes and some lower cestodes are identified and discussed.
Parasitology Research, 2011
We present the first ultrastructural description of spermiogenesis and of the spermatozoon of Rub... more We present the first ultrastructural description of spermiogenesis and of the spermatozoon of Rubenstrema exasperatum (Omphalometridae), an intestinal parasite of Sorex araneus (Soricidae). Spermiogenesis begins with the formation of the differentiation zone delimited at the base by the ring of the arched membranes and bordered by cortical microtubules. This area contains two centrioles associated with striated rootlets and with an intercentriolar body. It also contains the nucleus and numerous mitochondria. The intercentriolar body is made up of seven electron-dense layers. The two centrioles give rise to two free flagella that grow orthogonally to the median cytoplasmic process. Additionally, flagellar rotation is followed by the proximodistal fusion of the flagella with the median cytoplasmic process, while the nucleus and mitochondria migrate along the spermatid. The constriction of the ring of arched membranes gives rise to the young spermatozoon. The mature spermatozoon of R. exasperatum shows several ultrastructural characters found in digenean spermatozoa such as two axonemes, mitochondrion, two bundles of parallel cortical microtubules, nucleus, and granules of glycogen. External ornamentation of the plasma membrane and spinelike bodies are also present in the spermatozoon of this species. In the present study, we produced additional spermatological data concerning a previously unexplored family, and we also compare our data to the existent ultrastructural descriptions within the Digenea in order to assess the use of several characters proposed as phylogenetic tools.
Journal of Helminthology, 2013
The current study was designed to increase the spermatological ultrastructural database on Digene... more The current study was designed to increase the spermatological ultrastructural database on Digenea, thus contributing to the future establishment of phylogenetic relationships within this group based on ultrastructural characteristics of both spermiogenesis and spermatozoa. Spermiogenesis in Elstia stossichianum begins with the formation of a differentiation zone containing two centrioles, two striated rootlets, a nucleus, several mitochondria and an intercentriolar body constituted by seven electron-dense layers. Each centriole develops into a free flagellum growing orthogonally to the median cytoplasmic process. Proximo-distal fusion of the flagella with the median cytoplasmic process occurs after flagellar rotation. Both nucleus and mitochondria migrate before the complete proximo-distal fusion of both flagella with the median cytoplasmic process. Finally, the constriction of the ring of arched membranes gives rise to the young spermatozoon. The mature spermatozoon of E. stossich...
Folia Parasitologica, 2013
the genus Mediogonimus Woodhead et Malewitz, 1936 includes liver parasites of arvicoline and muri... more the genus Mediogonimus Woodhead et Malewitz, 1936 includes liver parasites of arvicoline and murine rodents from North America and Europe (see Jones 2008). to date, this genus includes only two species, namely Mediogonimus ovilacus Woodhead et Malewitz, 1936 and Mediogonimus jourdanei Mas-coma et rocamora, 1978. the genus Mediogonimus was initially placed in the subfamily Prosthogoniminae lühe, 1909 in the family Prosthogonimidae lühe, 1909. later, other authors included this subfamily in the family Plagiorchiidae lühe, 1901 or lepodermatidae odhner, 1910 (now synonymized with Plagiorchiidae). The classification and taxonomic status of Prosthogonimidae have varied considerably according to authors. the Prosthogonimidae have been considered a family closely related to the cephalogonimidae looss, 1899, both families included in the superfamily Plagiorchioidea lühe, 1901, due to morphoanatomical aspects (see Jones 2008). Brooks et al. (1989), who accept the latter family status, propose placing it in the superfamily Microphalloidea Ward, 1901, although it is unclear how they reached this conclusion based on their morphological phylogenetic analysis (see cribb et al. 2001). recently, the relationship between cephalogonimids and prosthogonimids was not corroborated by molecular analysis (olson et al. 2003). According to the latter authors, they represent different clades and prosthogonimids are the sister group of the microphalloidean family Pleurogenidae travassos, 1921. these results are in agreement with Jones (2008) who considers that the family Prosthogonimidae should belong to the superfamily Microphalloidea. the controversies concerning this family are common to most digenean taxa, being recurrent problems to the establishment of relationships within the Platyhelminthes. in order to help clarifying such relationships in the Platy