The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
F. Oberwinkler - One of the best experts on this subject based on the ideXlab platform.
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Teliospores of smut fungi teliospore walls and the development of Ornamentation studied by electron microscopy
Protoplasma, 1998Co-Authors: M. Piepenbring, R. Bauer, F. OberwinklerAbstract:The walls of mature teliospores and the development of Ornamentation, as seen by transmission electron microscopy, are described for 37 genera of smut fungi, based on observations of ca. 120 species and on literature. Structural diversity of mature teliospore walls is due to differences in spore wall layers forming the spore wall (endosporium, middle layer, exosporium, Ornamentation) and to different elements forming the Ornamentation (exosporium, ornaments, sheath, hyphal wall, adjacent fungal cells, material of the host). During teliosporogenesis the outer layers are usually deposited first. At the beginning of the formation of the Ornamentation the plasma membrane may be smooth or undulated carrying the developing ornaments on its tips or in its depressions. The Ornamentation of some genera appears similar when seen by scanning electron microscopy, but can be the product of different developmental patterns (e.g., warts of species of Farysia, Tilletia , and Ustilago ), however, warty and reticulate Ornamentation can both be produced by similar developmental processes (shown, e.g., for species of Cintractia and Tilletia ). Typical structures of the mature teliospore wall and developmental patterns based on homologous similarities are described for the following groups of genera or species: Macalpinomyces, Melanopsichium, Sporisorium , and Ustilago infecting members of the family Poaceae; Kuntzeomyces, Testicularia , and Trichocintractia; Anthracoidea, Cintractia, Heterotolyposporium piluliforme , and Tolyposporium junci; Glomosporium, Sorosporium , and Thecaphora; Conidiosporomyces, Erratomyces, Ingoldiomyces, Neovossia, Oberwinkleria , and Tilletia; Entyloma , and genera of the Doassansia group; Liroa, Microbotryum, Sphacelotheca, Ustilago infecting dicotyledons, and Zundeliomyces; Aurantiosporium, Fulvisporium , and Ustilentyloma . Special characteristics of the teliospore wall were observed for the genera Dermatosorus, Doassinga, Entorrhha, Farysia, Mycosyrinx, Rhamphospora , and some species of Tolyposporium .
Yann Quilichini - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructure of the spermatozoon of Lecithostaphylus parexocoeti (Digenea, Microphalloidea, Zoogonidae) parasite of the flying fish Cheilopogon pinnatibarbatus (Teleostei, Exocoetidae) off Senegal and their implication on the phylogenetic relations
Zoomorphology, 2020Co-Authors: Aïssatou Bâ, Abdoulaye J. S. Bakhoum, Papa Ibnou Ndiaye, Cheikh Tidiane Ba, Bernard Marchand, Rodney A Bray, Yann QuilichiniAbstract:This study shows the ultrastructure of the mature spermatozoon of Lecithostaphylus parexocoeti (Digenea, Microphalloidea, Zoogonidae) parasite of the flying fish Cheilopogon pinnatibarbatus (Exocoetidae) captured in the Atlantic Ocean near Dakar (Senegal). This is the first report of L. parexocoeti from Senegal and from this host species. The mature spermatozoon is filiform and exhibits two axonemes of the 9+“1” pattern of the Trepaxonemata, an external Ornamentation associated with spine-like bodies, parallel cortical microtubules, a nucleus, two mitochondria and granules of glycogen. The particularities of the spermatozoon of L. parexocoeti are the location of the first mitochondrion and the morphology of its anterior extremity with only cortical microtubules and external Ornamentations of the plasma membrane. To our knowledge, this type of anterior extremity has never been described in the superfamily Microphalloidea. However, the ultrastructure of the posterior extremity of the spermatozoon corresponds to the fasciolidean type that was previously described in the Zoogonidae.
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ultrastructural characteristics of the mature spermatozoon of the digenean sclerodistomum italicum stossich 1893 hemiuroidea sclerodistomidae intestinal parasite of hypocanthus amia teleostei carangidae
Tissue & Cell, 2017Co-Authors: P Ndiaye, Cheikh Tidiane Ba, Yann Quilichini, Adji Mama Marigo, Volodymyr V Tkach, Bernard MarchandAbstract:Abstract The mature spermatozoon of Sclerodistomum italicum is filiform, tapered at both ends and shows the following features: 2 axonemes of the 9 + “1” pattern of the Trepaxonemata, mitochondrion, nucleus and parallel cortical microtubules. The specific features of the spermatozoon of S. italicum include the simultaneous presence of two types of extramembranous Ornamentations, the presence of short cortical microtubules in the anterior part of the spermatozoon and the presence of only one bundle of cortical microtubules in the median part of the spermatozoon. Thus far these structures are known only in the Hemiuroidea. The presence of filamentous Ornamentation in the anterior extremity of the spermatozoon has not previously been described in the Sclerodistomidae. Similar to spermatozoa of other hemiuroideans, S. italicum lack spine-like bodies described in spermatozoa of many digenean taxa. The posterior extremity of the spermatozoon exhibits the same ultrastructural characteristics typical of the Hemiuroidea.
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ultrastructural study of the spermatozoon of hemiurus appendiculatus digenea hemiuroidea hemiuridae a parasite of boops boops pisces teleostei sparidae off senegal
Tissue & Cell, 2016Co-Authors: Ayatoulaye Dione, P Ndiaye, Cheikh Tidiane Ba, Yann Quilichini, Papa Mbagnick Diagne, Bernard MarchandAbstract:The mature spermatozoon of Hemiurus appendiculatus exhibits the general pattern described in most of the digenean namely, two axonemes of the 9 + "1" pattern of the Trepaxonemata, a nucleus, a filiform mitochondrion, external Ornamentations of the plasma membrane and parallel cortical microtubules located on one side of the spermatozoon. In this study, we show for the second time in a digenean spermatozoon the presence of microtubules of the second axoneme associated each in a short length with an external Ornamentation, seven cortical microtubules, a terminal bulge in the anterior spermatozoon extremity separate from the remainder of the spermatozoon by a transverse constriction and the simultaneous presence of the external Ornamentation of the plasma membrane with a filamentous Ornamentation. The external Ornamentations have a differentiated distribution, cover almost the anterior region of the spermatozoon, are more abundant around the first axoneme and extend backwards over a short distance around the second axoneme. This study also allowed us to reveal for the first time the existence in the Hemiuroidea of an axoneme that begins to disrupt before reaching the front end of the mitochondrion.
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Sperm ultrastructure of Helicometra epinepheli (Platyhelminthes, Digenea, Opecoelidae), parasite of Epinephelus fasciatus (Pisces, Teleostei).
Histology and Histopathology, 2011Co-Authors: Yann Quilichini, J. Foata, J.-l. Justine, R. A. Bray, B. MarchandAbstract:This paper describes the ultrastructure of the mature spermatozoon of the digenean Helicometra epinepheli. The ultrastructural elements observed are: two axonemes with a 9+"1" pattern of Trepaxonemata, four attachment zones, a nucleus, two mitochondria, external Ornamentation of the plasma membrane, spine-like bodies and cortical microtubules. A particularity of this spermatozoon is the presence of an apical cone. However, the spermatozoon presents the general pattern of the Opecoelidae and thus differs from Helicometra fasciata (which appears as an exception in this family) by several ultrastructural features: the presence of external Ornamentation and spine-like bodies and the arrangement of cortical microtubules around the first mitochondrion in the region of the Ornamentation. Each ultrastructural feature is discussed and compared with the literature to highlight characters which could be useful for phylogeny.
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sperm ultrastructure of the digenean siphoderina elongata platyhelminthes cryptogonimidae intestinal parasite of nemipterus furcosus pisces teleostei
Parasitology Research, 2009Co-Authors: Yann Quilichini, Rodney A Bray, J. Foata, Jeanlou Justine, Bernard MarchandAbstract:The ultrastructure of the spermatozoon of Siphoderina elongata was studied by transmission electron microscopy. A description and drawings of the mature spermatozoon are presented in this paper. Several ultrastructural elements of this male gamete have been observed: a nucleus, two mitochondria, two axonemes of 9 + "1" pattern, external Ornamentation of the plasma membrane, spine-like bodies and cortical microtubules. The presence, the location or the number of these elements have been compared with other digenean spermatozoa. Moreover, a close attention was paid to the organization of the external Ornamentation region. This zone presents a single row of cortical microtubules disposed in a semi-circle around a mitochondrion and associated with external Ornamentation and spine-like bodies. The aim of this study is to highlight criteria which can be interesting in Platyhelminthes phylogeny.
M. Piepenbring - One of the best experts on this subject based on the ideXlab platform.
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Teliospores of smut fungi teliospore walls and the development of Ornamentation studied by electron microscopy
Protoplasma, 1998Co-Authors: M. Piepenbring, R. Bauer, F. OberwinklerAbstract:The walls of mature teliospores and the development of Ornamentation, as seen by transmission electron microscopy, are described for 37 genera of smut fungi, based on observations of ca. 120 species and on literature. Structural diversity of mature teliospore walls is due to differences in spore wall layers forming the spore wall (endosporium, middle layer, exosporium, Ornamentation) and to different elements forming the Ornamentation (exosporium, ornaments, sheath, hyphal wall, adjacent fungal cells, material of the host). During teliosporogenesis the outer layers are usually deposited first. At the beginning of the formation of the Ornamentation the plasma membrane may be smooth or undulated carrying the developing ornaments on its tips or in its depressions. The Ornamentation of some genera appears similar when seen by scanning electron microscopy, but can be the product of different developmental patterns (e.g., warts of species of Farysia, Tilletia , and Ustilago ), however, warty and reticulate Ornamentation can both be produced by similar developmental processes (shown, e.g., for species of Cintractia and Tilletia ). Typical structures of the mature teliospore wall and developmental patterns based on homologous similarities are described for the following groups of genera or species: Macalpinomyces, Melanopsichium, Sporisorium , and Ustilago infecting members of the family Poaceae; Kuntzeomyces, Testicularia , and Trichocintractia; Anthracoidea, Cintractia, Heterotolyposporium piluliforme , and Tolyposporium junci; Glomosporium, Sorosporium , and Thecaphora; Conidiosporomyces, Erratomyces, Ingoldiomyces, Neovossia, Oberwinkleria , and Tilletia; Entyloma , and genera of the Doassansia group; Liroa, Microbotryum, Sphacelotheca, Ustilago infecting dicotyledons, and Zundeliomyces; Aurantiosporium, Fulvisporium , and Ustilentyloma . Special characteristics of the teliospore wall were observed for the genera Dermatosorus, Doassinga, Entorrhha, Farysia, Mycosyrinx, Rhamphospora , and some species of Tolyposporium .
Bob B M Wong - One of the best experts on this subject based on the ideXlab platform.
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female Ornamentation and the fecundity trade off in a sex role reversed pipefish
Ecology and Evolution, 2018Co-Authors: Kenyon B Mobley, John R Morrongiello, Matthew Warr, Dianne J Bray, Bob B M WongAbstract:Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female Ornamentation and fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the disk-shaped, ventral-striped female ornament, body width, and stripe thickness. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female fecundity. Rather, females that have larger ornaments have higher fecundity and thus accurately advertise their reproductive value to males without incurring a cost to fecundity. We also investigated the relationship between female body size and egg size and found that larger females suffer a slight decrease in egg size and fecundity, although this decrease was independent of female Ornamentation. More broadly, considered in light of similar findings in other taxa, lack of an apparent fecundity cost of Ornamentation in female pipefish underscores the need to revisit theoretical assumptions concerning the evolution of female Ornamentation.
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female Ornamentation and the fecundity trade off in a sex role reversed pipefish
bioRxiv, 2018Co-Authors: Kenyon B Mobley, John R Morrongiello, Matthew Warr, Dianne J Bray, Bob B M WongAbstract:Sexual ornaments found only in females are a rare occurrence in nature. One explanation for this is that female ornaments are costly to produce and maintain and, therefore, females must trade-off resources related to reproduction to promote ornament expression. Here, we investigate whether a trade-off exists between female Ornamentation and fecundity in the sex-role reversed, wide-bodied pipefish, Stigmatopora nigra. We measured two components of the disk-shaped, ventral-striped female ornament, body width and stripe thickness. After controlling for the influence of body size, we found no evidence of a cost of belly width or stripe thickness on female fecundity. Rather, females that have larger ornaments have higher fecundity and thus accurately advertise their reproductive value to males without incurring a cost to fecundity. We also investigated the relationship between female body size and egg size and found that larger females suffered a slight decrease in egg size and fecundity, although this decrease was independent of female Ornamentation. More broadly, considered in light of similar findings in other taxa, lack of an apparent fecundity cost of Ornamentation in female pipefish underscores the need to revisit theoretical assumptions concerning the evolution of female Ornamentation.
Bernard Marchand - One of the best experts on this subject based on the ideXlab platform.
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Ultrastructure of the spermatozoon of Lecithostaphylus parexocoeti (Digenea, Microphalloidea, Zoogonidae) parasite of the flying fish Cheilopogon pinnatibarbatus (Teleostei, Exocoetidae) off Senegal and their implication on the phylogenetic relations
Zoomorphology, 2020Co-Authors: Aïssatou Bâ, Abdoulaye J. S. Bakhoum, Papa Ibnou Ndiaye, Cheikh Tidiane Ba, Bernard Marchand, Rodney A Bray, Yann QuilichiniAbstract:This study shows the ultrastructure of the mature spermatozoon of Lecithostaphylus parexocoeti (Digenea, Microphalloidea, Zoogonidae) parasite of the flying fish Cheilopogon pinnatibarbatus (Exocoetidae) captured in the Atlantic Ocean near Dakar (Senegal). This is the first report of L. parexocoeti from Senegal and from this host species. The mature spermatozoon is filiform and exhibits two axonemes of the 9+“1” pattern of the Trepaxonemata, an external Ornamentation associated with spine-like bodies, parallel cortical microtubules, a nucleus, two mitochondria and granules of glycogen. The particularities of the spermatozoon of L. parexocoeti are the location of the first mitochondrion and the morphology of its anterior extremity with only cortical microtubules and external Ornamentations of the plasma membrane. To our knowledge, this type of anterior extremity has never been described in the superfamily Microphalloidea. However, the ultrastructure of the posterior extremity of the spermatozoon corresponds to the fasciolidean type that was previously described in the Zoogonidae.
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ultrastructural characteristics of the mature spermatozoon of the digenean sclerodistomum italicum stossich 1893 hemiuroidea sclerodistomidae intestinal parasite of hypocanthus amia teleostei carangidae
Tissue & Cell, 2017Co-Authors: P Ndiaye, Cheikh Tidiane Ba, Yann Quilichini, Adji Mama Marigo, Volodymyr V Tkach, Bernard MarchandAbstract:Abstract The mature spermatozoon of Sclerodistomum italicum is filiform, tapered at both ends and shows the following features: 2 axonemes of the 9 + “1” pattern of the Trepaxonemata, mitochondrion, nucleus and parallel cortical microtubules. The specific features of the spermatozoon of S. italicum include the simultaneous presence of two types of extramembranous Ornamentations, the presence of short cortical microtubules in the anterior part of the spermatozoon and the presence of only one bundle of cortical microtubules in the median part of the spermatozoon. Thus far these structures are known only in the Hemiuroidea. The presence of filamentous Ornamentation in the anterior extremity of the spermatozoon has not previously been described in the Sclerodistomidae. Similar to spermatozoa of other hemiuroideans, S. italicum lack spine-like bodies described in spermatozoa of many digenean taxa. The posterior extremity of the spermatozoon exhibits the same ultrastructural characteristics typical of the Hemiuroidea.
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ultrastructural study of the spermatozoon of hemiurus appendiculatus digenea hemiuroidea hemiuridae a parasite of boops boops pisces teleostei sparidae off senegal
Tissue & Cell, 2016Co-Authors: Ayatoulaye Dione, P Ndiaye, Cheikh Tidiane Ba, Yann Quilichini, Papa Mbagnick Diagne, Bernard MarchandAbstract:The mature spermatozoon of Hemiurus appendiculatus exhibits the general pattern described in most of the digenean namely, two axonemes of the 9 + "1" pattern of the Trepaxonemata, a nucleus, a filiform mitochondrion, external Ornamentations of the plasma membrane and parallel cortical microtubules located on one side of the spermatozoon. In this study, we show for the second time in a digenean spermatozoon the presence of microtubules of the second axoneme associated each in a short length with an external Ornamentation, seven cortical microtubules, a terminal bulge in the anterior spermatozoon extremity separate from the remainder of the spermatozoon by a transverse constriction and the simultaneous presence of the external Ornamentation of the plasma membrane with a filamentous Ornamentation. The external Ornamentations have a differentiated distribution, cover almost the anterior region of the spermatozoon, are more abundant around the first axoneme and extend backwards over a short distance around the second axoneme. This study also allowed us to reveal for the first time the existence in the Hemiuroidea of an axoneme that begins to disrupt before reaching the front end of the mitochondrion.
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sperm ultrastructure of the digenean siphoderina elongata platyhelminthes cryptogonimidae intestinal parasite of nemipterus furcosus pisces teleostei
Parasitology Research, 2009Co-Authors: Yann Quilichini, Rodney A Bray, J. Foata, Jeanlou Justine, Bernard MarchandAbstract:The ultrastructure of the spermatozoon of Siphoderina elongata was studied by transmission electron microscopy. A description and drawings of the mature spermatozoon are presented in this paper. Several ultrastructural elements of this male gamete have been observed: a nucleus, two mitochondria, two axonemes of 9 + "1" pattern, external Ornamentation of the plasma membrane, spine-like bodies and cortical microtubules. The presence, the location or the number of these elements have been compared with other digenean spermatozoa. Moreover, a close attention was paid to the organization of the external Ornamentation region. This zone presents a single row of cortical microtubules disposed in a semi-circle around a mitochondrion and associated with external Ornamentation and spine-like bodies. The aim of this study is to highlight criteria which can be interesting in Platyhelminthes phylogeny.
