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1

Spermatological characters of Acanthobothrium crassicolle Wedl, 1855 (Tetraphyllidea, Onchobothriidae), a parasite of the common stingray Dasyatis pastinaca

100%
Marigo A. M., Eira C., Ba C. T., Miquel J.
Acta Parasitologica
|
2011
|
tom 56
|
nr 2
We describe the spermiogenesis process and the ultrastructural characters of the spermatozoon of Acanthobothrium crassicolle by means of transmission electron microscopy, including cytochemical analysis for glycogen. Spermiogenesis in A. crassicolle begins with the formation of the differentiation zone that contains two centrioles associated with striated rootlets and an intercentriolar body. The latter is formed by one electron-dense layer. The centrioles develop into two free flagella that first grow orthogonally to a median cytoplasmic process and then undergo flagellar rotation becoming parallel to that median cytoplasmic process. After flagellar rotation only one of the flagella completes its growth and both short and long flagella undergo proximodistal fusion with the median cytoplasmic process. In the final stages of spermiogenesis, the nucleus becomes filiform and migrates into the spermatid body. Later, the ring of arched membranes constricts and the spermatozoon is liberated from the residual cytoplasm. The ultrastructural organization of the spermatozoon of A. crassicolle follows the general pattern of spermatozoa of the other Tetraphyllidea-Onchobothriidae species, but exhibits some differences. It is filiform, tapered at both extremities and lacks mitochondrion. It contains two axonemes of unequal length showing the 9 + “1“ pattern of Trepaxonemata, a nucleus, parallel cortical microtubules and electron-dense granules of glycogen. The anterior extremity of the male gamete contains a single crested body surrounding a thin and long apical cone. This type of apical cone has never been described in a tetraphyllidean spermatozoon. Another particularity is the presence of a single electron-dense microtubule at the vertex of the crested body.
2
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Implication of Phyllobothrium lactuca [Cestoda, Tetraphyllidea, Phyllobothriidae] spermiogenesis on phylogenesis within the Tetraphyllidea

100%
Sene A., Ba C. T., Miquel J., Marchand B.
Wiadomości Parazytologiczne
|
1998
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tom 44
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nr 3
3

Ultrastructure of the spermatozoon of Paroniella reynoldsae [Cyclophyllidea, Davaineidae] an intestinal parasite of Corvus albus [Aves, Corvidae]

100%
Ba C. T., Ba A., Marchand B.
Acta Parasitologica
|
2005
|
tom 50
|
nr 3
The mature Paroniella reynoldsae spermatozoon exhibits an apical cone of electron-dense material about 2.2 µm long and 0.65 µm wide at its base and two helicoidal crest-like bodies roughly 100 to 150 nra thick. The latter are of different lengths, spiralled and make an angle of about 45° with the spermatozoon axis. The axoneme is of the 9 + '1' trepaxonematan pattern and does not reach the posterior extremity of the gamete. The nucleus is an electron-dense cord 0.25 µm thick coiled in a spiral around the axoneme. The cytoplasm exhibits a posterior densification and contains few small electron-dense granules in regions I, II and V of the spermatozoon. In regions III and IV, it is divided into irregular compartments by walls of electron-dense material. The cortical microtubules are spiralled at an angle of about 45°. The presence of an electron-lucent apical cone containing numerous small granules of electron-dense material has never, to our knowledge, been reported in a cestode. Likewise, a crest-like body forming a terminal spot of electron-dense material located in the prolongation of the apical cone has never been described before in a cestode. Moreover, in this study, we try to show the existence of tight reciprocal phylogenetic relationships between genera within the Davaineidae and the Anoplocephalidae.
4

Ultrastructural study of the spermatozoon of Echinocotyle dolosa [Cestoda, Cyclophyllidea, Hymenolepididae]

100%
Ba A., Ba C. T., Marchand B.
Acta Parasitologica
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2002
|
tom 47
|
nr 2
The mature E. dolosa spermatozoon exhibits an apical disc of electron-dense material about 0.1 µm thick and eight helicoidal crested-like bodies roughly 0.1 µm thick. The latter are of different lengths, spiralized and make an angle of about 40° with the spermatozoon axis. The axoneme is of the 9 + '1' pattern, central in regions I and II, and eccentric in regions III and IV of the gamete. The cortical microtubules are spiralized. The nucleus is a polylobulate compact cord of electron-dense material 0.3-0.7 µm wide, located in parallel to the axoneme and overpassing the posterior extremity. The cytoplasm contains numerous electron-dense granules in regions III and IV, with an increase in electron-density at the posterior end of sperm. The contour of the regions III and IV of the gamete and also that of the nucleus are irregular and polylobulate. This type of polylobulation has never been described in a cestode. Similarly, an apical disc of electron-dense material has never been observed in a cestode spermatozoon; nor has a nucleus of roughly 0.3-0.7 µm in diameter been described in the Cyclophyllidea. In addition, we report for the first time the existence of eight crested-like bodies in a cestode of birds.
5

Spermiogenesis and sperm ultrastructure of Carmyerius endopapillatus [Digenea, Gastrothylacidae], a parasite of Bos taurus in Senegal

100%
Seck M. T., Marchand B., Ba C. T.
Acta Parasitologica
|
2008
|
tom 53
|
nr 1
Ultrastructural study of spermiogenesis and of the spermatozoon of Carmyerius endopapillatus has enabled to describe some characteristics of this digenea. The intercentriolar body situated between the two striated roots and the two centrioles, presents a symmetric organization. Both external bands of this intercentriolar body are made up of a row of granules. During spermiogenesis, a flagellar rotation of 90° is described. The old spermatid does not present external ornamentations. The spermatozoon is characterized, in its anterior region, by the presence of a lateral expansion exhibiting one spinelike body. In C. endopapillatus, external ornamentations are localized only at the level where the lateral expansion appears. The posterior extremity of spermatozoon exhibits a nucleus surrounded by a plasmic membrane lacking microtubules, but presenting a small lateral expansion. This is the first species of Gastrothylacidae family studied by transmission electron microscopy.
6

Ultrastructure of the spermatozoon of Calliobothrium verticillatum [Cestoda, Tetraphyllidea, Oncobothriidae]

100%
Quilichini Y., Foata J., Ba C. T., Marchand B.
Acta Parasitologica
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2007
|
tom 52
|
nr 3
The ultrastructure of the spermatozoon of Calliobothrium verticillatum (Cestoda, Tetraphyllidea, Oncobothriidae) parasite of the smoothhound shark, Mustelus mustelus L. (Pisces, Carcharhiniformes), was studied by transmission electron microscopy. This spermatozoon presents five regions characterized by several ultrastructural elements: an apical cone, a crested body, two axonemes of 9 + “1” pattern, electron-dense granules, a nucleus and cortical microtubules. In the present study, three of these features were the subject of a detailed attention. The first is the presence of two axonemes, which confirms that the Tetraphyllidea, Oncobothriidae possess two axonemes whereas the Tetraphyllidea, Phyllobothriidae possess only one axoneme. The second is the presence of one crested body, a criterion homogeneous in the Tetraphyllidea but heterogeneous among the different orders of Cestoda. The third is the number and the disposition of cortical microtubules. These three criteria seem to be interesting for phylogeny.
7
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Striated rootlets in spermatids of Anoplocephaloides dentata [Anaplocephalidae] and Dipylidium caninum [Dipylidiidae]: a new finding in the Cyclophyllidea

100%
Miquel J., Ba C. T., Marchand B.
Wiadomości Parazytologiczne
|
1998
|
tom 44
|
nr 3
8

Spermiogenesis and ultrastructure of the spermatozoon of Wardula capitellata (Digenea, Mesometridae), an intestinal parasite of the sparid teleost Sarpa salpa in Senegal

88%
Bakhoum A. J. S., Ndiaye P. I., Sene A., Ba C. T., Miquel J.
Acta Parasitologica
|
2012
|
tom 57
|
nr 1
The spermiogenesis process in Wardula capitellata begins with the formation of a differentiation zone containing two centrioles associated with striated rootlets and an intercentriolar body. Each centriole develops into a free flagellum orthogonal to a median cytoplasmic process. Later these flagella rotate and become parallel to the median cytoplasmic process, which already exhibits two electron-dense areas and spinelike bodies before its proximodistal fusion with the flagella. The final stage of the spermiogenesis is characterized by the constriction of the ring of arched membranes, giving rise to the young spermatozoon, which detaches from the residual cytoplasm. The mature spermatozoon of W. capitellata presents most of the classical characters reported in digenean spermatozoa such as two axonemes of different lengths of the 9 + “1” trepaxonematan pattern, nucleus, mitochondrion, two bundles of parallel cortical microtubules and granules of glycogen. However, some peculiarities such as two lateral expansions accompanied by external ornamentation of the plasma membrane and spinelike bodies characterize the mature sperm. Moreover, a new spermatological character is described for the first time, the so-called cytoplasmic ornamented buttons.
9

Spermiogenesis and sperm ultrastructure of Scaphiostomum palaearcticum Mas-Coma, Esteban et Valero, 1986 [Trematoda, Digenea, Brachylaimidae]

88%
Ndiaye P. I., Miquel J., Ba C. T., Feliu C., Marchand B.
Acta Parasitologica
|
2002
|
tom 47
|
nr 4
Spermiogenesis in Scaphiostomum palaearcticum begins with the formation of a zone of differentiation, which comprises striated rootlets associated with the two centrioles and an intercentriolar body in-between. It is characterised by an asynchronic flagellar rotation and subsequent proximo-distal fusion with a median cytoplasmic process. The migration of the nucleus toward the median cytoplasmic process before its fusion with the free flagella is also described. However, in the case of S. palaearcticum, the mitochondrion migrates toward the median cytoplasmic process before the fusion of the second axoneme. Attachment zones are also formed before the fusion of the axonemes with the median cytoplasmic process. The mature spermatozoon of S. palaearcticum is filiform and tapered at both ends and presents all the features found in the Digenea gamete: two axonemes, mitochondrion, nucleus and two bundles of parallel cortical microtubules. Nevertheless, certain features allow us to distinguish S. palaearcticum from other digenetic trematodes.
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