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1

Tubulin immunocytochemistry of the spermatozoa in the cestode Mesocestoides litteratus [Mesocestoididae]

100%
Miquel J., Marchand B.
Acta Parasitologica
|
2001
|
tom 46
|
nr 2
2

Fertilization in the cestode Echinococcus multilocularis (Cyclophyllidea, Taeniidae)

81%
Swiderski Z., Miquel J., Azzouz-Maache S., Petavy A.-F.
Acta Parasitologica
|
2016
|
tom 61
|
nr 1
3

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

81%
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.
4
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Origin and ultrastructure of the outer coat surrounding mature eggs of Mosgovoyia ctenoides (Cestoda, Anoplocephalidae)

81%
Mlocicki D., Swiderski Z., Miquel J., Eira C.
Wiadomości Parazytologiczne. Suplement
|
2007
|
tom 53
5

Ultrastructural studies on egg envelopes surrounding the miracidia of Mediogonimus jourdanei Mas-Coma et Rocamora, 1978 [Digenea, Microphalloidea, Prosthogonimidae]

81%
Swiderski Z., Bakhoum A. J. S., Mlocicki D., Miquel J.
Acta Parasitologica
|
2010
|
tom 55
|
nr 3
245-253
The intrauterine, mature and fully embryonated eggs of the prosthogonimid trematode Mediogonimus jourdanei Mas-Coma et Rocamora, 1978 were examined by means of transmission electron microscopy (TEM), using high pressure freezing, freeze substitution and infiltration with resin techniques. Each embryonated egg is composed of a miracidium surrounded by three envelopes: (1) the egg shell, (2) the outer and (3) inner envelopes. Egg envelopes play an important role in the protection, metabolism, storage of nutritive reserves and the general biology of the M. jourdanei egg. The inner envelope is characterised by large, flattened nuclei, and its syncytial cytoplasm contains a heavy accumulation of glycogen, lipid droplets, mitochondria and large vesicles. These traits indicate that this layer has the features of a metabolically-active syncytial layer with an energy storage capability. In the infective eggs observed before the hatching of the miracidium, areas of so-called “focal cytoplasmic degradation” were frequently observed, which may be involved in the autolytic process of all components of this envelopes.
6
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Ultrastructure of the mature spermatozoon in the genus Fasciola L., 1758: a comparative analysis of F. hepatica L., 1758 and F. gigantica Cobbold, 1856

81%
Miquel J., Ndiaye P. I., Eira C., Marchand B.
Wiadomości Parazytologiczne. Suplement
|
2004
|
tom 50
7

Ultrastructure of digenean trematode eggs (Platyhelminthes: Neoophora): A review emphasizing new comparative data on four European Microphalloidea

81%
Conn D. B., Swiderski Z., Miquel J.
Acta Parasitologica
|
2018
|
tom 63
|
nr 1
8

Ultrastructural and cytochemical study on vitellogenesis in the diphyllidean cestode Echinobothrium euterpes (Echinobothriidae) and its phylogenetical implications

81%
Swiderski Z., Mackiewicz J. S., Eira C., Miquel J.
Acta Parasitologica
|
2011
|
tom 56
|
nr 2
The first description of vitellogenesis in the Diphyllidea is presented in this paper. Though the type of vitellogenesis and mature vitellocyte in Echinobothrium euterpes appear to be unique among the Eucestoda, however, they somewhat resemble that observed in the two orders of the lower cestodes, Tetraphyllidea and Proteocephalidea. Vitellocyte maturation is characterized by: (1) an increase in cell volume; (2) extensive development of short, parallel, frequently concentric cisternae of GER that produce dense proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) progressive formation of saturated lipid droplets; their continuous enlargement and fusion; (5) formation of small accumulations of glycogen particles scattered between and among lipid droplets in the cytoplasm of maturing vitellocytes; (6) concentration of dense proteinaceous granules in the peripheral layer of cytoplasm, around the cell plasma membrane; and (7) vacuolization of cytoplasm of mature vitellocytes accompanied by a rapid increase in its volume. A new, unreported type of dense proteinaceous granules, situated around the limiting plasma membranes of mature vitellocytes, is described. Vitellogenesis evidently differs from that with typical shell-globules and shell-globule clusters previously reported in other taxa of lower cestodes. Cytochemical staining with periodic acidthiosemicarbazide-silver proteinate for glycogen indicates a strongly positive reaction for glycogen particles between and around large unsaturated lipid droplets of the maturing and mature vitellocytes. Some hypotheses concerning the interrelationship between this pattern of vitellogenesis, possible mode of egg formation, embryonic development and diphyllidean life cycle, and their phylogenetic implications are drawn and discussed.
9

Natural infection of Oryctolagus cuniculus [Lagomorpha, Leporidae] by Gongylonema neoplasticum [Nematoda, Gongylonematidae] in Portugal

81%
Eira C., Miquel J., Vingada J., Torres J.
Acta Parasitologica
|
2006
|
tom 51
|
nr 2
Gongylonema neoplasticum was identified in the oesophagus of 14 wild rabbits (Oryctolagus cuniculus) from Portugal. This is the first record of Gongylonema neoplasticum in a naturally infected lagomorph species in Europe. This paper presents the most relevant measurements of adult worms and some of their surface features seen by scanning electron microscopy. Epidemiological aspects of G. neoplasticum such as geographical distribution, host spectrum and biological features are discussed.
10
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Implication of Phyllobothrium lactuca [Cestoda, Tetraphyllidea, Phyllobothriidae] spermiogenesis on phylogenesis within the Tetraphyllidea

81%
Sene A., Ba C. T., Miquel J., Marchand B.
Wiadomości Parazytologiczne
|
1998
|
tom 44
|
nr 3
11

Helminth parasites of the red fox [Vulpes vulpes L., 1758] in the Iberian Peninsula: an ecological study

81%
Segovia J. M., Torres J., Miquel J.
Acta Parasitologica
|
2004
|
tom 49
|
nr 1
Thirty-four helminth species were obtained from the helminthological analysis of 399 foxes in the Iberian Peninsula. The species found were classified into three groups. Uncinada stenocephala, Eucoleus aerophilus and Pearsonema plica were classified as core species. The secondary species included Mesocestoides spp., Taenia polyacantha, Toxascaris leonina, Toxocara canis, Angiostrongylus vasorum, Crenosoma vulpis, Pterygodermatites affinis and Physaloptera sibirica. The remainder, including Alaria alata, Brachylaima sp., Metorchis bilis, Opistliorchis felineus, Taenia crassiceps, T. hydatigena, T. taeniaeformis, T. pisiformis, Echinococcus granulosus, Joyeuxiella pasqualei, J. echinorhynchoides, Diplopylidium noelleri, Aonchotheca putorii, Trichuris vulpis, Dirofilaria immitis, Toxocara cati, Ancylostoma caninum, Vigisospirura potekhinae, Molineus patens, M. legerae, Spirocerca lupi, Mastophorus maris and Macracanthorhynchus catulinus were considered as satellite species. A significantly high prevalence of trematodes was found in certain peninsular areas. The most prevalent and abundant cestodes were Mesocestoides spp. Nematodes were the most numerous set of species encompassing several of the most prevalent species. The findings of A. putorii and V. potekhinae constitute new host records for Vulpes vulpes, in the Iberian Peninsula (in the case of the capillariid) and in its entire geographical range (in the case of the spirurid). D. noelleri is also reported for the first time as parasitizing foxes in Europe. The majority of the species found are host generalists and have indirect life cycles. The richness of the helminth community seems to be strongly influenced by the broadness of the alimentary spectrum in different peninsular areas.
12

The red fox, Vulpes vulpes L., as a potential reservoir of zoonotic flukes in the Iberian Peninsula

81%
Segovia J. M., Torres J., Miquel J.
Acta Parasitologica
|
2002
|
tom 47
|
nr 2
A parasitological survey of 396 red foxes (Vulpes vulpes L.) from the Principat d'Andorra, 34 Spanish provinces and Serra da Malcata (Portugal) was carried out to evaluate the fluke status of this wild canid in the Iberian Peninsula. Special attention was devoted to the epidemiological role of this canid in maintaining the potential zoonotic distomatosis. Four fluke species were detected: adults of Brachylaima sp., Alaria alata, Opistorchis felineus and Metorchis bilis. Seventeen foxes (4.3%) were infected by at least one of these digeneans. All flukes with an aquatic life cycle were found mainly (26.9%) in a delimited zone (called zone A), characterised by high amount surface water, with A. alata being the most prevalent species (19.2%). Metorchis bilis is more frequently and widely distributed throughout Iberia than O. felineus. Since both flukes have a very similar life cycle, this might be the result of a distinct distribution pattern of their appropriate snails. This study shows that a relatively large natural focus of potential zoonotic flukes (zone A) is located in central Iberia, near the boundary of Portugal with Spain.
13

Ecological aspects influencing the helminth community of the wood mouse Apodemus sylvaticus in Dunas de Mira, Portugal

81%
Eira C., Torres J., Vingada J., Miquel J.
Acta Parasitologica
|
2006
|
tom 51
|
nr 4
This paper presents the first extensive data on the helminth community of the wood mouse Apodemus sylvaticus in a coastal sand dune area in Portugal. The 557 hosts analysed in this study were trapped seasonally between autumn 2002 and summer 2005 across 6 habitat types. Twelve helminth species were detected among which, Taenia parva larvae, Angiostrongylus dujardini, Heligmosomoides polygyrus, Syphacia stroma and S. frederici constitute the component species, accounting for 98.7% of all worms. H. polygyrus was the most prevalent helminth parasite. Species richness varied according to habitat and season. The highest species richness was found in sand dunes during winter whereas the lowest was detected along lake margins also during the winter. Some differences in prevalence and mean intensity values were found in relation to year (T. parva larvae and H. polygyrus), habitat (A. dujardini), season (T. parva larvae, H. polygyrus, A. dujardini and S. stroma) and host sex (T. parva larvae and S. stroma). These differences are discussed both in view of the host’s biology and habitat characteristics.
14

Ultrastructural and cytochemical studies on vitellogenesis in the trypanorhynch cestode Parachristianella trygonis Dollfus, 1946 [Eutetrarhynchidae]

81%
Swiderski Z., Miquel J., Neifar L., Mackiewicz J. S.
Acta Parasitologica
|
2007
|
tom 52
|
nr 2
During vitellogenesis in Parachristianella trygonis Trypanorhyncha, Eutetrarhynchidae) we distinguished four stages: (1) gonial or stem cell stage; (2) early differentiation stage concentrated on protein synthetic activity and shell-globule formation; (3) advanced differentiation stage with main cell activity concentrated on carbohydrate synthesis (glycogenesis) and massive glycogen storage in the form of α-glycogen rosettes and β-glycogen particles; and finally (4) mature vitellocyte stage. Early vitellocyte maturation is characterised by: (1) an increase in cell volume; (2) extensive development of large, parallel cisternae of GER that produce proteinaceous granules; (3) development of Golgi complexes engaged in packaging this material; (4) continuous enlargement of proteinaceous granules within vacuoles and their transformation into shell-globule clusters composed of heterogeneous material. Cytochemical staining with periodic acid-thiosemicarbazide-silver proteinate for polysaccharides indicated a strongly positive reaction for the presence of α-glycogen rosettes and β-glycogen particles in the advanced stage of vitellocyte maturation. Both protein synthesis for shell-globule formation and carbohydrate synthesis or glycogenesis, important storage of nutritive reserves for the developing embryos, observed during cytodifferentiation of P. trygonis vitellocytes overlap in time to some extent. Mature vitelline cells are very rich in three types of cell inclusions accumulated in large amounts in their cytoplasm: (1) shell-globule clusters, playing an important role in egg-shell formation; (2) numerous large lipid droplets, as well as a high accumulation of lipid and α-glycogen rosettes and β-glycogen particles that undoubtedly represent important nutritive reserves for the developing embryos. Despite the fact that the type of vitellogenesis and ultrastructure of the mature vitellocyte in P. trygonis appears to differ to some extent from those of three other trypanorhynch species, its general pattern and ultrastructure greatly resembles those observed in other lower cestodes. Factors that may have contributed to the qualitative and quantitative variation in lipids during vitellogenesis among the four species of Trypanorhyncha, are identified and discussed.
15

Spermatological characters in the Dipylidiidae Stiles, 1896 [Cestoda, Cyclophyllidea]

81%
Miquel J., Swiderski Z., Marchand B.
Acta Parasitologica
|
2005
|
tom 50
|
nr 1
The present paper compares the ultrastructural data on spermatology of three dipylidiid species (Dipylidium caninum, Joyeuxiella echinorhynchoides and J. pasqualei) and establishes a general pattern of spermiogenesis and main ultrastructural characters of the mature spermatozoa for the Dipylidiidae. Spermiogenesis is characterized by an external growth of the flagellum followed by a proximodistal fusion of the latter with the cytoplasmic extension. The centrioles are associated with striated rootlets which are thin in D. caninum and well-developed in Joyeuxiella spp. The most characteristic features of the mature spermatozoa of the three species are the presence of a single crest-like body and a periaxonemal sheath. Nevertheless, the three compared species differ in the thickness of these structures. Differences are also observed in the length of the apical cone.
16
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Striated rootlets in spermatids of Anoplocephaloides dentata [Anaplocephalidae] and Dipylidium caninum [Dipylidiidae]: a new finding in the Cyclophyllidea

81%
Miquel J., Ba C. T., Marchand B.
Wiadomości Parazytologiczne
|
1998
|
tom 44
|
nr 3
17

Fertilization in the cestode Gallegoides arfaai [Mobedi et Ghadirian, 1977] Tenora et Mas-Coma, 1978 [Cyclophyllidea, Anoplocephalidae]

81%
Swiderski Z., Conn D. B., Miquel J., Mlocicki D.
Acta Parasitologica
|
2004
|
tom 49
|
nr 2
Fertilization in the anoplocephalid cestode Gallegoides arfaai with uniflagellate spermatozoa was examined by means of light and transmission electron microscopy. Fertilization in this species occurs in the oviduct lumen or in the fertilization canal proximal to the ootype, where the formation of the embryonic capsule precludes sperm contact with the oocyte. Cortical granules are not present in the cytoplasm of oocytes of this species. However, two other types of large bodies containing granular material, one of homogeneous moderate electron density and one of heterogeneous moderate electron density, are present in the perinuclear cytoplasm of the oocytes. Spermatozoa coil spirally around the oocytes and syngamy occurs by lateral fusion of oocyte and sperm plasma membranes. In the ootype, one vitellocyte associates with the fertilized oocyte, forming a membranous capsule which encloses both cell types. In this stage, spirally coiled sperm flagella adhere partly to the external oocyte surfaces, and partially enter into the perinuclear cytoplasm. Usually, several loops of the spermatozoon occur within the oocyte cytoplasm. The electron-dense sperm nucleus becomes progressively electron-lucent within the oocyte cytoplasm after entry. Simultaneously with chromatin decondensation, the elongate sperm nucleus changes shape, forming a spherical male pronucleus, which attains the size of the female pronucleus. Cleavage begins immediately after pronuclear fusion.
18

Ultrastructure of spermiogenesis in the caryophyllidean cestode Wenyonia virilis Woodland, 1923, with re-assessment of flagellar rotation in Glaridacris catostomi Cooper, 1920

81%
Miquel J., Swiderski Z., Mackiewicz J. S., Ibraheem M. H.
Acta Parasitologica
|
2008
|
tom 53
|
nr 1
The ultrastructure of spermiogenesis in Wenyonia virilis Woodland, 1923, a caryophyllaeid cestode from the silurid Nile fish Synodontis schall (Bloch et Schneider, 1801), is described by means of transmission electron microscopy (TEM) for the first time. Spermiogenesis follows the characteristic caryophyllidean type and is initiated by the formation of a differentiation zone. This area, delimited at its base by a ring of arching membranes and bordered by cortical microtubules, contains two centrioles associated with typical striated rootlets with a reduced intercentriolar body between them. The apical area of the differentiation zone exhibits electron-dense material that is present only during the early stages of spermiogenesis. Only one of the centrioles develops into a free flagellum that grows at an angle of >90° in relation to the cytoplasmic extension. Spermiogenesis is also characterized by a flagellar rotation and a proximodistal fusion of the flagellum with the cytoplasmic extension. The most interesting features observed in W virilis are the presence of a reduced, very narrow intercentriolar body and the unique type of flagellar rotation >90°. Results are compared with those described in two caryophyllideans, Glaridacris catostomi Cooper, 1920 and Khawia armeniaca (Cholodkovski, 1915). Contrary to the original report of Świderski and Mackiewicz (2002), that flagellar rotation has never been observed in spermiogenesis of G. catostomi, re-assessment of their description and illustrations leads us to conclude that flagellar rotation must logically occur in that species. The value of various morphological features of sperm in phylogenetic inference is discussed.
19

Spermiogenesis and sperm ultrastructure of the liver fluke Fasciola hepatica L., 1758 [Digenea, Fasciolidae]: transmission and scanning electron microscopy, and tubulin immunocytochemistry

81%
Ndiaye P. I., Miquel J., Fons R., Marchand B.
Acta Parasitologica
|
2003
|
tom 48
|
nr 3
We describe here the ultrastructure of spermiogenesis and the mature spermatozoon of Fasciola hepatica (Trematoda, Digenet Fasciolidae) by means of scanning (SEM) and transmission electron microscopy (TEM). Spermiogenesis in F. hepatica follows the general pattern of digeneans. However, this is the first report of a flagellar rotation of about 120° in Digenea. The mature spermatozoon of F. hepatica is a filiform cell of about 275 µm in length. SEM and whole mount TEM revealed a helical pattern of axonemes around the sperm body. The spermatozoon presented the same ultrastructural organization as the congenent F. gigantica. The most interesting features of the male gamete of F. hepatica therefore are the dorsolateral cytoplasmic expansion, the external ornamentation of the cell membrane and the spine-like bodies. We also analysed the distribution pattern of tubulin in the microtubular cytoskeleton of F. hepatica by means of monoclonal anti-tubulins (anti-α-tubulin, anti-β-tubulin, anti-aα -acetylated tubulin and anti-α-tyrosinated tubulin). These anti-tubulins labelled axonemal and cortical microtubules but not the central core of the 9+‘1’ trepaxonematan axoneme.
20

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

71%
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.
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