Ultrastructural study of spermiogenesis and the spermatozoon in Catenotaenia pusilla, an intestinal parasite of Mus musculus

2000 ◽  
Vol 74 (1) ◽  
pp. 73-81 ◽  
Author(s):  
C. Hidalgo ◽  
J. Miquel ◽  
J. Torres ◽  
B. Marchand
Keyword(s):  
Cross Section ◽  
Anterior Extremity ◽  
Intestinal Parasite ◽  
Mature Spermatozoon ◽  
Cortical Microtubules ◽  
Spiral Pattern ◽  
Cytoplasmic Extension ◽  
Apical Cone ◽  
Flagellar Rotation ◽  
Unequal Length

AbstractThe ultrastructure of spermiogenesis and the mature spermatozoon in Catenotaenia pusilla (Cestoda: Catenotaeniidae) is described. Spermiogenesis is characterized by the presence of a single axoneme which grows on the outside of a cytoplasmic extension at an angle of 45°. Flagellar rotation and proximodistal fusion are produced in this process. The centrioles lack striated roots and an intercentriolar body. In the mature spermatozoon four different regions are described. The anterior extremity is capped by an apical cone and presents two helical crest-like bodies of unequal length. The axoneme, of the 9 + ‘1’ pattern of the Trepaxonemata, presents a periaxonemal sheath. The cortical microtubules form a spiral pattern at an angle of about 40° to the hypothetical spermatozoon axis. The nucleus is kidney- to horseshoe-shaped in cross section. Granules and proteinaceus walls are not observed in the spermatozoon of C. pusilla.

Spermiogenesis and spermatozoon of the tapeworm Parabothriocephalus gracilis (Bothriocephalidea): Ultrastructural and cytochemical studies

2010 ◽  
Vol 55 (1) ◽  
Author(s):  
Lenka Šípková ◽  
Céline Levron ◽  
Mark Freeman ◽  
Tomáš Scholz
Keyword(s):  
Electron Microscopy ◽  
Anterior Extremity ◽  
Mature Spermatozoon ◽  
Dense Material ◽  
Apical Region ◽  
Cortical Microtubules ◽  
Electron Dense Material ◽  
Dense Granules ◽  
Cytoplasmic Extension ◽  
Transmission Electron

AbstractSpermiogenesis and spermatozoon ultrastructure of the tapeworm Parabothriocephalus gracilis were described using transmission electron microscopy (TEM). Spermiogenesis is characterized by the formation of a zone of differentiation with two centrioles associated with striated rootlets, and an intercentriolar body between them. The two flagella undergo a rotation of 90° until they become parallel to the median cytoplasmic extension with which they fuse. Electron-dense material is present in the apical region of the zone of differentiation in the early stages of spermiogenesis. This electron-dense material is characteristic for the orders Bothriocephalidea and Diphyllobothriidea. The mature spermatozoon contains two axonemes of the 9 + ‘1’ trepaxonematan pattern, nucleus, parallel cortical microtubules and electron-dense granules of glycogen. The anterior extremity of the spermatozoon exhibits a single helical electron-dense crested body 130 nm thick. One of the most interesting features is the presence of a ring of cortical microtubules surrounding the axoneme. This character has been reported only for species of the order Bothriocephalidea and may be unique in this cestode group.

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

2012 ◽  
Vol 57 (1) ◽  
Author(s):  
Abdoulaye Bakhoum ◽  
Papa Ndiaye ◽  
Aminata Sène ◽  
Cheikh Bâ ◽  
Jordi Miquel
Keyword(s):  
Plasma Membrane ◽  
Intestinal Parasite ◽  
Mature Spermatozoon ◽  
Cytoplasmic Process ◽  
Cortical Microtubules ◽  
Differentiation Zone ◽  
Sarpa Salpa ◽  
First Time ◽  
External Ornamentation ◽  
Free Flagellum

AbstractThe 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.

scholarly journals Ultrastructure of mature spermatozoa of three Bucephalidae (Prosorhynchus longisaccatus, Rhipidocotyle khalili and Bucephalus margaritae) and phylogenetic implications

Parasite ◽  
2018 ◽  
Vol 25 ◽  
pp. 65 ◽  
Author(s):  
Papa Ibnou Ndiaye ◽  
Bernard Marchand ◽  
Cheikh Tidiane Bâ ◽  
Jean-Lou Justine ◽  
Rodney A. Bray ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Anterior Extremity ◽  
Posterior Extremity ◽  
Anterior Part ◽  
Mature Spermatozoon ◽  
Cortical Microtubules ◽  
Lateral Expansion ◽  
Phylogenetic Implications ◽  
External Ornamentation ◽  
Mature Spermatozoa

We describe here the mature spermatozoa of three species of bucephalids, namely Bucephalus margaritae, Rhipidocotyle khalili and Prosorhynchus longisaccatus. This study provides the first ultrastructural data on the genera Bucephalus and Rhipidocotyle and enabled us to confirm the model of the mature spermatozoon in the Bucephalinae. The spermatozoon exhibits two axonemes with the 9 + “1” pattern of the Trepaxonemata, one of which is very short, lateral expansion, external ornamentation of the plasma membrane located in the anterior extremity of the spermatozoon and associated with cortical microtubules, spine-like bodies, a mitochondrion, and a nucleus. The maximum number of cortical microtubules is located in the anterior part of the spermatozoon. However, more studies are needed to elucidate if spine-like bodies are present in all the Bucephalinae or not. In the Prosorhynchinae, the mature spermatozoon exhibits a similar ultrastructural pattern. Some differences are observed, particularly the axoneme lengths and the arrangement of the spine-like bodies. The posterior extremity of the spermatozoon in the Bucephalinae exhibits only the nucleus, but prosorhynchines have microtubules.

Comparative ultrastructure of the spermatozoa of Inermicapsifer guineensis and Inermicapsifer madagascariensis (Cestoda, Anoplocephalidae, Inermicapsiferinae), intestinal parasites of rodents in Senegal

1994 ◽  
Vol 72 (9) ◽  
pp. 1633-1638 ◽  
Author(s):  
Cheikh Tidiane Bâ ◽  
Bernard Marchand
Keyword(s):  
Anterior Extremity ◽  
Posterior Extremity ◽  
Intestinal Parasites ◽  
Sperm Nucleus ◽  
Dense Material ◽  
Cortical Microtubules ◽  
Electron Dense Material ◽  
Apical Cone ◽  
Comparative Ultrastructure ◽  
Electron Lucent

Spermatozoa of Inermicapsifer guineensis and Inermicapsifer madagascariensis are filiform and tapered at both extremities. The anterior extremity exhibits an apical cone of electron-dense material and two helical ridges. The axoneme, of the 9 + "1" pattern, is surrounded over part of its length by a sheath of electron-dense material. At the posterior extremity the cytoplasm contains electron-dense material. In regions III and IV of the spermatozoa the cytoplasm is subdivided into compartments of electron-lucent material limited by irregularly spaced walls of electron-dense material. The sperm nucleus is a compact cord wound in a spiral around the axoneme. Cortical microtubules are helically arranged down the length of the spermatozoa except at the posterior extremity where they run parallel to the spermatozoon axis. In I. madagascariensis, cortical microtubules may not extend as far as the posterior extremity of the spermatozoa; the dense periaxonemal material exists in regions I to IV of the spermatozoon and the nucleus never coils more than once around the axoneme.

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

2011 ◽  
Vol 56 (2) ◽  
Author(s):  
Adji Marigo ◽  
Catarina Eira ◽  
Cheikh Bâ ◽  
Jordi Miquel
Keyword(s):  
General Pattern ◽  
Male Gamete ◽  
Ultrastructural Organization ◽  
Dense Layer ◽  
Cytoplasmic Process ◽  
Dense Granules ◽  
Transmission Electron ◽  
Apical Cone ◽  
Flagellar Rotation ◽  
Means Of Transmission

AbstractWe 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.

scholarly journals Investigating the Economical Performance of Four Suggested Designs for the Heat Exchangers

2020 ◽  
Vol 38 (4) ◽  
pp. 863-870
Author(s):  
Khaled M.K. Pasha ◽  
Mohamed Mahmoud El-Fawal
Keyword(s):  
Reynolds Number ◽  
Cross Section ◽  
Spiral Pattern ◽  
Pressure Loss Coefficient ◽  
A Value ◽  
Cross Section Area ◽  
Section Area ◽  
Rectangular Pattern ◽  
Air Passage ◽  
Spiral Type

It is required to investigate the economy of the performance of four suggested heat exchanger designs. The economy criteria are expressed by the ratio of the Nusselt number, Nu, and the pressure loss coefficient, ΔP∗. The four patterns are; rectangular, zigzag, spiral, and narrow-spiral. The air passages of each one of the four types have the same cross-section area and air passage length. Also, the inlet air temperature and flow rate for both; the air and water are the same in the four types. The narrow-spiral pattern has an equal passage thickness for both air and water. Reynolds number, Re, of values; 2535, 7606, 12677, 17748, 20284, 22819, 25355, (based on the hydraulic diameter of the cross-section) are investigated. For validation, the rectangular pattern type was checked experimentally, and the results were close to those of the prediction. For all values of the Reynolds number, the suggested narrow-spiral pattern exhibited the highest values of Nu/ΔP∗. At the Reynolds number of 25355, the ratio, Nu/ΔP∗ could achieve a value of about 15.74 for the narrow-spiral type. For each suggested pattern, (Nu/ΔP∗) and Re are correlated in a suitable formula.

scholarly journals A comparative study of the ultrastructural characteristics of the mature spermatozoa of two fellodistomids Tergestia clonacantha and T. laticollis and contribution to the phylogenetic knowledge of the Gymnophalloidea

Parasite ◽  
2020 ◽  
Vol 27 ◽  
pp. 67
Author(s):  
Papa Ibnou Ndiaye ◽  
Bernard Marchand ◽  
Cheikh Tidiane Bâ ◽  
Jean-Lou Justine ◽  
Rodney Alan Bray ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
New Caledonia ◽  
General Pattern ◽  
Mature Spermatozoon ◽  
Cortical Microtubules ◽  
Transmission Electron ◽  
Ultrastructural Model ◽  
Ultrastructural Characteristics ◽  
External Ornamentation ◽  
Mature Spermatozoa

The ultrastructure of the mature spermatozoa of Tergestia clonacantha and T. laticollis collected from the digestive tracts of fishes from New Caledonia is described using transmission electron microscopy and compared to that of related species. The spermatozoa of the two species exhibit the general pattern described in most digeneans, namely two axonemes with the 9 + “1” pattern of the Trepaxonemata, nucleus, mitochondrion, cortical microtubules, an external ornamentation of the plasma membrane, spine-like bodies and granules of glycogen. The spermatozoa of T. clonacantha and T. laticollis show the same ultrastructural model with some specificities in each case, particularly in the disposition of the structures in the posterior extremities of the spermatozoon. This study confirms that ultrastructural characters of the mature spermatozoon are useful tools for the phylogenetic analysis of the Digenea.

Ultrastructure of spermiogenesis and mature spermatozoon of Skrjabinoporus merops (Cyclophyllidea, Metadilepididae)

2006 ◽  
Vol 51 (3) ◽  
Author(s):  
Aneta Yoneva ◽  
Katia Georgieva ◽  
Yana Mizinska ◽  
Boyko Georgiev ◽  
Stoyanka Stoitsova
Keyword(s):  
Proximal Part ◽  
Mature Spermatozoon ◽  
Differentiation Zone ◽  
Region I ◽  
The Family ◽  
Cytoplasmic Protrusion ◽  
Flagellar Rotation ◽  
First Time ◽  
Region Ii ◽  
Free Flagellum

AbstractThe ultrastructure of the mature spermatozoon and the spermiogenesis of a cestode belonging to the family Metadilepididae is described for the first time. The mature spermatozoon of Skrjabinoporus merops is characterized by twisted peripheral microtubules, the presence of a single crested body, periaxonemal sheath and electron-dense rods, and the absence of intracytoplasmic walls and inclusions (glycogen or proteinaceous granules); no peripheral microtubules where nucleus contacts the external plasma membrane. Four morphologically distinct regions of the mature spermatozoon are differentiated. The proximal part (Region I) contains a single crested body, periaxonemal sheath is absent in some (proximal) sections and is present in others situated closer to the nucleus. The central Region II is nucleated, and is followed by Region III that contains a periaxonemal sheath. The distal pole, Region IV, is characterized by disintegration of the axoneme. Spermiogenesis follows the type III pattern (Bâ and Marchand 1995) although in S. merops a slight flagellar rotation is observed. The differentiation zone is characterized by the absence of striated roots and intercentriolar body; two centrioles are present, one of which gives rise to a free flagellum. The latter rotates and undergoes proximodistal fusion with the cytoplasmic protrusion of the differentiation zone. Spermiological characters of S. merops are similar to those of the families Taeniidae and Catenotaeniidae. The mature spermatozoon differs from those of the Dilepididae (where the metadilepidid species have previously been classified) by the lack of glycogen.

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