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

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.

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Spermatozoon ultrastructure in two monorchiid digeneans

PeerJ ◽

10.7717/peerj.2488 ◽

2016 ◽

Vol 4 ◽

pp. e2488 ◽

Cited By ~ 1

Author(s):

Yann Quilichini ◽

Abdoulaye J.S. Bakhoum ◽

Jean-Lou Justine ◽

Rodney A. Bray ◽

Cheikh T. Bâ ◽

...

Keyword(s):

Electron Microscopy ◽

Male Gamete ◽

Mature Spermatozoon ◽

Cortical Microtubules ◽

General Morphology ◽

Transmission Electron ◽

Means Of Transmission ◽

First Time ◽

External Ornamentation ◽

Phylogenetical Relationship

Spermatological characteristics of species from two monorchiid genera,OpisthomonorchisandParamonorcheides, have been investigated, for the first time, by means of transmission electron microscopy. The ultrastructural study reveals that the mature spermatozoon ofOpisthomonorchis dinemaandParamonorcheides selarisshare 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 ofO. dinemaandP. selarisare 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 spermatozoon type. Other interesting finds concern the spermatological similarities between monorchiid spermatozoa and the mature spermatozoon reported in the apocreadiidNeoapocreadium chabaudi. These similarities allow us to suggest a close phylogenetical relationship between the Monorchiidae and the Apocreadiidae, although more studies are needed, especially in the unexplored taxa.

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

Acta Parasitologica ◽

10.2478/s11686-010-0003-9 ◽

2010 ◽

Vol 55 (1) ◽

Cited By ~ 18

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.

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

Parasite ◽

10.1051/parasite/2018065 ◽

2018 ◽

Vol 25 ◽

pp. 65 ◽

Cited By ~ 5

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.

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Spermiogenesis in two paramphistomes from Nile fish in Egypt: an ultrastructural study

Journal of Helminthology ◽

10.1017/s0022149x07409816 ◽

2007 ◽

Vol 81 (3) ◽

pp. 219-226 ◽

Cited By ~ 16

Author(s):

A.A. Ashour ◽

K. Garo ◽

I.S. Gamil

Keyword(s):

Electron Microscopy ◽

Mature Spermatozoon ◽

Basal Bodies ◽

Sperm Ultrastructure ◽

Parasitic Helminths ◽

Ultrastructural Studies ◽

Cytoplasmic Extension ◽

Transmission Electron ◽

Digenetic Trematodes ◽

External Ornamentation

AbstractThe process of spermiogenesis in two paramphistomes,Sandonia sudanensisandBasidiodiscus ectorchisfrom the Nile fishSynodontis schallin Egypt was studied by transmission electron microscopy. Spermiogenesis is characterized by the outgrowth of the zone of differentiation, presenting two basal bodies separated by a microtubule organizing centre, each basal body developing into a flagellum. Proximodistal fusion of these flagella with a median cytoplasmic extension gives rise to the spermatozoon. The mature spermatozoon possesses two axonemes of the 9+‘1’ pattern typical of parasitic helminths. There are few ultrastructural studies on spermiogenesis in paramphistomes, which are considered the most primitive digenetic trematodes. The present study provides new and more detailed information on this process, including the presence of a lateral flange and external ornamentation of the cell membrane. The value of sperm ultrastructure as a taxonomic tool in phylogeny is also discussed.

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Spermatological characteristics of Elstia stossichianum (Digenea, Mesometridae) from the intestine of the cow bream (Sarpa salpa) off Dakar, Senegal

Journal of Helminthology ◽

10.1017/s0022149x12000478 ◽

2012 ◽

Vol 87 (4) ◽

pp. 422-431 ◽

Cited By ~ 7

Author(s):

A.J.S. Bakhoum ◽

P.I. Ndiaye ◽

C.T. Bâ ◽

J. Miquel

Keyword(s):

Mature Spermatozoon ◽

Cytoplasmic Process ◽

Cortical Microtubules ◽

Lateral Expansion ◽

Differentiation Zone ◽

Sarpa Salpa ◽

Ultrastructural Characteristics ◽

First Time ◽

External Ornamentation ◽

Free Flagellum

AbstractThe 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. stossichianum exhibits two axonemes of different length of the 9+‘1’ trepaxonematan pattern, a nucleus, a mitochondrion, 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 formation of cytoplasmic ornamented buttons during the final stages of spermiogenesis is reported here for the first time.

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The ultrastructure of spermatogenesis and spermatozoa in Pseudodiplorchis americanus (Monogenea: Polystomatidae)

Canadian Journal of Zoology ◽

10.1139/z93-227 ◽

1993 ◽

Vol 71 (8) ◽

pp. 1609-1619 ◽

Cited By ~ 3

Author(s):

J. Cable ◽

R. C. Tinsley

Keyword(s):

General Pattern ◽

Adult Life ◽

Mature Spermatozoon ◽

Structural Features ◽

Taxonomic Position ◽

Cortical Microtubules ◽

Standard Pattern ◽

Male Gametes ◽

Basic Characteristics ◽

Mature Spermatozoa

The basic characteristics of spermatogenesis and the ultrastructure of the mature spermatozoa show uniformity throughout the parasitic platyhelminths, and the monogenean Pseudodiplorchis americanus follows this general pattern. Primary spermatogonia undergo mitosis to produce 8 primary spermatocytes which divide by meiosis to produce 16 secondary spermatocytes and eventually a syncytial rosette of 32 spermatids. Each spermatid differentiates into a mature spermatozoon bearing two axonemes, a nucleus, a mitochondrion, and cortical microtubules. Although transmission of P. americanus is restricted to only a few nights each year, the production of male gametes appears to be continuous throughout adult life and exhibits no seasonality. Characteristically, cortical microtubules run the entire length of polyopisthocotylean spermatozoa but they are absent along part of the spermatozoon of P. americanus and one other polystomatid species previously examined. This variation on the standard pattern separates the Polystomatidae from the rest of the Monogenea and emphasises the distinctive taxonomic position and the homogeneity of many structural features within this platyhelminth family.

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The comparative ultrastructure of spermatozoa from Bothrimonus sturionis Duv. 1842 (Pseudophyllidea), Pseudanthobothrium hanseni Baer, 1956 (Tetraphyllidea), and Monoecocestus americanus Stiles, 1895 (Cyclophyllidea)

Canadian Journal of Zoology ◽

10.1139/z84-152 ◽

1984 ◽

Vol 62 (6) ◽

pp. 1059-1066 ◽

Cited By ~ 34

Author(s):

Barbara M. MacKinnon ◽

Michael D. B. Burt

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Plasma Membrane ◽

Main Body ◽

Posterior Portion ◽

Transmission Electron ◽

Dense Nucleus ◽

Comparative Ultrastructure ◽

Electron Lucent ◽

Mature Spermatozoa

The mature spermatozoa from Bothrimonus sturionis (Pseudophyllidea), Pseudanthobothrium hanseni (Tetraphyllidea), and Monoecocestus americanus (Cyclophyllidea) were examined using transmission electron microscopy. Transverse sections of the sperm of B. sturionis indicate that the number of sperm axonemes varies from one to eight, with approximately one-third of the sperm containing two axonemes. Likewise, the number of peripheral microtubules lying just within the external plasma membrane varies from 12 to 20. The nucleus is electron lucent and fibrous in appearance. The spermatozoa of B. sturionis show great variation in the material examined and the majority of them are believed to be aberrant. The spermatozoon of P. hanseni contains a single axoneme with the nucleus wrapped in a crescent around it in the anterior region of the sperm. The posterior portion of the spermatozoon is characterized by a helical flange which projects from the main body of the sperm. The spermatozoon of M. americanus is elongate and slender, containing a single axoneme with an electron-dense nucleus coiled around it in the anterior one-third of the sperm. Electron-opaque bodies, which may be glycogen, fill the cytoplasm. The spermatozoa of all three species contain neither an acrosome nor mitochondria. The flagella of all the spermatozoa have a 9 + "1" arrangement of microtubules. The importance of the ultrastructure of spermatozoa in the phylogeny and taxonomy of cestodes is discussed.

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

Acta Parasitologica ◽

10.2478/s11686-012-0008-7 ◽

2012 ◽

Vol 57 (1) ◽

Cited By ~ 13

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.

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Ultrastructure of telocytes, a new type of interstitial cells in the myocardium of the Chinese giant salamander (Andrias davidianus)

European Journal of Histochemistry ◽

10.4081/ejh.2019.3021 ◽

2019 ◽

Vol 63 (2) ◽

Author(s):

Tingting Ge ◽

Yaqiong Ye ◽

Hui Zhang

Keyword(s):

Electron Microscopy ◽

Tissue Regeneration ◽

Structural Characteristics ◽

Interstitial Cells ◽

Andrias Davidianus ◽

Transmission Electron ◽

Close Proximity ◽

Chinese Giant Salamander ◽

New Type ◽

Ultrastructural Characteristics

Telocytes (TCs) are new interstitial cells, and they are involved in tissue regeneration, particularly in heart. Therefore, TCs are suggested to be a promising cell in regenerative medicine. However, the information of location structural characteristics and functions of TCs is still limited. In this study, cardiac TCs of the Chinese giant salamanders (Andrias davidianus) were identified by transmission electron microscopy. TCs were located in the interstitium between cardiomyocytes (CM). TCs possessed distinctive ultrastructural characteristics, including one to two very long and thin moniliform telopodes (Tps), emerging points from the cell body, caveolae, dichotomous branchings, labyrinthic systems, neighbouring exosomes and homo-cellular contacts between Tps. TCs/Tps were frequently observed in close proximity to cardiomyocytes. Moreover, Tps established hetero-cellular contacts with cardiomyocytes. Our results confirm the presence of TCs in the myocardium of the A. davidianus. This will help us to better understand roles of TCs in amphibian hearts.

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Ultrastructure of spermiogenesis and mature spermatozoon of Angularella beema (Clerc, 1906) (Cestoda, Cyclophyllidea, Dilepididae)

Acta Parasitologica ◽

10.2478/s11686-006-0040-6 ◽

2006 ◽

Vol 51 (4) ◽

Cited By ~ 3

Author(s):

Aneta Yoneva ◽

Jordi Miquel ◽

Zdzisław Świderski ◽

Katia Georgieva ◽

Yana Mizinska ◽

...

Keyword(s):

Mature Spermatozoon ◽

Cortical Microtubules ◽

Cestode Species ◽

Family Presence ◽

Differentiation Zone ◽

Type Iv ◽

The Family ◽

Cytoplasmic Protrusion ◽

Ultrastructural Characteristics ◽

First Time

AbstractThe ultrastructure of the spermiogenesis of a dilepidid cestode species is described for the first time. The spermiogenesis of Angularella beema is characterised by absence of both flagellar rotation and proximodistal fusion. The differentiation zone is surrounded by cortical microtubules and is delimited by a ring of arching membranes. It contains two centrioles, one of which develops the axoneme that grows directly into the elongating cytoplasmic protrusion. This pattern of spermiogenesis was described as the Type IV spermiogenesis of cestodes. Among cestodes, similar pattern of spermiogenesis is known in the family Hymenolepididae and in some representatives of the family Anoplocephalidae. The mature spermatozoon of A. beema consists of five regions differing in their ultrastructural characteristics. It is characterised by the presence of cortical microtubules (spirally arranged at angle of 30–40° to the spermatozoon axis) and a single crested body. There is a periaxonemal sheath in certain parts of the spermatozoon as well as glycogen-like granules between the periaxonemal sheath and the cortical microtubules. The comparisons of the mature spermatozoon of A. beema with those of other two dilepidid species (Dilepis undula and Molluscotaenia crassiscolex) demonstrate some variation within the family: presence of periaxonemal sheath in A. beema and D. undula and its absence in M. crassiscolex; presence of electron-dense rods in D. undula and their absence in A. beema.

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