Spermatozoon ultrastructure in two monorchiid digeneans

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.

Download Full-text

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 ◽

10.1051/parasite/2020066 ◽

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.

Download Full-text

Ultrastructure and cytochemistry of the mature spermatozoon of Khawia armeniaca (Cholodkovsky, 1915) (Caryophyllidea: Lytocestidae), a parasite of Capoeta capoeta sevangi (De Filippi, 1865) (Teleostei, Cyprinidae)

Helminthologia ◽

10.2478/helm-2020-0040 ◽

2020 ◽

Vol 57 (4) ◽

pp. 353-360

Author(s):

M. Matoušková ◽

M. Bruňanská ◽

J. Nebesářová ◽

L. G. Poddubnaya

Keyword(s):

Anterior Part ◽

Male Gamete ◽

Longitudinal Axis ◽

Mature Spermatozoon ◽

Ultrastructural Organization ◽

Cortical Microtubules ◽

Transmission Electron ◽

Cytochemical Technique ◽

First Time ◽

Region Ii

SummaryThe mature spermatozoon of Khawia armeniaca, a monozoic caryophyllidean parasite of templar fish Capoeta capoeta sevangi (De Filippi, 1865) from the Lake Sevan, Armenia, has been studied using transmission electron microscopy and cytochemical technique of Thiéry (1967) for the first time. The mature spermatozoon of K. armeniaca consists of a single axoneme with the 9+‘1’ trepaxonematan structure, cortical microtubules and nucleus which are situated parallel to the longitudinal axis of the spermatozoon, and a moderately electrondense cytoplasm with glycogen particles. The cortical microtubules are arranged in one continuous semicircle beneath the plasma membrane in Region II and anterior part of Region III of the mature spermatozoon. The two opposite rows of cortical microtubules are observed in the remaining nuclear and at the beginning of the postnuclear part (Regions III, IV) of the male gamete The number of cortical microtubules is remarkably variable in the spermatozoa of various Khawia species. K. armeniaca exhibits the highest number of cortical microtubules in comparison with K. sinensis and K. rossittensis. Glycogen was detected in the cytoplasm of prenuclear (II), nuclear (III) and postnuclear (IV) regions with different ultrastructural organization of the mature spermatozoon of K. armeniaca. Variations of sperm ultrastructural characters within caryophyllideans and other cestodes are discussed.

Download Full-text

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.

Download Full-text

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.

Download Full-text

Experimental investigation of interfaces in graphene materials/copper composites from a new perspective

RSC Advances ◽

10.1039/c6ra07606h ◽

2016 ◽

Vol 6 (57) ◽

pp. 52219-52226 ◽

Cited By ~ 19

Author(s):

Dan-dan Zhang ◽

Zai-ji Zhan

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Experimental Investigation ◽

Interface Microstructure ◽

Graphene Plane ◽

Transmission Electron ◽

New Perspective ◽

Means Of Transmission ◽

First Time

The interface microstructure between the constituent phases in graphene/Cu composites, namely graphene plane–Cu (Dp) and graphene edges–Cu (De), were observed for the first time from the two directions by means of transmission electron microscopy.

Download Full-text

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.

Download Full-text

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.

Download Full-text

Spermiogenesis and sperm ultrastructure in Calicotyle affinis Scott, 1911 (Platyhelminthes, Monogenea, Monopisthocotylea, Monocotylidae)

Helminthologia ◽

10.1515/helm-2017-0039 ◽

2017 ◽

Vol 54 (4) ◽

pp. 348-357 ◽

Cited By ~ 1

Author(s):

M. Bruňanská ◽

L. G. Poddubnaya

Keyword(s):

Inner Core ◽

Mature Spermatozoon ◽

Proximal Region ◽

Transmission Electron ◽

New Findings ◽

Means Of Transmission ◽

Two Stages ◽

First Time ◽

Monocotylid Monogenean ◽

Electron Lucent

SummarySpermatological characteristics ofCalicotyle affinisScott, 1911, an endoparasitic monocotylid monogenean from the cloaca of a holocephalan fishChimaera monstrosaL, have been investigated by means of transmission electron microscopy for the first time. Spermiogenesis exhibits features basically similar to those of the congenericCalicotyle kroyeriandCalicotyle australiensis, but there are some new findings with respect to the formation and fine structure of the spermatozoon including the remarkable complex end-piece (EP). Morphogenesis of the EP, which is located at the anterior (proximal) region of the late spermatid, includes two stages: (1) the centriolar region is continuous with a cytoplasmic mass of the zone of differentiation, the electron-dense surface of the spermatid undergoes significant changes in the sculpturing and the inner core of developing spermatid is electron-lucent; (2) after central fusion of the arching membranes a definitive structure of the EP is subsequently evolved, finally comprising 3 – 4 electron-dense discs attached to a central common electron-lucent column. The EP is considered as a synapomorphy of the generaCalicotyle+Dictyocotyle. The mature spermatozoon ofC.affiniscomprises the EP, two parallel axonemes of almost equal lengths with the 9 + “1” trepaxonematan pattern, mitochondrion, nucleus, and a reduced number of parallel cortical microtubules (1 – 3). The posterior (distal) extremity of the mature spematozoon contains a single tapering axoneme. Ultrastructural characteristics of the mature spermatozoon ofC. affiniscoincide mostly with those of congenericC. australiensis. Variations of the spermatological characters within the genusCalicotyle, betweenCalicotyleand enigmaticDictyocotyleas well as other monocotylid monogeneans are discussed.

Download Full-text

Ultrastructural Analysis of the Salivary Glands of Gromphadorhina Portentosa (Schaum)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100080614 ◽

1977 ◽

Vol 35 ◽

pp. 638-639

Author(s):

P.J. Dailey

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Salivary Glands ◽

Secretory Vesicles ◽

The Past ◽

Transmission Electron ◽

Means Of Transmission ◽

Gromphadorhina Portentosa ◽

Scanning Electron ◽

Topographical Relief

The structure of insect salivary glands has been extensively investigated during the past decade; however, none have attempted scanning electron microscopy (SEM) in ultrastructural examinations of these secretory organs. This study correlates fine structure by means of SEM cryofractography with that of thin-sectioned epoxy embedded material observed by means of transmission electron microscopy (TEM).Salivary glands of Gromphadorhina portentosa were excised and immediately submerged in cold (4°C) paraformaldehyde-glutaraldehyde fixative1 for 2 hr, washed and post-fixed in 1 per cent 0s04 in phosphosphate buffer (4°C for 2 hr). After ethanolic dehydration half of the samples were embedded in Epon 812 for TEM and half cryofractured and subsequently critical point dried for SEM. Dried specimens were mounted on aluminum stubs and coated with approximately 150 Å of gold in a cold sputtering apparatus.Figure 1 shows a cryofractured plane through a salivary acinus revealing topographical relief of secretory vesicles.

Download Full-text

Quartz Crystallite Size and Moganite Content as Indicators of the Mineralogical Maturity of the Carboniferous Chert: The Case of Cherts from Eastern Asturias (Spain)

Minerals ◽

10.3390/min11060611 ◽

2021 ◽

Vol 11 (6) ◽

pp. 611

Author(s):

Celia Marcos ◽

María de Uribe-Zorita ◽

Pedro Álvarez-Lloret ◽

Alaa Adawy ◽

Patricia Fernández ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Crystallite Size ◽

Archaeological Sites ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Infrared And Raman Spectroscopy ◽

First Time ◽

Geological Formations

Chert samples from different coastal and inland outcrops in the Eastern Asturias (Spain) were mineralogically investigated for the first time for archaeological purposes. X-ray diffraction, X-ray fluorescence, transmission electron microscopy, infrared and Raman spectroscopy and total organic carbon techniques were used. The low content of moganite, since its detection by X-ray diffraction is practically imperceptible, and the crystallite size (over 1000 Å) of the quartz in these cherts would be indicative of its maturity and could potentially be used for dating chert-tools recovered from archaeological sites. Also, this information can constitute essential data to differentiate the cherts and compare them with those used in archaeological tools. However, neither composition nor crystallite size would allow distinguishing between coastal and inland chert outcrops belonging to the same geological formations.

Download Full-text