Ultrastructual studies on spematids and sertoli cells during early spermogenesis in the bandicoot Peramelea nasuta geoffroy (Marsupialia)

1967 ◽  
Vol 15 (5) ◽  
pp. 881 ◽  
Author(s):  
CS Sapsford ◽  
CA Rae ◽  
KW Cleland
Keyword(s):  
Plasma Membrane ◽  
Nuclear Envelope ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Close Contact ◽  
Cell Cytoplasm ◽  
Axial Filament ◽  
Stage Of Development ◽  
The Future ◽  
Nuclear Protrusion

The present paper deals with spermiogenesis up to and including the attachment of spermatids to Sertoli cells. The first observed step in spermatid differentiation was the development of the anlage of the middle piece and principal piece. This anlage, called the axial filament complex, has the structure of a cilium and arises from the future longitudinal centriole, while the latter, together with the future transverse centriole, lies in the vicinity of the Golgi complex. The definitive acrosomal vacuole, which ultimately becomes attached to and invaginates the nuclear envelope, is formed by the enlargement and coalescence of Golgi vacuoles. While this definitive vacuole is developing, the centrioles and attached axial filament complex migrate to the opposite pole of the nucleus. Before and during migration a number of accessory structures are developed in association with the centrioles, and one of these structures, the proximal junctional body, invaginates the nuclear envelope when the centrioles reach their definitive abacrosomal position. During this period, a cytoplasmic canal forms around the intraspermatid part of the axial filament complex. The definitive acrosomal vacuole ultimately extends out to make close contact with the plasma membrane of the spermatid. This stage of development is followed by a process of nuclear protrusion, initiated by the migration of the nucleus towards the region of contact between acrosomal vacuole and spermatid plasma membrane. During the migratory phase, that part of the nuclear envelope previously invaginated by the acrosomal vacuole becomes everted and the latter collapses, finally becoming sandwiched in between the nucleus and the plasma membrane of the spermatid. The nucleus subsequently projects from the surface of the spermatid, its acrosome-covered apex becoming coneshaped. During these phases of development the accessory structures elaborated in association with the centrioles, and which now lie in the neck region of the spermatid, have become more highly organized. The manchette begins to develop in spermatids at the stage at which the acrosome has become sandwiched in between the nucleus and the plasma membrane of the spermatid. Concurrently the spermatids become surrounded on all sides by Sertoli cell cytoplasm. In the later stages of nuclear protrusion, the manchette elongates and its walls become thicker. The protruding nuclei become orientated with their acrosome-covered apices facing towards the basement membrane of the tubules. Aggregations of finely granular material appear in Sertoli cell cytoplasm in the region of contact with the acrosomal vacuole. The possible role of the manchette and of Sertoli cell cytoplasm in the phenomenon of nuclear protrusion and orientation is discussed.

Ultrastructural studies on the development and form of the principal piece sheath of the bandicoot spermatozoon

1970 ◽  
Vol 18 (1) ◽  
pp. 21 ◽  
Author(s):  
CS Sapsford ◽  
CA Rae ◽  
KW Cleland
Keyword(s):  
Plasma Membrane ◽  
Dense Material ◽  
Axial Filament ◽  
Ultrastructural Studies ◽  
The Future ◽  
Membrane Bound ◽  
End To End ◽  
Principal Piece

The first components of the sheath to develop are two longitudinal columns, characterized by alternating light and dark bands. The columns, which lie on opposite sides of the future principal piece, are initially associated with the axial filament complex but soon make contact with the plasma membrane. Subsequently a layer of moderately dense material grows outwards from the lateral aspects of each column. The outgrowths lie just beneath the tail plasma membrane and contain evenly spaced filaments which are connected with the dark bands of the columns. The outgrowths from corresponding sides of each column eventually meet each other and the filaments they contain join end-to-end. Some parts of the sheath, separated from the plasma membrane by an expansion of the cytoplasm of the intraspermatid tail, become invested by membrane bound vacuoles. The filaments form into groups, and filaments within groups converge to produce the anlagen of the ribs of the mature sheath. The filaments lose their identity in these anlagen, which, like the columns, develop much finer filamentous structures. The ribs, and subsequently the columns, lose contact with the tail plasma membrane. The mature sheath, the ultrastructure of which is described in detail, is developed by further modification of the rib anlagen and longitudinal columns.

Proteins of the membrane skeleton in rat Sertoli cells

1986 ◽  
Vol 86 (1) ◽  
pp. 145-154
Author(s):  
E. Ziparo ◽  
B.M. Zani ◽  
A. Filippini ◽  
M. Stefanini ◽  
V.T. Marchesi
Keyword(s):  
Plasma Membrane ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Primary Cultures ◽  
Membrane Skeleton ◽  
Permeabilized Cells ◽  
Protein 4.1 ◽  
Molecular Weights ◽  
Gamma Subunits ◽  
Alpha Beta

Analogues of the alpha, beta and gamma subunits of human spectrin and erythroid protein 4.1 have been detected in rat Sertoli cell primary cultures. Immunofluorescence of permeabilized cells showed that erythroid type spectrin, protein 4.1 and actin co-distribute within the cells as filamentous structures. Fodrin-like molecules were distributed in a diffuse manner, mostly associated with the plasma membrane. Immunoprecipitation and immunoblotting experiments indicated that the polypeptides present in rat Sertoli cells are immunologically related and display molecular weights similar to their analogues in the human erythroid and non-erythroid membrane skeleton.

Hormonal regulation of spermatid binding

1991 ◽  
Vol 100 (3) ◽  
pp. 623-633
Author(s):  
D.F. Cameron ◽  
K.E. Muffly
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Hormonal Regulation ◽  
Unit Area ◽  
Junctional Complex ◽  
Cell Cytoplasm ◽  
Coculture Model ◽  
Ectoplasmic Specialization

A Sertoli-spermatid coculture model is described in which a large percentage (greater than 76%) of round spermatids remain viable for 48 h and bind to Sertoli cells. The effects of follicle-stimulating hormone (FSH) and testosterone on spermatid binding (expressed as the spermatid density; SD = the number of spermatids per unit area of Sertoli cell cytoplasm), ultrastructure of the Sertoli-spermatid junctional complex, and distribution in the Sertoli cell of junction-related F-actin and vinculin are described. Following 48 h of incubation, neither FSH alone nor testosterone alone affected spermatid binding to Sertoli cells beyond that observed in control cocultures. However, the combination of FSH and testosterone (FSH + testosterone) resulted in a significant increase in the density of spermatids bound to Sertoli cells. Junction-related structure of the Sertoli cell cytoskeleton between the Sertoli cell and the pre-step 8 spermatid was different than that observed between the Sertoli cell and the post-step 8 spermatid. The junction-related cytoskeletal modification of the Sertoli cell (JCMS) in the latter was similar in appearance to the well-described ‘Sertoli ectoplasmic specialization’ observed adjacent to post-step 8 spermatids in vivo. FSH + testosterone and FSH alone, but not testosterone alone, resulted in the peripheral distribution of actin and vinculin, which otherwise remained in stress fiber-like structures throughout the Sertoli cell. Results show that maximal spermatid binding to Sertoli cells in vitro requires FSH + testosterone and is associated with the peripheral distribution of actin and vinculin.

Ultrastructual studies on maturing spermatids and on sertoli cells in the bandicoot Perameles nasuts Geoffroy (Marsupialia)

1969 ◽  
Vol 17 (2) ◽  
pp. 195 ◽  
Author(s):  
CS Sapsford ◽  
CA Rae ◽  
KW Cleland
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Neck Region ◽  
Secretory Activity ◽  
Axial Filament ◽  
Middle Piece ◽  
Proximal Extremity ◽  
Nuclear Ring ◽  
Nuclear Rotation ◽  
Cyclic Changes

This paper describes maturation changes in bandicoot spermatids after the latter have become embedded in Sertoli cells and are orientated within the seminiferous tubule. The changes are recorded as taking place in four stages, namely the stage of nuclear flattening and condensation, the stage of nuclear rotation, and the early and late post-rotational stages. The changes in shape and reduction in volume of the nucleus taking place during these stages are described, together with the division of the nuclear contents into condensed chromatin and the less electron-dense parachromatin. The disposition of nuclear pores in relation to the distribution of these two substances is discussed. A possible means of the disposal of redundant nuclear envelope substance is outlined. An account of the modifications taking place in the structures of the neck region is given and it is shown that both transverse and longitudinal centrioles persist until the terminal stages of spermiogenesis, when the latter centriole disappears. As a result of the migration of the annulus and the attached proximal extremity of the cytoplasmic canal, the axial filament complex of the future middle piece is left in contact with the general spermatid cytoplasm, and thus is created a pathway whereby spermatid mitochondria can migrate to this part of the complex to form the mitochondria1 sheath of the middle piece. Details are presented of the changes in form, throughout spermiogenesis, of spermatid mitochondria as well as of the acrosome, manchette, and nuclear ring. A description is given of specialized changes in that part of Sertoli cell cytoplasm immediately adjacent to the spermatid acrosome. It is thought that these changes are indicative, and mark out the extent, of a Sertoli cell-spermatid attachment. Cyclic changes in the overall form as well as in the endoplasmic reticulum and mitochondria of Sertoli cells are recorded. Pinocytotic activity in Sertoli cells and spermatids, as well as secretory activity in Sertoli cells, is examined.

300 IMMUNO-EXPRESSION OF POTENTIAL FACTORS REGULATING SERTOLI CELL PROLIFERATION IN THE PREPUBERTAL BOAR

2006 ◽  
Vol 18 (2) ◽  
pp. 257
Author(s):  
J. Baldrighi ◽  
W. Averhart ◽  
T. Phillips ◽  
K. Carnes ◽  
R. Hess ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Cell Proliferation ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
Testis Size ◽  
Regulatory Factors ◽  
Time Points ◽  
Stage Of Development ◽  
Potential Factors ◽  
P27 Kip1

Today's pork production is very dependent on reproductive efficiency. Any improvements in the production capability (e.g., number of sperm produced) of the animals involved would be invaluable. Many researchers have examined methods to improve oocyte production, but have not focused on the concentration of sperm produced from a single boar used for artificial insemination (AI). The benefit of using AI is that a greater number of females can be bred to a single boar; thus the total amount of sperm per ejaculation is the main factor in the efficiency of AI. An increase in the number of Sertoli cells leads to an increase in testis size and the number of sperm produced because there are a finite number of germ cells that can be supported by the Sertoli cell during spermatogenesis. Therefore, by examining the factors that control the growth and differentiation of Sertoli cells, the amount of sperm per ejaculation in an individual boar can be increased. The purpose of this research is to begin a systematic analysis of cell cycle regulators expressed in the Sertoli cell during testicular development in the pig. By using pigs of different ages, we will establish a baseline of what regulatory factors are present at different time points in the developing Sertoli cell. Identification of certain factors could lead to an increase in sperm production by enabling the growth of Sertoli cells or inhibition of the natural reduction of these cells. Immunohistochemistry (IHC) analysis was performed on testis tissues from different males (n = 2) at various ages (3, 7, 14, 25, and 50 days) prior to puberty. Tissues were fixed in modified Davidson's fixative, embedded in paraffin, and sectioned; slides were processed for IHC. After antigen retrieval, endogenous hydrogen peroxidase was blocked with 0.6% H2O2 and sections were incubated overnight at 4°C with the appropriate antibody. The following antibodies were used to examine the factors controlling Sertoli cell proliferation: GATA-4 (transcription factor specific for developing and adult pig Sertoli cells), Ki67 (a nuclear protein present in all phases of the cell cycle except G0), cyclin-dependent kinase inhibitor p27 (Kip1), and steroid receptors AR (androgen receptor) and LH2 (estrogen receptor). The slides were then incubated with an appropriate secondary antibody, visualized with DAB chromagen, and counterstained with Mayer's hematoxylin. Immunostaining using p27 (Kip1) revealed no positive staining in any of the days tested, as there is cell division during all of these time points. Protein expression for Ki67 stained mildly after Day 25, suggesting that Sertoli cells became more active at this stage of development. The AR weakly stained and GATA-1 stained intensely at all time points. The data for LH2 were inconclusive and the procedure needs to be performed again. These experiments only give a glimpse of the regulatory factors involved in Sertoli cell proliferation in the developing boar testis. Further studies are being planned to explore other potential factors involved.

THE ROLE OF SERTOLI CELLS IN THE ORGANIZATION OF SPERM BUNDLES IN THE TESTIS OF SADURIA ENTOMON (LINNAEUS, 1758) (ISOPODA, VALVIFERA)

Crustaceana ◽  
1999 ◽  
Vol 72 (9) ◽  
pp. 1067-1078 ◽  
Author(s):  
Zofia Hryniewiecka-Szyfter ◽  
Elzbieta Gabala ◽  
Adam Babula
Keyword(s):  
Sertoli Cell ◽  
Sertoli Cells ◽  
Close Contact ◽  
Cell Protrusion ◽  
Cellules De Sertoli ◽  
Precursor Material ◽  
Matrix Components ◽  
Cellule De Sertoli ◽  
Saduria Entomon

AbstractUltrastructural observations show that in Saduria entomon (L., 1758) sperm bundles are organized already in the testis, and that a crucial function in this process is played by Sertoli cells, whose protrusions are connected with maturing spermatids. The specific arrangement of maturing spermatids around a Sertoli cell protrusion and their turned-out tails lying centrally in channels reflect the arrangement of spermatozoa in a later bundle. One might assume, therefore, that the pattern along which sperm bundles are organized, which results from their specific structure, is made possible by the way in which the lumen of the testis is penetrated by protrusions of the Sertoli cells. A further role of the Sertoli cells is to produce and secrete matrix components and precursor material for extracellular tubules. Both structures are permanent elements of sperm bundles in isopods. In S. entomon extracellular tubules have a diameter of 80 nm, and their assembling proceeds in close contact with the membrane of a Sertoli cell protrusion. Des observations ultrastructurales montrent que, chez Saduria entomon (L., 1758), les masses spermatiques sont deja organisees dans le testicule et qu'un role crucial dans le processus est joue par les cellules de Sertoli, dont les protrusions sont connectees avec les spermatides en maturation. L'arrangement specifique de ces dernieres autour d'une protrusion de cellule de Sertoli et de leurs queues retournees en position centrale dans les canaux reflete l'arrangement des spermatozoodes dans une masse ulterieure. On peut de ce fait presumer que le modele suivant lequel les masses spermatiques sont organisees, et qui resulte de leur structure specifique, est rendu possible par la facon par laquelle les protrusions des cellules de Sertoli penetrent le testicule. Un autre role des cellules de Sertoli est de produire et de secreter les composants de la matrice et le materiel precurseur pour les tubules extracellulaires. Les deux structures sont des elements permanents des masses spermatiques chez les isopodes. Chez S. entomon, les tubules extracellulaires ont un diametre de 80 nm, et leur assemblage s'effectue en etroit contact avec la membrane d'une protrusion de cellule de Sertoli.

Abnormal microtubular systems in mouse spermatids associated with a mutant gene at the T-locus

Development ◽  
1974 ◽  
Vol 32 (3) ◽  
pp. 749-761
Author(s):  
Gerald B. Dooher ◽  
Dorothea Bennett
Keyword(s):  
Plasma Membrane ◽  
Nuclear Envelope ◽  
Sertoli Cells ◽  
Small Proportion ◽  
Mutant Gene ◽  
The Other ◽  
Biochemical Characteristics ◽  
Large Numbers ◽  
Ordered Array ◽  
T Locus

Fine structural observations of spermiogenesis in sterile mice homozygous for the t -allele tw2 reveal that spermatids develop severe morphological abnormalities during spermiogenesis. In a small proportion of late spermatids the nuclear envelope develops broad areas of discontinuity except at the level of the acrosome. Manchette microtubules, which in normal spermatids form an orderly perinuclear array, appear to undergo premature depolymerization in cells of this type although flagellar structures differentiate normally. The majority of late spermatids, on the other hand, contain unusually large numbers of disorganized microtubules. Spermatid head shapes likewise become very abnormal. Both acrosomal and post-acrosomal portions of the nucleus exhibit malformations. The presence of disorganized microtubular arrays is believed to contribute to the observed nuclear deformations. Although condensation of the chromatin occurs in these cells, the spermatids seldom survive to maturity. Most of the cells are phagocytized by Sertoli cells. Late spermatids from tw2 homozygotes are abnormal in that they fail to maintain a precisely ordered array of microtubules during the concluding stages of spermiogenesis.This defect may reflect an underlying abnormality in the structural or biochemical characteristics of the plasma membrane with which the microtubules become associated.

Arrangement of Mitochondria in Spermatozoa of the Mexican Axolotl, Ambystoma Mexicanum

1973 ◽  
Vol 31 ◽  
pp. 626-627
Author(s):  
Ezzatollah Keyhani ◽  
Larry F. Lemanski ◽  
Sharon L. Lemanski
Keyword(s):  
Plasma Membrane ◽  
Sperm Motility ◽  
Substrate Oxidation ◽  
Ambystoma Mexicanum ◽  
Axial Filament ◽  
Mexican Axolotl ◽  
Middle Piece

Energy for sperm motility is provided by both glycolytic and respiratory pathways. Mitochondria are involved in the latter pathway and conserve energy of substrate oxidation by coupling to phosphorylation. During spermatogenesis, the mitochondria undergo extensive transformation which in many species leads to the formation of a nebemkem. The nebemkem subsequently forms into a helix around the axial filament complex in the middle piece of spermatozoa.Immature spermatozoa of axolotls contain numerous small spherical mitochondria which are randomly distributed throughout the cytoplasm (Fig. 1). As maturation progresses, the mitochondria appear to migrate to the middle piece region where they become tightly packed to form a crystalline-like sheath. The cytoplasm in this region is no longer abundant (Fig. 2) and the plasma membrane is now closely apposed to the outside of the mitochondrial layer.

Freeze-etch observations on the tight junctions of sertoli cells grown in organ culture with FSH

1978 ◽  
Vol 36 (2) ◽  
pp. 340-341
Author(s):  
Rita Meyer ◽  
Zoltan Posalaky ◽  
Dennis Mcginley
Keyword(s):  
Organ Culture ◽  
Tight Junctions ◽  
Sertoli Cell ◽  
Germ Cells ◽  
Sertoli Cells ◽  
Barrier Function ◽  
Cell Junction ◽  
Intramembranous Particles ◽  
Junctional Complexes ◽  
Oriented Parallel

The Sertoli cell tight junctional complexes have been shown to be the most important structural counterpart of the physiological blood-testis barrier. In freeze etch replicas they consist of extensive rows of intramembranous particles which are not only oriented parallel to one another, but to the myoid layer as well. Thus the occluding complex has both an internal and an overall orientation. However, this overall orientation to the myoid layer does not seem to be necessary to its barrier function. The 20 day old rat has extensive parallel tight junctions which are not oriented with respect to the myoid layer, and yet they are inpenetrable by lanthanum. The mechanism(s) for the control of Sertoli cell junction development and orientation has not been established, although such factors as the presence or absence of germ cells, and/or hormones, especially FSH have been implicated.

Effect of nitric oxide on Sertoli cell microtubule of piglets

2009 ◽  
Vol 6 (3) ◽  
pp. 257-263 ◽  
Author(s):  
Yang Li ◽  
Wang Xian-zhong ◽  
Yang Meng-bo ◽  
Zhang Jia-hua
Keyword(s):  
Nitric Oxide ◽  
Enzyme Activity ◽  
Protein Kinase ◽  
Cell Viability ◽  
Sodium Nitroprusside ◽  
Sertoli Cell ◽  
Sertoli Cells ◽  
High Concentration ◽  
Treatment Results ◽  
Anti Oxidant

AbstractTo illustrate the effect of nitric oxide (NO) on the microtubules of Sertoli cells (SC), SCs of piglets were treated with sodium nitroprusside (SNP). Changes in cell viability, anti-oxidant activity, enzyme activity and p38 mutagen-activated protein kinase (p38MAPK) activation were detected. The results were as follows. A low concentration of NO can keep SC microtubule and cell viability normal, and a high concentration of NO could increase p38MAPK activation, decrease anti-oxidant activity and transferrin secretion, and destroy the structure and distribution of the microtubules. The results suggest that SNP treatment results in an increase in NO in SCs and decreased cell anti-oxidant activity. The high concentration of NO destroys cell microtubules by activating p38MAPK.

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