bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of compounds structurally related to taurine and of taurine uptake inhibitors on the motility of hamster sperm in vitro
Authors: Gwatkin Ralph B. L. 
Published: February 2005

AbstractSeveral taurine‐related compounds, taurine antagonists and taurine uptake inhibitors were tested for their effect on hamster sperm motility in vitro. Hypotaurine was approximately three times more effective than taurine. N‐methyltaurine and taurocyamine were less effective. Inactive taurine‐related compounds were not effective blockers of taurine's spermtimulating activity. However, 1‐(4‐nitrophenyl)‐2‐dimethylaminomethyl‐l‐propenone, a taurine uptake inhibitor, completely suppressed sperm motility at a molar concentration equal to, or less than, that of the taurine added to the incubation medium and also suppressed the motility‐sustaining action of the cumulus oophorus.
Effects of selenium deficiency on the shape and arrangement of rodent sperm mitochondria
Authors: Wallace Edith , Cooper George W. , Calvin Harold I. 
Published: February 2005

AbstractSelenium‐deficient male mice were obtained by feeding a selenium‐deficient diet for three successive generations to Swiss‐Webster mice. Examination of epididymal sperm by transmission electron microscopy revealed progressively increasing alterations in the shape and arrangement of mitochondria within the midpiece. Other midpiece anomalies included acute bends, disorientation of the axoneme and dense fibers, and cytoplasmic masses at atypical locations. Some cross sections showed both the principal piece and midpiece within the same plasma membrane. Negatively stained whole mounts of mitochondrial ghosts prepared from epididymal sperm of normal and first‐generation selenium‐deficient mice and rats indicated that the selenium‐deficient ghosts were smaller, less curved, and more fragile than those of normal sperm mitochondria. Thus, selenium appears to be required for the normal development or stabilization of mitochondria1 shape during spermiogenesis in these rodents.
Binding to spermatozoa of a major soluble protein secreted by the epididymis of the lizard Lacerta vivipara
Authors: Depeiges Annie , Dufaure Jean‐Pierre 
Published: February 2005

AbstractA major soluble protein occurring in two forms, a monomer (protein L) and a polymer, has been identified in the voluminous secretory granules produced by the epithelium of Lacerta vivipara epididymis. An antiserum was raised against protein L and used as an immunohistochemical probe. Indirect immunofluorescence microscopy has indicated that protein L is able to bind to the heads of the spermatozoa. By incubating spermatozoa with buffers of increasing ionic strength and by using nonionic detergents it was not possible to remove completely the protein L. Therefore it was concluded that the binding of protein L to the spermatozoa was not labile and might play an important role in the physiology of the spermatozoa, which is presently under investigation with this convenient model.
Structural changes in bovine oocytes during final maturation in vivo
Authors: Kruip T. A. M. , Cran D. G. , van Beneden T. H. , Dieleman S. J. 
Published: February 2005

AbstractOn the basis of structural observations bovine oocytes were grouped into four successive classed: 0, those before the luteinizing hormone (LH) surge; 1, those up to 8 h following the LH peak level; 2, those between 8 and 19 h after the LH peak level; and 3, those between 19 h after the LH peak level and ovulation.Oocytes in class 0 had mitochondria located in a generally peripheral position. Interior to the mitochondria were elements of rough endoplasmic reticulum (RER) and numerous membrane‐bound vesicles which bore ribosome‐like particles on their outer surface. The first visible changesater the LH peak level as seen in class 1 were the formation of the periviteline space with loss of contact between the cumulus cells and the oocyte, and ruffing of the nuclear envelope. These changes were followed b the resumption of meiosis as defined by germinal‐vesicle breakdown (GVBD), the disappearance of RER, and the formation fo clusters of mitochondria in association with lipid droplets and elementrs of smooth endolasmic reticulum (SER).The period between 8 and 19 h following LH peak level (class 2) was characterized by intensive clustering of mitochoncria in association with lipid droplets and elements of SER, conversion of lipid, fusion of vesicles, and the appearance of ribosomes in the cytoplasm. During the final stage (class 3), the polar body was extruded, the mitochondria dispersed, and the majority of the organelles became located toward the center of the cell. The relatively organelle‐free cortical region contained cortical granules immediately adjacent to the plasma membrane together with aggregates of tubular SER. The structural changes are discussed in the context of follicular steroidogenesis and oocyte developmental competence.
Cytoplasmic and sperm nuclear transformations in fertilized ammonia‐activated sea urchin (Arbacia punctulata) eggs
Authors: Longo Frank J. 
Published: February 2005

AbstractStudies examining cytoplasmic and sperm nuclear transformations in sea urchin (Arbacia punctulata) eggs inseminated at different periods after ammonia activation have been caried out at the light‐ and electron‐microscopic levels of observation. Arbaca eggs treated with ammonia‐seawater demonstrated chromosome condensation after DNA synthesis and underwent a chromosome cycle similar to that described for Lytechinus [Mazia, 1947]. Cortical granule reaction, fertilization cone formation, and sperm aster development in eggs fertilized at 20 (interphase), 50 (prometaphase), and 180 (interphase) min after ammonia activation were structurally simialr to processes in untreated zygotes. Cyclical changes in the formation of fertilization cones and sperm asters, as reported for eggs fertilized after activation by agents that induce a cortical granule reaction, were not observed. Although sperm nuclear transformations were prolonged (14 vs 18 min), male pronuclei that developed in eggs fertilized 20 min after ammonia activation were morphologically similar to those observed in fertilized, untreated ova and incorporated 3H‐thymidine. Sperm incorporated into eggs at 50 min after ammonia activation underwent nuclear envelope breakdown and chromatin despersion; however, 3H‐thymidine incorporation was not observed, and male pronuclei rarely developed (less than 5% of all specimens examined). Subsequent to dispersion, the paternal chromatin condensed into chromosomes which were associated with an aster. These results demonstrate that although ammonia‐activated eggs inseminated at interphase or prometaphase undergo similar cytoplasmic alterations, sperm nuclear transformations vary with the chromosome cycle of the egg.
cAMP‐dependent phosphorylation associated with activation of motility of Ciona sperm flagella
Authors: Opresko L. K. , Brokaw C. J. 
Published: February 2005

AbstractDemembranated spermatozoa of Ciona do not become motile when provided with MgATP, unless their motility is activated in vivo before demembranation or unless the demembranated spermatozoa are activated in vitro with cAMP or with the catalytic subunit of a cAMP‐dependent protein kinase. CAMP causes a greater than fivefold enhancement of 32P incorporation by demembranated spermatozoa. Analysis by one‐dimensional PAGE and autoradiography shows several axonemal protein bands that become 32P‐labeled during in vitro activation with cAMP and identifies protein bands whose labeling is specifically reduced if motility of the spermatozoa is activated before demembranation, suggesting that these proteins also become phosphorylated during activation of motolity in vivo. These phosphorylated proteins appear to include dynein heavy‐chain components, but axonemal tubulin is not phosphorylated. Partially phosphorylated spermatozoa can be activated by an increase in KCI concentration, which appears to dissociate one phosphorylated component from the axoneme.
The evolution of the nematode spermatozoon
Authors: Baccetti B. , Dallai R. , De Zio S. Grimaldi , Marinari A. 
Published: February 2005

AbstractThe main features of the Nematode sperm cell are the absence of a flagellum and of an acrosome. Transition forms have never been described, as in other animal phyla also reaching the aflagellate condition, like Platyhelminths and Arthropods. The absence of the flagellum must be considered as a definitive acquisition in the group. In addition, centrioles have been demonstrated to be lacking in most cases. The absence of the acrosome is the second general feature of the Nematode sperm cell. Among other features, more or less common to the Nematodes, the most important and general is the presence in the cell periphery of spheroidal membranous vesicles, originated from the Golgi complex but not involved in fertilization or in the production of ascaridin granules. These are absent only in the Ascarid Aspiculuris and the Dorylaimiid Xiphinema, both kinds of sperm having a peculiar shape. These granules are possibly involved in cell motility. Some Nematode sperm have proteinaceous crystalline inclusions originated from the rough endoplasmic reticulum, called ascaridin granules, the role of which remains obscure. A third important feature is the absence of a nuclear envelope, characterizing all described Nematode spermatozoa, the only exception being the Enoplid Mesacanthion, which seems to be for this reason the most primitive model in the group. Other features are the reduced number, or total absence of, the chondriome, an amoeboid movement not owing to an actomyosin system and a dense halo of 10‐nm filaments surrounding the perinuclear cytoplasm.In this apparently homogeneous picture, three main evolutionary steps can be recognized. The first one, represented by the primitive Enoploid Mesacanthion, is that of a sperm conserving the nuclear envelope, surrounded by a few mitochondria and many membranous vesicles. The second, the most typical of the group, present in high Enoplida, and in Rhabditida, Strongylida, Ascarida, Spimrida, Trichinellida, is that of roundish, amoeboid spermatozoa devoid of a nuclear envelope but containing mitochondria, membranous vesicles, filaments, microtubules, sometimes centrioles, and sometimes ascaridin granules. The third step is apparently a simplification of the second; in fact, in Tylenchida and Dorylaimiida, the sperm is devoid of membranous vesicles, while in Mononchida and Dioctophymatida it is devoid of mitochondria. Aspiculuris, also devoid of membranous vesicles and having a big mitochondrial derivative, can be assigned to the same level. Nematode sperm evolution does not seem therefore to be a progressive acquisition of new characters, but rather a radiation from an already perfect model of some further simplifications occurring in parallel in most of the orders.
Fine structure of the spermatozoa of Chiton marginatus (mollusca: Amphineura), with special reference to nucleus maturation
Authors: Russell‐Pinto F. , Azevedo C. , Barandela T. 
Published: February 2005

AbstractThe spermatozoon of Chiton marginatus is a long uniflagellate cell displaying structural features of “modified sperm.” The nucleus presents a conical shape with a long apical cylindrical extension. The chromatin is homogeneously dense. Scattered inside the condensed nucleus, a few nuclear lacunae are visible. The acrosomal complex is lacking. Some mitochondria are located in a laterofrontal structure side by side with the nucleus. The typical midpiece is absent. The cytoplasm forms a thin layer around the nucleus and the mitochondria. The proximal centriole is in a basal nuclear indent. The distal centriole serves to form the axoneme tail with the usual microtubular pattern.During nuclear maturation, the early spermatid nucleus is spherical and contains fine granular chromatin patches. The nuclear envelope shows a deposit of dense material at the base of the nucleus, forming a semicircular invagination occupied by a flocculent mass. In middle spermatid stage, the chromatin gets organized in filaments, coiled as a hank, attached over the inner surface of the basal thickening of the nuclear envelope. The nucleus starts to elongate anteroposteriorly. At the pointed apical portion of the spermatid, a group of microtubules is observed seeming to impose external pressure to the nucleus giving rise to the long apical nuclear point. The mitochondria have a basal position. Late spermatids have an elongated conical nucleus. The chromatin filaments are further condensed, and lacunae appear inside the nucleus. Some mitochondria migrate to a lateral position.
Effects of surfactants on the fertilizing capacity and acrosome reaction of sea urchin spermatozoa
Authors: Nakano Eizo , Hino Akiya , Furuse Kazumaro 
Published: February 2005

AbstractThe effects of seven surfactants on spermatozoa of the sea urchin, Hemicentrotus pulcherrimus, were studied. All these surfactants induced the acrosome reaction and inhibited the fertilizing capacity of spermatozoa. There was a statistically significant correlation between the concentrations that induce the acrosome reaction and inhibit fertilization. The critical micelle concentrations (CMC) of surfactants in sea water were almost even and these values, which are inherent physical properties of surfactants, did not provide a direct measure of their inhibitory effect of fertilization. Among seven surfactants, p‐menthanyl‐phenol polyoxyethylene (8.8) ether (TS‐88) with a characteristic hydrophobes was the most potent both in the induction of acrosome reaction and in the inhibition of fertilization. Various ethylene oxide adducts to p‐menthanyl‐phenol were also tested for the purpose of comparison. It is suggested that the effects of surfactants on sea urchin spermatozoa at low concentrations reflect their activity associated with the hydrophobic group inherent in each surfactant.
The attachment of acrosome‐intact sperm to the surface of zona‐free hamster oocytes
Authors: Koehler James K. , Smith Dianne , Karp Laurence E. 
Published: February 2005

AbstractThe attachment of acrosome‐intact mammalian sperm to zona‐free hamster vitelli has been investigated using light and electron microscopy. Uncapacitated sperm from hamsters, stallions, bulls, rabbits, and humans can attach firmly to the oocyte surface by means of microvillus processes. The general appearance of such attachments mimics the events seen during the interaction of acrosome‐reacted sperm with the oolemma. Very close, junction‐like connections develop between apical portions of sperm and oolemma after initial attachment, but no evidence of sperm penetration was observed. Significant species differences were noted with respect to the avidity of the sperm‐egg interaction. Bull, horse, and rabbit sperm showed a high degree of attraction for vitelli; hamster and human sperm interácted at a lower level. Thus, in the species tested, an acrosome reaction is not a prerequisite for sperm attachment to the zona‐free oolemma.
The antigenicity of the rabbit sperm acrosomes and the reversible sterility induced in the immunized rabbits
Authors: Srivastava P. N. , Tandon H. O. , Kumar V. 
Published: February 2005

AbstractRabbits were immunized against their alloantigens extracted from the sperm acrosome. The sequential method of extraction, first by MgCl2 then by detergents, provided the plasma and outer acrosomal membranes and their contents in the first step and the inner acrosomal membrane and its components in the next step. Both groups of antigens appear to have produced monospecific antisera. The MgCl2 extract antiserum lost its sperm immobilization and agglutination activities on absorption to its antigen. The detergent extract, under similar treatment, remained unaffected. Therefore, the agglutination and immobilization factors resided on the plasma membrane. The decrease in sperm concentration suggested that the immunogen affected the germinal epithelium. The reduction in the semen volume and seminal enzymes seems to indicate that the accessory sex glands were also affected by the treatment.The antiserum blocked the dissolution of the hamster and rabbit zona pellucida by the MgCl2 extract. The normal serum had no such effect. Both the normal and immune sera inhibited acrosin equally well while the antisera inhibited other proteinases, arylsulfatase, and β‐N‐acetylhexosaminidase to a significantly greater extent. Immunized rabbits failed to impregnate females as long as the antibody titer remained high. As the titer declined these animals became fertile and the females delivered normal litters.
An ultrastructural study of the establishement of the testicular cysts during spermatogenesis in the sea anemone Actinia fragacea (Cnidaria: Anthozoa)
Authors: Larkman Alan U. 
Published: February 2005

AbstractSpermatogenesis in the sea anemone Actinia fragacea takes place in numerous testicular cysts located in the mesoglea of the gonads. Prospermatogonia arise among the bases of the gonadal epithelial cells bordering the mesoglea, and later migrate into the mesoglea to establish the cysts. The prospermatogonia arise singly, but soon most are found as small groups within the endoderm. They are small cells, 6–7 μm in diameter, and have relatively large nuclei with a single nucleolus. Their cytoplasm is dense, and contains dense bodies and nuage material as well as Golgi, mitochondria, and individual cisternae of endoplasmic reticulum. Each prospermatogonium bears a flagellum, originating in a groove or channel in the cytoplasm.A small proportion of prospermatogonia enter the mesoglea singly, but most migrate as elongate groups or “slugs” of cells. As they enter, the groups often become constricted into hour‐glass shapes, and they become covered by the endodermal basal lamina. During the later stages of entry, the last part of the group to enter retains contact with the bases of the epithelial cells, which are dragged into the mesoglea behind the germ cells. This contact between germ cells and endoderm persists throughout spermatogenesis and prevents closure of the mesoglea behind the group. The endodermal cells involved begin specialization to form the trophonema. Once entry is complete, the groups enlarge rapidly to form the testicular cysts. A small number of germ cells appear to remain behind in the endoderm after most have entered the mesoglea, and the possible significance of these cells is discussed.
Normal levels of zinc and sulfhydryls in morphologically abnormal populations of spermatozoa from moderately zinc‐deficient rats
Authors: Wallace Edith , Calvin Harold I. , Salgo Miklos P. , Dennis James E. , Ploetz Karin 
Published: February 2005

AbstractZinc is required for spermatogenesis in mammals and is concentrated in the dense outer fibers of the sperm tail, where it is associated with cysteine‐rich protein. To investigate the effects of marginal zinc deficiency upon dense fiber formation and upon sperm quality in general, weanling Sprague‐Dawley rats were administered a commercial low‐zinc diet, supplemented with phytate, for approximately 60 days, and were compared with controls fed the same diet plus 50 ppm zinc in their drinking water. The following characteristics of the zinc‐deficient rats were significantly lower than in the controls: body weight, testis weight, epididymis weight, seminal vesicle weight, sperm content of the cauda epididy‐midis, sperm motility, testis zinc, and hair zinc. By contrast, the levels of sperm zinc and sperm sulfhydryls were the same in the zinc‐deficient and control rats. The zinc‐deficient rats displayed a highly variable spectrum of sperm defects, which included decapitation, disorganized and redundant tail elements, and superfluous cytoplasm. However, abortive dense fiber development was only rarely observed. Apparently, even when availability of zinc is limited and reduced sperm production ensues, elaboration of dense fibers rich in zinc and sulfhydryls continues to be obligatory for the completion of spermiogenesis.
Structural components of sea urchin sperm nuclei
Authors: Kunkle Mel 
Published: February 2005

AbstractThe sea urchin sperm nucleus rapidly loses its conoid morphology and becomes more voluminous and spherical upon its entry into the egg cytoplasm during fertilization. This investigation has attempted to determine what are the structural constraints placed upon the sperm nucleus, so that further investigations might determine the egg cytoplasmic factors that are responsible for modifying nuclear morphology. Isolated sperm nuclei were subjected to various extraction procedures in order to remove the majority of the proteins (histones) and also the DNA; subsequently, the residual structures were processed for and examined by electron microscopy. The data presented in this investigation demonstrate the removal of the sperm nuclear histones plus other nonhistone proteins has no effect on the conoid morphology of the sperm nucleus, yet this protein removal has a profound effect on the structure of the nuclear chromatin. It is also shown that removal of the majority of the nuclear DNA has no effect on the shape of the sperm nucleus. These results indicate that there are other components (possibly a nuclear matrix) associated with the sperm nucleus that are responsible for maintaining its conoid morphology.
Sperm head structure in the hydromyinae (rodentia:Muridae): A further evolutionary development of the subacrosomal space in mammals
Authors: Breed W. G. 
Published: February 2005

AbstractThis scanning and transmission electron microscopical study has been performed to determine the extent of the development of the subacrosomal space in the sperm head of various members of the subfamily, the Hydromyinae, which is a diverse group of murid rodents occurring in various habitats in Australia. Sperm of all species from the three tribes of Hydromyini, Uromyini, and Conilurini investigated in this study had a head with three hooks although their absolute and relative lengths varied markedly. The top hook was similar in structure to that present in many other murid rodents and had a typical pseudoperforatorium present. The two ventral hooks had nuclear material basally, apical to which a large extension of the subacrosomal space occurred. Studies of testicular sections showed that the ventral hooks were formed late in spermiogenesis largely after condensation of the nucleus during which time electron dense material accumulated within them. No structure homologous to these hooks has been found in sperm from any other mammalian group, but, as the three tribes of Hydromyinae probably diverged about 20 million years ago, the extension of the subacrosomal space presumably evolved prior to this date.
A separate catalase and peroxidase in sea urchin sperm
Authors: Boldt Jeffrey , Alliegro Mark C. , Schuel Herbert 
Published: February 2005

AbstractThe release of hydrogen peroxide (H2O2) by the fertilized sea urchin egg has been shown to assist in the prevention of polyspermy [Coburn et al, 1981; Boldt et al, 1981]. Physiological data suggested that egg‐derived H2O2 reacts with a phenylhydrazine‐sensitive sperm peroxidase to inactivate sperm, while a 3‐amino‐1,2,4‐triazole‐sensitive catalase acts to protect sperm from H2O2 [Boldt et al, 1981]. Strongylocentrotus purpuratus sperm contain heat and pronase labile catalase and peroxidase activities. Differential extraction of sperm (hypotonic phosphate buffer for catalase and Triton X‐100 at high ionic strength for peroxidase) results in complete separation of these enzyme activities. The catalase is highly sensitive to inhibition by azide and 3‐amino‐1,2,4‐triazole, and less sensitive to inhibition by phenylhydrazine. The peroxidase is highly sensitive to inhibition by phenylhydrazine and relatively insensitive to 3‐amino‐1,2,4‐triazole and azide. These results show that two distinct H2O2 reactive enzymes, catalase and peroxidase, are present in sea urchin sperm, and are consistent with our hypothesis concerning the biological functions of these enzymes in fertilization.