bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in mitochondrial protein composition during testicular differentiation in mouse and bull
Authors: Hecht Norman B. , Bradley Francis M. 
Published: February 2005

AbstractThe morphology of testicular mitochondria changes markedly during spermatogenesis from a form normally seen in somatic cells to a “germ cell” form in which the matrix is diffuse and vacuolated and finally to a form with a condensed matrix seen in spermatozoa. Colloidal silica gel gradients and high‐resolution, two‐dimensional gel electrophoresis were used to define the changes in density and polypeptide composition that occur in testicular mitochondria during spermatogenesis. Similar densities were observed for mitochondria isolated from the same bovine or murine tissue, but mitochondria from different tissues usually had different densities. Mitochondria from testis of calf, bull, or sexually mature mouse had densities of 1.06 gm/cm3 while liver mitochondria were more dense, having a density of 1.09 gm/cm3. “Somatic‐type” testicular mitochondria from calf and “germ cell‐type” mitochondria from sexually mature mouse or bull had similar densities, 1.06 gm/cm3, while the density of mitochondria from ejaculated spermatozoa differed, ρ = 1.08 gm/cm3. Analysis of polypeptide composition of somatic and germ cell mitochondria from testes of prepuberal and sexually mature animals and from highly enriched populations of pachytene primary spermatocytes and round spermatids revealed a staining pattern of mitochondrial proteins that was markedly constant throughout development with most polypeptides being conserved and a few specific spots changing in abundance. Marked differences were detected, however, when mitochondria from ejaculated spermatozoa were compared with those from testis with many minor and major polypeptides missing and several new polypeptides present at high concentration.
On the mechanism of action of bonellin on the sea urchin egg
Authors: Cariello Lucio , Giudici Marina De Nicola , Tosti Elisabetta , Zanetti Laura 
Published: February 2005

AbstractIn this paper we report on the mechanism of action of bonellin on sea urchin eggs. Bonellin acts in the same way as porphyrins, ie, by causing the crosslinking of membrane proteins and the peroxocompounds formation. A possible role of membrane organization related to cleavage formation is discussed.
Use of zona‐free hamster ova to assess sperm fertilizing ability of bull and stallion
Authors: Brackett B. G. , Cofone M. A. , Boice M. L. , Bousquet D. 
Published: February 2005

AbstractZona‐free hamster ova interacted with bull and stallion spermatozoa after treatment of ejaculated semen to capacitate the sperm cells. Sperm conditioning by prolonged incubation in BWW medium (18–26 hr) prior to insemination was effective for capacitation of bull and stallion sperm. Preincubation of bull sperm for 70 or 105 min in defined medium (DM) with NaCl content elevated to result in 350 m0sM/kg also led to penetration of hamster vitelli. More rapid sperm conditioning was possible and higher proportions of interacting vitelli followed insemination with bull or stallion sperm exposed to high ionic strength DM (380–390 m0sM/kg) for 10 min before incubation in isotonic DM prior to insemination, the treatment adopted in subsequent work.Initial efforts to assess relative fertilizing ability of freshly ejaculated semen from two fertile bulls (A and B) in A1 usage resulted in uniformly high ( > 90%) levels of sperm‐vitelli interaction (for both) when the hamster ova employed resulted from superovulation with PMSG and HCG. Following use of ova from untreated hamsters sperm samples of bull A and bull B interacted with 53.8% and 84.9% (P < 0.05) of zona‐free hamster ova, respectively. Conception data (60–90 day nonreturn rates) resulting from A1 with semen collected during the same interval but processed and stored in liquid nitrogen prior to use revealed an inverse relationship to proportions of vitelli interacting with fresh sperm; nonreturn rates were 69.3% and 66.3% for bull A and bull B, respectively. A similar treatment effected capacitation of frozen‐stored bull semen to enable sperm‐vitelli interaction. These findings encourage additional efforts to correlate testing of processed semen with fertility.
The relationship between parthenogenetic embryonic development and cumulus cell‐oocyte intercellular coupling during oocyte meiotic maturation
Authors: Eppig John J. 
Published: February 2005

AbstractIntercellular coupling between cumulus cells and oocytes persists after oocyte meiotic maturation has been initiated. The experiments described here focus on the relationship between oocyte‐cumulus cell intercellular coupling during maturation and the subsequent embryonic development of spontaneous mouse parthenotes. Several lines of evidence suggest that this coupling during oocyte maturation is required for the acquisition of the capacity for spontaneous mouse parthenotes to develop embryologically. First, the period of time that LT/Sv oocytes remained coupled to cumulus cells during oocyte maturation in vivo corresponded to that required for the acquisition of the capacity for parthenogenetic embryonic development. Second, the longer that cumulus cells were present during Fpontaneous oocyte maturation in vitro, the higher was the percentageofova undergoing subsequent parthenogenetic development. Third, cumulus cell‐free oocytes cocultured with cumulus cell‐enclosed oocytes during the maturation period in vitro did not develop embryologically. Fourth, intercellular coupling between cumulus cells and oocytes persisted throughout the oocyte maturation period in vitro. Fifth, incubation of oocyte‐cumulus cell complexes in medium containing follicle‐stimulating hormone (FSH) promoted uncoupling and decreased the percentage of ova undergoing parthenogenetic development. Thus, cell‐to‐cell communication, mediated via the intercellular coupling pathway between cumulus cells and oocytes, plays an important role during oocyte maturation and relates to subsequent preimplantation development.
Requirement of extracellular calcium ions for various stages of fertilization and fertilization‐related phenomena in the hamster
Authors: Yanagimachi R. 
Published: February 2005

AbstractUsing a semi‐chemically defined medium, the requirement of extracellular Ca2+ for survival, capacitation, and acrosome reaction of spermatozoa as well as various stages of fertilization in the hamster was studied. A Ca2+‐deficient environment is unfavorable for long‐term survival of spermatozoa. Sperm capacitation may occur in Ca2+‐deficient media, but not as efficiently as in normal media. The acrosome reaction definitely requires extracellular Ca2+. Other processes or phenomena that require extracellular Ca2+ are initiation and maintenance of hyperactivated motility of spermatozoa, penetration of acrosome‐reacted spermatozoa into the zona pellucida, fusion of the spermatozoa with eggs, and the development of pronuclear eggs into two‐cell embryos. Extracellular Ca2+ is apparently unnecessary for the attachment of spermatozoa to the zona and egg surfaces, decondensation of the sperm nucleus, and the development of sperm and egg pronuclei within the egg. These results were compared with data obtained in other species such as the sea urchin, mouse, rat and guinea pig.
Evidence suggesting that L‐fucose is part of a recognition signal for sperm‐zona pellucida attachment in mammals
Authors: Huang Thomas T. F. , Ohzu Eiji , Yanagimachi R. 
Published: February 2005

AbstractExperiments were designed to test the effects of simple sugars and complex polysaccharides on the attachment of mammalian spermatozoa with the zona pellucida. In the guinea pig, L‐fucose was a twofold better inhibitor of the attachment compared to other sugars at 50 mM. Fucoidin, an algal polysaccharide rich in sulfated L‐fucose, was a very potent inhibitor, completely blocking attachment at a concentration of 100 μg/ml. Several other highly sulfated glycosaminoglycans showed no inhibitory activity, suggesting the fucoidin effect was not simply due to its charge or sulfate. In addition, fragments of fucoidin, generated by partial hydrolysis and isolated using Biogel P‐2, were nearly as inhibitory as the native molecule on a weight basis. Fucoidin also inhibited sperm‐zona attachment in the hamster and human; thus, its effect is not species specific. The data suggest that L‐fucose may be part of a recognition signal between mammalian gametes.
Sperm tail entry into the mouse egg in vitro
Authors: Gaddum‐Rosse P. , Blandau R. J. , Langley L. B. , Sato K. 
Published: February 2005

AbstractCumulus‐free mouse eggs were placed on microscope slides and inseminated with capacitated mouse spermatozoa. Fertilization could then be observed through the phase contrast microscope and recorded by time‐lapse cinematography. Following the penetration of the fertilizing spermatozoon through the zona pellucida and the fusion of the sperm head with the vitelline membrane, the entire sperm tail gradually entered the vitellus. The time required for tail incorporation into the vitellus as measured in 49 eggs varied from 3 h 3 min to 5 h 49 min, with a mean time of 4 h 23 min. When tail incorporation began, the greater part of the flagellum was still outside the zona pellucida; occasionally it slipped into the perivitelline space, but generally it remained outside the zona and shortened by degrees as incorporation proceeded. The motility of the fertilizing spermatozoon declined abruptly very soon after fusion of the sperm head with the vitellus and remained at a very low level during the 3–6 h required for tail incorporation. Sperm motility, therefore, does not appear to be the main determinant in tail incorporation and the primary mechanism responsible for it remains unclear. As the sperm tail slowly entered the vitellus, the second meiotic division was completed with concomitant extrusion of the second polar body. Key stages in second polar body formation were correlated with events in tail incorporation. Differences between fertilization in vitro and in vivo are discussed.
Biochemical and ultrastructural characterizations of nucleoprotamine in human sperm heads treated with micrococcal nuclease and salt
Authors: Tanphaichitr Nongnuj , Sobhon Prasert , Chalermisarachai Panpaka , Chutatape Chutima 
Published: February 2005

AbstractPreparation of human sperm heads containing mainly nucleoprotamines as their chromatin constituent was described. Acrosome‐depleted human sperm heads were treated with micrococcal nuclease followed with 2 M NaCl. The treatment specifically removed nucleohistone as small chromatin fragments from the human sperm heads. The nuclease‐NaCl‐treated sperm head pellets primarily contained nuclease‐resistant nucleoprotamine as their chromatin. Transmission electron microscopic study showed that there were two populations of the nuclease‐NaCl‐treated human sperm head pellets. One population had thick nucleoprotamine cords of ˜650–1,200 Å in diameter, and the other had thin nucleoprotamine cords of ˜330–420 Å.
A morphologic, cytochemical, and chromatographic analysis of lipid yolk formation in the oocytes of the dog
Authors: Tesoriero John V. 
Published: February 2005

AbstractThe oocytes of carnivorous mammals are distinguished by the presence of large amounts of a lipid, yolk like material. In the oocytes of the dog, lipid yolk formation marks one of the earliest indications of occyte maturation. In early primary oocytes, the yolk bodies are scattered within the ooplasm, while in later stages they are in discrete clusters. Lipid yolk material appears to be formed by at least two mechanisms. Throughout most of oogenesis the oocyte contains scattered dense granular bodies that become vacuolated by droplets of lipid material and may be transformed, by this process, into lipid yolk bodies. These granular bodies are highly reactive for acid phosphatase and are positive for glycoprotein with the PA‐CA‐methenamine technique. In addition, other glycoprotiein‐rich yolk bodies appear to arise from many of the small dictyosomes. In secondary follicles these two mechanisms often appear to act conjointly with the dense vacuolated granules coalesing with the larger yolk bodies. Small yolk bodies are intensely reactive for glycoprotein, becoming less reactive as they enlarge and mature. The developing yolk bodies are often associated with the acid phosphatase‐positive granules. The peripheral portions of the larger yolk bodies are faintly reactive for both acid phosphatase and glycoprotein. All reactivity is lost in mature yolk bodies. Thin layer chromatography of the total lipids extracted from isolated oocytes reveals a pattern that is consistent among dogs of the same and of different breeds. The most abundant lipid fraction from each dog oocyte extraction stains strongly for glycolipid.
Fine structure of the mature spermatozoon of rhynchocinetes typus, crustacea decapoda
Authors: Dupré E. , Barros C. 
Published: February 2005

AbstractRhynchocinetes typus spermatozoa obtained from the vas deferens have the shape of a round‐headed nail. The head measures 30 μm in diameter and 14 μm of height. At the center of the flat face of the head emerges a single rigid spike of 53 μm in length. Cross sections of this spike show that it has a wall of 0.4 μm in thickness and a core of 0.6 to 0.8 μm. The outer surface of the spike has a longitudinal striation. When the spermatozoa are placed in sea water it is possible to observe the unfolding of rays. The number of rays in different spermatozoa of the same individual varies from 9 to 13. Each ray is formed by a channel‐like sheath that contains a rigid rod that occupies about 1/3 the length of the ray. This rod has a transverse striation with a periodicity of 185A. The rays are bound among them by a thin membranous sheet that is highly folded in vas deferens spermatozoa. At the distal end of each ray there is a rigid spine of 50 μm in length. The nucleus is coplanar to the radial plane and it extends through the rays. The structure and ultrastructure of R typus spermatozoa depart from that reported for spermatozoa of other Caridea species.
Studies on the polymorphic spermatozoa of a marine snail. 2. Genesis of the eupyrene sperm
Authors: Buckland‐Nicks John , Williams Daphne , Chia Fu‐Shiang , Fontaine Arthur 
Published: February 2005

AbstractSpermiogenesis of the eupyrene sperm in the snail, Fusitriton oregonensis, was studied with light and electron microscopes. Endoplasmic reticulum, which encircles the nucleus in each spermatid, appears to connect with the Golgi body and to interconnect between adjacent spermatids via cytoplasmic bridges. It is suggested that as the Golgi body migrates around the nucleus the endoplasmic reticulum may circulate with it. The alignment of the proacrosome with the nucleus is effected by a 180° rotation of the Golgi body, after which it separates and migrates posteriorly with the residual cytoplasm. Each sperm possesses a well‐developed intracellular digestive system as indicated by multivesicular bodies, residual bodies, and myeloid figures. Autophagy begins in the residual cytoplasm before it is released from the middle piece. Microtubules are found outside the nucleus and mitochondria during the final stages of spermiogenesis, when elongation is almost complete. These microtubules appear to be involved in the final shaping and twisting process, in which torsion is locked in the nucleus and the mitochondria spiral around the axoneme. The annulus attaches the distal centriole to the plasma membrane in the early spermatid and as flagellar production begins they move towards the implantation fossa at the base of the nucleus. There are two centrioles in the early spermatid, the distal centriole and procentriole. The small procentriole fuses with the distal centriole in the intranuclear canal to form the centriolar cap of the basal body. This cap is pushed through the end of the nuclear tube and is separated from the subacrosomal space by only the nuclear membranes.
Development of membrane excitability in mammalian oocytes and early embryos
Authors: Eusebi Fabrizio , Colonna Rosella , Mangla Franco 
Published: February 2005

AbstractDevelopmental aspects of the capability to generate an action potential have been studied in mouse oocytes and early embryos, taking the peak level and the rate of rise of the action potential as parameters of cell excitability. We report here that experimentally induced membrane excitability in mouse oocytes appears throughout oogenetic growth, further develops throughout meiotic maturation, does not undergo main changes at fertilization, and slightly decreases throughout early cleavage, at least up to the four‐cell stage of embryonic development. Calcium is involved in the rising phase of action potential throughout oogenesis, maturation, and early embryonic development.
Reproduction in mice: Spermatozoa as factors in the development and implantation of embryos
Authors: Chaykin Sterling , Watson J. Gary 
Published: February 2005

AbstractThe effects on mouse embryo development in vivo of varying the numbers of spermatozoa used in artificial inseminations was studied. The two criteria used in the evaluation of the progress of embryo development were 1) ability to reach the two‐cell stage and 2) success of development from the two‐cell stage through implantation. A 44% reduction in the yield of two‐cell embryos and a 67% reduction in the number of implants was observed when C3HeB/FeJ females were inseminated with one‐twentieth the number of spermatozoa estimated to be present in a typical ejaculate. The reduction in the yield of two‐cell embryos was substantially reversed by a second insemination of a large number of heat‐inactivated spermatozoa 12 hr after the first insemination. The sperm‐dependent reduction in development from the two‐cell stage through implantation was prevented only by normal viable (unheated) spermatozoa. These results were rationalized by the hypothesis that in female C3HeB/FeJ mice spermatozoa serve physiological functions beyond the fertilization of ova and that spermatozoa may act to foster early embryo development through modulation of the environments embryos experience as they move through the reproductive tract.
Comparison of strains and culture media used for mouse in vitro fertilization
Authors: Ackerman Steven B. , Swanson R. James , Adams Peter J. , Wortham J. W. Edward 
Published: February 2005

AbstractSuccess rates of superovulation in response to gonadotropic hormone treatment and in vitro fertilization (ie, mitotic cleavage following insemination) of mouse eggs from outbred CD‐1, hybrid CB6Fl, or hybrid B6CBAF1, mice were compared using either a mouse inseminationmedium, modified Krebs‐Ringer‐bicarbonate (m‐KRB), or a human insemination medium, Ham's F10 nutrient mixture. Inseminations were performed in either organ culture dishes or screw‐top, flat‐side tissue culture tubes. Mean superovulation rates (± SD) were 24.2 (5.1) for CD‐1, 33.0 (5.8) for CB6F1, and 16.3 (6.6) for B6CBAF1 mice. For in vitro cleavage the best combination of mouse strain, insemination medium, and culture container was achieved using CB6F1, mice, m‐KRB medium, and culture tubes. However, Ham's medium used with either hybrid mouse strain was shown to be employable for fertilization of mouse eggs in vitro as a quality control assay and/or experimental model system for testing the human in vitro fertilization procedure.
Dithiothreitol, a disulfide‐reducing agent, inhibits capacitation, acrosome reaction, and interaction with eggs by guinea pig spermatozoa
Authors: Yanagimachi R. , Huang T. T. F. , Fleming A. D. , Kosower N. S. , Nicolson G. L. 
Published: February 2005

AbstractCapacitation of guinea pig spermatozoa in vitro was inhibited by the disulfide‐reducing agent dithiothreitol (DTT). Even a brief treatment with DTT inhibited capacitation unless an oxidizing agent (glutathione disulfide) was present in the posttreatment medium. Precapacitated spermatozoa were unable to undergo the acrosome reaction in the presence of DTT, indicating that this reagent also blocks the acrosome reaction. Acrosome‐reacted spermatozoa were incapable of attaching to and penetrating the zona pellucida in the presence of DTT. Even when acrosome‐reacted spermatozoa were directly brought to the surface of zona‐free eggs, they were unable to bind to and fuse with the egg plasma membrane so long as DTT was present in the medium. These observations suggest that the tertiary and quaternary structures of sperm surface proteins regulated by their thioldisulfide status are of critical importance in the physiology and function of spermatozoa preliminary to and in the process of fertilization.
Isolation of the inner acrosomal‐nuclear membrane complex from rabbit spermatozoa
Authors: Rahi Hamid , Sheikhnejade Gholamreza , Srivastava Prakash N. 
Published: February 2005

AbstractRabbit spermatozoa were passed through a Bio‐Glas 2500 (BG) column to yield pure cytoplasmic droplets and consequently the droplet‐free spermatozoa. Rapid decondensation of sperm nuclei was achieved by 1 mM dithiothreitol (DTT) and 1.5 M NaCl. This treatment caused removal of the plasma and the outer acrosomal membranes. The viscosity of decondensed nuclei was reduced by pancreatic DNase. Further elution of the suspension from BG column yielded a membrane complex. On the basis of electron microscopic observations and the enzyme analysis, these membranes appeared to be the inner acrosomal‐nuclear membrane complex (IANC). The IANC was also prepared from isolated sperm head by DTT‐NaCl and Dnasetreatment and low‐speed centrifugation.
Change in phosvitin kinase activity during early development of the sea urchin
Authors: Fujino Yukio , Yasumasu Ikuo 
Published: February 2005

AbstractProtein kinase, which phosphorylated phosvitin at the expense of ATP but did not phosphorylate casein, protamine, and histone mixture, was obtained by DEAE‐cellulose column chromatography of the extract from the embryos of the sea urchin, Strongylocentrotus intermedius. This enzyme, partially purified by DEAE‐cellulose column, reversibly catalyzed the reaction of phosvitin phosphorylation. This indicates that the sea urchin embryos contain phosvitin kinase. Phosvitin kinase in sea urchin embryos is somewhat different from that found in the other types of cells, which are able to phosphorylate casein as well as phosvitin. In unfertilized eggs, the activity of this enzyme was found only in the supernatant fraction obtained by centrifuging the homogenate at 10,000g for 20 min. The activity in the embryos at the swimming and the mesenchyme blastula stage was higher than in unfertilized eggs, and was localized in the sedimentable fraction obtained by centrifuging the homogenate of the embryos at 10,000g for 20 min. The highest activity of phosvitin kinase was observed in the embryos at the mesenchyme blastula stage, and the enzyme activity became quite low at the late gastrula stage. The activity and the intracellular distribution of phosvitin kinase changed during the development. The enzyme in this sedimentable fraction was not solubilized with 1% Triton X‐100 but was extracted by 1 M NaCl.
A modified column for sperm isoelectric focusing
Authors: Rahi Hamid , Srivastava Prakash N. 
Published: February 2005

AbstractA modified U‐shaped column is described for efficient isoelectric focusing of spermatozoa, other cells, and protein. The washed spermatozoa of the rabbit showed a PI of 4.4. After sonication, heads and tails focused at same pH, indicating similar and equal charge.