bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mammalian oocytes exhibit specific recognition of the RGD (ARG‐Gly‐Asp) tripeptide and express oolemmal integrins
Authors: Fusi F. M. , Vignali M. , Gailit J. , Bronson R. A. 
Published: February 2005

AbstractIntegrins are a family of cell adhesion receptors involved in many cell–cell and cell–matrix interactions. Some of these heterodimeric receptors, such as α5b̃1 and αvb̃1, specifically recognize the amino acid sequence Arg‐Gly‐Asp (RGD) within their ligands. The RGD sequence is found in fibronectin, vitronectin, and other extracellular matrix proteins. Our results demonstrate that the oolemmas of eggs from human and several other mammalian species contain receptors capable of binding to RGD ligands, and that integrin subunits are expressed by oocytes. Four distinct techniques were utilized to identify the presence of functional integrins on mammalian eggs. RGD‐binding receptors were detected on the surfaces of zona‐free eggs from all species tested. Covaspheres coated with PepTite‐2000, which contains RGD, bound to the eggs and formed rosettes. Rosetting was competitively inhibited by PepTite‐2000 and by GRGDTP, a soluble RGD peptide, but not by RGES. An ELISA using polyclonal antibodies directed against the cytoplasmic tails of the integrin subunits identified the integrin subunits α5, b̃1, and αv, but not b̃3, in detergent extracts of Syrian hamster eggs. A dot blot confirmed the presence of αv in hamster egg lysates. Finally, the integrin subunits α2, α5, α6, but not α4, were detected on the surfaces of zona‐free eggs from human and Syrian hamster. Immunobeads coated with monoclonal antibodies specific for α2, α5, and α6 bound to the eggs and formed rosettes. A similar rosetting was obtained from beads coated with polyclonal antibody against the vitronectin receptor (αvb̃3/b̃5). These observations suggest that the integrins α2b̃1, α5b̃1, α6b̃1, and one or more integrins containing αv are expressed by oocytes. We propose that these integrins may play important roles in fertilization and implantation. © 1993 Wiley‐Liss, Inc.
Modulation of embryonic NA+‐K+‐ATPase activity and mouse preimplantation development in vitro in media containing high concentrations of potassium
Authors: Dumoulin John C. M. , Evers Johannes L. H. , Michiels Anton H. J. C. , Pieters Math H. E. C. , Bras Marijke , Land Jolande A. , Geraedts Joep P. M. 
Published: February 2005

AbstractThe effect of various potassium concentrations (ranging from 1.4 mM to 30 mM K+) in modified Tyrode's medium on the culture of mouse zygotes obtained after in vitro fertilization to the blastocyst stage was examined. A clear dose‐dependent negative effect of increasing K+ concentrations on the preimplantation embryonic development in vitro was found. We have previously shown that significantly more two‐cell embryos reach the blastocyst stage when cultured during the second day postinsemination in medium supplemented with taurine. Because taurine, an amino acid that abounds in the reproductive tract, has been reported to inhibit the enzyme Na+‐K+‐adenosine triphosphatase (Na+‐K+‐AT‐Pase), we used two other conditions known to inhibit the Na+‐K+‐ATPase to study their effect on mouse embryo development. Culturing embryos during a short period (the second day postinsemination) in low extracellular K+ concentrations (1.4 mM) or in medium supplemented with ouabain (50 μM) showed positive effects similar to those of culturing in medium with taurine (10 mM). This beneficial effect of ouabain was found in various K+ concentrations tested, including the high concentrations present in the oviduct. Although the effects of low K+ and taurine can possibly be ascribed to their other cellular effects, the effect of ouabain shows that inhibition of the Na+‐K+‐ATPase during the two‐cell stage in the mouse is beneficial for further embryonic development to the blastocyst stage. © 1993 Wiley‐Liss, Inc.
Sperm penetration through the zona pellucida of salt‐stored hamster eggs is delayed
Authors: Stewart‐Savage J. 
Published: February 2005

AbstractOne of the problems in assaying sperm capacitation is that live eggs mount a block to polyspermy at the zona pellucida. To circumvent this problem, researchers have started to use salt‐stored eggs to assay sperm capacitation (Boatman et al., Gamete Res 19:19–29, 1988; Yoshimatsu et al., Gamete Res 21:115–126, 1988). These researchers have demonstrated that the zonae of salt‐stored eggs were penetrable by capacitated sperm, but they did not examine whether the timing of penetration of fully capacitated sperm was altered. This report shows that zona penetration by fully capacitated sperm is delayed in both short‐term salt‐treated eggs (2 hr) and in eggs stored in salt for >2 days. These results indicate that the zona is modified when eggs are treated with a high‐salt solution. © 1993 Wiley‐Liss, Inc.
Binding of a murine proteinase inhibitor to the acrosome region of the human sperm head
Authors: Boettger‐Tong Holly L. , Aarons David J. , Biegler Beth E. , George Bobby , Poirier Gary R. 
Published: February 2005

AbstractProteinase inhibitors are present in the various glands, tissues, and secretions of the male reproductive tract. Some of these inhibitors bind to the acrosomal region of the sperm, and their release during in vitro or in utero incubation suggests that they may play a role in capacitation. In the mouse, the binding site for a trypsin‐acrosin inhibitor, the acceptor, has been implicated in capacitation, zona binding, and the acrosome reaction. This presentation demonstrates that a component, molecular weight ˜T20,000, on the human sperm head may recognize the murine inhibitor. Furthermore, the acrosome reaction can be induced in capacitated human sperm by immunoaggregation of bound murine inhibitor. The data indicate that the proteinase inhibitor binding site on the human sperm head may, as with a similar site on murine sperm, play a role in the early events of fertilization. © 1993 Wiley‐Liss, Inc.
Effects of electrical stimulation before or after in vitro fertilization on sperm penetration and pronuclear formation of pig oocytes
Authors: Funahashi Hiroaki , Stumpf Todd T. , Terlouw Steve L. , Day Billy N. 
Published: February 2005

AbstractThe effects of exposure of pig oocytes to an electrical pulse on sperm penetration and pronuclear formation were determined before or after in vitro fertilization (IVF). After in vitro maturation (IVM) or after collection from oviducts of unmated gilts, pig oocytes either were not exposed or were exposed to an electrical pulse (a 10 sec pulse at 4.0 V mm−1 AC followed by a 30 μsec pulse at 120 V mm−1 DC), followed 30 min later by IVF. The incidence of male pronuclear formation of both IVM and in vivo‐matured oocytes at 12 hr after insemination was decreased from 59% and 100%, respectively, to 2% and 36%, respectively, by the electrical pulse, but the penetration rates (88–100%) and polyspermic rates (79–100%) were not affected by exposure to an electrical pulse. Similarly, when pig IVM oocytes were exposed to an electrical pulse at 6 hr after insemination, electrical activation did not decrease penetration rates (93% vs. 90%), polyspermic rates (83% vs. 91%), or number of spermatozoa in penetrated oocytes (4.0 ± 0.5 vs. 4.6 ± 0.5) but did decrease the rate of male pronuclear formation from 58% to 18%. When oocytes were examined at 6 hr after insemination, 75% of them had been penetrated and resumed meiotic progression, but all sperm heads in penetrated oocytes were fully condensed or only partially decondensed. The percentage of penetrated eggs with multiple female pronuclei was increased when oocytes were exposed to an electrical pulse in all experimental series. In summary, electrical activation of pig oocytes before or just after IVF does not prevent sperm penetration but does inhibit male pronuclear formation and increases the formation of multiple female pronuclei. © 1993 Wiley‐Liss, Inc.
Does the zona pellucida select spermatozoa from the medium with higher fertilizing potential?
Authors: Tarín J. J. , Trounson A. O. 
Published: February 2005

AbstractThe present study was carried out to test whether the zona pellucida selects spermatozoa with higher fertilization potential. Fertilization rates of mouse oocytes after sperm microinjection under the zona pellucida (SMUZ) of zona‐bound spermatozoa and of spermatozoa incubated in the absence of oocytes and treated (acid‐treated group) or not (control group) with acid Tyrode's solution were compared. SMUZ was performed at 15, 30, 60, and 90 min after the insemination of fresh oocytes required for selecting spermatozoa bound to the zona pellucida. At these times, the percentages of acrosome‐reacted spermatozoa (PARS) were evaluated using the chlortetracycline fluorescence method. Fertilization rate in the three groups analysed increased from 25.9% to 47.3% in the control group, from 29.3% to 44.0% in the acid‐treated group, and from 19.5% to 40.0% in the zona‐bound group from 15 to 90 min after insemination, respectively. The global fertilization potential was significantly lower in the zona‐bound group compared to the other two groups. The PARS in the zona‐bound group at 15 (11.48 ± 3.02); 30 (16.74 ± 3.71), and 90 (19.68 ± 3.68) min after insemination were significantly (P < 0.05) lower than those found in the acid‐treated group (39.26 ± 6.69, 38.20 ± 6.24, and 42.83 ± 5.39, respectively). At 90 min after insemination, the PARS in the zona‐bound group was also significantly (P 0.05) lower than the control group (36.72 ± 4.51). No significant correlation between either time and PARS or PARS and fertilization rate was observed. It appears that the zona pellucida does not select from the medium spermatozoa with higher fertilization potential. © 1993 Wiley‐Liss, Inc.
Confocal and fluorescence microscopic study using lectins of the distribution of cortical granules during the maturation and fertilization of pig oocytes
Authors: Yoshida Mitsutoshi , Cran David G. , Pursel Vernon G. 
Published: February 2005

AbstractA study was carried out to determine whether pig cortical granules (CGs) could be visualized using fluorescein isothiocyanate (FITC)‐labelled lec‐tins. Following labelling with FITC‐labelled peanut agglutinin (FITC‐PNA), fluorescent spots were observed that had a distribution during maturation and fertilization entirely consistent with that observed by electron microscopy. For the first 18 h of in vitro maturation, most of the fluorescent spots of FITC‐PNA were distributed throughout the cortical cytoplasm. Thereafter, the CGs underwent centrifugal migration to form a monolayer next to the plasma membrane. Following penetration by sperm, fluorescent spots were extruded into the perivitelline space, where they aggregated forming fluorescent clumps, which subsequently formed a reticulate structure surrounding the egg. Fluorescence was gradually lost such that by 18 h after insemination none could be detected in 70% of the eggs. The results indicate that CGs in pig oocytes contain galactosyl‐rich glycoconjugates and that FITC‐PNA is a useful probe for their rapid visualization and examination. © 1993 Wiley‐Liss, Inc.
Effect of follicle‐stimulating hormone and luteinizing hormone during bovine in vitro maturation on development following in vitro fertilization and nuclear transfer
Authors: Keefer C. L. , Stice S. L. , Dobrinsky J. 
Published: February 2005

AbstractThe effects of luteinizing hormone (LH) (0, 100, 10,000 lU/ml) and follicle‐stimulating hormone (FSH) (20 μg/ml) supplementation during in vitro maturation of slaughterhouse‐derived oocytes on polar body formation and embryo development subsequent to in vitro fertilization and nuclear transfer were evaluated. Go‐nadotropin supplementation of maturation medium in the presence of serum neither enhanced the proportion of oocytes forming a polar body nor significantly affected development following in vitro fertilization or nuclear transfer, except at the highest LH concentration. A very high concentration of LH (10,000 lU/ml) significantly decreased polar body formation, initial cleavage, and blastocyst development (P < 0.05). © 1993 Wiley‐Liss, Inc.
Origin of a sperm motility inhibitor from boar seminal plasma
Authors: Iwamoto Teruaki , Tanaka Hiroki , Osada Takao , Shinagawa Toshihito , Osamura Yoshiyuki , Gagnon Claude 
Published: February 2005

AbstractWe have investigated the origin of the sperm motility inhibitor (SPMI) from boar seminal plasma. SPMI was measured by its capacity to inhibit the motility of demembranated spermatozoa and by an enzyme‐linked immunosorbant assay (ELISA). Among the various reproductive and now reproductive tissues and fluids tested, only the seminal vesicle fluid and seminal plasma contained significant amounts of SPMI biological activity and SPMI antigen. Like other seminal vesicle fluid proteins, SPMI is diluted 6‐ to 8‐fold upon ejaculation. By immunohistochemical detection at the light microscope with antibodies obtained from rabbits immunized with SPMI purified from boar seminal plasma, SPMI was found in the cytosol and/or on the plasma membrane bordering the lumen of the seminal vesicles. At the electron microscope level, SPMI appeared to be present only on the surface of the secretory cells. The data indicate that SPMI originates from a single tissue, the seminal vesicle, and suggest that only the mature form present on the luminal surface of the gland can react with the antibody generated from rabbits immunized with the secreted form of SPMI. © 1993 Wiley‐Liss, Inc.
Cryogenic protection of oocytes with antifreeze proteins
Authors: Arav A. , Rubinsky B. , Fletcher G. , Seren E. 
Published: February 2005

AbstractProteins belonging to a family of compounds known as “antifreeze proteins” interact with occytes and protect the oolemma from damage at cryogenic temperatures. Experiments were performed with pig oocytes rapidly cooled to cryogenic temperatures in vitrifying solutions with and without antifreeze proteins. Four different types of antifreeze polypeptides and glycoproteins were tested. The integrity of the oolemma was examined with Fluoroscein Diacetate (FDA) staining and morphological examinations. Results show that the pig oocyte oolemma is a primary site of injury during exposure to low temperatures and that all the different proteins have a similar ability to interact with and protect the oolemma. Our results may be important in developing solutions for long‐term preservation of oocytes at cryogenic temperatures (cryopreservation). © 1993 Wiley‐Liss, Inc.
Protein phosphorylation patterns during in vitro maturation of the goat oocyte
Authors: Gall L. , Le Gal F , De Smedt V. 
Published: February 2005

AbstractProtein phosphorylation patterns were studied by radiolabelling goat cumulus oocyte complexes with [32P]orthophosphate for various periods of time. The radiolabelled denuded oocytes were assessed for nuclear status and were used individually for gel electrophoresis. This study demonstrated that specific changes in protein phosphorylations were programmed during goat oocyte maturation. One of the most prominent changes was a general increase in the phosphorylation rate at germinal vesicle breakdown (GVBD). From 8 hr of culture, dominant phosphoprotein bands with apparent molecular weights of 27, 31, 40, and 50 kD were observed; they remained at this level until the metaphase II stage. In the molecular weight range of 65–80 kD, the protein phosphorylation pattern exhibited characteristic differences, with a complex series of phosphoproteins appearing and disappearing, during maturation. Addition of 6‐dimethylaminopurine (6‐DMAP) at the onset of culture blocked the maturation process after GVBD and induced a dramatic condensation of chromatin. When added at different times after GVBD, 6‐DMAP invariably induced chromosome condensation. This inhibition was partly reversible; i.e., after removal of the drug, oocytes were able to progress only until metaphase l. © 1993 Wiley‐Liss, Inc.
In vitro‐cultured bovine granulosa and oviductal cells secrete sperm motility‐maintaining factor(s)
Authors: Ijaz Ahmad , Lambert Raymond D. , Sirard Marc‐Andre 
Published: February 2005

AbstractSince bovine cumulus oophorous and oviductual cell cultures are known to support and maintain frozen‐thawed bovine sperm viability and motility for extended time periods, we investigated whether granulosa cell (GC)‐ and oviductual cell (OC)‐conditioned media have similar effects. GC and OC were cultured for 3 days in TCM‐199 medium supplemented with 10% fetal calf serum. At that time, the supernatant was discarded from GC and the monolayers were covered with Sp‐TALP medium containing 6 mg/ml bovine serum albumin, while the OC were recovered by centrifugation and transferred to culture bottles containing Sp‐TALP. Two days later, GC‐conditioned and OC‐conditioned Sp‐TALP were recovered and dialyzed, and their retentates were lyophilized. Bovine follicular fluid (BFF) was also dialyzed, and its retentate was lyophilized. When sperm were incubated in GC‐ or OC‐conditioned media, motility remained above 62% and 42% at 6 hr and 30 hr, respectively, and motility was higher than that of the control both at 6 hr (39%; P < 0.001) and at 30 hr (9%; P < 0.0001). Similarly, when sperm were incubated in the lyophilized retentates of GC‐ and OC‐conditioned media and in BFF at a dose of 0.1, 0.5, or 1.0 mg/ml, the motility rates were higher both at 6 hr (P < 0.05) and at 30 hr (P < 0.01) compared to the control. The increase in motility was dose dependent; a 1.0 mg/ml dose improved (P < 0.05) motility compared to a 0.1 mg mg/ml dose. Heat treatment of the retentates of GC, OC, and BFF at 55°C for 30 min did not destroy their ability to support and maintain motility. However, heating at 100°C for 5 min destroyed their ability to support motility. Molecular sieving of retentates on Sephancryl S‐300 yielded fractions that were highly effective (P < 0.01) in enhancing and maintaining motility compared to the other fractions. In conclusion, GC and OC secrete nondialyzable, heat‐labile factor(s), which support and maintain sperm viability and motility for up to 30 hr. © 1994 Wiley‐Liss, Inc.
Relationship between sperm nucleus remodelling and cell cycle progression of fragments of mouse parthenogenotes
Authors: Szöllösi Maria S. , Borsuk Ewa , Szöllösi Daniel 
Published: February 2005

AbstractNucleate and anucleate fragments of parthenogenetically activated mouse oocytes, as well as cybrids obtained by fusion of anucleate fragments (cytoplasts) of maturing and activated matured oocytes were fertilized at different time after activation. Remodelling of the sperm nucleus was studied by electron microscopy at 1.5 and 3 h after fertilization and, in addition, at 14 h in cybrids. Results show that (1) the nuclear envelope of the sperm nucleus can break down when the insemination takes place after the end of M‐phase, but the capacity of the parthenote cytoplasm to remodel the sperm nucleus is restricted in time. (2) Male chromatin can decondense within the old, unbroken nuclear envelope, but in such cases formation of a male pronucleus, one of the two nuclei of zygote possessing inactive nucleoli, is never observed. © 1994 Wiley‐Liss, Inc.
Introduction of exogenous DNA into somatic and germ cells of chickens by microinjection into the germinal disc of fertilized ova
Authors: Naito Mitsuru , Sasaki Erika , Ohtaki Megumi , Sakurai Michiharu 
Published: February 2005

AbstractThe plasmid DNA, pAcZ, containing Escherichia coli β‐galactosidase (lacZ) gene under the control of chicken β‐actin gene promoter was injected in a linearized form into the germinal disc of fertilized chick ova at the single‐cell stage. The manipulated embryos were cultured by the method of Naito et al. (1990) until hatching. The rate of hatching was 11.8% (31/263), and 19 males and 6 females were matured. DNA from blood and semen samples of the 25 matured chickens was analyzed for the presence of the injected DNA by Southern blot hybridization. The injected DNA was detected in the blood DNA of one male and in the sperm DNA of another male up to 13 months after hatching, indicating that the injected DNA was stably maintained in these chickens. Restriction digestion analysis of the injected DNA suggested that it was not rearranged and was organized as head‐to‐tail multimers. The copy numbers of the DNA were 0.07–0.02 in the blood DNA of one male per diploid genome, and 0.02–0.015 in the sperm DNA of another male, indicating that the exogenous DNA was present in limited populations of blood and sperm cells. © 1994 Wiley‐Liss, Inc.
Peroxidase activities in bull spermatozoa
Authors: Pavlova S. K. , Kanchev L. N. , Alexandrov M. Ts. 
Published: February 2005

AbstractThe present study was carried out to determine the localization of peroxidase activity in bull spermatozoa. 3,3′‐Diaminobenzidine (DAB) was used as a substrate for revealing peroxidase activity, and light and electron microscopic analysis of the results obtained was performed. Peroxidase activity was detected in the mitochondria of the middle piece and the outer acrosomal membrane. Catalase was excluded as an enzyme, catalyzing the detected peroxidase activity. Concerning the biochemical properties of bull sperm peroxidases, peroxidase activity was found to be manifested in a large pH range, 4–10.5. Bull sperm peroxidase activity appeared to be temperature sensitive and azide sensitive and could be readily inhibited by phenylhydrazine. Electrophoretic analysis of the proteins from bull sperm extracts separated in a Davis‐Ornstein system of 7% polyacrylamide gel, followed by the determination of peroxidase activity on the polyacrylamide gels, revealed that all 14 sperm protein fractions available on the gel possessed peroxidase when benzidine was used as a substrate. The possible reasons for the electrophoretic heterogeneity of bull sperm peroxidases are discussed. © 1994 Wiley‐Liss, Inc.
Chromatin condensation and histone H1 kinase activity during growth and maturation of rabbit oocytes
Authors: Jelíanková Ladislava , Kubelka Michal , Motlík Jan , Guerrier Pierre 
Published: February 2005

AbstractFully grown rabbit oocytes, isolated from preovulatory follicles, exhibit highly condensed bivalents within an intact germinal vesicle while a very low level of histone H1 kinase activity could be detected in their extracts. Chromatin condensation started in growing oocytes isolated from antral follicles presenting a diameter of 0.5 mm. This event was accompanied by a transient rise in histone H1 kinase activity which culminated in large antral follicles measuring 0.75 to 1 mm in diameter.However, the extent of histone H1 kinase activity observed in these growing oocytes remained far less important than that recorded in extracts prepared from in vitro cultured metaphase I and metaphase II oocytes. Moreover, this activity was insufficient to induce germinal vesicle breakdown which will only occur with an increasing efficiency, following in vitro culture of medium, large, and fully grown antral follicles. © 1994 Wiley‐Liss, Inc.
Fate of sperm organelles during early embryogenesis in the rat
Authors: Shalgi Ruth , Magnus Amnon , Jones Roy , Phillips David M. 
Published: February 2005

AbstractThe report is part of a continuing study in which we employ monoclonal antibodies to membrane domains and internal organelles of rat spermatozoa in order to trace events during maturation, capacitation, fertilization, and early development. In the present study, we have used immunocytochemistry at the light and EM levels to localize one antibody, 5A5, to the fibrous sheath and a second, 3D5, to the outer mitochondrial membrane. Antibody 5A5 does not stain the fibrous sheath of spermatozoa of rodents other than the rat, while 3D5 can be localized to the outer mitochondrial membrane of rat, hamster, and mouse spermatozoa. In order to follow these antibodies during fertilization and early embryogenesis, we developed a method to stain internal components of zygotes and early embryos. Our findings suggests that the fibrous sheath disappears prior to the first cleavage and that mitochondria can be detected up to the 2‐cell stage in mouse and the 4‐cell stage in rat. © 1994 Wiley‐Liss, Inc.