bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oviduct function in pigs, with particular reference to the pathological condition of polyspermy
Authors: Hunter R. H. F. 
Published: February 2005

AbstractBecause the exceptionally high incidence of polyspermic fertilisation has been emphasised as a major defect in systems of in vitro fertilisation in pigs, the aetiology of the condition has been analysed in a series of experiments in vivo in the search for a common underlying cause and possible means of mitigation. Whereas the defense mechanism against polyspermy in pig oocytes is classically viewed as a zona reaction, more recent evidence suggests a secondary block at the vitelline surface. Both blocks may be compromised in situations leading to polyspermy, although deleterious influences seem to be expressed principally in an inadequate zona block, as judged by the presence of perivitelline spermatozoa.Postovulatory aging of mammalian oocytes prior to sperm penetration leads to polyspermy, as can be demonstrated in pig eggs. The primary lesion may concern the cortical reaction, owing to a delayed and incomplete exocytosis of the vesicular contents. Eggs ovulated after gonadotrophin treatment during the luteal phase of the cycle show a high incidence of polyspermic penetration (60.6%), as do those shed at estrus in animals treated with progesterone systemically (40%) or by local microinjections in the oviduct wall (32.3%). Whereas progesterone may be modifying interactions of the gametes and responses of the egg organelles in all four above experimental situations, enhanced numbers of spermatozoa ascending a more patent isthmus appear to be the principal cause of polyspermy. Support for this hypothesis comes from isthmus resection with re‐anastomosis of remaining portions of the oviduct (32.4% polyspermy), and surgical insemination directly into the oviducts (33.8% polyspermy). Recent experiments draw attention to a role for oviduct epithelial glycoproteins in modulating the extent of polyspermy in vitro. The role of such oviduct macromolecules in gamete interactions in vivo is considered.
Human α‐fetoprotein purified from amniotic fluid enhances growth factor‐mediated cell proliferation in vitro
Authors: Keel Brooks A. , Eddy Kevan B. , Cho Sechin , May Jeffrey V. 
Published: February 2005

AbstractUsing a primary monolayer culture of porcine granulosa cells (pGC) as an in vitro cell proliferation assay, we have examined the growth‐promoting activity of α‐fetoprotein (AFP) purified from term cord blood and midtrimester amniotic fluid. Increasing concentrations (2.5–20%) of crude human cord blood (CB) increased pGC proliferation, while identical concentrations of crude amniotic fluid (AF) were ineffective. When the cell system was maximally stimulated, AF dose dependently decreased cell proliferation. AFP purified from AF and CB (1.25–5.0 μg/ml) was not mitogenic alone, but, in the presence of epidermal growth factor (EGF) + insulin‐like growth factor (IGF‐I) (10 ng/ml each), AFP dose dependently increased cell proliferation to nearly double that of EGF + IGF‐I alone. The response of pGC to the proliferative effects of AF‐AFP and CB‐AFP were identical at each dose of AFP tested. These results indicate that although crude, pooled midtrimester AF does not display the mitogenic activity seen in cord blood, AFP purified from pooled AF significantly synergizes with growth factors to increase cell proliferation markedly.
Analysis of protamines isolated from alcohol preserved epididymides
Authors: Lee Catherine , Mazrimas Joe , Balhorn Rod 
Published: February 2005

AbstractProtamines 1 and 2 have been isolated from the sperm of frozen and isopropanol preserved Syrian hamster (Mesocricetus auratus) epididymides and analyzed by gel electrophoresis, high‐performance liquid chromatography (HPLC), and amino acid analysis and sequencing. The results show that alcohol preservation does not alter the primary structure of the two sperm nuclear proteins and that the preservation of mammalian reproductive organs in alcohol is a viable alternative to freezing tissues collected in the field. Sperm were isolated from tissues fixed in isopropanol for as long as 7 months without detectable adverse effects on either the isolation of sperm or the primary structure of the protamines.
Activation and subsequent degradation of proacrosin is mediated by zona pellucida glycoproteins, negatively charged polysaccharides, and DNA
Authors: Eberspaecher Uwe , Gerwien Jens , Habenicht Ursula‐Friederike , Schleuning Wolf‐Dieter , Donner Peter 
Published: February 2005

AbstractBoar proacrosin (E.C. 3.4.21.10, Mw 53 kD) was isolated by a modified method and subjected to autoactivation. Previously described molecular intermediates of 49 and 43 kD and a stable form (β‐acrosin, 35 kD) were identified by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. Autoactivation was expedited in the presence of either zona pellucida glycoproteins, fucoidan, or DNA. The end point of this accelerated conversion was the complete degradation of otherwise stable β‐acrosin via the formation of a characteristic active intermediate protein of 30 kD. All intermediate molecular forms observed during proacrosin activation/conversion exhibited the N‐terminal sequence of the boar acrosin heavy chain, indicating a C‐terminal processing mechanism. Hence zona pellucida glycoproteins stimulate proacrosin activation as well as acrosin degradation. Such a mechanism of proenzyme activation and degradation is to our knowledge described here for the first time and points to a previously unrecognized role of zona pellucida during gamete interaction.
Developmental potential and chromosome constitution of strontium‐induced mouse parthenogenones
Authors: O'Neill G. T. , Rolfe L. R. , Kaufman M. H. 
Published: February 2005

AbstractThe brief exposure of recently ovulated mouse oocytes to M16 embryo culture medium supplemented with strontium chloride (M16 Sr2+) for 2–10 min was observed to induce a high incidence of parthenogenesis. A lower incidence of activation and a significant rate of oocyte degeneration was observed when oocytes were incubated in M16 Sr2+ medium for 20–60 min. The majority of the oocytes exposed to this agent for 2–10 min developed as single‐pronuclear haploid parthenogenones. The incidence of this parthenogenetic class was reduced as the duration of exposure to M16 Sr2+ was increased from 2 to 30 min. Under these conditions a greater proportion of the activated oocytes developed as two‐pronuclear diploid parthenogenones, due to failure of second polar body extrusion. The activation frequency and the proportionate incidence of the pathways of parthenogenetic development observed following the exposure of ovulated oocytes to calcium‐free M16 medium differed significantly from that induced by exposure to M16 Sr2+. Cytogenetic analysis of the single‐pronuclear haploid class of Sr2+‐induced parthenogenones at metaphase of the first‐cleavage mitosis has shown that this agent did not induce a significant increase in the incidence of chromosome segregation errors during the completion of the second meiotic division. Analysis of the developmental potential of the two‐pronuclear class of diploid Sr2+‐induced parthenogenones during the preimplantation stages of embryogenesis revealed that their cell number and rate of cell division were less than those of fertilised embryos retained either in vivo or in vitro. The novel methods of activating oocytes indicated in this study present new opportunities to improve the efficiency of embryo cloning techniques with the ruminant species.
Acrosome reaction induced by immunoaggregation of a proteinase inhibitor bound to the murine sperm head
Authors: Aarons David , Boettger‐Tong Holly , Holt Ginger , Poirier Gary R. 
Published: February 2005

AbstractZP3, a glycoprotein of the murine zona pellucida, functions both to bind acrosome intact sperm and to induce the acrosome reaction. Solubilized whole zonae as well as purified ZP3 are able to induce acrosome reactions in capacitated sperm. Pronase digests of whole zonae yield glycopeptides that bind to sperm but are unable to induce acrosome reactions. However, immunoaggregation of these glycopeptides results in the exocytosis of the acrosome in the majority of treated sperm. The data suggest that ZP3 triggers the acrosome reaction by the aggregation of ZP3 binding sites on the sperm head. If aggregation of ZP3 binding sites is important in the induction of the acrosome reaction, then it may be possible to induce the acrosome reaction in the absence of zona by immunoaggregation of the sites. This presentation deals with the immunoaggregation of a proteinase inhibitor of seminal vesicle origin (SVI) that binds to a site on the sperm head known to participate in zona binding. We show that capacitated murine sperm, pretreated with the SVI, will acrosome react, as determined by Coomassie brilliant blue staining, when incubated with rabbit antiinhibitor antiserum (anti‐SVI). The percentage of SVI‐treated sperm displaying an acrosome reaction is dependent on the concentration of the immune serum. Sperm stain positive for intact acrosomes when anti‐SVI Fab fragments or normal rabbit serum is substituted for the immune serum. However, when capacitated sperm, treated with both SVI and anti‐SVI Fab fragments, are incubated with goat antirabbit IgG, the majority of sperm acrosome react. The data suggest that the aggregation of SVI bound to the sperm surface, in the absence of zona glycoproteins, is sufficient to induce the acrosome reaction.
Production of transgenic mice from cryopreserved fertilized ova
Authors: Leibo S. P. , De Mayo Francesco J. , O'Malley Bert 
Published: February 2005

AbstractCryopreserved fertilized mouse ova were used to generate transgenic mice via micromanipulation. Five DNA constructions were injected into a total of 1,052 cryopreserved ova, of which 683 (65%) survived the injection and were transferred into recipients. Of 35 recipients, 66% became pregnant and littered a total of 88 pups. As controls, these DNA constructions were also injected into 1,123 fresh ova, of which 744 (66%) survived and were transferred. Of 42 recipients, 79% became pregnant and littered a total of 167 pups. That is, 22% of fresh ova that were transferred developed into live pups, whereas only 13% of cryopreserved ova did so.Of the pups born, 42 of the 167 (25%) produced from fresh ova were transgenic, and 28 of the 88 (32%) produced from cryopreserved ova were transgenic. In terms of the injected ova that had been transferred, 5.6% of the 744 fresh and 4.1% of the 683 frozen ova developed into transgenic mice. These data indicate that the efficiency of production of transgenic mice from cryopreserved ova is close to that from fresh ova. That observation and the fact that cryopreserved ova allow more efficient utilization of animals suggest that cryopreserved ova can be used instead of fresh ova to produce transgenic mice.
Enhancement of acrosome reaction and subzonal insemination of a single spermatozoon in mouse eggs
Authors: Palermo Gianpiero , Van Steirteghem André 
Published: February 2005

AbstractThe acrosome reaction in mouse spermatozoa was induced by various means. These were 1) varying incubation time in T6 medium, 2) incubation in T6 medium with added A23187, 3) incubation in T6 medium with added dbcGMP and imidazole, 4) exposure to an electric field, and 5) a combination of incubation in a medium with dbcGMP and imidazole and electroporation. The mean percentages of acrosome‐free spermatozoa obtained by these various methods and assessed on the basis of both Bryan's stain and immunolocalization by FITC‐labeled monoclonal antibodies increased by steps from 36% to 67%, 73%, 86%, and 92%.Individual spermatozoa from the various treatments were afterwards microinjected under the zona pellucida of a mouse oocyte. The fertilization rate for eggs microinjected with a spermatozoon treated with A23187, dbcGMP, and imidazole, by electroporation and by a combination of the last two methods also increased by steps from 17% to 34%, 36%, and 70%, respectively.Ninety‐five percent of the fertilized oocytes reached the early blastocyst stage, thirty‐eight percent of these blastocysts implanted in pseudopregnant mice, and twenty‐eight percent developed to term. These results indicated the varying degrees of success of different ways of inducing acrosomal loss in spermatozoa and their subsequent success rates in fertilization and further in vitro and in vivo development.
Effects of oxygen toxicity on early development of mouse embryos
Authors: Umaoka Yoh , Noda Yoichi , Narimoto Katsuhiko , Mori Takahide 
Published: February 2005

AbstractTo examine the effects of oxygen toxicity on embryonic development, mouse pronuclear embryos were cultured under low oxygen conditions with or without superoxide dismutase (SOD), and the blastulation rate was compared with that of embryos cultured under standard conditions. The blastulation rate of mouse pronuclear embryos cultured under standard conditions was only 1.5% (2/131). This rate was increased significantly, to 28.5% (43/151), when the embryos were cultured under low oxygen conditions; and to 31.0% (35/113) when SOD (500 μg/ml) was added to the medium under standard conditions; the rate was increased to 75.2% (115/153) when the embryos were cultured under low oxygen conditions in the presence of SOD. The minimum effective concentration of SOD in the culture medium was 50 μg/ml under conditions of 5% O2. The blastulation rate was significantly decreased after 1‐hr exposure of pronuclear embryos to room atmospheric oxygen concentration (20% O2), and subsequent culture under 5% O2 with SOD did not result in an improved blastulation rate. Culture with SOD under 5% O2 promoted the development of two‐cell stage embryos to the blastocyst stage. When two‐cell stage embryos were collected 48 hr after hCG and cultured for 66 hr, their blastulation rate was similar to that of embryos collected from mice 114 hr after hCG. These results suggested that embryonic development in vitro is greatly affected by atmospheric oxygen throughout the early embryonic stages and that this harmful effect can be prevented by culturing embryos under low oxygen conditions and in the presence of SOD.
Effect of oocyte maturation medium on in vitro development of in vitro fertilized bovine embryos
Authors: Rose Teresa A. , Bavister Barry D. 
Published: February 2005

AbstractThe objective of this study was to examine the effects of different culture media used for maturation of bovine oocytes on in vitro embryo development following in vitro fertilization. Oocytes were aspirated from 2–5 mm follicles of ovaries collected at a local abattoir. The oocyte‐cumulus complexes (OCCs) were cultured for 23–25 h in one of seven commercially available media supplemented with 6 mg/ml bovine serum albumin (BSA), 0.25 mM pyruvate, 10 μg/ml luteinizing hormone (LH), 0.5 μg/ml follicle‐stimulating hormone (FSH), and 1 μg/ml estradiol. After maturation for 23–25 h, all eggs were subjected to the same in vitro fertilization protocol using modified TALP medium and subsequently cultured in the same serum‐free embryo culture medium (HECM‐1/BSA) for 8 days, after which embryo development was assessed. Five media (SFRE, MEMα, TCM199, MEMα/+, RPMI:MEMα) better supported normal oocyte maturation as determined by embryo development to the two‐cell (76–82%), morula/blastocyst (25–32%), and blastocyst (12–19%) stages. Oocytes that were matured in Waymouth's medium MB 752/1 or Ham's F‐12 had a significantly reduced incidence of cleavage to the two‐cell stage (52% and 37%, respectively), which was not attributed to failure of fertilization. Of the eggs that did cleave to the two‐cell stage in these two media, 27% and 9% developed to morulae/blastocysts but only 6% and 3%, respectively, developed into blastocysts. This study demonstrates that (1) the culture medium used for bovine oocyte maturation can markedly affect subsequent embryo development at several stages, including blastocysts, and (2) bovine oocytes can be matured and fertilized and develop to blastocysts in serum‐free medium.
Perivitelline space of mammalian oocytes: Extracellular matrix of unfertilized oocytes and formation of a cortical granule envelope following fertilization
Authors: Dandekar P. , Talbot P. 
Published: February 2005

AbstractExtracellular matrices (ECM) present around unfertilized and fertilized mammalian oocytes were studied ultrastructurally in samples prepared in the presence of ruthenium red to facilitate stabilization of extracellular materials. Unfertilized mouse, hamster, and human oocytes have an ECM comprising granules and filaments in their perivitelline spaces (PVS). This matrix is more abundant in the human than in hamsters and mice. The granule/filament matrix appears identical to the matrix seen between cumulus and corona radiata cells following ruthenium red processing and previously shown to comprise protein and hyaluronic acid. By including ruthenium red during fixation, it is possible to demonstrate the existence of cortical granule exudate in the PVS of fertilized oocytes from hamsters, mice, and humans. Much of the cortical granule exudate is trapped in the PVS and forms a new coat around the fertilized oocyte. This material is particulate when stained with ruthenium red and appears to be uniformly dispersed around the entire oocyte surface. We refer to this new coat as the cortical granule envelope. This envelope is observed in the PVS of all developmental stages up to and including blastocysts in all three species. Following hatching of mouse and hamster blastocysts, the cortical granule envelope is no longer present. Possible functions of this envelope are discussed.
Expression of ribosomal protein genes in mouse oocytes and early embryos
Authors: Taylor Kent D. , Pikó Lajos 
Published: February 2005

AbstractThe quantitative changes in the mRNAs for ribosomal proteins L7a, L18a, and S15 were assayed in slot hybridization experiments using labeled cRNA probes with total RNA from late growth‐phase oocytes, ovulated eggs, and early embryos through the blastocyst stage. All three mRNAs showed a similar developmental pattern of prevalence, but their copy numbers per oocyte or embryo fluctuated according to developmental stage. There are on an average about 17,000 copies of each mRNA in the late growth‐phase oocyte; this number drops to one‐fifth to one‐tenth in the ovulated egg and two‐cell embryo but increases rapidly during cleavage to about 25,000 in the eight‐cell embryo and about 42,000 in the blastocyst. A comparison of the levels of these mRNAs with the reported rates of ribosomal protein synthesis (LaMarca and Wassarman, 1979) suggests that, in late growth‐phase oocytes, ribosomal protein synthesis is regulated primarily at the translational level and is kept low by some factor limiting mRNA utilization. On the other hand, the high rate of ribosome biosynthesis during early embryogenesis from the two‐cell stage onward appears to involve the coordinate activation and transcription of ribosomal RNA and ribosomal protein genes coupled with the immediate translational utilization of ribosomal protein mRNAs.
Joint effects of sodium chloride, glutamine, and glucose in mouse preimplantation embryo culture media
Authors: Lawitts J. A. , Biggers John D. 
Published: February 2005

AbstractA new medium, SOM, produced by simplex optimization, has been used to study the joint effects of NaCl, glutamine, and glucose on the development of outbred CF1 mouse zygotes to the blastocyst stage. Contrary to previous reports, glucose has no significant inhibiting effect on development to the blastocyst stage in this medium. Even in the presence of 5 mM glucose, 70% of the embryos develop to at least four cells, and 60% reach the blastocyst stage. Raising the concentration of NaCl from 75 to 125 mM, in the absence of glutamine, progressively inhibits development. Moreover, the response to glutamine depends on the concentration of NaCl in the medium. When the NaCl concentration is low, glutamine inhibits development. In contrast, when the NaCl concentration is high, glutamine protects against the inhibitory effect of the salt. We propose that glutamine protects against high concentrations of NaCl in the medium by acting as an organic osmolyte.
U2 small nuclear RNA localization and expression during bovine preimplantation development
Authors: Watson Andrew J. , Arcellana‐Panlilio Mayi , Schultz Gilbert A. , Wiemer Klaus E. 
Published: February 2005

AbstractThis study describes the localization of the U2 small nuclear RNA (snRNA) and the major U snRNA group ribonucleoproteins (snRNPs) during bovine preimplantation development. In vitro maturation, fertilization, and oviductal epithelial cell coculture methods were employed to produce several developmental series totalling over 2,000 preimplantation‐stage bovine oocytes and embryos. These oocytes and preimplantation embryos were processed for in situ hybridization, immunofluorescence and Northern blotting methods. The U2 snRNA and the major U group snRNPS were localized initially over the germinal vesicle (GV) of preovulatory oocytes but following GV breakdown were released throughout the ooplasm. They subsequently reassociated with both pronuclei during fertilization. From the two‐cell to the blastocyst stages, the U2 snRNA and U snRNPs were localized to the interphase nucleus of each blastomere. The levels of U2 snRNA throughout bovine preimplantation development were determined by probing a Northern blot containing total RNA isolated from the following preimplantation bovine embryo stages: one to two cell, eight to 16 cell, early morula (>32 cell), and late morula/early blastocysts. The levels of U2 snRNA remained constant between the one‐cell and eight‐to 16‐cell bovine embryo stages but increased 4.4‐fold between the eight‐ to 16‐cell stage and the late morula/early blastocyst stages. The results suggest that a maternal pool of snRNAs is maintained in mammalian preimplantation embryos regardless of the duration of maternal control of development.
Natural degenerating mitochondria in ovarian follicles of a cyprinodontidae fish, Epiplatys spilargyreus (teleost)
Authors: Thiaw Omar Thiom , Mattei Xavier 
Published: February 2005

AbstractThis study examines the evolution of mitochondria in the follicular cells during the development of the ovarian follicle in the teleostean fish Epiplatys spilargyreus. The mitochondria are few in number until the end of previtellogenesis; their matrix is dense, and their cristae are well developed. They proliferate during vitellogenesis and then are modified by deterioration of their matrix. Multilamellar structures are organized in the vacuolized mitochondria. During postvitellogenesis, these modifications become more advanced. The mitochondria degenerate, leaving vacuoles that contain heterogeneous structures, which will be released into the intercellular spaces. At the end of these mitochondrial transformations, the follicular cells degenerate. They release the elements which will participate in forming the secondary envelope. © 1992 Wiley‐Liss, Inc.