bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mouse preimplantation embryo development in vitro: Effectof sodium concentration in culture media on RNA synthesis and accumulation and gene expression
Authors: Ho Yugong , Doherty Adam S. , Schultz Richard M. 
Published: February 2005

AbstractResults of previous studies indicate that culture of preipmlantation mouse embryos in SOM medium containing 85 mM NaCl promotes better development in vitro, as well as supporting higher rates of protein synthesis, when compared to culture in SOM containing 125 mM NaCl (Anbari and Schultz, 1993, Mol Reprod Dev 35:24–28; Biggers et al., 1993, Mol Reprod Dev 34:380–390). In the present study we compare the effect of culturing embryos in these 2 media on several aspects of RNA synthesis and gene expression in order to determine whether the reduced development in SOM containing 125 mM NaCI and lower rates of protein synthesis are correlated with decreases in RNA synthesis and stability and changes in gene expression. Although no apparent differences in the metabolism of [3H]uridine to UMP, UDP, and UTP and its incorporation into total RNA are observed when 2‐cell embryos are cultured to the morula stage in either medium, a 20% decrease in the rate of mRNA synthesis is found when embryos are cultured in SOM containing 125 mM NaCl. In addition, pulse‐chase experiments reveal that total mRNA is less stable when the embryos are cultured in SOM containing 125 mM NaCl. Using a reverse transcription‐polymerase chain reaction to assay for changes in the relative amounts of specific mRNAs, the relative amounts of mRNAs for IGF‐I and IGF‐II and their cognate receptors are dramatically reduced in embryos cultured in SOM containing 125 mM NaCl, whereas only a mild reduction is observed in the relative amount of actin mRNA. In contrast, when freshly isolated morulae are cultured to the blastocyst stage in either of these 2 media, similar amounts of these mRNAs are observed. Last, high‐resolution, 2‐dimensional gel electrophoresis reveals significant changes in the pattern of protein synthesis when the embryos are cultured in SOM containing 125 mM NaCl. Results of these experiments suggest that culture of embryos in medium containing lower concentrations of NaCl that are normally present in various culture media results in higher rates of mRNA synthesis and greater mRNA stability. These changes in RNA synthesis may underlie, at least in part, the improved development in vitro that is fostered by SOM containing 85 mM NaCl. © 1994 Wiley‐Liss, Inc.
Assessment of sister chromatid exchange in mouse embryos produced by microsurgical fertilization
Authors: Hirayama Toshio , Quinn Patrick , Marrs Richard P. 
Published: February 2005

AbstractThe treatment of male factor‐related infertility has been approached with the advent of several methods for microsurgical fertilization, such as the partial dissection of the zona pellucida (PZD) and the injection of sperm into the perivitelline space (PVSI) of oocytes. These techniques are designed to increase sperm‐oolemma interaction by circumventing passage of the sperm through the zona pellucida. The present study was performed to evaluate the influence of PZD and PVSI on the in vitro development of mouse embryos by assessing the rate of sister chromatid exchange (SCE). SCE is considered to be a sensitive indirect indicator of DNA lesions due to various conditions. Oocytes were cultured in vitro after PZD or PVSI and then examined for SCE. There was no significant difference in SCE between control and treatment groups of embryos and the values were similar to those reported by Saito et al. (Fertil Steril 41:460–464, 1984). The rate of SCE was low during the first two mitotic cycles, then increased from cycle two to three before declining slightly between the 3rd and 4th cycles of cell division. These data demonstrate that the direct interaction of sperm and oocyte by PZD or PVSI did not have an adverse effect on the development of mouse embryos as assessed by the rate of SCE. © 1994 Wiley‐Liss, Inc.
In vitro incubation of golden (syrian) hamster ovarian oocytes and human sperm with a human oviduct specific glycoprotein
Authors: Reuter Laura M. , O'Day‐Bowman Mary B. , Mavrogianis Patricia A. , Fazleabas Asgerally T. , Verhage Harold G. 
Published: February 2005

AbstractThe objective of this study was to determine if human oviduct specific glycoprotein (huOGP) would associate with hamster ovarian oocytes and human sperm during in vitro incubation. The huOGP used in these studies was partially purified from human hydrosalpinx fluid. Hamster ovarian oocytes and human sperm samples were incubated in culture medium with and without huOGP. Association of huOGP was assessed by indirect immunofluorescence assay using a polyclonal antibody prepared against huOGP. Intense fluorescence of the zona pellucida, and bright but uneven fluorescence of the perivitelline space, were observed in hamster ovarian oocytes following incubation in the presence of huOGP. A similar but more uniform pattern of fluorescence was observed when hamster oviductal oocytes (positive controls) were incubated in culture medium alone. Fluorescence was absent when oocytes were assayed with preimmune serum. The association of huOGP with the zona pellucida and perivitelline space appeared to be specific since thyroglobulin, a large molecular weight glycoprotein, and human serum albumin, the major protein in oviduct fluid, did not associate with the hamster oocytes nor inhibit huOGP association when included in the culture medium. Fluorescence was absent when human sperm incubated with huOGP were assayed with antiserum to huOGP. However, human sperm fluoresced when incubated with a uterine glycoprotein, CUPED, which had previously been shown to bind to cat sperm during in vitro incubation. Sperm also fluoresced brightly when human sperm antibody was used as a positive control. Solubilization of sperm membrane proteins postincubation and analysis of these proteins by 1‐D SDS‐PAGE followed by immunoblotting also failed to show an association of huOGP with human sperm. Electron microscopy of sperm both pre‐ and postsolubilization confirmed that the sperm membranes were removed by this process. In conclusion, the association of huOGP with hamster oocytes in vitro suggests that huOGP may associate with human oocytes in vivo, whereas that may not be true for human sperm in vivo. The association of huOGP with oocytes may serve to facilitate the process of fertilization and early embryonic development within the oviduct. © 1994 Wiley‐Liss, Inc.
Analysis of segregation in a human male reciprocal translocation carrier, t(1;11) (p36.3;q13.1) by two‐colour fluorescence in situ hybridization
Authors: Spriggs Elizabeth L. , Martin Renee H. 
Published: February 2005

AbstractUsing centromeric probes specific for chromosomes 1 and 11, 13,071 sperm nuclei from a male reciprocal translocation heterozygote, 46, XY, t(1;11) (p36.3;q13.1), were analyzed by fluorescence in situ hybridization (FISH). Decondensed sperm nuclei were simultaneously hybridized with DNA probes for chromosome 1 (pUC177) and chromosome 11 (D11Z1). Results were as follows: 1/11 (82.45%), 1/1/‐ (3.45%), ‐/11/11 (4.85%), 1/1/11 (1.20%), 1/11/11 (1.14%), 1/‐ (4.33%), ‐/11 (2.50%), 1/1/11/11 (0.06%), 1/1/1/‐ (0.02%). Because both the normal chromosome and its translocated derivative carry the same centromeric sequences, FISH cannot differentiate between sperm resulting from alternate segregation and those produced by adjacent I segregation. Using the same donor, comparable segregation patterns were obtained from sperm chromosome karyotypes (Spriggs et al., 1992: Hum Genet 88:447–452) and from MII spermatocytes (Goldman and Hulten, 1993: Cytogenet Cell Genet 63:16–23), demonstrating that selection is not a factor in the human sperm/hamster oocyte fusion technique or during meiosis. Although FISH does not provide the detailed information afforded by sperm karyotyping, it is a valuable technique for studying segregation patterns in translocation heterozygotes. © 1994 Wiley‐Liss, Inc.
Liposome‐mediated DNA transfer into chicken primordial germ cells in vivo
Authors: Watanabe M. , Naito M. , Sasaki E. , Sakurai Michiharu , Kuwana T. , Oishi T. 
Published: February 2005

AbstractIn embryogenesis, avian primordial germ cells (PGCs) circulate temporarily in the blood vessels at stages 10–15 (Hamburger and Hamilton, 1951), before reaching the gonads. In an attempt to transfer cloned genes into PGCs, liposome consisting of reporter plasmid DNA and N‐[1‐(2,3‐Dioleoyloxy)propyl]‐N, N, N‐trimethyl‐ammoniummethylsulfate was injected into the marginal veins of embryos at stages 11‐‐15. As reporter plasmids, pRSVZ and pAcZ harboring the Escherichia coli lacZ gene driven, respectively, by the Rous sarcoma virus (RSV) promoter and the chicken β‐actin gene promoter were used. First, 55 embryos were injected with liposome containing pRSVZ and stained for the bacterial β‐galactosidase activity 24 hr after injection. In all the embryos, cells positive for β‐galactosidase activity were observed among the blood cells, endothelial cells, and endocardium cells of the heart, suggesting that transfection took place within the circulatory system. Then, embryos were injected with liposome containing pRSVZ or pAcZ, and stained 2 or 3 d after injection. PGCs positive for β‐galactosidase activity were observed in the gonads in four out of 44 embryos injected with pRSVZ, and 29 out of 71 embryos injected with pAcZ, indicating that the plasmid DNA was transferred into PGCs developing normally. The average number of positive PGCs per embryo was 0.2 and 2.1, respectively, when pRSVZ and pAcZ were introduced. The difference in the number of positive PGCs detected after introduction of the two plasmids suggests that the actin promoter has a higher level of transcriptional activity in PGCs than does the RSV promoter. © 1994 Wiley‐Liss, Inc.
Proenkephalin transgenic mice: A short promoter confers high testis expression and reduced fertility
Authors: O'Hara Bruce F. , Donovan David M. , Lindberg Iris , Brannock Michael T. , Ricker Deborah D. , Moffatt Christopher A. , Klaunberg Brenda A. , Schindler Charles , Chang Thomas S. K. , Nelson Randy J. , Uhl George R. 
Published: February 2005

AbstractThe regulation and possible function of the preproenkephalin gene in testis were studied in vivo in transgenic mice containing: (1) bases −193 to +210 of the human proenkephalin gene and an additional one kilobase of 3' proenkephalin flanking sequence driving expression of bacterial chloramphenicol acetyltransferase (CAT), and (2) the same promoter and flanking sequences driving expression of a rat proenkephalin cDNA. Five lines of mice, designated HEC1–5, expressed the first construct and 10, HER1–10, the second. Each HEC male and many HER males showed dramatic expression of the transgene in the testis, although much lower expression was observed in the brain and other enkephalin‐producing tissues. High levels of expression in testis can thus be achieved with a very short promoter region and do not require intron A sequences previously considered necessary. Altered enkephalin expression may affect testicular function. One founder, HER8, displayed grossly abnormal testicular morphology and was completely infertile. A second founder, HER6, had low sperm motility. Two offspring from other lines also displayed subnormal fertility. These studies support a role for specific promoter sequences in testis expression and may further support a significant role for proenkephalin in testicular function. © 1994 Wiley‐Liss, Inc.
Isolation and partial purification of plasma membrane from porcine oocytes
Authors: Ash Kendall , Berger Trrish , Munn Robert J. , Horner Catherine M. 
Published: February 2005

AbstractEgg plasma membrane (EPM) was isolated in comparatively large amounts from porcine slaughterhouse ovaries. Ovaries were minced, and the oocyte containing fluid was filtered to retrieve zona pellucidae–intact oocytes. The oocytes were homogenized and filtered again to remove zona pellucidae. The egg filtrate was subjected to differential centrifugation to remove membrane bound organelles and the remaining plasma membrane containing material was pelleted by ultracentrifugation. Plasma membranes were further separated from cellular material by sucrose density gradient centrifugation and were collected from portions of the gradient that correspond to the densities of plasma membrane. The purity of isolated plasma membranes was assessed by membrane marker enzyme analysis and transmission electron microscopy. Activities of the plasma membrane marker enzymes 5' nucleotidase and alkaline phosphatase increased from nondetectable levels in the egg filtrate to relatively high levels in the plasma membrane preparation. Marker enzymes for mitochondrial and lysosomal membranes fell from detectable levels in the egg filtrate to levels that were at the lower limits of the assays to detect in the final preparation. Evidence provided by binding of biotin‐labeled EPM to capacitated sperm suggests that the isolated EPM retains its biological activity. The procedure presented here represents a novel method of isolating procine egg plasma membranes for further study involving sperm–egg interaction. © 1994 Wiley‐Liss, Inc.
Antibody‐induced changes on rabbit sperm surface inhibit gamete interaction
Authors: Shaha Chandrima 
Published: February 2005

AbstractInteraction of specific ligands with cell surface molecules may induce reorganization of surface components. A monoclonal antibody (B‐12) against sperm surface antigens of 40kDa size induced molecules on the plasma membrane overlying the acrosome of rabbit sperm to cluster in small aggregates at 0°C (patching). At an elevated temperature of 37°C these clusters of antigen antibody complexes collected into a large aggregate on one pole of the cell forming a cap (capping). This cap‐like structure showed a reduction in size over a period of time and eventually disappeared from the sperm surface. Inhibition of capping by sodium azide indicated that it is an energy‐dependent process. Patching of antigens did not require energy. Involvement of sperm head cytoskeleton in the process of capping was evident from potentiation of cap formation by cytoskeleton disrupting agents like cytochalasin B and D. Patching of antigen antibody complexes was not affected by either of the agents. The loss of antigen antibody complexes from sperm surface was mainly due to shedding of the complexes in the surrounding media. Sperm with patches of antigen antibody complexes did not adhere to oocytes. Sperm from the group where a majority of the sperm were denuded of the antigen antibody complexes also did not bind to oocytes. © 1994 Wiley‐Liss, Inc.
Purification and characterization of β‐glucuronidase from bull seminal plasma and its role in fertilization
Authors: Rethinaswamy Asokan , Yang Chul‐Hak , Srivastava Prakash N. 
Published: February 2005

AbstractBull seminal plasma contains high levels of β‐glucuronidase. The present study describes the isolation and characterization of β‐glucuronidase, and its role in fertilization. β‐glucuronidase was purified by ion exchange chromatography, saccharolactone‐agarose affinity chromatography, and gel filtration. The specific activity of the purified enzyme was 4,414 μmoles/mg protein/min. The purified enzyme showed a single band on 7.5% PAGE. On SDS‐PAGE, the enzyme appeared to consist of four identical subunits of Mr 75,000 each. The apparent Km and Vmax for β‐glucuronidase were 0.4 mM and 5.7 μmol/min using phenolpthalein mono‐β‐glucuronic acid as the substrate. β‐glucuronidase appeared to accelerate the cumulus dispersion in vitro. © 1994 Wiley‐Liss, Inc.
Characterization of chromatin‐condensing proteins during spermiogenesis in a neogastropod mollusc (Murex brandaris)
Authors: Càceres Carme , Ribes Enric , Muller Sylviane , Cornudella Lluís , Chiva Manel 
Published: February 2005

AbstractDuring the process of chromatin cndensation in the spermiogenesis of the neogastropod mollusc Murex brandaris, the nuclear protein complement undergoes a complex series of changes. These changes lead to the appearance of three small protamines in the ripe sperm nuclei. We have characterized this system electrophoretically and at the compositions with antibodies elicited against a specific spermatozoan protamine. Our results indicate that the complex pattern of chromatin condensation during spermiogenesis in this species (M. brandaris) may be modulated by a series of post‐translational (and intranuclear) modifications of DNA‐interacting proteins, such as precursors to the sperm protamines. The amino acid composition of each sperm protamine is remarkably simple (lys + arg + gly ≥96 mol%). This system of spermiogenic/spermatozoal proteins in the neogastropod M. brandaris clearly differs from that in patellogastropods and archaeogastropods, and it may be helpful in understanding evolutionary changes in the chromatin condensation pattern during the spermiogenesis of gastropod molluscs. © 1994 Wiley‐Liss, Inc.
Epidermal growth factor enhances oocyte maturation in pigs
Authors: Ding Jianchi , Foxcroft George R. 
Published: February 2005

AbstractEpidermal Growth Factor (EGF) has been reported to stimulate nuclear maturation in porcine oocytes (Sommer et al., 1992). The objective of this experiment was to test the effect of EGF alone or in combination with gonadotropins and follicular shell coculture, on cytoplasmic maturation of oocytes in vitro. A preliminary experiment tested the effective dose of EGF for stimulation of oocyte nuclear maturation in our culture system. Nuclear maturation rates (MII%) of 67.2 ± 4.6, 81.1 ± 8.6, and 80.7 ± 5.1 for oocyte complexes cultured in the presence of 0.1, 1, and 10 ng/ml EGF, respectively, were significantly higher (P < 0.05) than for oocytes cultured in the absence of EGF (18.1 ± 9.4%). In the main experiment a 2 × 2 × 2 factorial random complete block design was used to examine the effect of EGF (1.0 ng/ml) alone or in combination with gonadotropins and follicular shell coculture on cytoplasmic maturation. Cytoplasmic maturation was evaluated by the ability of oocytes to decondense sperm nuclei after sperm penetration. EGF alone did not stimulate cytoplasmic maturation in oocytes in vitro (P > 0.05). However, EGF showed a positive interaction (P < 0.05) with gonadotropin treatment on male pronuclear formation. We conclude that EGF alone can stimulate nuclear maturation in pig oocytes, and EGF can interact with gonadotropins to enhance cytoplasmic maturation. A high level of cytoplasmic maturation of in vitro matured pig oocytes could be achieved using a combination of EGF, gonadotropin, and follicular shell supplementation to the culture environment. © 1994 Wiley‐Liss, Inc.
Function of FGF‐4 in limb development
Authors: Niswander Lee , Martin Gail , Tickle Cheryll , Vogel Astrid 
Published: February 2005

AbstractThe apical ectodermal ridge plays a central role in limb development through its interactions with the underlying mesenchyme. Removal of the AER results in cessation of limb outgrowth and leads to truncation of the limb along the proximo‐distal axis. The many functions attributed to the ridge include maintenance of the progress zone mesenchyme. Here, cells are stimulated to proliferate, are maintained in an undifferentiated state, and are assigned progressively more distal positional values as the limb grows. The AER also functions to maintain the activity of the polarizing region, a region of mesenchyme which is thought to provide the primary signal for patterning along the antero‐posterior axis.We have begun to explore the function of fibroblast growth factor‐4 (FGF‐4) during limb development. FGF‐4, which encodes an efficiently secreted protein, is expressed in the AER. We have previously demonstrated that FGF‐4 protein can stimulate limb mesenchyme proliferation and can induce the expression of a downstream homeobox gene, Evx‐1 (homologue of the Drosophila even‐skipped gene), that is normally regulated by a signal from the AER. To determine to what extent FGF‐4 protein can substitute for the AER to allow normal limb outgrowth, we performed experiments on the developing chick limb in ovo. Remarkably, we find that after AER removal, the FGF‐4 protein can provide all the signals required for virtually normal outgrowth and patterning of the limb. Further studies indicate that proliferation of progress zone cells is not sufficient, and that an additional signal is produced by the posterior mesenchyme in response to FGF‐4 which enables progress zone cells to acquire progressively more distal fates. Thus FGF‐4 maintains progress zone activity through a combination of at least two signals—one that acts directly on progress zone cells to stimulate their proliferation, and one that acts indirectly by maintaining the production of patterning signal(s) by the posterior mesenchyme. We further show that failure of the posterior mesenchyme to produce this signal correlates with failure to maintain polarizing activity. This raises the possibility that the signal produced by the posterior mesenchyme and required for progressive proximo‐distal limb patterning is identical to the polarizing activity. Further experiments demonstrate that retinoic acid, which mimics the activity of the polarizing region, can supply this signal. In conclusion, the finding that a single growth factor can serve as both the direct and indirect signals required to maintain progress zone activity provides a simple mechanism for ensuring that growth and pattern formation are linked in the developing limb. © 1994 Wiley‐Liss, Inc.
Relationship between morphology and chromosomal constitution in human preimplantation embryo
Authors: Pellestor F. , Girardet A. , AndréO B. , Arnal F. , Humeau C. 
Published: February 2005

AbstractIn in vitro fertilization (IVF) procedures, morphologic embryo grading is the sole criteria for selection of embryos transferable in utero. Cytogenetic analysis of preimplantation embryos was performed to investigate the relationship between chromosomal status and morphologic quality of preimplantation eggs. Aneuploidy was the most frequently observed abnormality. In addition, various types of aberrations such as polyploidy, haploidy, mosaicism, and fragmentation were also found. Our results, pooled with data drawn from previous reports, demonstrated the prognostic value of the embryo grading system as a means for eliminating chromosomally abnormal embryos. In contrast, data suggested that some aspects of the IVF process might be responsible for the occurrence of these abnormalities. © 1994 Wiley‐Liss, Inc.
Pdha‐2: A model for studying transcriptional regulation in early spermatocytes
Authors: C. Iannello Rocco , C. Young Julia , Kola Ismail 
Published: February 2005

AbstractPrecise temporal and tissue‐specific expression of genes during spermatocyte differentiation is crucial for the formation of functional spermatozoa. However, the mechanisms that regulate gene expression during spermatogenesis are poorly understood. One testisspecific gene, Pdha‐2, is beginning to emerge as a potentially important model for the study of these events. This review focuses on our current understanding of the expression and regulation of Pdha‐2 during spermatogenesis. © 1994 Wiley‐Liss, Inc.