bluuebunny/crossref_metadata_2025_split huggingface dataset:
Maturation of hamster epididymal sperm motility and influence of the thiol status of hamster and rat spermatozoa on their motility patterns
Authors: Yeung C. H. , Oberländer G. , Cooper T. G. 
Published: February 2005

AbstractA method for objective quantification of hamster sperm movement parameters as an indicator of maturation along the epididymis was established using a computerised system. Analysis of spermatozoa released into medium from five epididymal regions showed that the most drastic increases in percentage motility and curvilinear velocity (VCL) occurred from the distal corpus to the beginning of the proximal cauda and in straight‐line velocity (VSL) from the beginning to a more distal site within the proximal cauda region. Both high osmolarity (400 mOsm/kg) and the thiol‐oxidising agent diamide (10 μM) increased flagellar straightness of distal corpus spermatozoa, but VSL was increased only with the latter. The thiol‐reducing agent dithiothreitol (DTT, 1mM) stimulated and maintained percentage motility and velocities of spermatozoa from the caput, stimulated only percentage motility of distal corpus sperm, but decreased velocities of those from the proximal cauda in prolonged incubation. In rats, diamide increased path straightness but not velocities of caput spermatozoa and yet caused immotility within 15 min, whereas DTT prolonged the maintenance of in vitro motility. The slight increases in kinematic parameters in the presence of DTT were enhanced by a 2‐min preincubation with diamide. The finding that the effects of DTT and diamide were not compensatory suggests that the influence of the SH/S‐S status on sperm movement is multifaceted, with decreasing sensitivity to stimulation upon sperm maturation. © 1994 Wiley‐Liss, Inc.
Effect of IGF‐I on pig oocyte maturation, fertilization, and early embryonic development in vitro, and on granulosa and cumulus cell biosynthetic activity
Authors: Xia Ping , Tekpetey Francis R. , Armstrong David T. 
Published: February 2005

AbstractPorcine granulosa cells have been shown previously to both secrete and respond to insulin‐like growth factor‐I (IGF‐I), suggesting an autocrine function of this peptide in the follicle. The present work was undertaken to determine possible effects of IGF‐I on in vitro maturation, in vitro fertilization, and early embryonic development in culture. Granulosa and cumulus cell proliferation and differentiation based on 3H‐thymidine uptake and progesterone production, respectively, were also assessed. The results showed that the cleavage rate of oocytes was markedly stimulated in a dose‐dependent manner by the addition of IGF‐I to the oocyte maturation medium (P < 0.05). Embryo development beyond the 8‐cell stage was improved by IGF‐I, reaching a maximum of 22% at 200 ng/ml IGF‐I. Treatment with IGF‐I after fertilization increased the percentage of total oocyte cleavage (P < 0.05) to approximately 52%, 43%, and 57% at, respectively, 25, 50, and 100 ng/ml IGF‐I. 3H‐thymidine incorporation by granulosa cells was significantly increased in cultures treated with FSH (3‐fold) or IGF‐I (6‐fold) compared to the control. For the cumulus cells, FSH caused a similar increase (3‐fold) in 3H‐thymidine incorporation while IGF‐I stimulated a 15‐fold increase. Progesterone production by the granulosa cells was increased to the same extent by treatment with FSH or IGF‐I (4.7 and 5.1‐fold, respectively). However, for the cumulus cells, while FSH caused a marked 16‐fold increase in progesterone production, IGF‐I caused only a marginal increase of 2.5‐fold. These results indicate a beneficial effect of IGF‐I on in vitro porcine oocyte maturation and pre‐implantation embryo development, suggesting a physiological role for IGF‐I in vivo. The in vivo effect of IGF‐I may be indirect via autocrine stimulation of cumulus and/or granulosa cells resulting in enhanced oocyte maturation and fertilization. © 1994 Wiley‐Liss, Inc.
Biochemical characterization of the boar sperm 42 kilodalton protein tyrosine kinase: Its potential for tyrosine as well as serine phosphorylation towards microtubule‐associated protein 2 and histone H 2B
Authors: Berruti Giovanna 
Published: February 2005

AbstractThe majority of cellular responses to changing environmental conditions is regulated by protein kinases. Spermatozoa have many special properties, including motility with demonstrated chemotaxis, the ability to undergo capacitation, and the acrosome reaction, which are in part controlled by extracellular signals and in which sperm kinases are considered to be involved. We have previously reported that there is a protein kinase activity, which phosphorylates the synthetic substrate poly‐(Glu, Tyr) with a Km value of 2.3 μM, and is inhibited by the tyrosine kinase inhibitor tyrphostin, in the protein extract from boar spermatozoa (Berruti and Porzio, 1992: Biochim Biophys Acta 1118:149–154). Now we have demonstrated that the enzyme is cytosolic, is active as a monomer of Mr 42,000, is stimulated by Mg2+ > Mn2+ but not by Ca2+, is renaturable, and can phosphorylate native protein substrates such as microtubule‐associated protein 2 (MAP2) and histone H2B both on the tyrosine and serine residues. N‐terminal sequence analysis suggests that it is a novel protein. These new findings imply that the boar sperm 42 kD kinase may be a novel member of the emerging class of dual‐specificity protein kinases, and they raise the intriguing question of its function in the protein kinase network mediating signal transduction in mammalian spermatozoa. © 1994 Wiley‐Liss, Inc.
Modulation of spermatozoa and zona pellucida properties by the soluble acrosome reaction‐inducing factor of the ovulated egg‐cumulus complex
Authors: Boatman Dorothy E. , Magnoni Gladys E. , Robbins Robert S. 
Published: February 2005

AbstractThree sources of hamster periovulatory fluids (± heat inactivation at 56°C), with bovine serum albumin (BSA) as control, were tested for effects on penetration of three classes of eggs by hamster sperm precapacitated in BSA. These fluids were a soluble extract of cumulus oophorus fluid (COF) from the ovulated hamster egg‐cumulus complex, serum, and follicular fluid. Egg types were ovulated, salt‐stored (ovulated), and follicular. In both COF and serum, there were significant differences among egg types in mean penetration, and significant effects of fluid addition. In contrast, there was no effect of follicular fluid and no differences between follicular and stored eggs. For the follicular eggs (combined data, normalized, ranked), patterns of response to the three factors (± heating) were different: only unheated COF and heated serum increased penetration significantly above BSA control levels (average rank 20.2, 41.4, 38, for BSA, COF (unheated), serum (heated), respectively). This indicated that the active component in COF was heat labile, not present in either serum or follicular fluid, and, therefore, of oviductal origin. Oviduct and/or COF exposure of eggs and sperm was tested for effects as an acrosome reaction inducing factor (ARIF) for acrosome reactions (AR; zonabound and free‐swimming sperm) and on sperm:zona binding and penetration. The COF ARIF for free‐swimming sperm AR was heat stable. Penetration of follicular eggs increased after incubation in COF prior to sperm addition, but a greater response occurred when COF was added to eggs with sperm. In kinetic experiments, 25 min following sperm attachment, follicular eggs had lost 41% of initially bound sperm, vs. 23% for ovulated eggs, and had only 16 AR sperm/egg, vs. 26 for ovulated. Follicular eggs incubated in COF (then washed three times) had the same number of bound AR sperm as ovulated eggs. Acid solubilized zona pellucida (ASZP) from ovulated eggs was more effective as an ARIF per zona than ASZP from follicular eggs. Zonae of follicular eggs, as eivdenced by dissolution times in β‐mercaptoethanol (β‐MEOH), were not “harder” than those of ovulated eggs. There were differences in lectin binding antigens on zonae of both fresh and stored, follicular and ovulated, eggs. We conclude that multiple biological factors orchestrate sperm:egg interactions in the ampulla. Our data are consistent with the presence of at least three effective components: (1) the oviductal lectin‐binding antigen (ZPO or oviductin), (2) an additional heat‐labile component, and (3) the heat‐stable ARIF for free‐swimming sperm. © 1994 Wiley‐Liss, Inc.
Mullerian‐inhibiting substance secretion is delayed in XX sex‐reversed dog embryos
Authors: Meyers‐Wallen V. N. , Palmer V. , Maclaughlin D. , Donahoe P. K. 
Published: February 2005

AbstractSertoli cell secretion of Mullerian‐inhibiting substance (MIS) begins shortly after testis differentiation. Mullerian ducts regress following MIS exposure during an embryonic critical period. In dogs with XX sex reversal, Mullerian ducts persist in the presence of testicular tissue. This study was conducted to determine whether MIS is present in ovotestes of XX sex‐reversed embryos during the period for Mullerian duct regression in normal males. XX sex‐reversed embryos and normal littermates were identified by a combination of karyotype and gonadal histology. The degree of regression in the adjacent Mullerian duct was scored. Immunohistochemical staining was used to detect MIS in the contralateral gonad. Testicular differentiation and MIS secretion were identified in XY embryos at all ages studied (35–46 days). Seminiferous tubules were not observed in gonads of embryos at risk of XX sex reversal between 35–38 days (n = 15), but were observed at 40 and 46 days (n = 3). Although positive staining for MIS was observed in ovotestes, adjacent Mullerian ducts persisted. The degree of seminiferous tubule development was reduced and MIS secretion was delayed in ovotestes, compared to normal testes. Mullerian duct persistence in this model is apparently due to an abnormality in the quantity and timing of MIS secretion during embryonic development.© 1994 Wiley‐Liss, Inc.
Role of FGFs in skeletal muscle and limb development
Authors: Olwin Bradley B. , Arthur Kirstin , Hannon Kevin , Hein Patrick , Zhou Zhaohui , Zuber Michael E. , Kudla Arthur J. , McFall Aidan , Rapraeger Alan C. , Riley Bruce , Szebenyi Györgyi , Fallon John F. 
Published: February 2005

AbstractFibroblast growth factors (FGFs) are a family of nine proteins that bind to three distinct types of cell surface molecules: (i) FGF receptor tyrosine kinases (FGFR‐1 through FGFR‐4); (ii) a cysteine‐rich FGF receptor (CFR); and (iii) heparan sulfate proteoglycans (HSPGs). Signaling by FGFs requires participation of at least two of these receptors: the FGFRs and HSPGs form a signaling complex. The length and sulfation pattern of the heparan sulfate chain determines both the activity of the signaling complex and, in part, the ligand specificity for FGFR‐1. Thus, the heparan sulfate proteoglycans are likely to play an essential role in signaling.We have recently identified a role for FGF in limb bud development in vivo. In the chick limb bud, ectopic expression of the 18 kDa form of FGF‐2 or FGF‐2 fused to an artificial signal peptide at its amino terminus causes skeletal duplications. These data, and the observations that FGF‐2 is localized to the subjacent mesoderm and the apical ectodermal ridge in the early developing limb, suggest that FGF‐2 plays an important role in limb outgrowth. We propose that FGF‐2 is an apical ectodermal ridgederived factor that participates in limb outgrowth and patterning. © 1994 Wiley‐Liss, Inc.
Role of interferons in the regulation of cell proliferation, differentiation, and development
Authors: J. Hertzog Paul , Y. Hwang Seung , Kola Ismail 
Published: February 2005

AbstractThere now appears to be evidence to support the view that the type I IFNs are naturally produced negative regulators of growth that also modify cell differentiation. Consistent with this, it appears that the ability to produce and respond to IFN is suppressed in early embryonic development when cell proliferation and differentiation are essential. In the later stages of fetal development, IFN production is de‐repressed, and cells show increased sensitivity to IFN, which may be important in regulating cell proliferation and/or differentiation processes or the interaction between fetal and maternal tissues. Interestingly, the IFN system can also be suppressed in disease states such as the development of tumours or in the establishment of a (chronic) viral infection. Therefore, understanding the developmental regulation of the IFN system may be important to understanding and controlling the IFN system in disease. More extensive studies of the developmental stage and tissue‐specific expression of type I IFNs and their receptors are necessary, as well as more direct in vivo experiments to further elucidate the role of the IFN system in reproduction and development. © 1994 Wiley‐Liss, Inc.
Affinity binding of hamster oviductin to spermatozoa and its influence on in vitro fertilization
Authors: Kimura Hitomi , Matsuda Junichiro , Ogura Atsuo , Asano Toshihiko , Naiki Masaharu 
Published: February 2005

AbstractThe aim of this study was to determine the influence of hamster oviductal glycoprotein (Oviductin) on in vitro gamete interaction. Oviductin was purified from the oviducts using lithium 3,5‐diiodosalicylate, followed by phenol extraction. Immunocytochemistry using indirect fluorescence staining revealed that oviductin binds to the sperm anterior acrosomal region. The specific binding of oviductin resulted in inhibition of in vitro fertilization in studies using cumulus‐free oocytes. The inhibitory effect was dependent on the concentration of oviductin and occurred in both ovarian and oviductal oocytes but not zona‐free oocytes, indicating that sperm‐zona interaction was interferred by oviduction. However, the inhibitory effect of oviductin sperm‐zona interaction was reduced when cumulus‐enclosed oocytes from ovaries and oviducts were used, indicating that the egg investment including cumulus oophorus has some effect on oviductin‐sperm complex and maintaining the fertilizing ability. © Wiley‐Liss, Inc.
Analysis of aspartic acid and asparagine metabolism in Xenopus laevis oocytes using a simple and sensitive HPLC method
Authors: M. O'Connor Clare 
Published: February 2005

AbstractThe amino acids in methanol‐soluble extracts of Xenopus oocytes were measured using a method involving precolumn derivatization with phenylisothiocyanate and reverse phase HPLC of the derivatized amino acids. This technique allows the estimation of asparagine and glutamine pools in oocytes, estimated as 70 and 283 pmoles per oocyte, respectively. The pool sizes of the other amino acids were similar to previously reported results obtained using conventional ion exchange chromatography and postcolumn derivatization with ninhydrin. The advantages of the method developed here include picomolar sensitivity and the enhanced resolution of asparagine and glutamine from other amino acids. The kinetics of aspartic acid and asparagine utilization were monitored following microinjection of oocytes with [3H]aspartic acid and [14C]asparagine. The aspartic acid pool turned over rapidly with a half‐time of <30 min. The asparagine pool was metabolized much more slowly and appeared to be utilized almost completely for protein synthesis. The absolute rate of protein synthesis in oocytes was calculated from the incorporation data and chemical pool measurements as ∼25 ng/hr‐oocyte. The methodology developed here may be useful in experimental situations involving limited amounts of biological material. © 1994 Wiley‐Liss, Inc.
Solubilization and partial purification from mouse sperm membranes of the specific binding activity for 3‐quinuclidinyl benzilate, a potent inhibitor of the zona pellucida‐induced acrosome reaction
Authors: R. Ward Cynthia , S. Kopf Gregory , T. Storey Bayard 
Published: February 2005

Abstract3‐Quinuclidinyl benzilate (QNB), a potent antagonist of muscarinic acetylcholine receptors, has been demonstrated to inhibit specifically the zona pellucida (ZP)‐inducud acrosome reaction (AR) in mouse sperm (Florman and Storey, 1982; Dev Biol 91:121–130). In this study we describe the solubilization and partial purification of the mouse sperm QNB binding activity which may represent a component of the putative receptor complex for ZP on the sperm plasma membrane. Sperm membranes were isolated from cell homogenates of washed, capacitated, epididymal mouse sperm. Scatchard plots of QNB binding to these membranes indicated a single class of binding sites with KD = 7.2 nM and Bmax = 8700 sites/cell. These binding characteristics are similar to those seen with QNB binding to whole cells (Florman and Storey, 1982, J Androl 3:157–164). Sperm membranes were solubilized using 1% digitonin/0.2% cholate, and the resultant detergent‐soluble fraction possessed QNB binding activity similar to that of intact membranes. The detergent‐soluble fraction maintained intact ZP receptor(s)–G protein coupling in that treatment of this fraction with either ZP or mastoparan resulted in a 35% or 65% increase in specific GTPγS binding, respectively. The solubilized membrane preparation was fractionated by gel permeation HPLC. A majority of specific QNB binding activity was confined to one HPLC fraction. Analysis of this fraction by SDS–PAGE revealed a complex of approximately 5 proteins unique to this fraction. The most prominent protein had a Mr of 72 kDa, which is within the Mr range for muscarinic receptors. A protein with Mr = 41 kDa was also present within this fraction. Subsequent pertussis toxin (PTX)‐catalyzed ADP‐ribosylation of this fraction revealed this protein to be the α subunit of the Gi class of G proteins. Although the QNB binding activity could not be positively identified, we propose that it is contained in one or more of the proteins unique to this fraction and that these proteins, including Gi, may act as part of a sperm receptor complex for the ZP. © 1994 Wiley‐Liss, Inc.
Mammalian cortical granules: Contents, fate, and function
Authors: Hoodbhoy Tanya , Talbot P. 
Published: February 2005

AbstractRecent studies have extended our knowledge regarding the contents of mammalian cortical granules (CG) and their function in postfertilization events. Cytochemical staining has demonstrated the presence of carbohydrates within mammalian CG, and lectin‐binding studies have shown that these carbohydrates include α‐Dmannose, α‐D‐GalNAc, and galactose residues in the hamster, α‐D‐mannose in the mouse and cat, and β‐D‐Gal(1,3)‐D‐GalNAc in the pig. Following fertilization and artificial activation, mannosylated material is released from CG and can be found on the oolemma and within the perivitelline space (PVS) of hamster oocytes. Fertilized or artificially activated rabbit, mouse, and human oocytes also release mannosylated, fucosylated and sialylated, and fucosylated material, respectively, which localizes to the oolemma. These glycosylated materials are probably of CG origin, although they have not been directly localized to the CG in rabbit, mice, and humans. The function(s) of the glycosylated material released from mammalian oocytes is not known, although it may participate in blocking polyspermy at the level of the plasma membrane, PVS, and/or zona pellucida (ZP), or it may facilitate preimplantation embryonic development. Proteinases, including tissue plasminogen activator, are also released from mammalian oocytes following fertilization and artificial activation, suggesting that they are of CG origin. These proteinases modify the ZP such that it is no longer receptive to sperm, and some proteinases have been suggested to bring about ZP hardening (an increased resistance to denaturing agents) by an unknown mechanism. Mouse ZP may also be hardened by an ovoperoxidase (cross‐links tyrosine residues) cytochemically identified in mouse CG and CG exudate. The phenomena of ZP hardening in mammalian zygotes is not well understood but is likely to function in blocking polyspermic penetration of the ZP and/or in protecting embryos during preimplantation development. Recently, a 75 kD protein (p75) has been immunocytochemically localized to mouse CG and to the PVS of fertilized oocytes and two‐cell embryos. The identity and function of p75 remains to be determined. Heparin binding placental protein may also be a CG component, since it is released from hamster oocytes following fertilization. It has not, however, been directly demonstrated to be a CG component, and its functions in fertilization and/or early embryonic development have yet to be defined. © 1994 Wiley‐Liss, Inc.
Identification of osteopontin (OPN) mRNA and protein in the rat testis and epididymis, and on sperm
Authors: Siiteri Jon E. , Ensrud Kathy M. , Moore Alison , Hamilton David W. 
Published: February 2005

AbstractWe have identified a bone cell adhesion molecule, osteopontin, in the rat testis and epididymis by Northern analysis, RT‐PCR, Western immunoblot analysis, and immunocytochemistry. A polyclonal antibody raised against rat epididymal fluid proteins was used to detect fusion proteins produced by a testis λgt11 cDNA library. Sequence analysis of one of four positive cDNA clones, designated as pREP5, revealed identity with the rat osteopontin (OPN) cDNA. The partial cDNA clone pREP5 encompasses 64% of the 1,457 residues reported by Oldberg et al. (1986; Proc Natl Acad Sci USA 83:8819–8823). Immunoblot analysis with a monoclonal antibody against OPN detects the presence of immunoreactive poly‐peptides in rat testis homogenates as well as in epididymal fluid and sperm extracts. Immunocytochemical localization to the basal and adluminal region of the seminiferous tubule suggests that OPN could be a Sertoli cell product. Indeed, Northern blot analysis of testicular cell preparations demonstated positive hybridization to Sertoli cellenriched RNA, but not to RNA isolated from interstitial cell preparations or to isolated germ cell RNA preparations. OPN is also detected in the rat epididymis and on epididymal spermatozoa. This is the first report on the presence of OPN mRNA and protein in rat testis and epididymis and on the presence of OPN on the surface of epididymal spermatozoa: The characterization of this protein in other tissue suggests that OPN could play a role in testicular cell adhesion during spermatogenesis and/or epididymal maturation, although other potential functions in the male reproductive tract are discussed. © 1995 Wiley‐Liss, Inc.