bluuebunny/crossref_metadata_2025_split huggingface dataset:
Separate effects of caffeine and dbcAMP on macaque sperm motility and interaction with the zona pellucida
Authors: Vandevoort Catherine A. , Tollner Theodore L. , Overstreet James W. 
Published: February 2005

AbstractCapacitation of macaque sperm with caffeine and dbcAMP is required for fertilization in vitro. This study determined the separate effects of caffeine and dbcAMP on sperm‐zona pellucida binding and the acrosome reaction of zona bound sperm. Semen from 6 cynomolgus macaques was washed through 60% Percoll, resuspended, and washed with BWW media and incubated for 2.5 hr. Caffeine, dbcAMP (2 mM each), or both (1 mM each) were added to aliquots of the sperm suspensions. Immature macaque oocytes were placed into drops of sperm suspensions, coincubated with sperm for 30 sec, and either fixed immediately or removed to sperm‐free media and incubated 1 hr before fixation. There were no significant diffences between groups in the percentage of live, acrosome‐reacted sperm in suspension. Treatment with caffeine and dbcAMP or with caffeine alone, significantly increased the number of sperm bound to each zona pellucida (96 ± 16 and 81 ± 17, respectively) compared to control and dbcAMP treatment (15 ± 4 and 28 ± 13). However, treatment with dbcAMP, alone and with caffeine, resulted in a higher percentage of acrosome‐reacted sperm on the zona (15.2 ± 2.1 and 9.0 ± 0.6) than control or caffeine treatment (3.0 ± 1.4 and 2.4 ± 0.5). Effects on sperm motility consistent with hyperactivation were detected only when both caffeine and dbcAMP were present. Although both caffeine and dbcAMP are presumed to increase or to produce the same effects as increased intracellular cAMP levels, these compounds have different effects on the ability of sperm to bind to the zona and to undergo the acrosome reaction. © 1994 Wiley‐Liss, Inc.
Sperm nuclear chromatin transformations in somatic cell‐free extracts
Authors: Banerjee Subhasis , Hulten Maj 
Published: February 2005

AbstractHeLa cell extracts induced decondensation of lysolecithin permeabilized Xenopus, pig, and human sperm chromatin; decondensation began almost immediately on incubation in the extract and was completed within 10–20 min. The average enlargements of human and pig sperm nuclei were 15‐fold and 3‐fold, respectively. The structural organization of pig and human sperm chromatin was significantly differnt. Decondensation was differentially inhibited by Mg++ and polyamines; inhibition was least for Xenopus and most for pig sperm nuclei. The nuclear membrane was disintegrated on chromatin dispersion, whereas the nuclei which failed to decondense exhibited distinct nuclear envelopes. The decondensing factors were stable at 65°C for 15 min. The dispersed chromatin was remodelled to somatic nucleosomal structures within 60 min. The remodelled chromatin could be recondensed to chromosome‐like structures, when incubated further in extracts from mitosis arrested HeLa cells. © 1994 Wiley‐Liss, Inc.
Insulin family growth factors have specific effects on protein synthesis in preimplantation mouse embryos
Authors: Shi C. Z. , Collins H. W. , Buettger C. W. , Garside W. T. , Matschinsky F. M. , Heyner S. 
Published: February 2005

AbstractPreviously constructed protein databases for two stages of preimplantation mouse embryogenesis, the compacted eight‐cell stage and the fully expanded blastocyst stage, have been used to analyze the effects of insulin, IGF‐I, and IGF‐II on protein synthesis in these developmental stages. Proteins were labeled by placing, for 2 hr, synchronous cohorts of 35–50 embryos into human tubal fluid (HTF) medium containing L‐[35S]‐methionine (1 mCi/ml) in the presence or absence of one of the growth factors. The embryos were then washed with medium and lysed. Samples were processed for 2‐D gel analysis. For each embryonic stage and each growth factor, four or five experimental replicates were done and the gel images were compared using the PDQUEST system. Using the computer‐assisted analysis, we were able to identify proteins that showed a statistically significant (P < 0.05) change in synthesis. At the eight‐cell stage of development insulin caused increased synthesis of two proteins and decreased synthesis in three proteins. Insulin‐treated blastocyst stage embryos exhibited an increased synthesis in eight proteins and decreased synthesis for one protein. The effect of IGF‐I at the eight‐cell stage of development was mostly inhibitory; the synthesis of only one protein increased and the synthesis of five proteins showed a decrease. Similar results were obtained with blastocyst stage embryos; four proteins demonstrated an increase in synthesis while 14 proteins showed a decrease. Eight‐cell stage embryos incubated with IGF‐II had seven proteins with a decreased synthesis, although in blastocyst stage embryos, nine proteins showed increased synthesis. However, seven IGF response proteins were found to be proteins that showed significant changes in isotope incorporation during the eight‐cell to blastocyst stage of development (Shi et al., 1993). In all, 54 proteins were affected, and these were unique; thus, protein synthesis in preimplantation mouse embryos is influenced by insulin and the IGFs, and further, each growth factor affects specific proteins. © 1994 Wiley‐Liss, Inc.
One‐minute exposure of 4‐cell mouse embryos to glucose overcomes morula block in CZB medium
Authors: Chatot Clare L. , Lewis‐Williams Jennifer , Torres Ioannis , Ziomek Carol A. 
Published: February 2005

AbstractOne‐cell mouse embryos that block at the 2‐cell stage can progress to the morula stage in CZB medium, but fail to cavitate and then swell and lyse. A 1‐min exposure to 27 mM glucose at the 4‐cell stage (∼42 hr) will support a high frequency of development to the blastocyst stage (75%) in the same medium. A glucose exposure is beneficial anytime between 30 and 54 hr of culture (67–73% blastocysts). Of a group of additional sugars and glucose analogues tested for their ability to replace glucose, only galactose was equivalent in promoting embryo development to the blastocyst stage (64% blastocysts). © 1994 Wiley‐Liss, Inc.
Effects of caffeine and casein phosphopeptides on fertilization in vitro of pig oocytes matured in culture
Authors: Nagai T. , Takenaka A. , Mori T. , Hirayama M. 
Published: February 2005

AbstractTwo experiments were conducted to assess the effects of caffeine and casein phosphopeptides (CPPs). One experiment tested the ability of frozenthawed epididymal spermatozoa from boar (A, B, C), of proven low in vitro fertilization rates, to penetrate pig follicular oocytes. The other experiment tested the ability of ejaculated spermatozoa to uptake Ca2+. In Experiment 1, oocytes matured in vitro were inseminated with spermatozoa (Boar A) in medium that contained 0, 2, 5, 10, 15, and 20 mM caffeine and CPPs (1 mg/ml), or in medium that contained the same caffeine concentrations without CPPs. When CPPs were added to the caffeine‐containing medium, significantly higher penetration rates were obtained than when the oocytes were inseminated in the CPPs‐free medium. When the oocytes were inseminated with the spermatozoa (Boar A, B, C) in medium that contained 5 mM caffeine and dephosphorylated CPPs (dCPP:1 mg/ml), the penetration rate was significantly lower than when the oocytes were inseminated with the spermatozoa in medium containing 5 mM caffeine and CPPs (1 mg/ml). In Experiment 2, the concentration of Ca2+ in ejaculated spermatozoa of proven low in vitro fertilization rates during incubation in the fertilization medium was determined with fluorescence, Fura2/AM. When the medium contained CPPs, the intracellular concentration of Ca2+ in spermatozoa increased with a peak of 113 nM after 90 min of incubation. The concentration of Ca2+ was gradually decreased in the medium without CPPs. However, addition of CPPs in the medium had no effect on the motility of spermatozoa in Experiments 1 and 2. These results indicate that CPPs promote Ca2+ uptake by spermatozoa and are effective for capacitation and/or acrosome reaction of spermatozoa leading to sperm penetration when caffeine is present in the medium and that the effect is reduced by dephosphorylation of CPPs. © 1994 Wiley‐Liss, Inc.
Redistribution of nuclear antigens linked to cell proliferation and RNA processing in mouse oocytes and early embryos
Authors: Vautier Dominique , Besombes Didier , Chassoux Danielle , Aubry Florence , Debey Pascale 
Published: February 2005

AbstractWe have systematically analyzed by indirect immunofluorescence the subcellular distribution of nuclear antigens in relation to developmental stages of maturing mouse oocytes and developing embryos. Antigens were of two types: (1) a protein whose nuclear localization in interphase somatic cells depends on their proliferative state protein recognized by a monoclonal antibody 43B1N, and (2) snRNP polypeptides recognized by autoimmune sera of anti‐Sm and anti‐RNP type. The protein recognized by 43B1N was present in the germinal vesicle of oocytes from antral follicles, but absent from the nuclei during the first hours of embryonic life up to the middle to late 2‐cell stage. Starting from this stage, it was always found in nuclei of interphase blastomeres, where its “speckles”; co‐localized with the speckles containing high concentrations of snRNP polypeptides. SnRNP polypeptides recognized by anti‐Sm and anti‐RNP sera were in turn found in nuclei of all developmental stages. When embryos were treated with aphidicolin or cytochalasin D to arrest cell division, the 43B1N reacting protein was again localized in the pronuclei at 42 hr post‐hCG, i.e., slightly later than the onset of transcriptional activity. These results suggest a progressive building up of nuclei during embryonic development, which could influence gene expression. © 1994 Wiley‐Liss, Inc.
Temporal and spatial expression of leukemia inhibitory factor in rabbit uterus during early pregnancy
Authors: Yang Zeng‐Ming , Le Su‐Ping , Chen Dong‐Bao , Harper Michael J. K. 
Published: February 2005

AbstractLeukemia inhibitory factor (LIF) has been shown to play an important role in the implantation of mouse blastocysts. The present study was designed to document the appearance of LIF in the rabbit uterus during early pregnancy and to determine whether changes just prior to implantation, similar to those in mice, occurred. LIF was localized in endometrial epithelium, myometrium, and endometrial glands. A low level of LIF was detected in the uterus of nonestrous and estrous females. LIF expression reached its highest level on day 5 of pregnancy and declined on days 6 and 7. By day 13 of pregnancy, little endometrial LIF was apparent. The expression of LIF on day 5 of pseudopregnancy was similar to that on day 5 of pregnancy. LIF expression was much higher at implantation sites than that at nonimplantation areas on day 7 of pregnancy. It is concluded that LIF may be important for the implantation of rabbit blastocysts. © 1994 Wiley‐Liss, Inc.
Plasma membrane block to sperm entry occurs in mouse eggs upon parthenogenetic activation
Authors: Tatone Carla , Van Eekelen Christina Grietje , Colonna Rosella 
Published: February 2005

AbstractThe ability of parthenogenetically activated mouse eggs to establish a plasma membrane (PM) block to sperm penetration was studied. Zona‐free eggs preloaded with Hoechst 33342 were activated by exposure to ethanol or OAG (1‐oleoyl‐2‐acetyl‐sn‐glycerol) and inseminated after different periods. Eggs challenged with sperm at 30‐ or 60‐min postactivation displayed a fertilization frequency significantly lower than that of control eggs. Conversely, when insemination was carried out at 120‐min postactivation, the proportion of fertilized eggs was equivalent to that observed in the control group. Moreover, we report that when the eggs were induced to resume meiosis without any notable loss of CGs (egg exposure to OAG at 100 μM external Ca2+ or to heat shock), a normal ability to be penetrated was recorded at 30‐min postactivation. Similar behaviour was exhibited by eggs that underwent a CG exocytosis close to that triggered by sperm in absence of nuclear activation (microinjection of inositol 1,4,5‐trisphosphate into the egg at 1 μM cytosolic concentration). Present data support the conclusion that parthenogenetically activated mouse eggs are capable of a transitory PM block response that requires both CG exocytosis and meiosis resumption to occur. © 1994 Wiley‐Liss, Inc.
Lipovitellin 2β is the 31 kD Ni2+‐binding protein (pNiXb) in Xenopus oocytes and embryos
Authors: Grbac‐Ivankovic Svetlana , Antonijczuk Katarzyna , Varghese Alison H. , Plowman Marilyn C. , Antonijczuk Adam , Korza George , Ozols Juris , Sunderman F. William 
Published: February 2005

AbstractAn Ni2+‐binding protein (pNiXb, 31 kD) present in mature Xenopus laevis oocytes and in embryos from fertilization in N/F stage 42, was isolated and characterized. After oocytes or embryos were fractionated by PAGE, electroblotted onto nitrocellulose, and probed with 63Ni2+, pNiXb was detected by autoradiography. pNiXb, a yolk protein located in the embryonic gut, was purified from yolk platelets by ammonium sulfate precipitation, delipidation, gel filtration chromatography, and HPLC analysis. During these steps, pNiXb copurified with lipovitellin 2. The N‐terminal sequence of purified pNiXb exactly matched that of Xenopus lipovitellin 2β, deduced from the DNA sequence of the Xenopus vitellogenin A2 precursor gene. Since pNiXb and lipovitellin 2β agree in N‐terminal sequence, amino acid composition, and apparent molecular weight, they appear to be identical. Based on a metalblot competition assay, the abilities of metal ions to compete with 63Ni2+ for binding to pNiXb were ranked: Zn2+ ≈ Cu2+ ≈ Co2+ > Cd2+ ≈ Mn2+ > Sn2+. This study shows that Xenopus lipovitellin 2β is a metal‐binding protein in vitro, and raises the possibility that it may function similarly in vivo. © 1994 Wiley‐Liss, Inc.
Nuclear transplantation by microinjection of inner cell mass and granulosa cell nuclei
Authors: Collas Philippe , Barnes Frank L. 
Published: February 2005

AbstractThe developmental potential of bovine inner cell mass (ICM) and somatic differentiated (granulosa cell) nuclei was investigated using nuclear transplantation. ICM blastomeres were isolated after immunosurgery of day 7 in vitro produced blastocysts and cumulus granulosa cells recovered from in vitro matured oocytes. Nuclear transplantation was carried out by microinjection of the lysed donor cells into enucleated mature oocytes. Oocytes were activated by three 0.2 kVcm−1/20 μs pulses in mannitol containing 100 μM Ca2+, with each pulse 22 min apart. Embryos were cultured in vitro for 7 days and blastocysts were transferred into recipients. ICM and granulosa cell donor nuclei directed 7% (20/304) and 9% (19/213) development to blastocysts, respectively. Fifteen blastocysts from ICM donors resulted in four pregnancies (27%) and two births. No pregnancy was detected with granulosa cell donors. The results illustrate the totipotency of ICM nuclei and indicate that granulosa cell nuclei promote preimplantation development of nuclear transplant embryos. © 1994 Wiley‐Liss, Inc.
Inhibition of flagellar motility of fowl spermatozoa by L‐carnitine: Its relationship with respiration and phosphorylation of axonemal proteins
Authors: Ashizawa Koji , Kamiya Tetsushi , Tamura Ikue , Tsuzuki Yasuhiro 
Published: February 2005

AbstractThe action of carnitine in regulating fowl sperm motility was investigated. As the concentration of L‐carnitine was increased (0–20 mM), the motility of intact and demembranated fowl spermatozoa was reduced at 30°C. Even the presence of 1 mM CaCl2 before the addition of 10 mM carnitine could not prevent the inhibition of motility at 30°C and 40°C. However, motility was restored by reducing the concentrations of carnitine. Carnitine also inhibited the oxygen consumption and ATP concentrations of intact spermatozoa, and caused a reduction in intracellular free Ca2+ concentrations. Phosphorylation of a 50 kDa protein and dephosphorylation of 24 kDa and 30 kDa proteins of demembranated spermatozoa were observed after the addition of carnitine. In contrast, the flagellar ATPase activity of crude dynein extract was not affected by the addition of carnitine. These results suggest that inhibitory effect of carnitine for motility may be directly on the axonemal phosphoproteins, but not directly on the dynein ATPase activity. The physiological role of carnitine for fowl spermatozoa in the ductus deferens is discussed. © 1994 Wiley‐Liss, Inc.
Expression of the complement regulatory protein CD59 on human spermatozoa: Characterization and role in gametic interaction
Authors: Fenichel P. , Cervoni F. , Hofmann P. , Deckert M. , Emiliozzi C. , Hsi B. L. , Rossi B. 
Published: February 2005

AbstractProtectin (CD59) is a complement regulatory protein which blocks the membrane attack complex during complement activation. CD59 was identifield on the human sperm surface by means of H19, an IgG1 anti‐protectin mouse monoclonal antibody. Using Indirect immunofluorescence, flow cytometry and immunoperoxidase, CD59 was found to be present on the whole plasma membrane including the head and tail of fresh ejaculated, capacitated and acrosome‐reacted spermatozoa. Immunoperoxidase staining of normal testicular sections indicated that this protein was already present on intraluminal germ cells. Analysis of this sperm protein by gel electrophoresis and immunoblotting revealed that its molecular weight of 20 kDa was comparable to that of CD59 expressed on peripheral blood cells (erythrocytes, lymphocytes) and that it was bound to the membrane through a glycophospholipid tail which could be released after treatment with phosphatidylinositol‐specific phospholipase C. Associated to membrane cofactor protein (CD46) and decay accelerating factor (CD55) located in the acrosomal membranes, CD59 may participate to the protection of male gametes against complement‐mediated damage as they travel through the female genital tract. Moreover CD59, known as an adhesion molecule involved in lymphocyte rosettes, may also participate in cell to cell adhesion during gametic interaction since H19 inhibited sperm binding and reduced the penetration rate and index during the hamster egg penetration test. © 1994 Wiley‐Liss, Inc.
Pregnancy‐associated endometrial expression of antileukoproteinase gene is correlated with epitheliochorial placentation
Authors: Badinga Lokenga , Michel Frank J. , Fields Michael J. , Sharp Dan C. , Simmen Rosalia C. M. 
Published: February 2005

AbstractUterine expression of the mRNA encoding antileukoproteinase (ALP) is highest in pig uterus during mid‐ to late pregnancy, suggesting a stage of pregnancy‐dependent role for this elastase/cathepsin G protease inhibitor in feto‐maternal interactions. To examine a potential relationship between uterine synthesis of ALP and the type of placentation in mammalian species, the expression of ALP mRNA and/or protein in pregnant mares, cows, rats, and mice was evaluated. Genomic DNA and mRNA hybridization analyses were performed using a porcine ALP cDNA as probe. The concentration of ALP protein in reproductive tissues was determined by RIA using a polyclonal antibody raised against a synthetic peoptide (ALP 16P) corresponding to amino acid residues 21–36 of the porcine ALP protein. A single ALP mRNA transcript of approximately 0.8 kb in length was detected in equine and bovine uterine tissues. The relative abundance of ALP mRNA in equine endometrium increased between days 125–170 (mid‐pregnancy), and then decreased by day 215 of pregnancy. Similarly, the steady state levels of ALP mRNA in bovine endometrium and myometrium were higher during mid‐ to late than during early pregnancy. The levels of ALP mRNA in bovine fetal cotyledon were low and did not change significantly with stage of pregnancy. No hybridization was detected to pregnant rat endometrial tissues, although high stringency Southern blot analysis of porcine, bovine, and rat genomic DNAs using porcine ALP cDNA as probe predicted a high degree of nucleotide sequence homology in their respective ALP genes. In pregnant cows, concentrations of ALP protein were higher in maternal endometrium and myometrium than in fetal cotyledon. Tissue ALP content in bovine uterus increased between days 17–89, and then decreased by day 248 of pregnancy. In contrast, no ALP protein was detected in cytosolic extracts prepared from endometrium of pregnant rats and mice. THe demonstrated synthesis of ALP mRNA and/or protein in the endometrium of the mare and the cow similar to that of the pig, but not in the endometrium of the rat and mouse, during pregnancy indicates a potential correlation between endometrial ALP expression and epitheliochorial type of placentation in mammalian species. © 1994 Wiley‐Liss, Inc.
Characterization and properties of steroid binding protein in Bufo arenarum serum
Authors: Fernández Silvia N. , Mansilla‐Whitacre Zulema C. , Miceli Dora C. 
Published: February 2005

AbstractSerum steroid binding properties of mature Bufo arenarum females were studied. Binding data obtained using charcoal adsorption assay and equilibrium dialysis methods indicates a single protein, named Bufo arenarum sex binding protein (Ba SBP), which binds 5 α‐dihydrotestosterone (DHT), testosterone (T), and estradiol‐17β (E2) with high affinity (107 M−1 – 108 M−1) and fair capacity (10−6 M). Scatchard plot analysis demonstrated the coexistence of two binding sites. Ba SBP has a sedimentation coefficient of 5.2 S in sucrose gradient centrifugation in low salt and under steady‐state conditions. The specificity of this protein, determined by competitive binding experiments, is comparable to human SBP. DHT and T bind with higher affinity than E2. Estriol and estrone competed poorly, while diethylstilbestrol and C21 steroids did not compete. The binding capacity of this protein is under estrogenic control. © 1994 Wiley‐Liss, Inc.
Parthenogenetic development of bovine oocytes matured in vitro for 24 hr and activated by ethanol and cycloheximide
Authors: Presicce Giorgio A. , Yang Xiangzhong 
Published: February 2005

AbstractThis research was undertaken to improve development of parthenogenetic embryos following various combined treatments of ethanol and cycloheximide. In Experiment 1 in vitro matured oocytes (IVM, 24 hr) were treated with 7% ethanol for 5 min followed by incubation in 10 μg/ml cycloheximide in Medium 199 for 0 (control), 5, 10, and 20 hr. Development to 2–8 cells following culture for 3 days was similar among treated groups (32–41%; P > 0.05), which was higher than that of controls (6%; P < 0.05). Experiment 2 compared pre‐ethanol exposures for 0, 1, 2.5, and 5 min, followed by 5 hr cycloheximide treatment on activation development. One‐ to 5‐min groups resulted in 42–44% cleavage contrasted to 1–12% for controls (P < 0.05). Experiment 3 examined the effect on oocyte development of ethanol and different concentrations of cycloheximide (0, 1, 5, and 10 μg/ml). Cleavage to 2–8 cells was similar among the 5 and 10 μg/ml cycloheximide groups (36% and 42%, P > 0.05) but lower (P < 0.05) for the 1 μg/ml group (24%) and the controls (2–13%). When 5 μg/ml cycloheximide was used (Experiment 4), pre‐exposure to ethanol (1, 2.5, and 5 min) resulted in more oocytes cleaved (38–41%) than in the cycloheximide alone group (0%) or the control (0%, P < 0.05). Experiment 5 tested blastocyst development of the activated oocytes with or without cytochalasin B treatment. Oocytes developed to blastocyts were 0%, 14%, 3%, and 3% (P < 0.05), respectively, for control, treatment with ethanol and cycloheximide in the presence, or absence of cytochalasin B, or electrical pulse plus cycloheximide. In conclusion, the combined ethanol and cycloheximide treatment supported high rates of parthenogenetic development using 24 hr IVM bovine oocytes. Blastocyst rate was significantly higher when cytochalasin B was added to the combined activation regimen. © 1994 Wiley‐Liss, Inc.