bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycoconjugates of the human sperm surface: Distribution and alterations that accompany capacitation in vitro
Authors: Cross Nicholas L. , Overstreet James W. 
Published: February 2005

AbstractWe have studied changes in the binding of fluoresceinated lectins to human sperm during in vitro capacitation. We first determined the surface labeling pattern of viable sperm obtained by the swim‐up procedure. Sperm were labeled with 100 μg/ml FITC‐conjugated lectin at 4°C for 30 min. We simultaneously used Hoechst stain 33258 as a supravital stain to help differentiate surface from intracellular lectin labeling. Of 14 lectins studied, six (phytohemagglutinin‐E, concanavalin A, Ricinus communis agglutinin‐I, and the lectins of wheat germ, Lens culinaris, and Pisum sativum) bound to the entire surface of sperm, sometimes with minor local heterogeneity. Three lectins (from peanut, Maclura pomifera, and soybean) usually bound in a punctate manner, with more label on the tail than on the head. Five lectins (Ulex europaeus, Dolichos biflorus, Helix pomatia, and Vicia villosa lectins, and lectin II of Griffonia simplicifolia) bound very poorly or not at all to the sperm surface. Sperm were also inspected for changes in surface lectin binding patterns after 0, 5, and 23 hr of incubation in a capacitating medium. Two lectins showed reproducible changes. The labeling by Maclura pomifera agglutinin decreased by 5 hr in eight of ten experiments, and among sperm labeled with concanavalin A, the incidence of sperm with a highly fluorescent anterior margin of the sperm head increased by about 3.5‐fold between 0 and 5 hr. The labeling pattern of the other lectins did not change.
Formation of the cylindrical structure during the acrosome reaction of abalone spermatozoa
Authors: Usui Noriko 
Published: February 2005

AbstractSpermatozoa of abalone Haliotis discus were examined before and during the acrosome reaction with special regard to one of the newly formed structures: a cylindrical structure surrounding a part of the elongated acrosomal process near the opening of the acrosomal vesicle. The structure, about 0.2 μm in diameter and about 1 μm in length, was revealed to be composed of a tightly coiled, fine tubular structure about 20 nm in diameter. In the course of the acrosome reaction, a triple‐spiral structure appeared in the anterior part of the acrosomal vesicle. Since this spiral structure was also composed of a tightly coiled 20 nm tubule(s), it was concluded that this structure was transformed into the single‐walled cylindrical structure by simple stretching in the direction of its longitudinal axis. In the clumps of spermatozoa that underwent acrosome reaction in suspension, the cylindrical structures were frequently found in contact with each other and/or other structures, indicating that they are very sticky.
Ethanol inhibits human and hamster sperm penetration of eggs
Authors: Rogers B. Jane , Cash Mervina K. M. , Vaughn William K. 
Published: February 2005

AbstractThe effect of alcohol on the fertilizing ability of both human and hamster spermatozoa was examined by an in vitro fertilization assay using hamster ova. Spermatozoa were incubated in capacitating media for 3 hr (hamster sperm) and 4 hr (human sperm). Hamster ova were inseminated with preincubated sperm and were examined after 2 to 3 hr. Ethanol was added to the capacitating media at concentrations of 25, 50, 100, 200, and 400 mg%. Fertilization of zona‐free hamster eggs by human spermatozoa was reduced from 49.6% in no alcohol to 16.7% in 400 mg% ethanol. Fertilization of hamster eggs by hamster sperm revealed a reduction from 63.6% to 33.7% in cumulus‐intact eggs and from 65.8% to 10.8% in cumulus‐free eggs in the presence of ethanol at 400 mg%. Hamster sperm acrosome reaction was reduced from 47% to 12%. When these hamster sperm with reduced acrosome reaction were placed with zona‐free hamster eggs, the 100% fertilization rate was not reduced; however, the fertilization index, which reflects the number of swelling sperm heads per egg, was reduced from 8.5 to 1.8. This suggests that as little as 12% of the sperm with an acrosome reaction is sufficient to fertilize 100% of the zona‐free eggs. If ethanol was added to the insemination media only, there was no inhibition of fertilization by human sperm or hamster sperm that had been previously capacitated in an ethanol‐free media. Removal of the ethanol from the preincubated sperm produced fertilization at control levels; thus the inhibitory effect is reversible. These results indicate that ethanol may affect fertilization by an inhibition of the capacitation and/or acrosome reaction process.
Effects of superovulatory doses of pregnant mare serum gonadotropin on oocyte quality and ovulatory and steroid hormone responses in rats
Authors: Yun Young W. , Yuen B. Ho , Moon Y. S. 
Published: February 2005

AbstractImmature rats (aged 28 days) were injected with 4, 20, or 40 IU pregnant mare serum gonadotropin (PMSG) and sacrificed every 6 or 12 hr. Control rats (4 IU) ovulated between 60 and 72 hr, whereas rats given superovulatory doses of PMSG (20 and 40 IU) ovulated between 24 and 72 hr. The oocyte count from the superovulated rats increased slightly between 24 and 36 hr and markedly between 48 and 72 hr. Degenerated oocytes were recovered 48 and 36 hr after administration of 20 and 40 IU PMSG, respectively. Thereafter, the proportion of degenerated oocytes was dose dependent and reached a maximum at 72 (30.9%, 20 IU) and 60 hr (61.0%, 40 IU). 17β‐estradiol content of the superovulated ovaries increased significantly (P < 0.01) from 36 hr and was maximal at 60 (20 IU) or 54 hr (40 IU), when compared to the control regimen. Administration of 40 IU PMSG resulted in a biphasic increase of progesterone content with the peaks at 36 and 60 hr. Androgen content of the superovulated ovaries was lower than control levels during the first 36 hr but was significantly (P < 0.01) higher thereafter. The results suggest that these alterations in the steroid response (particularly androgens) from 36 hr onward following superovulation may be responsible for the coincidental occurrence of abnormal oocytes, possibly by disturbing the specific intrafollicular steroid environment essential for complete maturation. In addition, oocyte aging that is due to earlier activation by the exogenous luteinizing hormone activity may be a contributing factor.
Dilauroylphosphatidylcholine liposome effects on the acrosome reaction and in vitro penetration of zona‐free hamster eggs by bull sperm: I. A fertility assay for fresh semen
Authors: Graham J. K. , Foote R. H. 
Published: February 2005

AbstractFresh sperm from five bulls having nonreturn rates ranging from 48% to 77% were treated with 15.7, 21.0, 26.2, 31.5, 36.7, and 42.0 μM dilauroylphosphatidylcholine (PC12) to induce the sperm acrosome reaction (AR). Treated sperm were incubated 3 hr with zona‐free hamster eggs at 39°C prior to fixation. The eggs were then stained and examined for sperm penetration. Differences in the percentages of motile sperm and of sperm exhibiting an AR among bulls were small when compared on a within‐liposome‐concentration basis. Increasing the PC12 concentration from 15.7 μM to 42.0 μM increased the percentage of sperm exhibiting an AR for all bulls. At the lowest lipid concentration (15.7 μM), the percentage of eggs penetrated by sperm from the five bulls was 6% to 36%, with 0% in controls. When sperm were incubated with increasing lipid concentrations, the egg penetration rate increased to over 80%, and the total number of sperm increased to over 100 per 36 eggs in each treatment for every bull. These penetration rates decreased at the highest lipid concentration. A correlation between the PC12 concentration maximizing egg penetration and the nonreturn rate of −.63 was found. The correlation between the PC12 concentration maximizing the total number of penetrated sperm per treatment and the bull nonreturn rate was −.96. It was concluded that PC 12 liposomes induce the AR in bull spermatozoa, which enables them to penetrate zona‐free hamster eggs. High fertility bulls required less lipid to induce the AR than did lower fertility bulls. Consequently, this assay of fresh semen could provide a laboratory method to estimate the fertility of a bull.
Dilauroylphosphatidylcholine liposome effects on the acrosome reaction and in vitro penetration of zona‐free hamster eggs by bull sperm: II. A fertility assay for frozen‐thawed semen
Authors: Graham J. K. , Foote R. H. 
Published: February 2005

AbstractFrozen‐thawed sperm from five bulls with fertility rates ranging from 48% to 77% were treated with seven concentrations of dilauroylphosphatidylcholine (PC12) liposomes to induce an acrosome reaction (AR) that enabled sperm to penetrate eggs. Treated sperm were incubated with liposomes for 7 min prior to insemination of zona‐free hamster eggs in vitro. Sperm and eggs were incubated 3 hr at 39°C prior to fixation, staining, and examination for sperm penetration and nuclear decondensation. The percentage of motile sperm immediately after thawing as well as after treatment with liposomes had a low correlation with sire fertility (r = .39 and ⩽.63, respectively). The percentage of sperm exhibiting an AR was more highly correlated with fertility (r ⩽ −.85). Similar correlations were found between fertility and the penetration rates of zona‐free hamster eggs or the total number of penetrating sperm. When data for two high and for two lower fertility buils were each grouped to increase information per data point the correlation between the PC12 concentration giving the maximum proportion of eggs penetrated and fertility was r = .92 (P ≤ .05). The correlation between the PC12 concentration producing the most total sperm penetrating the eggs and fertility r = .97 (P ≤ .05). It was concluded that PC12 liposomes induced an AR in bull sperm frozen‐thawed in egg yolk extender. Frozen‐thawed sperm from low fertility bulls require less PC12 to induce the AR and to penetrate zona‐free hamster eggs than do sperm from higher fertility bulls. These differences in lipid requirements may help to provide a quick, direct laboratory assay method to estimate the fertility of frozen bull semen.
Parthenogenetic activation of cattle follicular oocytes in vitro with ethanol
Authors: Nagai T. 
Published: February 2005

AbstractCattle follicular oocytes cultured in vitro for 24–33 h were treated with ethanol to induce artificial activation. When oocytes were cultured for 27–33 h before ethanol treatment, 60–68% of oocytes were activated and were found to have a female pronucleus(ei). In contrast, maturation culture of oocytes for 24–26 h resulted in low activation rates (25–38%). The female pronucleus was formed in the activated oocytes within 8–10 h of incubation after ethanol treatment. And it became visible under interference‐contrast microscope by centrifugation for 3 min at 15,000g and 10 min at 20,000g. These results indicate that ethanol treatment is effective for activation of cattle follicular oocytes and that the pronucleus formed in the activated oocyte can be visualized by centrifugation.
Ultrastructural localization of labeled acrosomal glycoproteins during in vivo fertilization in the rabbit
Authors: Kopečný V. , Fléchon J.‐E. 
Published: February 2005

AbstractRabbit spermatozoa were labeled predominantely in their acrosomal glycoproteins by 1‐3H‐glucosamine during spermiogenesis. Ova fertilized in vivo by spermatozoa labeled 22 days earlier were analyzed by fine‐structure autoradiography for the localization of the label. The latter was found associated with 1) the fused membranes of the acrosomal cap remaining on the zona pellucida surface, 2) the material released on the zona surface after the acrosome reaction and possibly detectable after tannic acid fixation, 3) the equatorial segment of the sperm head and the preequatorial swellings, and 4) other sperm components, eg, the sperm tail. No labeling, on the other hand, was detected on the denuded leading edge of spermatozoa found either in the penetration slit or in the perivitelline space. Our observations suggest the involvement of acrosomal glycoproteins in different mechanisms of sperm/zona pellucida interaction but are not in favor of a major role of (enzymatic) glycoproteins bound to the inner acrosomal membrane during the penetration of the zona pellucida.
Intermolecular cross‐linking of vitelline envelope polypeptides predominates in the hardened sea urchin fertilization envelope
Authors: Santiago Lyric , Carroll Edward J. 
Published: February 2005

AbstractAt fertilization, the sea urchin egg vitelline envelope (VE) elevates, and a subset of released cortical granule proteins, paracrystalline protein fraction (PCF), associates with the VE to form the fertilization envelope (FE). Cortical granule peroxidase cross‐links FE polypeptides by phenolic coupling of tyrosyl residues. We have used an immunological approach to determine which polypeptides are linked together in the hardened FE of Strongylocentrotus purpuratus. Soluble polypeptides were extracted from hardened FEs, and antibodies were prepared in rabbits against the insoluble envelope matrix (FE ghost). Whole immune serum and purified IgGs each reacted with FE ghosts when using an enzyme‐linked immunosorbent assay. VEs isolated by means of three published procedures cross‐reacted with the immune serum and purified IgGs. Soluble FE polypeptides also cross‐reacted with whole immune serum and IgGs owing to the presence of VE polypeptides. Hyalin, a protein not found in FEs, and PCF did not cross‐react with antiserum against FE ghosts. To determine which VE polypeptides were cross‐linked in the hardened FE, VE polypeptides were immunoblotted by using antiserum against FE ghosts. Most of the VE polypeptides that ranged from 68,000 to 283,000 molecular weight cross‐reacted with the antibody.
Actin and calmodulin coexist in the equatorial segment of ejaculated boar sperm
Authors: Camatini Marina , Casale Antonella 
Published: February 2005

AbstractThe direct overlay technique with iodinated calmodulin on boar sperm fractions evidenced a strong bond in the 45,000 molecular weight, which is the region recognized by anti‐actin antibodies. This result and the close codistribution of the two staining patterns for calmodulin and actin with immunofluorescence and immunoelectronmicroscopy suggest a possible interaction between calmodulin and actin in boar sperm.
Isolation of a stable apical segment of the guinea pig sperm acrosome
Authors: Stojanoff A. , Bourne H. , Andrews A. G. , Hyne R. V. 
Published: February 2005

AbstractThe large apical segments of guinea pig sperm acrosomes were mechanically separated from the spermatozoa and subsequently isolated by density gradient centrifugation. The isolated acrosomal caps were very stable and maintained their crescent morphology when suspended in sucrose‐based medium buffered at pH 5.6, with or without the acrosin inhibitor p‐aminobenzamidine (pAB). Examination under the electron microscope showed that the acrosomal caps were free of plasma membrane and were bound by an outer acrosomal membrane which was discontinuous. Enzymatic analysis after lysis of the caps indicated that acrosin and hyaluronidase were present with high specific activity, while only a trace amount of acid phosphatase activity and no arylsulphatase, phospholipase A2, or phospholipase C activities were present. Significant particulate acrosin activity, but only trace amounts of soluble acrosin activity, could be detected in the isolated acrosomal caps if assayed immediately after isolation in the absence of pAB. However, soluble acrosin activity of high specific activity was obtained after the acrosomal caps were extracted by 10% glycerol buffered at low pH (pH 3.0). The new procedures provide a means to isolate and purify guinea pig sperm apical acrosomal segments rapidly.
Lectin binding sites in the vitelline envelope of Bufo arenarum oocytes: Role in fertilization
Authors: del Pino Enrique J. , Cabada Marcelo O. 
Published: February 2005

AbstractIncubation of dejellied spawned oocytes from Bufo arenarum with different lectins results in a decrease of oocyte fertility. Concanavalin A was the most effective lectin; phytohem‐agglutinin P and wheat germ lectin were less effective. Agglutinin from soybean was scarcely active. These lectin effects could be ascribed to a hindering of specific sites for some proteases, since the same treatment renders the oocyte vitelline envelope insensitive to spermatolysin (an essential requisite for fertilization) and to trypsin. Also in this case concanavalin A was the most effective lectin. Univalent concanavalin A was also effective in blocking the fertility of dejellied oocytes. These results indicate that the residues of α‐D‐glucose and α‐D‐mannose present in the vitelline envelope are involved in gamete interactions in Bufo arenarum. This idea is also supported by the finding that dejellied oocytes (fertilizables) have a number of binding sites for concanavalin A that is three or four orders of magnitude higher than coelomic or fertilized oocytes (both not penetrable by spermatozoa).
Follicular characteristics associated with viable pregnancy after in vitro fertilization in humans
Authors: Nayudu P. L. , Gook D. A. , Lopata A. , Sheather S. J. , Lloyd‐Smith C. W. , Cadusch P. , Johnston W. I. H. 
Published: February 2005

AbstractThe aim of this study has been the development of a noninvasive method of predicting the pregnancy potential of human oocytes and embryos intended for in vitro fertilization and embryo replacement. A multifactorial system which distinguishes, with a high degree of accuracy, between normal pregnancy, abnormal pregnancy, and non‐pregnancy‐producing embryos is reported. The variables included are (1) follicular fluid proteins alpha1‐antitrypsin, complement C3, immunoglobulin IgG2, and total protein, and total proteoglycan level separated by isoelectric focusing; (2) follicular volume; and (3) an embryo appearance rating. The study group consisted of (1) follicles which produced embryos of known performance after transfer (a) when the number of embryos transferred = the number of implantations and, (b) where one embryo transferred = no pregnancy; (2) follicles which produced oocytes which did not cleave after insemination; and (3) follicles from which no oocyte was aspirated. Canonical discriminant analysis of follicular fluid variables and follicular volume has been used to characterize the oocyte performance groups. Correct classification was achieved in 69% of normal pregnancy, 70% of abnormal pregnancy, 33% of no pregnancy, and 47% of no cleavage oocytes. An embryo appearance rating was included with the above variables for a separate discriminant analysis of only those oocytes which had formed embryos after insemination. Correct classification was achieved in 81% of normal‐pregnancy, 70% of abnormal‐pregnancy, and 70% of nopregnancy embryos.
Binding of morphologically abnormal sperm to mouse egg zonae pellucidae in vitro
Authors: Kot Mary C. , Handel Mary Ann 
Published: February 2005

AbstractThe ability of morphologically abnormal mouse sperm to bind to the zona pellucida of the egg was examined with techniques of fertilization in vitro. After incubation with sperm, cumulus‐free ova were scored by either phase microscopy or scanning electron microscopy for the number and type of sperm bound. The percentages of abnormal sperm bound to zonae were compared to the percentages of abnormal sperm in the inseminating suspension. In general, all abnormal classes (except broadly spatulate sperm) bound to zonae at a frequency significantly lower than their representation in the inseminating suspension. However, when the percentage of abnormal sperm was quite high, no significant difference existed between frequencies of abnormal sperm bound and in the inseminating solution. The percentage of abnormal sperm bound did not increase significantly over time. Scanning electron microscopy studies demonstrated that the association of abnormal sperm with the zona pellucida varied according to sperm morphology. Normal and some abnormal sperm bound at an angle perpendicular to the zona, while more grossly abnormal sperm bound to ova tangentially.
A quantitative assay for capacitation: Evaluation of multiple sperm penetration through the zona pellucida of salt‐stored hamster eggs
Authors: Boatman Dorothy E. , Andrews Jane C. , Bavister Barry D. 
Published: February 2005

AbstractThe endpoint for sperm capacitation occurs when spermatozoa become able to penetrate intact zonae pellucidae of unfertilized homologous eggs. Activation of eggs stimulated by sperm fusion or by gamete aging initiates changes in zonae pellucidae that bar further sperm entry. This zona block mechanism reduces the usefulness of eggs as indicators for sperm capacitation. Egg storage in concentrated salt solutions destroys the zona block mechanism while retaining the biological sperm receptor/activator functions of the zona pellucida [Yanagimachi et al., Fertil Steril 31:562–574, 1979]. We have developed techniques for the quantitative assay of capacitation using multiple sperm penetration into zonae and have evaluated the sperm‐response characteristics of hamster eggs stored in a modified salt solution (STOR). Sperm, preincubated in capacitating or noncapacitating treatments (CAP or NOCAP, respectively), were coincubated with unfertilized and fertilized STOR‐treated zonae for 4 hr. Then zonae were stripped of externally bound sperm and the sperm heads in the perivitelline space (PVS) were fluorescently labeled with Hoechst dye 33342. Entry of CAP sperm into the PVS of STOR‐treated unfertilized eggs was highly correlated with sperm concentration (Rw equals; .859) and was log linear from 1 × 103–2 × 105 CAP sperm/ml. At 2 × 105 CAP sperm/ml, the mean number of PVS sperm was 63.5 and the maximum observed was 158. NOCAP sperm very rarely penetrated unfertilized zonae (2 sperm into 75 eggs). Few CAP sperm entered the PVS of STOR‐treated fertilized eggs (two sperm into 54 eggs at 2 × 105 sperm/ml) unless the sperm concentration was raised to high levels. Differences between replicates were due to male but not female (ie, egg) differences. We conclude that (1) STOR‐treated unfertilized zonae can be used to accurately quantitate differences between sperm capacitation and/or fertility states and (2) the availability of large numbers of homogeneous “shelf‐stable” zonae will make it feasible to perform hamster sperm capacitation bioassays on a large scale.
Evaluation of assay conditions for the zona‐free hamster ova bioassay of boar sperm fertility
Authors: Berger Trish , Horton M. B. 
Published: February 2005

AbstractThe ability to penetrate zona‐free hamster ova may be a very useful test of fresh and frozen boar sperm fertility. These studies were designed to optimize assay conditions prior to evaluation of the accuracy of the bioassay in predicting boar sperm fertility. The ability to penetrate zona‐free hamster ova was greater in sperm washed on a Percoll gradient than in sperm washed by dilution and centrifugation. Penetrating ability was greater in sperm from the sperm‐rich fraction than from the whole ejaculate but did not differ among different aliquots of the sperm‐rich fraction and did not decrease when the prewashing interval was increased from 15 to 85 min. Frequency of collection of ejaculates (1, 3, or 5 times per week) did not affect the penetrating ability of the sperm. Penetration rate was greater when sperm were coincubated with zona‐free hamster ova at 39°C compared to 37°C. Sperm from an infertile boar had reduced penetrating ability compared to sperm from fertile boars (11% vs 93%, P < .001). These studies suggest that the zona‐free hamster ova bioassay may be a useful assessment of fresh boar sperm fertility.