bluuebunny/crossref_metadata_2025_split huggingface dataset:
The response of rhesus monkey sperm motility to cervical mucus and solid surfaces
Authors: Katz D. F. , Phillips D. M. 
Published: February 2005

AbstractMovement characteristics of rhesus monkey spermatozoa were analyzed using high‐speed cinemicrography. In the first experiment, spermatozoa were studied at 100 frames/sec in diluted semen near a surface, and after entering ovulatory cervical mucus from a bonnet monkey. In mucus, the spermatozoa swam more slowly, with reduced flagellar beat frequencies. The beat shape was altered, and there was less lateral yawing of the sperm head. In the second experiment, spermatozoa in diluted semen were studied at 500 frames/sec in deep preparations, while swimming near a surface or when in the midplane of these preparations. Those sperm in the midplane swam faster, but with lower beat frequencies than those near the surface, and exhibited much more pronounced yawing motions. Such distinctions in sperm motion are probably hydromechanical in origin and may be significant during transport in the female.
Artificial insemination of the American lobster (Homarus)
Authors: Talbot P. , Thaler C. , Wilson P. 
Published: February 2005

AbstractA technique has been developed for artificially inseminating freshly molted female lobsters (Homarus). Using the criterion that eggs were fertilized if they showed development of normal cleavage patterns, at least 49.5% of the inseminated females extruded fertilized eggs. Sixty‐two percent of the fertilized eggs developed to the eyespot stage, and 26.6% of these subsequently hatched. Eggs were not fertilized in 7.7% of the extrusions. In 42% of the samples, it was not possible to establish whether fertilization had occurred because either samples were collected prior to initiation of cleavage or eggs were too poorly preserved to assess cleavage with confidence. It is probable that many of the eggs that were evaluated as equivocal were also fertilized. This technique should be valuable in the experimental and commercial aquaculture of lobsters and might be directly applicable to other crustaceans.
The evolution of hamster sperm motility during capacitation and interaction with the ovum vestments in vitro
Authors: Katz David F. , Cherr Gary N. , Lambert Hovey 
Published: February 2005

AbstractMovement characteristics of golden hamster spermatozoa were studied upon collection from the cauda epididymis, during an incubation which capacitates the spermatozoa in vitro, during penetration of the cumulus, and during attachment to and penetration of the zona pellucida. High‐speed videomicrography was employed to quantitate flagellar beat frequency and shape. The status of the acrosome was also assessed. During capacitation, hamster spermatozoa become increasingly invigorated before the onset of hyperactivated motility. Within the cumulus, beat frequency and curvature are reduced, apparently in response to the physical resistive properties of the matrix material. These properties appear to vary within the cumulus. Initial attachment to the zona precedes completion of the acrosome reaction, is non‐rigid, and is accompanied by increased beat frequency and curvature. Subsequently, the onset of rigid binding to the zona, completion of the acrosome reaction, and increased flagellar beat frequency are very closely associated in time. The latter produces an increase in thrust against the zona. Preliminary results indicate that ensuing zona penetration requires not more than five minutes, is at oblique angles, and is associated with a continuation of vigorous flagellar beating.
Ultrastructure of the sperm and spermatogenesis of three species of Mytilidae (mollusca, bivalvia)
Authors: Hodgson A. N. , Bernard R. T. F. 
Published: February 2005

AbstractThe mature sperm of three species of the subfamily Mytilinae (Choromytilus meridionalis, Mytilus galloprovincialis, Aulacomya ater) are of the primitive type. The sperm are 50–55 μm long, with a distinct head, midpiece of four to six mitochondria, and tail. In all three species the acrosome is in the form of an elongated hollow cone; yet each has its own characteristic morphology, indicating that sperm ultrastructure can be used as an aid to bivalve identification. A reexamination and comparison of the acrosomes from five subclasses of bivalve show that each subclass has an acrosome with a unique form. The process of spermatogenesis is similar in all three species; early spermatogonia are located close to the wall of the germinal follicle, and successive stages are displaced toward the center. Observations support the theories of acrosome formation by coalescence of numerous proacrosomal vesicles and of reduction in mitochondrial number by mitochondrial fusion.
Lower temperature of the cauda epididymidis facilitates the storage of sperm by enhancing oxygen availability
Authors: Djakiew D. , Cardullo R. 
Published: February 2005

AbstractThe temperature coefficients for the oxygen consumption rate of sperm from the rat, mouse, bull, and sea urchin were measured to be within a range of 2.7 to 3.0. For a reduction in temperature from 37°C to 30°C, the respiration rate of mammalian sperm declined by a factor of approximately 2.1. Hence, the availability of oxygen to sustain these sperm substantially increased over this temperature range. In addition, the solubility of oxygen in cauda epididymidal fluid increased by 7.6% for a decline in temperature from 37°C to 30°C. The increased availability of oxygen to sperm at the lower temperature is related to the increased storage capacity of the cauda epididymidis in scrotal mammals. In this context, it is suggested that the evolutionary migration of the cauda epididymidis to a cooler, extra‐abdominal location may have been influenced by the increased availability of oxygen to sperm and hence resulted in an increased capacity to sustain and thereby store more sperm per unit volume of duct.
Immunochemical localization of epididymal protein DE on rat spermatozoa: Its fate after induced acrosome reaction
Authors: Cameo Mónica S. , Echeverria Fernanda Gonzalez , Blaquier J. A. , Burgos M. H. 
Published: February 2005

AbstractThe localization of rat epididymal protein DE on cauda epididymis spermatozoa was studied with a specific antibody and the peroxidase antiperoxidase (PAP) immunocyto‐chemical reaction. At the light microscopic level, all spermatozoa appeared to be labeled over the dorsal portion of the head, whereas tails were negative. This observation was confirmed using scanning electron microscopy. A large number of particles were seen on the external surface of the plasma membrane covering the acrosomal region and a smaller number on the postacrosomal portion. Flagella appeared free of particles. Sperm suspensions were incubated in conditions that induce capacitation and the acrosome reaction, and, in this instance, the permanence of protein DE on the vesicles and the postacrosomal region of the membrane were observed. The localization of this epididymal protein on the sperm surface is compatible with a role in the gamete interaction process.
Developmental capacity of mouse oocytes following maintenance of meiotic arrest in vitro
Authors: Downs Stephen M. , Schroeder Allen C. , Eppig John J. 
Published: February 2005

AbstractIt was shown previously that the frequencies of fertilization and pre‐ and post‐implantation embryonic development of mouse oocytes matured in vitro were similar to those of oocytes matured in vivo (Schroeder and Eppig, Dev Biol 102:493–497, 1984). The present study determined the developmental capacity of mouse oocytes after they had been maintained in meiotic arrest in vitro by substances thought to be important regulators of meiosis in vivo. Oocytes were maintained in meiotic arrest for 12 or 24 h in medium containing maturation inhibitor(s), washed free of inhibitor, and cultured 16 h in inhibitor‐free (control) medium to permit meiotic maturation. Four different medium supplements were used to maintain meiotic arrest: (1) 100 μM dibutyryl cAMP plus 1 mM hypoxanthine; (2) 4 mM hypoxanthine plus 0.75 mM adenosine (H + AR); (3) 300 μM dibutyryl cAMP; and (4) 50 μM IBMX. Parallel groups of oocytes were treated to the same experimental protocol except that no inhibitory compounds were used; eg, oocytes were cultured a total of 28 or 40 h in control medium that permitted the resumption of maturation. These latter groups tested the effect of extended culture of mature oocytes on subsequent development. Control oocytes were cultured 16 h in control medium. Oocytes were inseminated and subsequently assessed for development to two‐cell and blastocyst stages. When oocytes were first cultured 12 or 24 h in medium that maintained meiotic arrest, development to two‐cells in all groups but one were within 10% of controls (70%). The 24 h H + AR group was the one exception (47% two‐cells). By contrast, culturing oocytes for 28 or 40 h in inhibitor‐free medium resulted in a precipitous decrease in development to two cells (27% and 7%, respectively). Blastocyst development followed the same pattern. When uridine (U) was added to H + AR medium, development to two cells was increased significantly. Also, the addition of FSH to the maturation medium significantly increased both two‐cell and blastocyst development in the H + AR and H + AR + U groups. Transfer of compacted morulae from the H + AR + U/FSH group into pseudopregnant hosts produced live young 19 days postinsemination.These data demonstrate that prolonged culture of oocytes matured in vitro decreased their capacity to undergo normal development following insemination, but if oocytes were maintained in meiotic arrest during prolonged culture and then allowed to mature spontaneously, their developmental potential was significantly preserved. These results also lend support for a physiological role of cAMP and purines in the maintenance of meiotic arrest in vivo.
Phosphoproteins are structural components of bull sperm outer dense fiber
Authors: Brito Mónica , Figueroa Jaime , Vera Juan C. , Cortés Patricia , Hott René , Burzio Luis O. 
Published: February 2005

AbstractTo isolate the bull sperm outer dense fibers, the cells were treated at room temperature with 0.05% cetyltrimethylammonium bromide and 7 mM 2‐mercaptoethanol. This treatment solubilized most of the sperm structure except for the sperm head and the fibrillar complex. The latter was purified by discontinuous sucrose gradient centrifugation. Electron microscopy showed that in the isolated complex each fiber remains attached to the corresponding segmented column of the connecting piece.Analysis of the fibrillar complex by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate showed three major components with molecular weights of 85,000, 33,000, and 11,000. These were purified, and their amino acid composition was found to be similar to that of the polypeptides of rat sperm outer dense fibers. Furthermore the components of 85,000 and 33,000 daltons contain about 2 mol of phosphoserine per mole of polypeptide, which indicates that they are phosphoproteins.
Flow sorting of X and Y chromosome‐bearing spermatozoa into two populations
Authors: Johnson L. A. , Flook J. P. , Look M. V. , Pinkel D. 
Published: February 2005

AbstractThe only established difference on which to base the separation of X and Y chromosome‐bearing spermatozoa is chromosomal constitution. This difference is quantifiable both from chromosome morphology (karyotype) and from DNA content. Flow cytometric techniques were used to measure relative DNA content of the X and Y populations and to flow‐sort spermatozoa from Chinchilla laniger. Epididymal spermatozoa were recovered in PBS, fixed in 80% ethanol, treated with papain and dithioerythritol, and stained for DNA with Hoechst 33342. Sperm nuclei were analyzed and sorted on an EPICS V flow cytometer/cell sorter, modified specifically for spermatozoa. Two clearly resolved peaks (coefficient of variation < 1.5%) with approximately 7.5% difference in DNA content between X and Y chromosome‐bearing spermatozoa were evident. Sperm nuclei were sorted from a portion of the X and Y peaks at a rate of 55 nuclei/sec for each population. Purities of individual X and Y populations averaged 95% as determined by reanalysis of the sorted populations. Successful sorting of Chinchilla X and Y chromosome‐bearing spermatozoa into separate populations may aid in the identification of a biochemical marker that could be used to discriminate between the two sperm populations and lead to a practical procedure for sexing spermatozoa.
Reproduction in mice: Protein kinase mimics the sperm effect on preimplantation embryo development
Authors: Chaykin Sterling , Davé Sheela 
Published: February 2005

AbstractThe creation of an environment in mouse fallopian tubes that is sufficient to sustain preimplantation embryo development is known to require the participation of spermatozoa in excess of those involved in the process of fertilization. We have now found that highly purified cAMP‐dependent protein kinase can substitute for spermatozoa in the facilitation of the first cleavage of mouse embryos. Both spermatozoa and purified protein kinase induce increases in fallopian phosphoproteins. It is suggested that nonfertilizing spermatozoa could exert their effects on preimplantation embryo development through the provision of protein kinase.
Incidence of chromosome anomalies in first‐cleavage mouse embryos obtained from frozen‐thawed oocytes fertilized in vitro
Authors: Glenister P. H. , Wood Maureen J. , Kirby Carol , Whittingham D. G. 
Published: February 2005

AbstractTo assess the effect of low temperature storage on mouse oocytes we (1) examined the capacity for normal development of embryos derived from frozen oocytes fertilized in vitro after transfer to pseudopregnant foster mothers and (2) analyzed the chromosome complement at the first cleavage division. Fewer frozen than control oocytes were fertilized (36% vs 66%), but after embryo transfer the proportion of fertilized eggs that implanted (67–68%) and formed normal foetuses (50–53%) was similar in the two groups. Freezing did not affect the observed incidence of aneuploidy (1.5–3.3%). The frequency of polyploid embryos derived from frozen oocytes was almost double that of controls (15.8% vs 8.5%), but it is unclear whether this is a real effect of freezing or is an artifact produced by the chromosome preparation technique.
Features of a seminal proteinase inhibitor‐ zona pellucida‐binding component on murine spermatozoa
Authors: Robinson Roderick , Richardson Richard , Hinds Kathy , Clayton Debra , Poirier Gary R. 
Published: February 2005

AbstractMurine cauda epididymal sperm contain sites on the plasma membrane over the apical portion of the acrosome that recognize proteinase inhibitors and the homologous zona pellucida. Ten times more of the component can be extracted from cauda and ductus sperm than from equal numbers of caput and corpus sperm. Likewise, few sperm from the upper epididymal regions are able to bind seminal inhibitor, while the majority of sperm from the cauda and ductus do bind. Cauda epididymal and ductus sperm lose little of their ability to bind inhibitor after a 4‐hour in vitro incubation in either a capacitating or a noncapacitating medium. The percentage of naturally inseminated sperm with the seminal inhibitor bound to their surface decreases to about 10 after 4 hours in utero. Approximately 80% of these sperm show positive fluorescence when given the opportunity to rebind the inhibitor, and these sperm do have an intact plasma membrane over the apical portion of the acrosome. Furthermore, after 4 hours in utero, the inhibitor bound in the same region of the sperm head as it did on freshly ejaculated sperm. The seminal inhibitor inhibits the binding of sperm to the zona if added during the first 15 minutes of incubation but has no effect on attachment.The data indicate that sperm gain the ability to bind the seminal inhibitor during the epididymal sojourn. Furthermore, this binding capacity is not lost during in vitro or in utero incubation. The site is not involved in sperm‐zona attachment but does participate in the binding of sperm to the zona.
Inhibition of in vitro fertilization by mouse anti‐mouse sperm sera and preliminary antigen identification
Authors: Hamilton Marilyn S. , Vernon Robert B. 
Published: February 2005

AbstractAntisperm antibodies are implicated as one causative factor of infertility, but the target antigens have not been identified. Immune responses to sperm antigens are qualitatively variable even within a single mouse strain. We took advantage of this variability and immunized individual female mice to allogeneic sperm to reflect their natural exposure during mating. We determined the ability of the individual sera to inhibit in vitro fertilization and to bind to sperm antigens separated by electrophoresis. Compared to preimmune sera, four of five immune sera significantly inhibited in vitro fertilization. The serum from individual mice bound variable panels of sperm antigens. By comparing the panels, we identified two polypeptides with molecular weights of 40,000 and 44,000 that were bound by all sera. We propose that these molecules may be good candidates for further investigation of the immunoprophylaxis of pregnancy.
Absorption of compounds in medium by the oil covering microdrop cultures
Authors: Miller K. F. , Pursel V. G. 
Published: February 2005

AbstractMicrodrops of medium under either paraffin or silicone oil are commonly used for culture of early mammalian embryos. Radiolabeled estradiol, progesterone, and androstenedione in drops of medium under oil decreased by 51, 89, and 77%, respectively, after 24‐hr incubation. Up to 14% of labeled estradiol moved to another drop of medium by passing through the oil. Several other substances tested (FSH, leucine, glucose, lactate, sodium ion, PGE2, PGF2α) did not pass into the oil. Both paraffin and silicone oils can alter the composition of culture medium by absorbing and transferring certain types of compounds.
Boar sperm surface glycoproteins: Isolation, localization, and temporal expression during spermatogenesis
Authors: Klint Marianne , Fridberger Anita , Menge Alan , Sällström Jan , Plöen Leif 
Published: February 2005

AbstractBoar sperm glycoprotein fractions were isolated by Lens culinaris hemagglutinin affinity chromatography of detergent‐solubilized ejaculated spermatozoa, followed by preparative sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis. In order to develop methods for further investigations of the sperm proteins, we proceeded with two of the isolated glycoproteins.Antibodies were raised in female rabbits against each of the two sperm glycoproteins. By a combination of immunosorbent chromatography, using the antibodies obtained, and preparative SDS polyacrylamide gel electrophoresis, highly purified sperm proteins were isolated. The sperm proteins were immobilized on Sepharose gel columns and specific immunoglobulin Fab fragments were enriched by affinity chromatography. The specificity of the Fab fragments was ascertained by immunoprecipitation analysis. The Fab fragments were used in indirect immunofluorescence analysis to localize the corresponding antigens on the surface of boar spermatozoa. Both antigens were exclusively confined to the postacrosomal region.Immunohistochemical staining of boar testis sections revealed that both antigens are expressed from the spermatid stage. This technique also revealed that one of the antigens congregated at the Golgi complex‐acrosome region during spermatogenesis.
Flow cytometry of X and Y chromosome‐bearing sperm for DNA using an improved preparation method and staining with Hoechst 33342
Authors: Johnson L. A. , Flook J. P. , Look M. V. 
Published: February 2005

AbstractA new and improved method of preparing mammalian spermatozoa for high resolution flow cytometric DNA analysis and flow sorting is described. Ejaculated or cryopreserved sperm were briefly sonicated to remove tails and then stained with Hoechst 33342. This simple procedure was found superior to more severe treatments of dimethylsulfoxide washes, fixation in 80% ethanol, and protease digestion of the sperm membranes and tails by papain. Flow cytometric DNA analyses of sperm samples subjected to varying sonication times indicated that X and Y chromosome‐bearing sperm populations could be well resolved with as little as 15‐sec sonication. In addition, a comparison of sonicated samples stained with four concentrations of bisbenzimide (Hoechst 33342) or 4′,6‐diamidino‐2‐phenylindole (DAPI) indicated that 2.5 or 5.0 μg/ml of Hoechst was sufficient to resolve the X and Y sperm populations. In order to quantitatively describe the flow cytometric data, several indices (sample quality, orientation and splitting) were developed.
Receiver‐operating characteristics curves for semen analysis variables: Methods for evaluating diagnostic tests of male gamete function
Authors: Peng H‐Q. , Collins J. A. , Wilson E. H. , Wrixon W. 
Published: February 2005

AbstractThis study draws on decision analysis to estimate the utility of seminal variables in predicting pregnancy. The infertile couples selected (n = 709) excluded those who had donor insemination or known female factors (history of pelvic infection, ovulatory disorders, endometriosis, and tubal disease). Diagnostic test properties were calculated with respect to pregnancy for two variables derived from the semen analysis report: sperm density, and the total number of motile sperm in the ejaculate (TMS). Receiver‐operating characteristic (ROC) curves based on sensitivity and specificity revealed that none of the proposed thresholds for sperm density or TMS is clearly a best choice. The highest positive predictive values for sperm density (75%) and TMS (75%) were associated with cutoff points at five million sperm per milliliter and five million motile sperm per ejaculate, respectively. The false positive rates when these cutoff points were used were 4.3% (sperm density) and 5.6% (TMS). ROC analysis provides visual and numeric vidence of the quality of a diagnostic test and constitutes a set of procedures for incorporating information from new tests of male gamete function into the diagnostic assessment of infertility.
Formation of the rupture site in preovulatory hamster and mouse follicles: Loss of the surface epithelium
Authors: Talbot Prudence , Martin Gary G. , Ashby Hansel 
Published: February 2005

AbstractChanges in the morphology of epithelial cells covering the sides and apex of ovarian follicles were examined in mice and hamsters during the final 13 hr before rupture using light and electron microscopy. At the time of the surge of luteinizing hormone, approximately 13 hr before follicle rupture, epithelial cells along the follicle sides are spherical, covered with microvilli, and remain so throughout the entire cycle. As ovulation approaches, cells at the apex become progressively flatter, increase in diameter, and undergo a reduction in the number and length of microvilli. By 2 hr before ovulation, the microvilli are present only along the boundary between adjacent cells and the cells are in different stages of degeneration. In some cells, the cytoplasm is electron dense and the nuclei are pyknotic. Other cells become electron lucent and cytoplasmic elements are leached from the cell. The apical plasma membrane is lost first over the center of the cell and later over the periphery. Epithelial cells detach from the apex individually until a large patch devoid of cells is formed. This includes the site of eventual rupture. The loss of epithelial cells from the apex of ovarian follicles of other species is compared with our results, and the processes involved in stretching, degeneration, and sloughing of the epithelial cells are discussed.