bluuebunny/crossref_metadata_2025_split huggingface dataset:
Progressive defects observed in mouse sperm during the course of three generations of selenium deficiency
Authors: Wallace Edith , Calvin Harold I. , Cooper George W. 
Published: February 2005

AbstractThree successive generations of mice were fed a Torula yeast based Se‐deficient diet with or without 0.1 ppm Se in the drinking water. The Se‐deficient mice, in the course of three generations, showed a decrease in body weight, testis weight, epididymal weight, and sperm production. The percentage of morphologically abnormal sperm increased in successive generations. The majority of sperm defects were found in the midpiece region of the tail. Many of these aberrant sperm were motile. A progressive decrease in fertility was noted during the first two generations of Se deficiency. This system confirms the essential role of Se in spermatogenesis and provides a model for the evaluation of the primary effect of Se deprivation on the structural development of sperm.
Nuclear and chromatin structure in rat spermatozoa
Authors: Koehler James K. , Würschmidt Utta , Larsen Mary Pat 
Published: February 2005

AbstractThe nuclei of mature mammalian spermatozoa contain a highly ordered, lamellar substructure, presumably constituting the nucleoprotein of the haploid chromosomal complement. With a view toward constructing a plausible model of chromatin packing in sperm, we have determined some of the quantitative parameters associated with these “nuclear lamellae” in rat spermatozoa. Epididymal sperm from white, Sprague‐Dawley rats were examined by conventional sectioning methods, freeze fracture of fixed and unfixed specimens, and by whole mount replica techniques. Fixation and glycerolation did not significantly alter nuclear structure as seen by freeze fracture. Numerical data obtained from cross fractures of sperm heads indicate that the number of lamellae are quite constant at 10.4 ± 1.8 and that the linear measure of the lamellae is 7.2 ± 2.3 μm per cross fracture. The total area of cross fracture, assuming an elliptical profile is 2.3 k 0.7 μm2 and the thickness of the lamellae is 18.2 ± 3.5 nm with a range of 13.5 to 25.5 nm. An estimate of the total surface area of the nuclear lamellae could be made from measurements of projected nuclear area (from replicas and sections) as 173 ± 15 μm2. From these data and the known amount of DNA in the rat sperm nucleus, a model can be proposed for the organization of the nucleoprotein in these lamellar sheets. It is suggested that the chromatin is arranged in a coiled‐coil configuration closely associated together in a side‐by‐side fashion and continuous in extent. Approximate calculations based on this simple model are within a factor of 2 or 3 of predicting the correct amount of DNA in the sperm nucleus.
Hormonal regulation of zona‐binding ability and fertilizing ability of rat epididymal spermatozoa
Authors: Fournier‐Delpech S. , Hamamah S. , Tananis‐Anthony C. , Courot M. , Orgebin‐Crist M.‐C. 
Published: February 2005

AbstractRat spermatozoa from the proximal caput, the proximal corpus, the middle corpus, and the distal cauda epididymidis were examined for their ability to bind to the zona pellucida after a 1‐, 2.5‐, or 4.5‐h incubation at 34°C with rat eggs in cumulus. Caput spermatozoa did not bind to the zona after 1, 2.5, or 4.5 h of incubation. Corpus spermatozoa did bind to the zona, but the percentage of eggs with bound spermatozoa and number of bound spermatozoa per egg increased with the length of incubation. Cauda spermatozoa bound readily to the zona pellucida, and their zona binding ability did not change with longer incubations. It thus appears that rat spermatozoa gradually acquire the ability to bind to the zona pellucida in the corpus epididymidis.The zona‐binding capacity of cold immobilized cauda spermatozoa, defined as the percentage of eggs with bound spermatozoa, increased with the number of spermatozoa incubated and reached a plateau characteristic of the endocrine status of the animal. After castration, zona‐binding ability is progressively lost from day 3 until day 10 where it is nil. Testosterone supplementation maintains zona‐binding ability to control levels. Similarly, fertilizing ability declines from day 5 after castration until day 10. Testosterone prevents this loss of fertilizing ability. It thus appears that the development of zona‐binding ability during epididymal transit is, like the development of fertilizing ability, under androgen regulation.The close correlation between the onset of fertilizing ability and zona‐binding ability during maturation, the loss of fertilizing ability and zona‐binding ability after castration, and the recovery of both fertilizing ability and zona‐binding ability with testosterone treatment suggests that the androgen‐dependent development of zona‐binding ability is an important component of the acquisition of sperm fertilizing ability during epididymal transit.
Factors influencing the penetration of human spermatozoa into cervical mucus in vitro
Authors: Katz D. F. , Overstreet J. W. , Tom R. A. , Hanson F. W. 
Published: February 2005

AbstractExperiments were conducted to determine some of the biological variables that may affect sperm penetration of human cervical mucus in vitro. Quantitative tests of cervical mucus penetration were carried out to determine the percentage of successful collisons (PSC) between seminal spermatozoa and the semen‐mucus interface. Fifteen duplicate comparisons and 15 triplicate comparisons of PSC values were made, each using individual samples of semen and mucus. In most cases the difference between any two comparisons was less than 10%, and there was no correlation between the magnitude of the difference between tests and the absolute value of the PSC. The triplicate comparison showed no correlation between the PSC values and the location of the mucus in the collection catheter (proximal, middle, distal). In 15 experiments the semen was serially diluted with an aliquot of its own plasma to determine the effect of sperm concentration on the PSC. No effects were observed until the sperm concentration fell below 10 × 106 sperm/ml, when the PSC appeared to increase. These results indicate that the tests should be applicable to all but the most severely oligospermic semen samples.
Influence of the flagellar wave development and propagation on the human sperm movement in seminal plasma
Authors: Serres C. , Feneux D. , Jouannet P. , David G. 
Published: February 2005

AbstractMicrocinematographic analysis (50 frames/sec) of the movement of 57 ejaculated human spermatozoa showed a heterogeneity of the flagellar parameters (velocity of the wave development (Vd), velocity of the wave propagation (Vc), beat frequency) corresponding to that of head trajectories (progressive velocity and amplitude of the lateral head displacement). According to our results the interdoublet sliding velocity might control the progressive velocity of the spermatozoa through the wave propagation velocity. The presence of the principal bend on the proximal part of the flagellum (20 μm) might inhibit the initiation of a new wave. The complex relation existing between Vc and Vd seems to indicate that the two velocities are partly independent of one another.
Anti‐inflammatory drugs promote polyspermic fertilization in sea urchins
Authors: Schuel Herbert , Traeger Eveline , Schuel Regina , Boldt Jeffrey 
Published: February 2005

AbstractSea urchin eggs are known to release H2O2 during the cortical reaction at fertilization to help prevent polyspermy by inactivating excess sperm in the vicinity. This process resembles the peroxidatic killing of bacteria by phagocytic leukocytes during inflammation. Associated with these reactions in leukocytes, arachidonic acid is released from phospholipids and can be oxidized via the cyclooxygenase pathway to produce prostaglandins. Nonsteroidal anti‐inflammatory drugs (NSAID) that are cyclooxygenase inhibitors in somatic cells were used to determine whether Arbacia punctulata and Strongylocentrotus purpuratus eggs use these processes to help prevent polyspermy. The potent cyclooxygenase inhibitor indomethacin causes a dose (10–100 μM) and sperm density dependent induction of polyspermy if added before the egg completes the cortical reaction. It does not retard elevation of the fertilization envelope and does not promote polyspermy by protecting sperm from peroxidatic inactivation by egg‐derived H2O2. Other potent cyclooxygenase inhibitors, flufenamate and meclofenamate, also induce polyspermy at 10–60 μM. Aspirin, a weak cyclooxygenase inhibitor in somatic cells, does not cause polyspermy at 5 mM. These findings provide evidence that prostaglandins or other cyclooxygenase‐derived metabolites may help assure monospermic fertilization in sea urchins.
The site of the acrosome reaction during in vivo penetration of the sheep oocyte
Authors: Crozet N. , Dumont M. 
Published: February 2005

AbstractIn vivo fertilization of sheep eggs has been studied by electron microscopy. Remnants of the acrosome reaction were present at the zona surface of every penetrated egg, indicating that the acrosome reaction in sheep occurs at the surface of the zona pellucida.To determine whether follicular oocytes could specifically bind spermatozoa, oocytes isolated from different size classes of antral follicles were transferred into the oviducts of mated ewes, recovered 4 hr 30 min later, and analyzed by electron microscopy. Oocytes from follicles up to 1 mm in diameter failed to bind spermatozoa and were not penetrated. In contrast, the zona of oocytes from follicles ⩾ 2 mm in diameter induced the acrosome reaction. These oocytes were penetrated but failed to achieve cortical granule exocytosis and so to mount a block to polyspermy. Moreover, sperm nuclei incorporated into the ooplasm did not decondense although the sperm nuclear envelope was dispersed.
Optimization of procedures for separation of motile and nonmotile bull and rabbit spermatozoa with bovine serum albumin gradients
Authors: Wall R. J. , Jerrard D. A. , Parrish J. J. , Foote R. H. 
Published: February 2005

AbstractThe effect of equipment design, separatory media, and time and temperature of separation were studied. Discontinuous 4%/10% bovine serum albumin (BSA) gradients were used to isolate highly motile spermatozoa in rabbit and bull semen. For all conditions tested, motility of spermatozoa collected from the 4% BSA gradient layer (top) was less than or equal to the motility of the unseparated controls. Fractions collected from the 10% BSA gradient layer contained highly motile spermatozoa. In experiment 1, washed bull spermatozoa were diluted with phosphate‐buffered saline (PBS) containing 2% BSA or 4% BSA before being fractionated on BSA columns contained in test tubes. Inclusion of BSA in PBS tended to reduce loss of motility during washing, but the proportion of sperm recovered was highest in PBS. In experiment 2, motility and recovery of buck spermatozoa collected from the 10% BSA gradient region tended to be higher when fractionation temperature was 30°C as compared to 35°C, and motility was significantly higher when incubation time was 30 min as compared to 1 hr. The proportion of sperm recovered was unaffected by incubation time. In experiments 1 and 2, 41 of 48 separations resulted in at least one fraction containing spermatozoa with motility greater than or equal to 90%. In the third experiment, the surface area on which bull and buck spermatozoa were layered was increased by forming the 4%/10% BSA gradients in conical supports. Separation of sperm on conically shaped columns was not as effective as on cylinders. The use of cylinders to support the BSA gradients and a separation time of 30 min at 30°C is recommended.
Changes in motility that accompany the acrosome reaction in hyperactivated hamster spermatozoa
Authors: Suarez Susan S. , Katz David F. , Meizel Stanley 
Published: February 2005

AbstractHigh‐speed videomicrography was used to compare the movement characteristics of hamster epididymal sperm which completed the acrosome reaction in vitro with those of unreacted sperm in the same sample. More than 90% of the motile sperm incubated for 4.25 hr in a modified Tyrode's medium containing bovine serum albumin, taurine, and epinephrine were hyperactivated and about half were acrosome reacted. The flagella of reacted sperm beat with significantly lower frequency and bent into more acute curves than those of unreacted sperm. Lowered beat frequencies were not attributable to aging, because sperm induced to react synchronously at 3.5 hr using lysophosphatidyl choline beat with similar lowered frequencies. Both acrosome‐reacted and unreacted hyperactivated sperm swam in circular trajectories resulting from asymmetrical flagellar beating. The flagellar beating of unreacted sperm was more symmetrical; consequently, they swam in larger circles and had the potential to cover space more rapidly. Some unreacted sperm, perhaps in transition towards hyperactivation, swam in helical trajectories.When preincubated sperm were added to slides containing oocytes in cumulus, some unreacted sperm initiated cumulus penetration. All reacted sperm failed to do so, adhering instead to the cumulus at its boundary. Reacted sperm attached to the zonae pellucidae of cumulus‐free oocytes via the region of the inner acrosomal membrane. Unreacted sperm attached via the equatorial region, but pivoted about the point of attachment, thus failing to generate sustained thrust against the zona. In conclusion, unreacted hyperactivated sperm have a different potential than reacted sperm for movement and interaction with egg vestments.
A preliminary report on the establishment of pregnancies in an in vitro fertilization (IVF) programme at the University of British Columbia (UBC)
Authors: Moon Young S. , Yuen Basil Ho , Pride Sheila M. , Rowe Timothy C. , Poland Betty J. , McComb Peter F. , Gomel Victor 
Published: February 2005

AbstractBetween July 1982 and November 1983, two pregnancies were established using in vitro fertilization and embryo transfer (IVF and ET) procedures with three different schedules to induce follicular maturation. All women were cycling normally and had inoperable or absent fallopian tubes. Of 83 oocytes aspirated from 24 patients (31 cycles), 75% were considered mature and 25% immature by the morphological characteristics of the oocytes and cumulus cells. Oocytes were preincubated for 6–24 hours, and after insemination, 60% cleaved to the two‐to‐four‐cell stage. The superovulation induction schedule employing hMG administered according to the individually adjusted treatment scheme established two pregnancies. This schedule was considered the superior regimen, as it gave the highest proportion of mature oocytes (89%) which cleaved (78%). The pregnancy‐attaining follicle showed a high progesterone:estradiol‐17β ratio (P4/E2) in its microenvironment of aspirated follicular fluid, culture media of granulosa cells, and oocyte‐cumulus complex. Our observations indicate a high P4/E2 ratio in the pregnancy‐attaining follicle, and thereby reflect a further parameter in influencing maturation of the oocytes most likely to implant.
Solubilization and enrichment of boar sperm membrane proteins
Authors: Klint Marianne , Sege Karin , Curman Bengt , Plöen Leif , Peterson Per A. 
Published: February 2005

AbstractBoar sperm membranes are rather resistent to the solubilizing effect of some detergents. Deoxycholate, an ionic detergent, was efficient in solubilizing sperm proteins but some nonionic detergents like Triton X‐100 displayed relatively poor capacity in rendering membrane proteins soluble. This may be due to sperm proteins being attached to submembraneous structures through bonds involving divalent cations, since mixtures of Triton X‐100 and ethylenediamine tetraacetic acid (EDTA) were almost as efficient as deoxycholate in solubilizing membrane proteins. Since intact spermatozoa were directly treated with detergents the solubilized proteins comprised a mixture of intracellular and membrane components. To enrich for membrane proteins, affinity chromatography on columns containing different lectins was carried out.SDS polyacryiamide gel electrophoresis of sperm glycoproteins desorbed from the various lectin columns demonstrated that each lectin bound a unique set of components although most glycoproteins were recovered from two or more columns. Columns containing Lens culinaris hemagglutinin yielded more sperm glycoproteins than any of the other lectin columns examined.The predominant amount of the sperm proteins recovered from the Lens culinaris lectin column was membrane derived, as the majority of the proteins were integrated into liposomes. It is concluded that sperm membrane proteins are efficiently solubilized by detergent in the presence of a chelator and that most of the membrane glycoproteins can easily be enriched by affinity chromatography on a lectin column. Proteins obtained in this way should serve as excellent starting material for the isolation of individual sperm membrane proteins.
The morphological and ultrastructural appearance of the crater defect in stallion spermatozoa
Authors: Johnson L. A. , Hurtgen J. P. 
Published: February 2005

AbstractThe appearance of the nuclear abnormality “crater defect” is described in spermatozoa from the domestic horse (Equadae). Under scanning electron microscopy, the defect appears as a severe depression at any area of the sperm nucleus or as a blister or swelling at some point on the sperm nucleus. Ultrastructurally, the crater appears as a nuclear vacuole containing amorphous material similar to that described in bull and boar sperm. The craters ranged in size from 0.5 to 2 μm in diameter. Within ejaculates of stallions having this defect, the percentages of sperm with crater defects varied widely over time, being as high as 60% and as low as 15%.
Interaction of isolated components from mammalian sperm and egg
Authors: Sullivan Robert , Bleau Gilles 
Published: February 2005

AbstractIn order to identify those proteins from the plasma membrane of hamster spermatozoa that exhibit an affinity for components of the zona pellucida we have used the Western blot technique. Zonae pellucidae from postovulatory hamster oocytes were solubilized by exposure to an acidic pH and then radiolabeled using the Bolton‐Hunter reagent. These 125I‐zona pellucida proteins retain their immunoreactivity and migrate in three heterogeneous bands when submitted to SDS‐PAGE electrophoresis. Membrane proteins from epididymal spermatozoa of mature hamsters were extracted by treatment with Nonidet P‐40 and then submitted to electrophoresis (SDS‐PAGE). The proteins in the gel were electrophoretically transferred to a nitrocellulose membrane and then probed with the radiolabelled zone pellucida proteins. 125I‐zona pellucida proteins bind preferentially to a sperm protein with a molecular weight of 26,400 ± 1,400 daltons (n = 9). Using a similar procedure it was shown that this protein also binds 125I‐Concanavalin A. The interaction between the sperm protein and the 125I‐zona pellucida proteins shows species specificity as demonstrated by the fact that the hamster 125I‐zona pellucida proteins do not bind to proteins extracted from ram, bull, and stallion spermatozoa. Whether this sperm protein could be implicated be implicated in the process of sperm‐egg interaction is under investigation.
Sperm aging in the male after sexual rest: Contribution to chromosome anomalies
Authors: Martin‐DeLeon Patricia A. , Boice Melinda L. 
Published: February 2005

AbstractThe chromosome complement was studied in first‐cleavage metaphases of mouse zygotes resulting from sperm aged in the male physiologically, after sexual rest. Females were inseminated by control males mating at 3‐day intervals while experimentals mated to males that had had a sexual rest of 14 or more days. A total of 1954 eggs were collected 33–35 h post‐HCG from 101 superovulated females mated to 42 controls and 43 experimental males. The fertilization rate was similar in both groups, being 84% and 85%, respectively. G‐banded or Q‐banded chromosomes were analyzed in 301 (68.3%) controls and 392 (49%) experimental first‐cleavage metaphases. The overall rate of chromosome anomalies in controls was 4.45% as compared to 10.94% in experimentals, a highly significant difference. In the experimental group compared to controls, the frequency of trisomy, triploidy, structural rearrangements, and tetraploidy increased from 3.9% to 6.9%, 0% to 1.6%, 0.8% to 2.8%, and 0% to 1.3%, respectively. The genomic source of origin of the abnormalities was determined on the basis of differential condensation of the genomes. In the experimentals, grossly unbalanced sperm (diploids, disomics, double disomics, and those with large fragments) fertilized significantly more oocytes compared to controls. Our results implicate an advantage either in numbers or fertilizing capability for chromosomally abnormal sperm in a physiologically aged population.
7‐aminoactinomycin D binding and the final stages of sperm chromatin processing in the mouse
Authors: Balhorn Rod , Kellaris Kennan , Corzett Michele , Clancy Colin 
Published: February 2005

AbstractQuantitative fluorescence microscopy is used to compare the binding of the fluorescent, 7‐amino derivative of actinomycin D to a sonication resistant fraction of late‐step mouse spermatids and sperm isolated from three regions of the epididymis. Staining conditions are described that optimize 7‐AMD binding to air‐dried smears of these cells and permit quantitative analyses of 7‐AMD binding to sperm chromatin at the single cell level. These studies show that the step 12–16 spermatid undergoes an 8–10‐fold reduction in 7‐AMD binding as it completes differentiation in the testis and progresses through the epididymis. The first 2–3‐fold reduction in binding, associated with biochemical changes in chromatin structure brought about during spermatid differentiation, occurs gradually and is complete by the time the sperm reaches the caput epididymis. An additional four‐fold reduction is observed as the sperm passes through the corpus. This final alteration, which occurs in a single concerted step, may be reversed by dithiothreitol treatment and appears to be effected through the formation of a final, small group of sperm nuclear protein disulfide crosslinks.
The development of meiotic competence in the rat: Role of hormones and of the stage of follicular development
Authors: Bar‐Ami S. , Tsafriri A. 
Published: February 2005

AbstractHypophysectomy of 15‐day‐old rats (hypox) markedly reduced the normal development of meiotic competence and abolished the development of antral follicles between days 21 and 31 postpartum (pp). Here the correlation among age of the rats, stage of follicular development, and meiotic competence was examined. Administration of pregnant mare's serum gonadotropin (PMSG‐3IU) or insertion of an estradiol‐17β (E2) capsule to hypox rats induced the development of meiotic competence provided the treatment started after day 20 pp. Hormonal treatments at an earlier age were not effective in inducing meiotic competence in hypox rats. The induction of meiotic competence by PMSG or E2 was associated with an increase in the number of granulosa cells and formation of follicular antrum. The finding that PMSG and E2 failed to induce meiotic competence when administered prior to day 21 pp suggests that the development of meiotic competence is an age‐dependent process. When the hormonal treatments commenced after day 21, both follicular development and meiotic competence were induced.