bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of the first and second factors released after hamster sperm make contact with the zona pellucida prior to fertilization in vitro
Authors: Hartmann John F. , Hutchison Cameron F. 
Published: February 2005

AbstractAn investigation was made as to the nature of two of the factors, termed S1, released within the first 30 minutes after contact is made between capacitated hamster sperm and the zona pellucida in vitro. Previous studies showed that these S1 factors were detected two and 20 to 25 minutes after the gametes were combined and that, based on filtration studies, the former possessed a molecular weight of less than 5,000 daltons. The present results show that the quantity of the 20–25‐minute S1 factor released into the supernatant increased linearly as a function of the sperm concentration. This factor passed unimpeded through a filter with a 5,000 molecular weight cutoff but only 42% of the activity traversed a filter with a cutoff of 2,000 daltons. The two‐minute S1 factor, in the virtual total absence of cells, was stable for 10 to 15 minutes, but lost significant activity upon longer incubation. Under the same conditions, the 20–25‐minute factor lost approximately 25% of its activity within 15 minutes, but remained stable at this level for at least 45 minutes of incubation. Both S1 factors were not affected by a mixture of glycosidases, but were inactivated by subtilisin, trypsin, and leucine aminopeptidase which was contaminated with endopeptidases. The activity of the two‐minute S1 factor appeared more susceptible to the action of the proteases than that of the 20–25‐minute S1 factor. In contrast to previous results obtained with the two‐minute S1 factor, the release of the 20–25‐minute S1 factor was not inhibited by the inclusion of soybean trypsin inhibitor a t concentrations which are known to inhibit penetration of the zona by the sperm. The results suggest that the two‐ and 20–25‐minute S1 factors are peptides which are not identical.
Inhibition of acrosin by oviductal secretory immunoglobulin A
Authors: Go K. , Mastroianni L. , Stambaugh R. 
Published: February 2005

AbstractA major inhibitor of acrosin in rhesus monkey and rabbit oviduct fluid, isolated by isoelectrofocusing in sucrose gradients, displayed a broad peak in the acidic region of the column and was demonstrated to contain secretory IgA specific for acrosin. Its identity was established by immunodiffusion, by the removal of acrosin inhibition with antisera to IgA (α‐chain), and by its correct molecular weight during ultracentrifugation. Purified human serum IgA also inhibited rabbit, rhesus monkey, and human acrosins, but neither purified human IgG nor IgM had any inhibitory effect on these acrosins. Neither oviduct fluid secretory IgA nor purified human serum IgA inhibited the activity of bovine pancreatic trypsin. The high specificity of secretory IgA for acrosin and its presence in every rabbit and rhesus monkey oviduct fluid specimen examined suggests a possible regulatory role for this antibody in reproduction.
Factors which may affect removal of protamine from sperm DNA during fertilization in the rabbit
Authors: Wiesel Saul , Schultz Gilbert A. 
Published: February 2005

AbstractIn order to derive information about possible mechanisms by which the sperm head is converted into the male pronucleus during fertilization in the rabbit, unfertilized egg homogenate was assayed for two enzyme activities. Protamine was extracted from rabbit sperm, purified, and labelled with [14C] in an in vitro reaction and used as a probe to assay for a protein kinase which could transfer [32P]PO4 from [γ‐32P]ATP onto the substrate. A kinase with a pH optimum of approximately 8.0 to 8.5 is described. Assays for the enzyme glutathione reductase were performed using homogenates from eggs or embryos at three early stages of development. Results suggest that oocytes can oxidize 2.58 × 10−6 μmol NADPH per minute per oocyte, unfertilized eggs 5.16 × 10−7 μmol NADPH per minute per ovum, and 20‐ to 24‐hour postcoitus fertilized eggs 2.30 × 10−6 μmol NADPH per minute per ovum. The relevance of these observations to male pronuclear formation is discussed.
The effects of taurine and hypotaurine on in vitro fertilization in the golden hamster
Authors: Leibfried M. Lorraine , Bavister Barry D. 
Published: February 2005

AbstractTaurine and hypotaurine were examined for their efficacy in replacing sperm motility factor (SMF), prepared from bovine adrenal cortex, for in vitro fertilization in the golden hamster. Combinations of these amino acids at concentrations of 0.001, 0.01, 0.1, and 1 mM together with 16 μM isoproterenol (a catecholamine β‐agonist) were added to the sperm incubations. After three hours of sperm preincubation, oviductal eggs were added to the sperm suspensions and examined for penetration and stage of fertilization after three or five hours of culture. At 0.001 mM, neither taurine or hypotaurine was capable of maintaining motility of hamster sperm for four to 4½ hours or of inducing fertilization. With all other concentrations, both amino acids were found to maintain motility of sperm as well as SMF. Hypotaurine stimulated motility to a greater extent than taurine and both required isoproterenol for the greatest motility. A low proportion of cumulus‐free ova were fertilized when sperm were preincubated with either amino acid alone over the range of 0.01 to 1 mM; however, over 80% fertilization was consistently obtained when isoproterenol was also present during sperm incubation. Proportions of ova fertilized with taurine or hypotaurine present during sperm preincubation were comparable to those achieved with SMF. The possibility that taurine or hypotaurine is the sperm motility factor is discussed.After three hours of sperm/egg incubation, a lag in the early events of fertilization was observed in experimental groups treated with one of the amino acids (0.01 mM) alone compared with groups treated with isoproterenol present. However, if sperm/egg incubation was extended from three to five hours, no increase in number of eggs penetrated was found. Therefore, the delay observed at three hours was considered a function of fewer numbers of capacitated sperm present in the absence of isoproterenol rather than of the need for an extended capacitation time.
The spermatogenesis of crustaceans. VII. Review of spermatozoon of the crayfish Astacus astacus (Malacostraca, Decapoda, Macrura, Reptantia)
Authors: López‐Camps J. , Bargalló R. , Bozzo M. G. , Durfort M. , Fontarnau R. 
Published: February 2005

AbstractThe star‐like spermatozoon of Astacus astacus consists of a spheroidal central body around which various prolongations of same, denominated spines, are arranged. In the interior of the gamete the following parts may be distinguished: (1) The acrosomic region, formed by a complex vesicle, or thick‐walled, helmetshaped body, whose opening is orientated towards the nuclear region. In the interior of the vesicle different structures can be appreciated. (2) The nuclear region, which is formed by a large cupuliform nucleus limited by a double membrane. In the nucleoplasm numerous bundles of microtubules, mixed with noncondensated chromatin fibers, are found. (3) The laminar region, present in other Decapoda, is practically nonexistent. Within the spines of these spermatozoa, only microtubules can be observed. The morphology of this crayfish is similar to that presented by Brachiura, another group of Reptantia.
Fertilization in the sea urchin arbacia punctulata inhibited by fluorescein dyes: Evidence for a plasma membrane mechanism
Authors: Finkel Toren , Levitan Herbert , Carroll Edward J. 
Published: February 2005

AbstractFertilization and ionophore activation of the sea urchin Arbacia punctulata were inhibited in the presence of six analogs of the dye fluorescein. The concentration of any one dye needed for blockage of sperm or Ca‐ionophoremediated activation in 50% of the eggs (I50) was a function of the dye's lipid solubility. Substantially higher concentrations of each dye were required to block activation by Ca‐ionophore (A23187) than were needed to inhibit sperm activation. A detailed study of the action of Erythrosin B (tetraiodofluorescein) showed that its effects were readily reversible. The I50 concentration of Erythrosin B increased as temperature increased from 10 to 25°C. The kinetics of blockage indicated that Erythrosin B blocked some early step in the program of fertilization. The results suggest that these anionic dyes may inhibit fertilization by preventing successful sperm‐egg fusion.
Effect of anti‐pig zona pellucida serum on fertilization in several mammals
Authors: Tsunoda Y. , Soma T. , Jinbu M. , Tachiura K. , Sugie T. 
Published: February 2005

AbstractThe effect of goat antiserum against isolated pig zonae pellucidae on fertilization in vivo was examined in the pig, cow, sheep, rabbit, rat, and mouse. As shown by indirect immunofluorescence, anti‐pig zona serum reacted strongly with the zonae of pig, cow, sheep, and rabbit, but the reaction with the zonae of mouse and rat was weak. Passive immunization with anti‐pig zona serum significantly, or completely, inhibited fertilization in all species. However, inhibition of fertilization was more pronounced in the pig, cow, sheep, rabbit, and mouse than in the rat. Inhibition of fertilization in the rabbit was also observed after passive immunization with antiserum absorbed with rabbit liver and kidney. All of the zonae recovered from the pig, cow, sheep, rat, and mouse after passive immunization with anti‐pig zona serum exhibited strong fluorescence, regardless of the incidence of fertilization. It was concluded that the pig and other mammalian zonae pellucidae tested have tissue‐specific antigens.
The generation and propagation of double waves in mosquito (Aedes notoscriptus) sperm‐tails
Authors: Swan M. A. 
Published: February 2005

AbstractIn the mosquito Aedes notoscriptus nine accessory tubules develop from the doublets of the axoneme whose single central fibre forms late in spermiogenesis. The 9 + 9 + 1 mosquito sperm‐tail propagates two waves of differing frequency and amplitude. The structural basis for the movement is of interest.Mosquito sperm were demembranated until all movement ceased and were reactivated with a solution containing adenosine triphosphate (ATP). They immediately moved in a normal fashion. Like untreated sperm, they always propagated double waves. This indicates that the plasma membrane does not control the double wave.After sonicating sperm treated as above, the high‐frequency, low‐amplitude waves sometimes propagated alone beyond a damaged region of sperm‐tail, whereas the large‐amplitude, low‐frequency waves never propagated alone beyond a damaged region. This suggests that the latter waves are generated by an anterior site, possibly the centriole or centriole adjunct. The structure that propagates the large amplitude wave is not known; possibly the accessory tubules may slide against the axonemal doublets.Any region of the sperm‐tail is capable of generating and propagating the low‐amplitude, high‐frequency wave, for which the structure responsible is probably the axoneme.
Immunoferritin labeling of rabbit spermatozoa
Authors: Schrader Steven M. , Eng Ludeman A. , Metz Charles B. 
Published: February 2005

AbstractFerritin‐conjugated goat IgG binds nonspecifically to rabbit sperm. This restricts use of ferritin‐labeled goat antiglobulins as indirect labels in rabbit sperm antigen localization. Ferritin‐conjugated Protein A does not bind nonspecifically to rabbit sperm and is a satisfactory substitute for indirect (“secondary”) labeling of sperm antigens.
cAMP‐dependent protein kinase in sea urchin embryos
Authors: Fujino Yukio , Yasumasu Ikuo 
Published: February 2005

AbstractcAMP‐dependent protein kinase in the supernatant fraction of the homogenate of sea urchin eggs and embryos obtained by centrifugation at 105,000g was investigated in the present study. In the previous report, the dissociation constant between cAMP‐binding proteins and cAMP changed during the development. This suggests that the nature of cAMP‐dependent protein kinase, which has been well established to be the major cAMP receptor, changes during the development. In the present study, four protein kinases were separated through DEAE‐cellulose column from the supernatant of unfertilized egg homogenate. One of them was cAMP‐dependent protein kinase. The others were cAMP‐independent ones. One among them was phosvitin kinase, and the others were not identified at present. The activity of cAMP‐dependent protein kinase gradually increased during a period from fertilization to the swimming blastula stage. During this period, cleavages occurred at a high rate, and the rate decreased after hatching out. Thus, it is supposed that cAMP‐dependent protein kinase in the supernatant may take a part in the mechanism of cleavage. The activity, however, became very low at the mesenchyme blastula, the gastrula, and the pluteus stages. cAMP‐binding capacity was observed in the sedimentable fraction and the supernatant fraction, respectively, obtained by 105,000g centrifugation at all stages examined. If the structure‐bound cAMP‐binding protein is also cAMP‐dependent protein kinase, it may play different roles in the mechanism of development.
Isolation and characterization of two proteinase inhibitors from the male reproductive tract of mice
Authors: Poirier Gary R. , Jackson James 
Published: February 2005

AbstractLow molecular weight, acid‐stable proteinase inhibitors from epididymal and seminal vesicle homogenates were isolated and characterized. The isolation procedure consisted of gel filtration, trypsin affinity, and ion exchange chromatography. The inhibitor from seminal vesicle homogenates has a molecular weight of approximately 6,200, and that of the epididymal inhibitor was estimated at 4,000. Antiserum directed against the seminal vesicle inhibitor did not react with epididymal components. The epididymal inhibitor shows competitive, whereas the seminal vesicle inhibitor shows noncompetitive inhibition against trypsin on double reciprocal plots. Both inhibitors are effective against trypsin and acrosin but not against chymotrypsin, kallikrein, thrombin, or plasmin. To verify site of origin and to investigate androgen dependency of the epididymal inhibitor, mice were efferentiectomized, orchiectomized, or orchiectomized with androgen supplementation. Gel filtration profiles of acid‐treated epididymal homogenates from normal and efferentiectomized animals show inhibitor peaks in the same regions. The concentration of acid‐stable inhibitor from epididymal homogenates decreased with orchiectomy but returned to normal values when exogenous androgen was supplied. These observations suggest that the low molecular weight inhibitor in the epididymal homogenates is distinct from that in the seminal vesicles. Furthermore, the inhibitor associated with epididymal homogenates is androgen‐dependent, and the epididymis is the site of origin of this inhibitor.
The effect of nicotine on sperm‐Egg interaction in the sea urchin: Polyspermy and electrical events
Authors: Dale B. , de Santis A. , Hagström B. E. 
Published: February 2005

AbstractWe have studied some of the effects of nicotine on sea urchin eggs, spermatozoa, and their interaction using electrical recording techniques and fertilization‐rate experiments. Pretreating eggs with nicotine enhances the fertilization rate, whereas this drug has an inhibitory effect on spermatozoa. Pulse‐treated eggs or eggs fertilized in the presence of nicotine give rise to attenuated step depolarizations, which may be attributed to a decrease in membrane resistance (Rm) of the egg or, in the latter case, to an alteration to the spermatozoon. Concurrently, with the change in the step depolarization there is a reduction in amplitude of the fertilization potential (FP) suggesting that the cortical reaction is in some way altered. Nicotine has no effect on the Rm of fertilized eggs or oocytes, where there are no cortical granules. We suggest that nicotine alters the cortex of sea urchin eggs–possibly by causing a partial dissolution of cortical granules–which renders the eggs more receptive to spermatozoa. The reductions in amplitude of the step depolarization and the FP are consequences of this alteration.
Some nucleocytoplasmic exchanges during spermiogenesis of boar, ram, and stallion
Authors: Courtens J. L. 
Published: February 2005

AbstractThe problem of how the successive nucleoproteins enter and leave the nucleus of mammalian spermatids is studied with electron microscopy in thick and thin sections of testis, stained en bloc with the procedure of Thiery and Rambourg [1976], which is able to immobilize small molecules. Staining at different pH values reveals that the stain could demonstrate some spermatidspecific nucleoproteins in elongating nuclei and the spermatozoa‐specific protamines in elongated nuclei of the boar, the ram, and the stallion. The stained substances enter or leave the nuclei at precise steps in spermiogenesis. They follow several ways inside a special apparatus made rigid with the manchette. The apparatus is composed of the endoplasmic reticulum, continuous with the nuclear envelope, and of the nuclear pockets continuous with the nuclear pores. In the stallion and the boar, cytoplasmic granules, surrounded by a double wall of membranes, fuse with the nuclear envelope at the time the protamines enter the nucleus.
Ultrastructural observations on cortical granules in human follicular oocytes cultured in vitro
Authors: Sathananthan A. H. , Trounson A. O. 
Published: February 2005

AbstractThe fine structure, distribution, and fate of cortical granules in human oocytes cultured in vitro are reported.Follicular maturation in women with blocked Fallopian tubes was induced by clomiphene citrate and human chorionic gonadotropin, and preovulatory eggs were obtained by improved methods of laproscopy and oocyte recovery. These oocytes were then inseminated and cultured in a modified Ham's F10 medium for 3 to 72 hr to assess their fertilizability.Cortical granules were observed in all 17 unfertilized oocytes investigated, which had completed various stages of meiotic maturation. A marked increase in their numbers was observed in oocytes cultured for 3 to 6 hr. There was no evidence of spontaneous cortical granule release in any of the oocytes studied.It is concluded that cortical maturation expressed by proliferation of cortical granules is as significant a criterion as nuclear maturation in assessing maturity and fertilizability of oocytes cultured in vitro. A short sojourn in culture before insemination could improve chances of normal fertilization and embryo development, which has been recently achieved in our laboratory.
Steroidogenesis by isolated porcine oocyte‐cumulus complexes: Lack of an inhibitory effect of low molecular weight fraction of porcine follicular fluid on conversion of androgen to estrogen
Authors: Schaerf Frederick W. , Anderson Larry D. , Channing Cornelia P. 
Published: February 2005

AbstractThe ability of isolated porcine oocyte‐cumulus complexes to secrete progesterone and convert androgens to estrogen during two days of culture was examined. We studied the effects of steroids, as well as a partially purified fraction of follicular fluid oocyte maturation inhibitor (Sephadex Peak A OMI), on the ability of oocyte‐cumulus complexes to mature and convert androgen to estrogen.The addition of 0.014, 0.14 or 1.4 μg/ml androstenedione to the culture medium resulted in a substrate dose‐dependent accumulation of estrogen in the culture medium after two days. Oocyte‐cumulus cell complexes secreted more estrogen in the presence of androstenedione than in the presence of testosterone (P < 0.05). The addition of 1.4 μg/ml testosterone, androstenedione, or estradiol, but not dihydrotestosterone, inhibited cumulus cell progesterone secretion (P < 0.001 versus untreated control culture). Oocyte maturation was not altered by the addition of steroids in doses up to and including 1.4 μg/ml. The Sephadex Peak A OMI fraction of pFFL inhibited oocyte maturation 51% (P < 0.01) and progesterone secretion 91% (P < 0.01) but had no effect on the conversion of androgens to estrogens. Cumulus cell monolayer formation was inhibited 71.5% (P < 0.01) by the Sephadex Peak A OMI fraction and 35.4% (P < 0.05) by the Sephadex Peak A OMI fraction plus androstenedione.These studies indicate that porcine oocyte‐cumulus complexes can convert androgens to estrogens and that partially purified OMI does not inhibit conversion of androgens to estrogen.
Sperm‐egg ratios and the site of the acrosome reaction during in vivo fertilization in the hamster
Authors: Cummins J. M. , Yanagimachi R. 
Published: February 2005

AbstractLittle is known about the timing of the mammalian sperm acrosome reaction during fertilization in vivo. To study this problem, female hamsters were inseminated at about the time of ovulation, and the contents of the ampullary regions of their oviducts were subsequently examined at various intervals. No living spermatozoa were recovered from ampullae earlier than 4 hr after insemination. The first appearance of living spermatozoa coincided closely with the first appearance of fertilized eggs in the same oviduct. The total numbers of living spermatozoa did not start to exceed the number of eggs in the same ampulla, until after 50% or more of the eggs had been fertilized. Hamster spermatozoa are highly efficient at making contact with eggs, and the fertilizing spermatozoon probably spends no more than 2½ –5½ min in penetrating the cumulus oophorus. Spermatozoa that enter the ampulla appear to be ready to undergo the acrosome reaction, and complete it while they are passing through the cumulus or shortly before, or after, contacting the surface of the zona pellucida.
Use of a radioimmunoassay technique to measure the titer of anti‐cow‐zona antibodies in marmoset monkeys
Authors: Hulme M. J. , Aitken R. J. , Richardson D. W. 
Published: February 2005

AbstractA double antibody radioimmunoassay technique is described for the measurement of anti‐zona antibodies in the peripheral plasma of marmosets actively immunized against intact cow zonae pellucidae. The method has been shown to be a reliable, repeatable indicator of antibody titer, enabling direct comparison of the response obtained between marmosets. This is the first report of a procedure describing the active immunization of a primate against zona antigens, and the first time a radioimmunoassay technique has been used to monitor profiles of anti‐cow zona antibody production following active immunization. The method should prove to be a useful tool in the evaluation of zona antigens as agents for immunocontraception.
Circular DNA in human and boar spermatozoa
Authors: McGrath J. P. , Evenson D. P. 
Published: February 2005

AbstractCircular DNA molecules were isolated from human and boar whole spermatozoa or spermatozoal nuclei and measured for size by electron microscopy. The DNA molecules derived from both mammals were heterogeneous in size ranging from 0.07 to 17 μm; nearly 75% of the molecules were ⩽0.5 μm in length. The mean lengths were 1.0 μm and 1.5 μm for circular DNAs isolated from human and boar spermatozoa, respectively. The origin and function of these molecules remains unknown.