Showing papers on "Sperm published in 1977"
TL;DR: Experimental results suggest that bindin may act by binding to carbohydrate receptors of vitelline layer glycoproteins, and speculation is made that sperm bindins may be the general mechanism by which animal sperm attach to eggs.
Abstract: The insoluble granular material of the acrosome vesicle of sea urchin sperm has been isolated and shown to be a single 30,500 dalton protein for which the name "bindin" is proposed. The data presented are consistent with the hypothesis that bindin is the adhesive responsible for the attachment of sperm to the vitelline layer of the egg. Experimental results suggest that bindin may act by binding to carbohydrate receptors of vitelline layer glycoproteins. The speculation is made that sperm bindins may be the general mechanism by which animal sperm attach to eggs.
401 citations
TL;DR: The component of the sperm extracts that was responsible for stimulating hamster sperm motility was found to be heat-stable and to have the same elution volume on a Sephadex G-10 column, suggesting that the active components may be similar or possibly the same.
Abstract: Extracts of washed spermatozoa from hamster and guinea pig cauda epididymidis and of human ejaculated sperm were all found to stimulate the motility of unwashed hamster epididymal spermatozoa in vitro and to support development of fertilizing ability. The motility of hamster spermatozoa was only sustained in the presence of both sperm extracts and appropriate energy substrates indicating a synergistic effect of the motility-stimulating component of the sperm extracts with energy sources. Albumin was also required for the development of fertilizing ability by hamster sperm. Comparison of different combinations of energy substrates indicated that pyruvate was the most important energy source for sperm motility and the acrosome reaction but glucose and lactate played suporting roles. In all 3 species examined the component of the sperm extracts that was responsible for stimulating hamster sperm motility was found to be heat-stable and to have the same elution volume on a Sephadex G-10 column with an estimated molecular weight of about 200. These properties are identical to those of the sperm motility-stimulating factor found in blood serum and adrenal gland suggesting that the active components may be similar or possibly the same.
382 citations
TL;DR: Conditions are described that permit the quantitative extraction of chromatin proteins from the epididymal sperm of the mouse and evidence is presented that suggests that this single band contains two protamine-like proteins.
Abstract: Conditions are described that permit the quantitative extraction of chromatin proteins from the epididymal sperm of the mouse. These proteins have been isolated free of contaminating tail proteins following removal of the tails with cetyltrimethylammonium bromide (CTAB). Without this treatment, numerous acid-soluble tail proteins coextract with the nuclear proteins isolated from partially purified heads. The proteins isolated in this manner do not require prior modification with iodoacetamide and show no evidence of proteolytic degradation. In acid-urea polyacrylamide gels, 99% of the sperm protein migrates as one electrophoretic band. Evidence is presented that suggests that this single band contains two protamine-like proteins.
222 citations
Book•
01 Jan 1977
TL;DR: Fate of Nonfertilizing Spermatozoa and Interaction of Spermutozoa with Somatic Cells and Fate of nonfertility-related events are studied.
Abstract: 1 * Early Studies.- 2 * The Egg.- 3 * The Sperm.- 4 * Gamete Transport.- 5 * Fertilization in Vitro.- 6 * Sperm Capacitation.- 7 * The Acrosome Reaction.- 8 * Attachment and Binding of the Sperm to the Zona Pellucida.- 9 * Penetration of the Zona Pellucida by the Sperm.- 10 * Fusion of the Sperm with the Vitellus.- 11 * The Prevention of Polyspermy.- 12 * Pronucleus Formation.- 13 * Metabolic Changes Associated with Fertilization.- 14 * Fate of Nonfertilizing Spermatozoa and Interaction of Spermatozoa with Somatic Cells.- 15 * Parthenogenesis.- Epilogue.- References.
201 citations
TL;DR: The data demonstrate a lack of direct correlation between sperm density in the ranges of 5 to 60 million/ml and pregnancy rates in couples where the wife is treated intensively, and emphasize the importance of considering infertility as a problem of a couple rather than as a specific disorder of one of the partners.
170 citations
TL;DR: Data indicate that a rise in intracellular calcium by influx from the extracellular space is a necessary condition for induction of the acrosome reaction.
143 citations
TL;DR: The species specific agglutination of unfertilised eggs by isolated bindin demonstrates the preservation of the species specific recognition event between the isolated protein and its receptor which should facilitate the in vitro reconstruction and analysis of the molecular mechanism of gamete adhesion.
Abstract: SPERMATOZOA adhere to eggs during sea urchin fertilisation1,2. The adhesion is between the acrosome process of the sperm and the vitelline layer covering of the egg3. During the sperm acrosome reaction, the membrane of the extending acrosome process becomes coated with protein derived from the sperm acrosome vesicle3,6. We believe4,5, like others3,6, that the acrosome vesicle protein binds the sperm to the egg by interacting with glycoprotein receptors on the egg vitelline layer4,5,7,8. We have isolated the insoluble contents of the acrosome vesicle and have shown it to be composed of a single protein of molecular weight 30,500 which we have named bindin4. In most interspecies inseminations sea urchin sperm fail to adhere to the vitelline layers of foreign eggs and fertilisation does not occur, even though sperm undergo the acrosome reaction in the presence of the foreign eggs9. Presumably this failure of gamete adhesion occurs because bindin, on the sperm acrosome process, does not bind to the glycoprotein receptors on the vitelline layers of eggs of another species. We report here the species specific agglutination of unfertilised eggs by isolated bindin. This demonstrates the preservation of the species specific recognition event between the isolated protein and its receptor which should facilitate the in vitro reconstruction and analysis of the molecular mechanism of gamete adhesion.
139 citations
TL;DR: Levels of fertility were high (greater than 88%) in White Leghorn hens inseminated weekly with diluted (1:4) semen containing as few as 20 million sperm and high fertility levels can be achieved with semen diluted 1:10 provided the insemination dose contains at least 100 million sperm.
133 citations
TL;DR: Data showed that transcervical sperm transport in rats requires 6--10 min after ejaculation for completion, and maintenance of an immobile posture by the male, and possibly by the female, at ejaculation facilitates the deposition of a tightly lodged vaginal plug and the transport of large numbers of sperm through the cervix.
Abstract: Six experiments were performed to investigate the effects of the rat's copulatory behavior on sperm transport in the female's reproductive tract. Data showed that (a) transcervical sperm transport in rats requires 6--10 min after ejaculation for completion; (b) transcervical transport of large numbers of sperm requires that the vaginal plug remain lodged tightly in the vaginal-cervical junction; (c) maintenance of an immobile posture by the male, and possibly by the female, at ejaculation facilitates the deposition of a tightly lodged vaginal plug and the transport of large numbers of sperm through the cervix; (d) a single intromission occurring within 2 min after ejaculation disrupts sperm transport, but more copulatory stimulation is required to disrupt sperm transport when delivered between 4 and 10 min after ejaculation; and (e) the average postejaculatory interval is long enough to prevent a male from disrupting the transport of most of his own sperm from the preceding ejaculation.
128 citations
TL;DR: The specificity of inhibition, and the affect of trypsin and concanavalin A on intact eggs, suggest that the receptor is a species- specific macromolecule located on the surface of the eggs.
Abstract: The possibility that the surface of the egg of the sea urchin Arbacia punctulata contains a species-specific receptor for sperm has been investigated The extent of fertilization of eggs of A punctulata, which is proportional to the number of sperm, is unaffected by the presence of either eggs or membranes prepared from eggs of Strongylocentrotus purpuratus In marked contrast, membranes prepared from eggs of A punctulata quantitatively inhibit fertilization of A punctulata eggs by A punctulata sperm Several lines of evidence indicate that this inhibition is due to the presence of a membrane-associated glycoprotein that binds to the sperm, thus preventing them from interacting with receptor on the surface of the eggs First, eggs treated with trypsin are incapable of being fertilized, although they can be activated with the Ca2+ ionophore A23187 Moreover, membranes prepared from eggs pretreated with trypsin do not inhibit fertilization of eggs Second, receptor isolated in soluble form from surface membranes binds to sperm and thus prevents them from fertilizing eggs; the inhibition by soluble receptor is species-specific Third, the soluble receptor binds to concanavalin A-Sepharose Fourth, eggs are incapable of being fertilized if they are pretreated with concanavalin A The specificity of inhibition, and the affect of trypsin and concanavalin A on intact eggs, suggest that the receptor is a species-specific macromolecule located on the surface of the eggs The sensitivity of the receptor to trypsin, and its ability to bind to concanavalin A, indicate that it is a glycoprotein
128 citations
TL;DR: Results indicate that cortical granule contents are capable of modulating sperm penetration of mouse eggs at both the zona pellucida and at the egg plasma membrane.
Abstract: The contents of cortical granules (cortical granule exudate = CGE) were recovered from zona-free mouse eggs inseminated in vitro with capacitated epididymal spermatozoa. Preincubation of cumulus-free, zona-intact eggs in CGE led to reduced penetration levels upon insemination. This reduction was CGE concentration- and time-dependent and was susceptible to inhibition by soybean trypsin inhibitor and by p-aminobenzamidine. Control experiments eliminated active contributions from the sperm suspension used to elicit granule release. CGE was also active in reducing penetration of zona-free eggs. These results indicate that cortical granule contents are capable of modulating sperm penetration of mouse eggs at both the zona pellucida and at the egg plasma membrane.
TL;DR: Observation that gamete membrane fusion occurs by fusion of the acrosomal tubule and a microvillus is presented provides a generalized pattern of molluscan fertilization.
Abstract: An ultrastructural investigation of the gametes and their interaction during the early events of fertilization in molluscs has been performed. A gamete binding event involving large numbers of sperm has been identified and examined in detail. The surface of the oocyte is projected into numerous microvilli which extend through the vitelline envelope. Tufts of fibrillar material radiate from the tips of these microvilli, forming a layer external to the vitelline envelope. The acrosomal vesicle of the mature spermatozoon contains two major components, which function differently during fertilization. The vesicle is indented at its adnuclear surface, constituting a preformed acrosomal tubule. This tubule does not elongate during the acrosome reaction. Completion of the reaction results in the formation of an extracellular coat, derived from one component of the acrosomal vesicle, on the anterior surface of the sperm. Sperm-egg binding is accomplished by an association of the extracellular coat on the reacted sperm and the fibrous tufts on the tips of the microvilli of the oocyte. Evidence that gamete membrane fusion occurs by fusion of the acrosomal tubule and a microvillus is presented. These observations provide a generalized pattern of molluscan fertilization.
TL;DR: It is concluded that when sperm granuloma follows vasectomy it vents the high pressure otherwise created by vasectomy and prevents disruption of sperm output in the vas fluid.
Journal Article•
TL;DR: It seems likely that regulation through the transient or permanent modulations of ionic content is widespread in the living world and that mechanisms for regulating cellular acivity at fertilization are utilized throughout the life span of the organism.
Abstract: The eggs of marine invertebrates particularly the echinoderms as sea urchins sand dollars and starfish are used for the study of fertilization. The specific recognition of the egg by the sperm is thought to occur when the sperm makes contact with the jelly coat that surrounds the egg. Substances in the jelly coat interact with the outer membranes of the sperm cell to release digestive enzymes that enable the sperm to dissolve a hole in the layers surrounding the egg so that the sperm can reach the surface of the egg. A single fertilizing sperm enters the egg. Once the sperm has entered the egg its nucleus rotates 180 degrees and migrates toward the nucleus of the egg. About 20 minutes later paternal and maternal nuclei fuse. With the condensation of the chromosomes and the 1st cleavage of the egg fertilization is completed. The fusion of a sperm and an egg triggers a series of transient changes in the concentration of ions that prevent the fusion of additional sperm and initiate development of the embryo. It seems likely that regulation through the transient or permanent modulations of ionic content is widespread in the living world and that mechanisms for regulating cellular acivity at fertilization are utilized throughout the life span of the organism.
TL;DR: The results presented in this paper indicate that albumin is the bovine follicular fluid protein involved in the in vitro induction of the hamster sperm acrosome reaction.
Abstract: Biochemical techniques were used to purify and identify the bovine follicular fluid protein involved in the in vitro induction of the acrosome reaction of hamster sperm. A follicular fluid protein fraction obtained by means of Sephadex G-1 50 and DEAE-Sephadex column chromatography, when combined with an Amicon XM-50 follicular fluid ultrafiltrate containing a motility factor, stimulated the acrosome reaction as effectively as intact follicular fluid. Further purification of the effective protein fraction by trichloroacetic acid precipitation and ethanol solubilization resulted in a highly purified preparation of serum albumin as identified by SDS disc-gel electrophoresis and immunoelectrophoresis. This highly purified albumin retains its full ability to induce the acrosome reaction in the presence of the XM-50 ultrafiltrate. The acrosome reaction inducing effectiveness of the albumin was dependent on its concentration. Similar treatment with trichloroacetic acid and ethanol further purified a crystalline bovine serum albumin to immunoelectrophoretic homogeneity and greatly increased its acrosome reaction inducing ability. This is the first demonstration that an appropriate treatment can greatly increase the acrosome reaction inducing ability of a serum albumin which was previously a poor inducer of acrosome reactions. The results presented in this paper indicate that albumin is the bovine follicular fluid protein involved in the in vitro induction of the hamster sperm acrosome reaction. The mechanism of action of albumin and/or its ligands in the acrosome reaction remains to be determined, but the mechanism appears to be more than just the maintenance of sperm viability and to require the presence of a sperm motility factor for optimal results.
TL;DR: Timing of development of naturally ovulated mouse eggs from sperm penetration to first cleavage, including that of DNA synthesis, was established and partial synchronization of ovulation was accomplished by shortening the length of the dark period to five hours.
Abstract: Timing of development of naturally ovulated mouse eggs from sperm penetration to first cleavage, including that of DNA synthesis, was established. In an attempt to limit variability, partial synchronization of ovulation was accomplished by shortening the length of the dark period to five hours, and partial synchronization of sperm entry was attempted by mating the females soon after the ovulated eggs reached the ampulla and by limiting the period at which mating could occur to only 20 minutes. Evidence of sperm penetration (presence of one or more sperm in perivitelline space or inside the vitellus) was found beginning 1.75 hours after the end of the mating period. Pronuclei were formed three to four hours after sperm entry. Pronuclear DNA, synthesis began about eight hours postmating, 3.25 to 4.5 hours after pronuclear formation, or about 6.25 to 8.5 hours after sperm entry; it was completed in almost all zygotes by 16 hours postmating. The first completed cleavage division was found 17 to 18 hours postmating, and almost all eggs had cleaved by 20 hours.
TL;DR: The DNA-content of sperm and testicular cells was measured by pulse-cytophotometry with high resolution and stoichiometric DNA-staining including that of mature sperm with a coefficient of variation below 2%.
Abstract: The DNA-content of sperm and testicular cells was measured by pulse-cytophotometry with high resolution. From flat sperm symmetric and narrow fluorescence distributions were obtained. Enzymatic treatment with papain or pronase and staining with an ethidiumbromide-mithramycin dye solution generate stoichiometric DNA-staining including that of mature sperm with a coefficient of variation below 2%.
TL;DR: Sperm recovered from the ductus deferens of male cats were capable of fertilizing recently ovulated feline ova in vitro without in vivo capacitation and Cleavage was not observed in any of the control ova which were not exposed to spermatozoa.
Abstract: Sperm recovered from the ductus deferens of male cats were capable of fertilizing recently ovulated feline ova in vitro without in vivo capacitation. No difference was found in the ability of the two defined culture media tested, a medium described for mouse ova culture by Biggers et al. and modified Ham’s F-b, to support in vitro fertilization. Seventy-nine percent of the ova exposed to sperm cleaved to the two-cell stage and many developed further in culture, some to the blastocyst stage. Cleavage was not observed in any of the control ova which were not exposed to spermatozoa.
TL;DR: The leu kocyte response can be elicited either by spermatozoa (from the epididymis or by semen (from vasectomized bucks), but is not elicited by ovulation (with human chorionic gonadotropin).
Abstract: Within 45 minutes after mating in the rabbit, numerous heterophil leukocytes adhere to the endothelium of venules in the vagina. Initial association appears to occur via small protuberances from the leukocyte which fit into small indentions in the endothelial cell. Following adherence, leukocytes flatten and pass between endothelial cells. A regular intercellular space separates the leukocyte from the endothelial cells. Leukocytes subsequently migrate through the connective tissue to the epithelium. By three hours postcoitus, the region beneath the basement lamina of the vaginal epithelium is crowded with numerous juxtaposed leukocytes. Leukocytes subsequently migrate between epithelial cells into the vaginal lumen where they actively engulf spermatozoa. Spermatozoa appear to be ingested head first. Numerous small filaments are observed in the leukocyte cytoplasm in the region adjacent to the sperm head. Degranulation of azurophyl granules follows sperm uptake. The leukocyte response can be elicited either by spermatozoa (from the epididymis) or by semen (from vasectomized bucks), but is not elicited by ovulation (with human chorionic gonadotropin). It is suggested that the response may be initiated because the vagina does not distinguish between semen, spermatozoa and bacterial infection.
TL;DR: A turbidimetric method has been developed for determining rapidly the fraction of sperm in human ejaculates which show the most vigorous motility, which may be the best candidates for fertilization.
TL;DR: In this article, in vivo samples of epididymal fluids were obtained through the use of micropuncture techniques and analyzed for Na+ and K+ concentrations and for sperm density.
TL;DR: The difference in the type of furrow between eggs inseminated in the animal half or at the equator is interpreted as a consequence of dissociating sperm entry from the cortical contraction which occurs in activation.
Abstract: Frog eggs are normally fertilized after reaching metaphase II. When eggs are inseminated prior to that, several sperm enter, but entry does not activate the egg. When such inseminated, immature eggs were maintained until they became mature and then were artificially activated, the eggs began to cleave. The cleavage furrows were irregular and often multiple, but the eggs developed to blastulae or partial blastulae. About 2 leads to 5% of the eggs developed to tadpoles. Typical asters were not associated with the entering sperm; rather, asters appeared only after activation. The sperm nucleus often formed chromosomes which were attached to small spindles. It is clear that sperm which remain for a time in unactivated egg cytoplasm, retain their ability to promote cleavage and development. Aster formation required not only sperm centrioles but also activated egg cytoplasm. Sperm which entered either near the equator or in the animal half of mature eggs usually produced normal cleavage furrows. Sperm which entered the animal half of immature eggs produced multiple animal half furrows when the egg was subsequently activated. In contrast, sperm which entered near the equator of immature eggs often failed to induce furrowing on subsequent activation or produced unusual equatorial furrows. The difference in the type of furrow between eggs inseminated in the animal half or at the equator is interpreted as a consequence of dissociating sperm entry from the cortical contraction which occurs in activation.
TL;DR: Sperm surface isoantigens can be detected on the surface of fertilized eggs by using cytotoxic (complement dependent) sperm-specific isoantisera, which may indicate their transfer from sperm to egg during fertilization.
Abstract: Sperm surface isoantigens can be detected on the surface of fertilized eggs by using cytotoxic (complement dependent) sperm-specific isoantisera. These isoantigens cannot be detected on unfertilized eggs. This may indicate their transfer from sperm to egg during fertilization.
TL;DR: In Merino rams the in situ measurement of scrotal volume combined with age gave good estimates of testes weight, number of sperm in the testes, and number of semen in the epididymides, andCorrelations among these variables are presented.
Abstract: There were large variations among 67 Merino and 25 Romney rams in testes weight, number of sperm in the testes, number of sperm per g testis, and number of sperm in the epididymides. Correlations among these variables are presented. In Merino rams the in situ measurement of scrotal volume combined with age gave good estimates of testes weight (r = 0.91), number of sperm in the testes (r = 0.77), and number of sperm in the epididymides (r = 0.82). In Romney rams, scrotal volume, scrotal circumference, mean in situ diameter, and length of the testis and the Σ length × diameter2 of the testes (testes volume) were compared as indirect methods of estimating testicular measurements. Except for testis length, which had lower relationships, all the in situ measurements had similar correlations with the testes weight (r = 0.92–0.94), number of sperm in the testes (r = 0.74–0.78), and number of sperm in the epididymides (r = 0.61–0.67). Scrotal volume had the advantage of high coefficients of variation (36...
TL;DR: Rhesus monkeys develop agglutinating and complement-dependent antisperm antibodies after vasectomy and 6 months later vasovasostomies in order to study whether these antibodies affect fertility.
Journal Article•
TL;DR: The Yucatan octopus, Octopus maya, was collected at Campeche, Mexico, transported to Hawaii, and incubated in glass funnels as discussed by the authors, where 200 animals were reared for the first month in a 20-liter aquarium.
Abstract: Eggs of the Yucatan octopus, Octopus maya, were collected at Campeche, Mexico, transported to Hawaii, and incubated in glass funnels. Benthic juveniles hatched from the large (17-mm) eggs and were reared on a variety of live and frozen foods. As many as 200 animals were reared for the first month in a 20-liter aquarium. No disease or parasite problems were encountered and nearly all well-fed juveniles survived to sexual maturity. The species was reared through four generations in the laboratory. Animals weighed 0.1 g at hatching and within 8.5 months attained an average weight of 3231 g. Mating was promiscuous and sperm were stored in the oviducts until spawning. Spawning occurred at 8-9 months of age. Up to 5,000 eggs were laid by large females and nearly 100% of fertilized eggs developed to hatching. Females brooded eggs during the 45-day period of development but artificial was as successful as natural incubation by the mother. Pos-reproductive senescent decline of both males and females was rapid and average life span was 300 days from hatching. Areas of biomedical research in which O maya could be a useful model were suggested and included neurobiology, comparative psychology, ontogeny of behavior, immunology, endocrinology, and studies of aging.
TL;DR: Although functional failure seems likely to be associated with an immunologic event neither sperm agglutination nor sperm immobilization seems to be the mechanism of that event.
Journal Article•
TL;DR: The total number of spermatozoa in a pre-vasectomy ejaculate was found to be correlated with an early immune response and with the titre values after 1 year, and the group of patients in whom agglutinins had developed 1 year after vasectomy were found to have significantly larger nodules at the sites of operation than those without sperm agglUTinins.
Abstract: Levels of sperm agglutinating antibodies in the serum and seminal plasma of 47 vasectomized men were studied immediately before and 9 days 1 2 and 3 months and 1 year after the operation. Another 30 men were examined retrospectively 1 year after vasectomy. At 1 year 62% of the 77 men had sperm agglutinating activity in serum while only 4% had agglutinins in the seminal plasma. Titers in serum detected by the gelatin agglutination test were almost universally above 4 (generally 32-2000) and ranged up to 4000 whereas seminal fluid titers were (with 1 exception) either 4 or 8. There was no clear-cut pattern of development of the agglutinins or of type of agglutination (determined in the slide agglutination test) but there was a predominance of tail to tail agglutination after 1 year. The total number of spermatozoa in a prevasectomy ejaculate was correlated an early immune response and with the titer values after 1 year. The group of patients in whom agglutinins had developed 1 year after vasectomy had significantly larger nodules at the sites of vasectomy than those without sperm antibodies.