Showing papers on "Sperm published in 1982"
TL;DR: The classical theory that sperm are small simply because of the difficulties of ensuring that ova do get fertilized may also explain sperm size, and both effects are likely to contribute to the stability of anisogamy.
455 citations
TL;DR: Findings suggested vigorous progressive sperm motility and acrosome integrity to be important features of good sperm samples and the first calf resulting from in vitro fertilization has been found to be completely normal.
Abstract: A repeatable procedure for fertilization of bovine ova in vitro is described. Oocytes were recovered from ovarian follicles or from oviducts near the time of ovulation following treatment of donors with pregnant mare's serum gonadotropin (PMSG) and prostaglandin F2 alpha (PGF2 alpha). For in vitro capacitation semen was incubated, then high ionic strength treated and subsequently incubated in defined medium prior to insemination of oocytes. In one experiment frozen bull semen was successfully used. In experiments with 4 bulls (B, C, D, F), 34 (43.6%) of 78 ova and 13 (19.7%) of 66 follicular oocytes were fertilized in vitro. In the last series (spermatozoa from Bull F) the fertilization of 22 (62.9%) of 35 tubal ova was achieved. In vitro development proceeded to the 8-cell stage. No fertilization in vitro followed use of one male (Bull E), even though his spermatozoa could penetrate zona-free hamster ova in vitro, and higher than usual bacterial contamination of his semen was implicated as the probable cause. Findings suggested vigorous progressive sperm motility and acrosome integrity to be important features of good sperm samples. In one experiment a 4-cell stage embryo was transferred with the result that the recipient gave birth to a normal bull calf on June 9, 1981. The first calf resulting from in vitro fertilization has been found to be completely normal.
452 citations
TL;DR: In the laboratory, fertilization rates achieved by male lemon tetras decline with spawning frequency, and the cost of producing sufficient sperm may reduce the intensity of sexual selection in this polygamous fish species.
Abstract: In the laboratory, fertilization rates achieved by male lemon tetras decline with spawning frequency. Even when the number of females is not limited, males can produce only four times as many offspring as females. Females show a preference for males that have not recently spawned as opposed to those that have. The cost of producing sufficient sperm to maximize fertilization rates may therefore reduce the intensity of sexual selection in this polygamous fish species.
355 citations
TL;DR: The data suggest that the zona pellucida can induce acrosome reactions in mouse spermatozoa and that these acrosomes are the ones which lead to the fertilization of zona-intact eggs.
309 citations
TL;DR: It is concluded that sperm counts and fertilizing capacity of sperm are not negatively influenced by old age, at least not in men with sustained sexual activity, however, the pituitary as well as the testis show signs of decreased endocrine reserve capacity in old age.
Abstract: Testicular functions were investigated in 23 grandfathers [60--88 yr old; 67 +/- 7.8 (mean +/- SD)], i.e. men with fertility proven earlier in life. They were recruited from a nonpatient population and led an active life, most of them with a permanent partner. The grandfathers were compared with a group of 20 unrelated healthy fathers, 24--37 years old (29.2 +/- 3.2). Whereas sperm density was higher in the older group, there were no significant differences in ejaculate volume and sperm morphology between the younger and older men. Sperm motility and seminal fructose, however, decreased with age. The fertilizing capacity of sperm as assessed in the heterologous ovum penetration test using zona pellucida-free hamster eggs did not decrease significantly with age. Whereas the basal serum testosterone and estradiol levels were not different between the younger and older men, the response to 2 days of hCG stimulation decreased significantly with age. This decrease was observed in older men whether they had frequent or infrequent sexual activity. Basal serum LH and FSH levels were elevated in the older men. The LH response to GnRH stimulation relative to basal; values was significantly reduce, while FSH responses did not change with age. We conclude that sperm counts and fertilizing capacity of sperm are not negatively influenced by old age, at least not in men with sustained sexual activity. However, the pituitary as well as the testis show signs of decreased endocrine reserve capacity in old age.
305 citations
TL;DR: These studies, in conjunction with those of the preceding paper dealing with surface galactosyltransferase changes during capacitation, directly suggest that galacto-transferase is at least one of the components necessary for sperm binding to the zona pellucida.
Abstract: Past studies have suggested that mouse sperm surface galactosyltransferase may participate during fertilization by binding N-acetylglucosamine (GlcNAc) residues in the zona pellucida. In this paper, we examined further the role of sperm surface galactosyltransferase in mouse fertilization. Two reagents that specifically perturb sperm surface galactosyltransferase activity both inhibit sperm-zona binding. The presence of the milk protein alpha-lactalbumin specifically modifies the substrate specificity of sperm galactosyltransferase away from GlcNAc and towards glucose and simultaneously inhibits sperm binding to the zona pellucida. Similarly, UDP-dialdehyde inhibits sperm binding to the zona pellucida and sperm surface galactosyl-transferase activity to identical degrees. Of five other sperm enzymes assayed, four are unaffected by UDP-dialdehyde, and one is affected only slightly. Covalent linkage of UDP-dialdehyde to sperm dramatically inhibits binding to eggs, while treatment of eggs with UDP-dialdehyde has no effect on sperm binding. Heat-solubilized or pronase-digested zona pellucida inhibit sperm-zona binding, and they can be glycosylated by sperm with UDP-galactose. Sperm are also able to glycosylate intact zona pellucida with UDP-galactose. Thus, solubilized and intact zona pellucida act as substrates for sperm surface GlcNAc:galactosyltransferases. Finally, pretreatment of eggs with beta-N-acetylglucosaminidase inhibits sperm binding by up to 86%, while under identical conditions, pretreatment with beta-galactosidase increases sperm binding by 55%. These studies, in conjunction with those of the preceding paper dealing with surface galactosyltransferase changes during capacitation, directly suggest that galactosyltransferase is at least one of the components necessary for sperm binding to the zona pellucida.
302 citations
TL;DR: Polyandry appears to be widespread in the Hymenoptera and may have evolved as a consequence of a sex determination mechanism that leads to the production of inviable or sterile diploid males.
Abstract: Allozyme data show that multiply inseminated honey bee queens utilize the sperm of at least three males at any given time and that the sperm are, to some extent, mixing in the spermatheca. Statisti...
199 citations
TL;DR: Investigation of seminal plasma constituents on Sephadex G200 gel columns found that procedures aiming at a change of membrane integrity of the prostasomes resulted in diminished effects on sperm progressive motility, explained by a probable dissipation of the electrochemical gradient of calcium ions.
Abstract: Seminal plasma constituents were separated on Sephadex G200 gel columns. The column eluate was analysed with regard to protein content, ATPase activity and promotive activity on sperm progressive motility. Two different chromatographic fractions were also subjected to electron microscopy after sedimentation by preparative ultracentrifugation. A maximum promotive value on sperm progressive motility coincided with a maximum ATPase activity value in a single peak from seminal plasma eluted first on the column and containing less protein than the other peaks appearing later in the chromatogram. This first peak was the only one containing ATPase activity and membrane-surrounded organelles named prostasomes. Other peaks, rich in protein but lacking ATPase and prostasomes, displayed a moderate and rather irregular pattern in reference to promotive activity on sperm progressive motility. Evidence is given that the positive effect by prostasomes is specific on sperm progressive motility. Hence, procedures aiming at a change of membrane integrity of the prostasomes resulted in diminished effects on sperm progressive motility. This could be explained by a probable dissipation of the electrochemical gradient of calcium ions.
195 citations
TL;DR: Of the conventional parameters of semen analysis examined, the most revealing was the morphologic character of the sperm, which was significantly poorer in the group with unexplained infertility than in the normal fertile control group and also showed a significant relationship with the presence of subnormal fertilizing capacity in the hamster egg assay.
193 citations
TL;DR: E eggs and sperm of the sea urchin Paracentrotus lividus of the Mediterranean are used for an in vitro study of fertilization kinetics and the role of the jelly is discussed.
Abstract: Eggs and sperm of the sea urchin Paracentrotus lividus of the Mediterranean are used for an in vitro study of fertilization kinetics. The results are analyzed in terms of two models. One of these models assumes that all sperm-egg encounters lead to permanent attachment; the other (less realistically) assumes that sperm continue their random search after an unsuccessful encounter. More than 100 spermatozoa per egg are needed to achieve a fertilization ratio of more than 95%. There are two explanations for this: only 1% of the egg surface is subject to fertilization, or only 1% of spermatozoa are intrinsically able to fertilize. In the same context, chemotactic attraction and the role of the jelly are discussed. Comparison with earlier work of Rothschild and Swann and of Hultin and Hagstrom clarifies some discrepancies between and within these papers.
189 citations
TL;DR: In this article, an inverse relationship was found between the number of sperm adherent to the zona and the proportion of sperm exhibiting binding of IgA or IgG immunoglobulins over the head, indicating that the presence of these antibodies in the acrosomal region of the sperm head inhibited their ability to attach to the human zona pellucida.
TL;DR: Hamster 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.
Abstract: Little 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.
TL;DR: Tests utilizing appropriate animal models for detecting alterations in male reproductive function using animal models were considered in detail and selected simple but precise and meaningful quantitative evaluations of testicular histology and motility would be enhanced.
TL;DR: The results define a molecular mechanism for one aspect of sperm capacitation, and help explain why removal of “decapacitation factos” is a necessary prerequisite for sperm binding to the zona pellucida.
Abstract: Studies using genetic and biochemical probes have suggested that mouse sperm surface galactosyltransferases may participate during fertilization by binding N- acetylglucosamine (GlcNAc) residues in the egg zona pellucida. In light of these results, we examined sperm surface galactosyltransferase activity during in vitro capacitation to determine whether changes in enzymatic activity correlated with fertilizing ability. Results show that surface galactosyltransferases on uncapacitated sperm was preferentially loaded with poly N-acetyllactosamine substrates. As a consequence of capacitation in Ca(++)-containing medium, these polylactosaminyl substrates are spontaneously released from the sperm surface, thereby exposing the sperm galactosyltransferase for binding to the zona pellucida. Sperm capacitation can be mimicked, in the absence of Ca(++), either by washing sperm in Ca(++)-free medium, or by pretreating sperm with antiserum that reacts with the galactosyltransferase substrate. In both instances, sperm galgactosylation of endogenous polylactosaminyl substrates is reduced, coincident with increased galactosylation of exogenous GlcNAc, and increased binding to the zona pellucida. Binding of capacitated sperm to the egg can be inhibited by pronase-digested high molecular weight polyactosaminyl glycoside extracted from epidymal fluids or from undifferentiated F9 embryonal carninoma cells. Thus, these glycosides function as "decapacitation factors" when added back to in vitro fertilization assays. These glycoside "decapacitation factors" inhibit sperm-egg binding by competeing for the sperm surface galactosyltransferase, since (a) they are galactosylated by sperm in the presence of UDP[(3)H]galactose, and (b) enzymatic removal of terminal GlcNAc residues reduces "decapacitation factio" competition. On the other hand "conventional" low molecular weight glycosides, isolated from either epididymal fluid or differentiated F9 cells, fail to inhibit capacitated sperm binding to the zona pellucida. These results define a molecular mechanism for one aspect of sperm capacitation, and help explain why removal of "decapacitation factos" is a necessary prerequisite for sperm binding to the zona pellucida.
TL;DR: Extracellular Ca2+ is apparently unnecessary for the attachment of spermatozoa to the zona and egg surfaces, decondensation of the sperm nucleus, and the development of sperm and egg pronuclei within the egg.
Abstract: Using a semi-chemically defined medium, the requirement of extracellular Ca2+ for survival, capacitation, and acrosome reaction of spermatozoa as well as various stages of fertilization in the hamster was studied. A Ca2+-deficient environment is unfavorable for long-term survival of spermatozoa. Sperm capacitation may occur in Ca2+-deficient media, but not as efficiently as in normal media. The acrosome reaction definitely requires extracellular Ca2+. Other processes or phenomena that require extracellular Ca2+ are initiation and maintenance of hyperactivated motility of spermatozoa, penetration of acrosome-reacted spermatozoa into the zona pellucida, fusion of the spermatozoa with eggs, and the development of pronuclear eggs into two-cell embryos. Extracellular Ca2+ is apparently unnecessary for the attachment of spermatozoa to the zona and egg surfaces, decondensation of the sperm nucleus, and the development of sperm and egg pronuclei within the egg. These results were compared with data obtained in other species such as the sea urchin, mouse, rat and guinea pig.
TL;DR: The results demonstrate that the apparent fertility of normal fertile men is compatible with a wide range of intrinsic sperm quality as reflected by penetration rates ranging from 14% to 90% and differences in the minimum concentration of motile spermatozoa required to initiate penetration.
TL;DR: In this article, the relationship of the parameters of seminal fluid analysis and seminal fluid leukocyte concentration to the in vitro sperm penetration assay (SPA) was studied in 217 men from infertile couples.
TL;DR: It is concluded that the fast block is essential to the prevention of polyspermy at the sperm concentrations normally encountered by the egg.
TL;DR: Analysis of the experimental data available concerning the effects of smoking on reproductive processes suggests an adverse influence on reproduction at several sites from gametogenesis to implantation.
TL;DR: It is suggested that proteoglycan present in follicular fluid at the time of ovulation may promote the acrosome reaction which precedes the ability of sperm to fertilize an ovum.
TL;DR: Variablity in motility and hatching was not correlated with sperm volume or age of the fish, and is believed to be due to differences in sperm quality between individuals, as well as technical constraints imposed by the short duration of motility in thawed spermatozoa.
Abstract: We describe a method for cryopreservation of milt from individual Brachydanio rerio using methanol and powdered milk as cryoprotectants. Motility was positively correlated with hatching, which averaged 51 ± 35.6% in a typical experiment. Variablity in motility and hatching was not correlated with sperm volume or age of the fish, and is believed to be due to differences in sperm quality between individuals, as well as technical constraints imposed by the short duration of motility in thawed spermatozoa.
TL;DR: DNA staining with 4-6 diamidino-2-phenylindole (DAPI) or an ethidium bromide mithramycin combination allows resolution of the X and Y populations in mouse sperm and is successful with sperm from the bull, ram, rabbit, and boar.
Abstract: The high condensation and flat shape of the mammalian sperm nucleus present unique difficulties to flow cytometric measurement of DNA content Chromatin compactness makes quantitative fluorescent staining for DNA difficult and causes a high index of refraction The refractive index makes optical measurements sensitive to sperm head orientation We demonstrate that the optical problems can be overcome using the commercial ICP22 epiillumination flow cytometer (Ortho Instruments, Westwood, MA) or a specially built cell orientating flow cytometer (OFCM) The design and operation of the OFCM are described Measurements of the angular dependence of fluorescence from acriflavine stained rabbit sperm show that it is capable of orienting flat sperm with a tolerance of +-7/sup 0/ Differences in the angular dependence for the similarly shaped bull and rabbit sperm allow discrimination of these cells We show that DNA staining with 4-6 diamidino-2-phenylindole (DAPI) or an ethidium bromide mithramycin combination allows resolution of the X and Y populations in mouse sperm They have also been successful with sperm from the bull, ram, rabbit, and boar Reliable results with human sperm are not obtained The accuracy of the staining and measurement techniques are verified by the correct determination of the relative content of these twomore » populations in sperm from normal mice and those with the Cattanach (7 to X) translocation Among the potential uses of these techniques are measurement of DNA content errors induced in sperm due to mutagen exposure, and assessment of the fractions of X and Y sperm in semen that may have one population artifically enriched« less
TL;DR: Evidence is provided that sperm-zona pellucida binding is mediated by ligands on the sperm surface containing fucose, galactose, N-acetylglucosamine and N- acetylgalactosamine residues.
TL;DR: Experiments to determine the details of sperm competition in the bowl and doily spider (Frontinella pyramitela: Linyphiidae), and the effect of female reproductive history on male mating behavior will be discussed below.
Abstract: Males generally produce many times more gametes than females. Consequently in species where males contribute nothing more to their offspring than gametes, there will be strong competition between males for fertilization of females' eggs (Bateman, 1948). This competition does not necessarily end when mating finally occurs. If females store sperm and have an opportunity to mate with more than one male, these males' sperm may still compete within the female reproductive tract (Parker, 1970). Sperm priority, the order in which stored sperm from several males is used in fertilization, can affect the evolution of male reproductive anatomy (Waage, 1979a), physiology (Bishop, 1920; Craig, 1967), and behavior (Parker, 1974; Waage, 197 9b). Spiders have a high potential for sperm competition because females store sperm for long periods (Bristowe, 1958; Valerio, 1970; Forster and Forster, 1973) and often mate with several males (Montgomery, 1903; Levi, 1968; Jackson, 1978, 1980a). Though much research has recently been done on the more obvious aspects of intermale competition in spiders (e.g., Rovner, 1968; Aspey, 1977; Christenson and Goist, 1979; Jackson, 1980b; Vollrath, 1980), little is known about sperm competition in the taxon (but see Jackson, 1980a and Vollrath, 1980). However, knowing the details of sperm competition is vital to understanding the operation of sexual selection and the evolution of associated traits in any animal group in which such competition may occur. Experiments to determine the details of sperm competition in the bowl and doily spider (Frontinella pyramitela: Linyphiidae), and the effect of female reproductive history on male mating behavior will be discussed below.
Journal Article•
TL;DR: Mouse seminal plasma (SP), a mixture of aqueous extracts of prostate, seminal vesicle, and epididymis, exerts potent immunosuppressive effects in vivo; these factors may serve to protect sperm from immunologic damage and prevent sensitization of females to sperm antigens after insemination.
Abstract: Mouse seminal plasma (SP), a mixture of aqueous extracts of prostate, seminal vesicle, and epididymis, exerts potent immunosuppressive effects in vivo The SP mixture completely suppressed both primary and secondary humoral immune responses in mice to low immunizing doses of antigen (bovine serum albumin or washed epididymal sperm), and also significantly suppressed the antibody response to high doses of immunizing antigen The humoral immune response to epididymal sperm was also suppressed when sperm were incubated in SP and then washed before immunization and when SP was administered at a secondary site (i p) at the time of sperm immunization (subcutaneous) When SP components were tested individually in in vitro assays, all of them (prostate, seminal vesicle, and epididymis) suppressed mitogen-induced lymphocyte transformation Prostatic fluid also inhibited complement-mediated hemolysis in a standard immune hemolytic assay These data indicate that potent immunosuppressive factors are present at several locations within the male reproductive tract; these factors may serve to protect sperm from immunologic damage and prevent sensitization of females to sperm antigens after insemination
TL;DR: Evidence suggests that carrier matrices not only facilitate the transport of sperm anteriorly from vaginal to infundibular regions, but also function as nutritional stores in female red‐sided garter snakes.
Abstract: Female red-sided garter snakes (Thamnophis sirtalis parietalis) store sperm from both late-summer and spring matings. Before winter dormancy, sperm are stored in specialized furrows in the vaginal portion of the oviduct, 3-6 cm anterior to the vent. After 6 weeks in dormancy, the epithelial cells lining this vaginal region hypertrophy and stain strongly with periodic acid-Schiff (PAS). This PAS+ epithelial border sloughs and associates with sperm. These aggregations of PAS+ material, which will be referred to as carrier matrices, move anteriorly through the oviduct. After 20 weeks in dormancy, most sperm are found in specialized infundibular storage regions. Spring mating induces a rapid degeneration of winter-stored sperm. Stored sperm are evacuated from infundibular storage receptacles within 6 hours after mating. Yet sperm from the spring mating are not evident in the oviduct until 24 hours after mating. Carrier matrices begin to form at this time. At 48 hours after mating, sperm, often associated with carrier matrices, appear in the infundibulum. At 40 days after mating, most sperm have moved into infundibular storage receptacles. Evidence suggests that carrier matrices not only facilitate the transport of sperm anteriorly from vaginal to infundibular regions, but also function as nutritional stores.
TL;DR: In this paper, the binding and fusion of human sperm to the oolemma of a Zona pellucida-free (ZPF) hamster oocyte has been studied.
TL;DR: Sera from men at risk for immunity to spermatozoa were screened for antisperm antibodies by immunobead binding following passive antibody transfer to antibody‐free sperm of fertile donors, finding a high degree of immobilization was found only when IgG binding occurred on the distal two‐fifths of the principal piece of the tail.
Abstract: Sera from men at risk for immunity to spermatozoa were screened for antisperm antibodies by immunobead binding following passive antibody transfer to antibody-free sperm of fertile donors. The percent motile sperm after incubation in diluted antibody positive serum in the presence of complement was compared with the regional distribution of immunoglobulins bound to the sperm surface. The extent of complement-mediated sperm immobilization varied with immunoglobulin class and with the location of antibody bound to the sperm surface. Tests utilizing complement-mediated immobilization of sperm are insensitive to the presence of antibodies of IgG and IgA classes that are directed against the head, the distal one-fifth of the sperm tail principal piece, or the tail end piece. A high degree of immobilization was found only when IgG binding occurred on the distal two-fifths to three-fifths of the principal piece of the tail or when IgM bound to the sperm tail end piece. (Am J Reprod Immunol. 2:222-224.)
TL;DR: It appears that, for mouse spermatozoa, the onset of fertility during epididymal transit parallels the ability to bind to zonae pellucidae.
Abstract: Mouse spermatozoa recovered from the caput, corpus, or cauda epididymidis were examined for their ability to bind the vitro to zonae pellucidae. Since spermatozoa from the caput epididymidis do not display progressive motility as compared with more mature spermatozoa, direct comparison of the different sperm populations may not measure zona binding ability validly. To equalize the motile properties of the spermatozoa, a method was developed to immobilize vigorously motile corpus and cauda spermatozoa. Reversible immobilization was achieved by incubation in 25 microM La3+ which resulted in a twitching, nonprogressive type of motility. La3+ incubation did not appear to affect the spermatozoa adversely, since vigorous motility (equivalent to the controls) of corpus and cauda sperm was displayed upon subsequent incubation in standard La3+-free culture medium. Moreover, cauda spermatozoa preincubated for 90 min in La3+ displayed levels of fertilization in vitro equivalent to their control counterparts. Using this La3+-immobilization technique, the zona binding ability of the different sperm population could be assayed. Gamete collision was insured under these conditions by shaking the gamete-containing dishes at 100 cycles/min. Regardless of the extent of sperm motility, a similar zona-binding pattern emerged: cauda sperm bound in high numbers, corpus sperm bound at some intermediate level (an average of 24% of cauda binding level), and caput sperm bound rarely (2% of cauda binding level). Thus it appears that, for mouse spermatozoa, the onset of fertility during epididymal transit parallels the ability to bind to zonae pellucidae. Unlike the interaction between spermatozoa and zonae, La3+ was unable to support sperm binding in to egg plasma membrane, supporting the view that mouse sperm may have different sites for interaction with the zonae pellucida and the egg plasma membrane.
TL;DR: Radioimmunoassays are used to follow plasma 11-oxotestosterone and glycoprotein gonadotropin levels related to sperm production in male rainbow trout at the onset of spermiation, and the quantities of collected sperm are positively correlated with the 11-Oxotest testosterone levels, but not with GTH secretion.