SEARCH · PubMed Health

Results for “Sperm”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

PubMed2004

Effect of adding cholesterol to bull sperm membranes on sperm capacitation, the acrosome reaction, and fertility.

When cholesterol is added to sperm membranes before cryopreservation, higher percentages of motile and viable cells are recovered after thawing. However, because one of the first steps in sperm capacitation is cholesterol efflux from the sperm plasma membrane, adding cholesterol to enhance cryosurvival may retard sperm capacitation. These studies evaluated the ability of sperm treated with cholesterol-loaded cyclodextrins (CLC) to capacitate, acrosome react, and fertilize oocytes. Control (non-CLC-treated) and CLC-treated sperm were treated with heparin, dilauroylphosphatidylcholine (PC12), or calcium ionophore A23187 (A23187) to capacitate and induce the acrosome reaction. Sperm capacitation, assessed by an increase in intracellular calcium level, and acrosome-reacted sperm were measured using flow cytometry. Fresh CLC-treated sperm cells underwent capacitation and/or the acrosome reaction at rates different from control samples, and the differences detected were dependent on the method used to induce sperm capacitation and the acrosome reaction. After cryopreservation, however, CLC-treated and control sperm underwent capacitation and the acrosome reaction at similar rates regardless of the method used to induce capacitation and the acrosome reaction. The primary concern for CLC-treated sperm, however, is whether this treatment would affect in vitro or in vivo fertility. Adding either control or CLC-treated cryopreserved sperm to bovine oocytes in vitro resulted in similar oocyte cleavage rates and blastocyst formation rates. In addition, when inseminated into heifers, pregnancy rates for control and CLC-treated sperm were also similar. Therefore, treating bull sperm with CLC permits greater numbers of sperm to survive cryopreservation while preserving the fertilizing potential of each individual sperm.

Acrosome Reaction↗

PubMed1991

Sperm competition influences sperm size in mammals.

Among mammals sperm competition leads to selection for increased sperm numbers but it is not known whether it also leads to changes in sperm size. Two contrasting theoretical predictions have been made. The first hypothesis relies on the assumption that there is a trade-off between sperm numbers and sperm size and predicts that, in species confronting sperm competition, there will be a concomitant decrease in sperm size as sperm numbers increase. In contrast, the second hypothesis suggests that longer sperm may outcompete rival sperm; if longer sperm may swim faster, they will reach the ova sooner and will be selected when sperm competition prevails. We tested these hypotheses in both primates and rodents. We report that males from species in which females mate promiscuously have longer sperm than species in which females mate with one male. In addition, we also found that sperm length is positively correlated with maximum sperm velocity. Our findings thus support the view that longer sperm may be adaptive in the context of sperm competition.

Adaptation, Physiological↗

PubMed1979

Isolation of human spermatozoa membrane antigens binding sperm-immobilizing and sperm-agglutinating antibodies.

Peptides of human spermatozoa were dissolved with Hyamine 2389 and Triton X-100 and separated by chromatography on Biogel P4 columns into seven fractions. The antigenic activities of the separated sperm-membrane fractions were tested according to their capacity to inhibit sperm agglutination and sperm immobilization (immune inhibition test) in human sera of sterile patients. Sperm-agglutinating and sperm-immobilizing activity was tested by the microtray agglutination and microtray immobilization test. A titer reduction was achieved only in sperm-immobilizing sera. Four sperm antigenic fractions revealed in the majority of the repeatedly tested sperm-immobilizing sera an inhibition of the antigen-antibody reaction. No reaction was observed after exhaustive absorption of the tested seven antigen fractions with sperm-agglutinating sera. Therefore the conclusion can be drawn that sperm-agglutinating and sperm-immobilizing antibodies react with different sperm antigens. Normal human sera without sperm antibodies served as control. As no sperm agglutination or sperm immobilization was obtained after absorption of these control sera our antigen fractions do not produce sperm agglutination or sperm immobilization.

Antigens, Surface↗

PubMed1986

Cytotoxic sperm antibodies inhibit sperm penetration of zona-free hamster eggs.

Zona-free hamster egg sperm penetration assay was used to study the effects of cytotoxic sperm antibodies on egg penetration by the sperm of fertile and infertile men. Twenty-nine fertile and 9 infertile men did not have significant cytotoxic sperm antibodies in their serum and seminal plasma; 7 infertile men were positive for these antibodies in serum and seminal plasma. Two others were positive in sera, and 14 were positive in seminal plasma. Sperm from 18 of 23 (78%) infertile men with sperm antibodies had poor egg penetration (less than or equal to 20%) compared with only 6 of 38 (16%) nonautoimmune men (P less than 0.0001). Sperm from nonautoimmune fertile men were coated with seminal plasma and serum of autoimmune men and serum of isoimmune women, resulting in a significant decrease in hamster egg penetration. Sixteen of 21 (76%) seminal plasma samples with cytotoxic sperm antibodies reduced the control sperm penetration of hamster eggs by greater than or equal to 50%. Coating of sperm from fertile men with serum and seminal plasma samples from non-sperm-immune fertile and infertile subjects did not alter their penetration of hamster eggs. Coating of sperm from autoimmune men with cytotoxic antibody-positive autologous seminal plasma samples resulted in a significant decrease of egg penetration. The inhibitory effect of antibody-positive seminal plasma samples on egg penetration by control sperm was abrogated when the samples were preabsorbed with sperm. It is concluded that cytotoxic sperm antibodies, especially those in seminal plasma, inhibit hamster egg penetration by autologous and control sperm. This may explain in part the incidence of infertility associated with sperm antibodies.

Animals↗

PubMed1988

Cholesterol efflux from bovine sperm. I. Induction of the acrosome reaction with lysophosphatidylcholine after reducing sperm cholesterol.

Methods were developed to quantitatively reduce the cholesterol (Chol)/phospholipid (PL) ratio of bovine sperm and to determine the effectiveness of this treatment in capacitating sperm. Washed sperm (2 x 10(8)) were incubated in 1.0 ml of modified Tyrode's solution (TS) containing unilamellar liposomes of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and [14C]-Chol (35:35:30 molar ratio, 300 nmol total PL). [3H]-triolein was included as a nonexchangeable marker. After 90 min at 39 degrees C, a 13% net exchange of [14C]-Chol from liposomes to sperm was observed (n = 4), and sperm motility was 80%. Sperm were then washed and 50 x 10(6) sperm were incubated as before with PC/PE liposomes containing no Chol. After 90 min, sperm were separated from liposomes by centrifugation. Measurement of [14C]-Chol in the liposomes (supernatant) and parallel gas chromatographic analysis of extracted, saponified liposomes (n = 4) indicated that 30% of sperm Chol was removed by this procedure. Chol efflux decreased percent motile sperm by less than 10% but reduced sperm velocity by more than 50%. Sperm incubated with no liposomes (control), with liposomes containing Chol (+Chol), and with Chol-free liposomes (-Chol) were washed and resuspended in TS with 0.2% BSA and 30 micrograms lysophosphatidylcholine (LPC)/mg bovine serum albumin (BSA). Percent sperm undergoing the acrosome reaction (AR) upon incubation with LPC-BSA was used as a measure of sperm capacitation. After 60 min of exposure to LPC-BSA at 39 degrees C, the mean (+/- SE) percent motile sperm for control, +Chol, and -Chol treatments was 57.0 +/- 4.9, 60.0 +/- 4.7, and 57.0 +/- 6.8, respectively. Corresponding values for percent AR were 14.0 +/- 3.4, 20.3 +/- 4.4, and 39.7 +/- 1.2. These results suggest that loss of Chol from bovine sperm may be an early step in sperm capacitation in this species.

Acrosome↗

PubMed1994

The effects of patients' sera with sperm-immobilizing antibodies on sperm of the Japanese monkey.

In order to study the interspecies cross-reactivity of sperm-immobilizing antibodies found in sera of women who were infertile for unknown reasons, we used the sperm-immobilization test to examine the effects of patients' sera with or without sperm-immobilizing antibodies on the sperm of the Japanese monkey (Macaca fuscata). Fourteen of 17 antibody-positive sera and 7 of 14 antibody-negative sera showed sperm-immobilizing activity with regard to monkey sperm. The sperm-immobilizing antibody that was active against both human and monkey sperm could be absorbed only by sperm from each corresponding species. The periodate treatment of human or monkey sperm markedly diminished their antibody-absorbing capabilities. Human and mouse monoclonal antibodies having sperm-immobilizing activity with regard to human sperm showed no sperm-immobilizing activity with regard to monkey sperm. These results indicate that the sperm-immobilizing activity of the sera of infertile women against human and monkey sperm might be due to antibodies with different specificities, which recognize a unique carbohydrate antigen epitope expressed in the sperm of each species.

Animals↗

PubMed2001

Inhibition of sperm motility does not affect live-dead separation of bull sperm by glass beads.

AIM: This study was designed to explore factors which influence binding of dead versus live sperm to glass filters. METHODS: Multiple semen collections from bulls were used to explore selective filtration of bull sperm as influenced by nonlethal inhibition of sperm motility with fluoride, killing of sperm by quick-freezing, alteration of the glass surface with silicone, and different intervals of sexual rest between semen collections. RESULTS: A comparison of glass spheres 100, 200 and 390 microm in diameter indicated that 200 microm spheres were optimal for selective filtration. Quantitative separation of live from dead sperm was demonstrated with a correlation between the percentage of motile sperm and retention of sperm by the filter of r = -0.87 (P < 0.05). Up to 0.02 mol/L NaFl did not alter the proportion of sperm retained by the filter despite inhibiting sperm motility during filtration, an inhibition which was reversible. Proportions of live-dead sperm, based upon eosin staining, were unaffected by fluoride. Coating the glass spheres with silicone greatly reduced selective filtration. Dead sperm adherence to glass was reduced and resistance to NaFl inhibition was increased by daily ejaculation versus one-week intervals of sexual rest. CONCLUSION: These studies indicate that the adherence of sperm to glass is primarily due to some form of physico-chemical change accompanying death of the sperm cell independent of active sperm motility. This attraction between the sperm plasma membrane and glass is modified by the age of the ejaculated sperm. This information is useful in evaluating different clinical procedures used for sperm separation.

Animals↗

PubMed2006

Tyrosine phosphorylation on capacitated human sperm tail detected by immunofluorescence correlates strongly with sperm-zona pellucida (ZP) binding but not with the ZP-induced acrosome reaction.

BACKGROUND: Protein tyrosine phosphorylation (TP) of human sperm is related to sperm capacitation and zona pellucida (ZP) binding. The aim of this study was to determine whether the TP of capacitated sperm is a useful marker for the ability of sperm to bind to the ZP and undergo the ZP-induced acrosome reaction (AR). METHODS: Semen samples were obtained from 115 subfertile men with sperm count > or =20 x 10(6)/ml, motility > or =25% and variable morphology. Motile sperm (2 x 10(6)/ml) selected by swim-up were incubated with four oocytes for 2 h, and the number of sperm bound to the ZP and the ZP-induced AR was examined. TP of sperm tail was assessed by immunofluorescence (IF) with anti-phosphotyrosine monoclonal antibody. The time course and effects of dibutyryl cyclic adenosine monophosphate (dbcAMP) and phorbol myristate acetate (PMA) on TP were also studied. RESULTS: TP was stimulated more by dbcAMP (P < 0.001) and less by PMA (P < 0.05). TP increased significantly with time of incubation of sperm. TP was not detectable on the surface of unfixed live sperm by either Dynabeads or IF. Sperm TP at 2, 4 and 20 h incubation was all significantly correlated with sperm-ZP binding but not with the ZP-induced AR. CONCLUSION: Sperm TP detected by IF correlates strongly with sperm-ZP binding capacity but not with the ZP-induced AR. This simple IF assay of TP may be a clinically useful test of sperm function that is predictive of normal sperm ZP-binding capacity.

Acrosome Reaction↗

PubMed1987

Purification of the sperm-binding factor and identification of a sperm attack molecule from the egg of the sea urchin, Hemicentrotus pulcherrimus.

A sperm-binding factor, which seems to have a primary role in binding sperm to the egg, was isolated from the egg surface of Hemicentrotus pulcherrimus and purified by monitoring the neutralization of the fertilization inhibition exerted by Fab fragments against crude sperm-binding factor. An improved purification for this sperm-binding factor is described in the present paper. The preparation of purified sperm-binding factor revealed one major protein band with an apparent molecular weight of 61,000 after sodium dodecylsulfate-polyacrylamide gel electrophoresis. A substance with the fertilization inhibitory effect on sperm, was isolated by diethylaminoethyl (DEAE)-Sephadex column chromatography in the course of purification of the sperm-binding factor and termed "sperm attack molecule." One precipitin line was formed between the sperm attack molecule and anti-crude sperm-binding factor serum in a double-immunodiffusion test. Fab fragments were prepared against partially purified sperm-binding factor or sperm attack molecule, and the effect of these Fab fragments on eggs was investigated. Anti-sperm-binding factor Fab fragments inhibited the fertilizability of eggs, whereas anti-sperm attack molecule Fab fragments did not. However, anti-sperm attack molecule Fab fragments impaired elevation of the vitelline layer. It is possible that the sperm attack molecule prevents polyspermy. Sperm attack molecule contains 3.7% neutral sugars. Its inhibitory effect was cancelled by trypsin or heat.

Animals↗

PubMed2003

PDC-109 (BSP-A1/A2) promotes bull sperm binding to oviductal epithelium in vitro and may be involved in forming the oviductal sperm reservoir.

Sperm reservoirs have been found in the oviducts of several species of mammals. In cattle, the reservoir is formed by the binding of sperm to fucose-containing glycoconjugates on the surface of oviductal epithelial cells. A fucose-binding molecule was purified from sperm extracts and identified as PDC-109 (BSP-A1/A2), a protein that is secreted by the seminal vesicles and associates with the plasma membrane of sperm upon ejaculation. The objective of this study was to demonstrate that PDC-109 promotes bull sperm binding to oviductal epithelium. PDC-109 was purified from bovine seminal plasma, and polyclonal antibodies were produced in rabbits. The antibodies detected PDC-109 on ejaculated sperm by indirect immunofluorescence and Western blots of extracts, but PDC-109 was not detected on epididymal sperm. When added to epididymal sperm, purified PDC-109 was absorbed onto the plasma membrane overlying the acrosome, as demonstrated by indirect immunofluorescence and by labeling sperm directly with fluorescein-conjugated PDC-109. When added to explants of oviductal epithelium, significantly fewer epididymal sperm than ejaculated sperm became bound. Addition of PDC-109 to epididymal sperm increased epithelial binding to the level observed for ejaculated sperm. In addition, binding of ejaculated sperm to oviductal epithelium was inhibited by addition of excess soluble PDC-109. Ejaculated sperm lost the ability to bind to oviductal epithelium after heparin-induced capacitation, but treatment with PDC-109 restored binding. These results demonstrate that PDC-109 enables sperm to bind to oviductal epithelium and plays a major role in formation of the bovine oviductal sperm reservoir.

Animals↗

PubMed2003

Low-density lipoprotein fraction from hen's egg yolk decreases the binding of the major proteins of bovine seminal plasma to sperm and prevents lipid efflux from the sperm membrane.

For sperm preservation, semen is generally diluted with extender containing egg yolk (EY), but the mechanisms of sperm protection by EY are unclear. The major proteins of bull seminal plasma (BSP proteins: BSP-A1/A2, BSP-A3, and BSP-30-kDa) bind to sperm surface at ejaculation and stimulate cholesterol and phospholipid efflux from the sperm membrane. Since EY low-density lipoprotein fraction (LDF) interacts specifically with BSP proteins, it is proposed that the sequestration of BSP proteins in seminal plasma by EY-LDF represents the major mechanism of sperm protection by EY. In order to gain further insight into this mechanism, we investigated the effect of seminal plasma, EY, and EY-LDF on the binding of BSP proteins to sperm and the lipid efflux from the sperm membrane. As shown by immunodetection, radioimmunoassays, and lipid analysis, when semen was incubated undiluted or diluted with control extender (without EY or EY-LDF), BSP proteins bound to sperm in a time-dependent manner, and there is a continuous cholesterol and phospholipid efflux from the sperm membrane. In contrast, when semen was diluted with extender containing EY or EY-LDF, there was 50%-80% fewer BSP proteins associated with sperm and a significant amount of lipid added to sperm membrane during incubation. In addition, sperm function analysis showed that the presence of EY or EY-LDF in the extender preserved sperm motility. These results show that LDF is the constituent of EY that prevents binding of the BSP proteins to sperm and lipid efflux from the sperm membrane and is beneficial to sperm functions during sperm preservation.

Animals↗

PubMed2006

The application of in vitro sperm competition test to evaluate the impact of ZP-derived peptides on fertilization capacity of cat sperm.

The present study aimed to establish a sensitive in vitro assay to assess the binding capacity of cat spermatozoa. Cat oocytes and epididymal sperm cells were isolated from gonads and cultured for in vitro fertilization. Before fertilization, the sperm cells were incubated either in 10 microM green dye Fluo-3-AM or 10 microM orange dye CellTracker Orange CMTMR (Molecular Probes), respectively. After removing the dyes by washing, sperm cells stained with each dye were added to medium drops containing oocytes in various proportions and cultured for 16 h at 37 degrees C, 5% CO(2). The oocytes were examined using fluorescence microscopy. Sperm bound to oocytes, and stained with different colors, were counted. When fresh epididymal sperm were mixed in at a specific proportion, the number of sperm bound to the zona pellucida (ZP) of oocytes reflected the proportion of differently colored sperm in the medium. This indicated that neither dye influenced the binding capacity of cat sperm. Mixing fresh and cryopreserved sperm, however, resulted in a higher number of fresh sperm bound to the oocyte surface in comparison to frozen-thawed sperm. Also, the pre-incubation of cat sperm cells with ZP derived peptide reduced the sperm binding capacity by 40%. In conclusion, the presented sperm competition assay allows assessment of fertilizing capacity of cat spermatozoa in vitro when a mixture of two different populations is used. The applied supravital fluorescence dyes do not affect motility and binding capacity of sperm cells and were clearly distinguishable under fluorescence microscopy. We demonstrate that the assay can be used to study the impact of sperm treatment, such as cryopreservation or pre-incubation in bioactive peptides, on fertilizing capacity.

Animals↗

PubMed2006

Cryopreservation of tench, Tinca tinca, sperm: Sperm motility and hatching success of embryos.

The aim of the present study was to elaborate cryopreservation methods for ex situ conservation of tench. Success of cryopreservation was tested during two series of experiments. The first set of experiments studied the effects of two types of cryoprotectants (DMSO and a combination of DMSO with propanediol at ratio 1:1) at concentrations of 8 and 10% and three different equilibration times in two different immobilization solutions (IS) (Kurokura 180 and Kurokura) before freezing (0.0, 2.0 and 4.0h after T(0)). The K4 cooling programme was used to freeze 1ml of cryoextended sperm using 1.8ml cryotubes. Main monitored parameter was hatching rate after using of cryopreserved sperm. The second set of experiments studied the volume effect of 0.5, 1 and 5ml straws and compared these with 1.8ml cryotubes as well as the effect of the cooling programme (K4 and L1). Following the results of the first study, a combination of DMSO and propanediol (ratio 1:1) at concentration of 10% was added to extended sperm in Kurokura 180 IS. Main monitored parameter was hatching rate after using cryopreserved sperm, supplementary parameters were sperm velocity and motility percentage assessed at 10s post-activation. Sperm was collected directly into IS and stored at 4 degrees C for 2.5h. Thereafter were sperm samples pooled, equlibred in IS (first set of experiments) or directly mixed with cryoprotectants (DMSO or a mixture of DMSO with propanediol at ratio 1:1) and transferred to 1.8ml cryotubes or straws (0.5, 1 and 5ml). Then the cryotubes/straws were directly transferred to pre-programmed PLANER Kryo 10 series III and cooled using two different cooling programmes including a slow cooling programme (a) named K4 (from +4 to -9 degrees C at a rate of 4 degrees Cmin(-1) and then from -9 to -80 degrees C at a rate of 11 degrees Cmin(-1)) and a rapid cooling programme (b) named L1 (directly from +4 to -80 degrees C at a rate of 20 degrees Cmin(-1)). Both slow (K4) and rapid (L1) cooled samples were held 6min at -80 degrees C. Finally, samples were transferred into liquid N(2). The frozen spermatozoa were thawed in a water bath (40 degrees C) according to the frozen volume and checked for fertilization and hatching rates. Percentage of sperm motility and sperm velocity were measured using video recorded frames. ANOVA showed a significant influence of frozen and fresh sperm in all treatments. The hatching rates of 33.8% were obtained when sperm was equilibrated for 0h before freezing in IS of Kurokura 180 and frozen with a 10% of mixture 1:1 of DMSO and propanediol into straws of 5ml and cooled using program L1. The velocity of frozen-thawed spermatozoa ranged from 31 to 46microms(-1) and in post-thawed sperm was not significantly different according to frozen sperm volume, but a higher velocity was obtained when sperm was fast frozen using programme L1. A large volume of frozen sperm could reveal the best procedure for freezing, but also for simulating methods of artificial propagation for future practical use of frozen tench sperm at a large scale.

Animals↗

PubMed1994

Creatine kinase immunocytochemistry of human sperm-hemizona complexes: selective binding of sperm with mature creatine kinase-staining pattern.

OBJECTIVE: To examine the clinical significance of the increased sperm cytoplasmic content that is due to a fault of spermatogenesis, we have further studied the relationship between increased sperm creatine kinase (CK) concentrations and diminished fertilizing potential in men. In the present work, we used CK immunocytochemistry of human sperm-hemizona (HZ) complexes to examine whether the distribution of mature (clear heads), intermediate (sperm heads with light stippling), and immature (heads with heavy stippling or with solid CK staining) spermatozoa bound to the HZ would follow the incidence of these sperm in the samples tested, or if there is a preferential binding by the mature sperm. DESIGN: Two pairs of HZ were exposed to washed semen and to their swim-up sperm fractions. The sperm and sperm-HZ complexes were treated with a CK antibody followed by horseradish peroxidase immunostaining, and the sperm were evaluated for maturity. SETTING: Men presenting for fertility evaluation were studied in two university-based andrology laboratories. RESULTS: The binding of the HZ was selective for mature sperm as indicated by the incidence of intermediate and immature sperm in washed semen versus bound to the HZ (intermediate: 20.0% versus 1.4%; immature: 7.6% versus 0.5% [mean +/- SEM]) or in swim-up sperm fractions versus the HZ (intermediate: 18.7% versus 3.4%; immature: 2.5% versus 0.2%). The binding was almost exclusive to normal sperm (96.4% to 98.1%) whether the HZ were exposed to washed semen or swim-up fractions in spite of the five to ten times higher incidence of intermediate and immature sperm. CONCLUSIONS: Mature sperm selectively bind to the zona. We suggest that spermatozoa with immature CK-staining patterns are deficient in the site(s) of oocyte recognition and binding.

Blotting, Western↗

PubMed2002

Utilisation of a sperm quality analyser to evaluate sperm quantity and quality of turkey breeders.

1. A relatively new instrument known as a Sperm Quality Analyzer (SQA) offers a rapid assessment of sperm quality and quantity by providing a sperm quality index (SQI). The SQA measures a combination of the intensity of sperm activity and motile concentration by determining the number and amplitude of sperm movements per second in a capillary tube as detected through light beam interference. 2. Because the SQA has not been tested for its potential use in turkeys, the objective was to determine if the SQA could accurately respond to changes in turkey sperm concentration, viability, and motility in semen collected from turkey breeders. 3. The effect of varying concentrations of sperm on SQI values was evaluated by diluting replicate pools of semen from 4 different aged turkey breeder flocks with saline. Results from all 4 flocks showed that semen dilutions greater than 20-fold resulted in a linear decline in SQI values. 4. Additional in vitro analysis evaluated the effects of turkey sperm viability on the SQI under conditions of constant sperm concentration. Incubated, live sperm was mixed in various proportions with thawed, dead sperm to determine changes in viability. Increased proportions of dead sperm caused a decline in the SQI. 5. To assess sperm motility, turkey semen was incubated under either aerobic (motile) or anaerobic (immotile) conditions. Varied amounts of immotile and motile sperm samples were mixed. A linear increase in the SQI was observed as per cent motile sperm increased. 6. These results indicate that the SQA can respond to differences in turkey sperm concentration, viability, and motility using in vitro analyses.

Animals↗

PubMed2000

Efficacy of sperm mobility assessment in commercial flocks and the relationships of sperm mobility and insemination dose with fertility in turkeys.

Our objectives were to evaluate: 1) the efficacy of the Sperm Mobility Test on commercial turkey farms, and 2) the influence of sperm mobility phenotype on fertility when insemination parameters are varied. In research flocks, differences in sperm mobility among toms are predictive of fertility. We wanted to test the efficacy of this sire selection test in practical, real-world situations, evaluating its usefulness in terms of assessing large numbers of toms, different strains of turkeys, and variable management practices. Utilizing field study results, controlled studies were then conducted to improve test parameters. For the field trials, semen from each of 405 breeder toms (11 strains or lines) was evaluated either in duplicate (n = 285) or in triplicate (n = 120). Sperm mobility was normally distributed among all toms tested, except for one strain. Because the sperm mobility indices for toms evaluated in these field trials were higher than those observed in research flocks, the Sperm Mobility Test was modified to increase the separation between high and low sperm mobility phenotypes by increasing the concentration of Accudenz. To determine the effects of sperm mobility and insemination dose on sustained fertility through time, hens from a research flock were inseminated twice before the onset of lay with sperm from toms classified as high-, average-, or low-mobility in concentrations of 25 to 400 million sperm per artificial insemination dose, and egg fertility was evaluated over a 5-wk period. Toms with the high-mobility sperm phenotype maintained higher fertility (P < 0.05) over the 5-wk period at all insemination doses compared with toms with low-mobility sperm. Toms with high-mobility sperm sired equal numbers of poults in a sperm competition study in which numbers favored low-mobility toms by 3:1. These results demonstrate that the Sperm Mobility Test can be used for on-farm evaluation of semen quality of toms in commercial flocks and that sperm mobility influences fertility and sire fitness.

Animals↗

PubMed1996

Fate of the sperm mitochondria, and the incorporation, conversion, and disassembly of the sperm tail structures during bovine fertilization.

Sperm incorporation and the conversion of the sperm-derived components into zygotic structures during in vitro fertilization of bovine oocytes was explored by combining ultrastructural studies with observations of the fertilizing sperm tagged with a mitochondrion-specific vital dye MitoTracker green FM. The zygotes fertilized by the MitoTracker-labeled sperm were fixed at various times after fertilization and then processed for immunocytochemistry to examine the distribution of DNA, microtubules, and sperm tail components, including the fibrous sheath and axonemal microtubules. We show here that the complete incorporation of the sperm, but not sperm-oocyte binding and oocyte activation, depends upon the integrity of oocyte microfilaments and is inhibited by the microfilament disrupter cytochalasin B. After sperm incorporation, the mitochondria are displaced from the sperm's connecting piece, and the sperm centriole is exposed to the egg cytoplasm. This event is followed by the formation of the microtubule-based sperm aster, which is responsible for the union of male and female pronuclei. Concomitantly, the major structure of the sperm principal piece, the fibrous sheath, disappears. After the first mitosis, the compact mitochondrial sheath can be seen in one of the blastomeres. An aggregate of the sperm mitochondria is observed at the entry of the second mitosis, although they remain in the vicinity of the nucleus and can later be seen at one pole of the metaphase spindle. The mitochondrial cluster is occasionally found in one of the blastomeres in the early-stage four-cell embryos, but it is no longer detected by the beginning of the third mitotic cycle. These data suggest that the disassembly of the sperm tail during bovine fertilization occurs as a series of precisely orchestrated events involving the destruction (fibrous sheath and mitochondrial sheath) and transformation (DNA, sperm centriole) of particular sperm structures into zygotic and embryonic components.

Acrosome↗

PubMed1993

Effects of sperm-immobilizing antibodies on sperm-zona pellucida tight binding.

OBJECTIVE: To evaluate the in vitro effects of sperm-immobilizing antibodies on sperm-zona pellucida (ZP) tight binding. DESIGN: The hemizona assay (HZA) was used to study the inhibitory effects of infertile women's sera with and without sperm-immobilizing antibodies on sperm ZP tight binding. These results were compared with those of monoclonal sperm-immobilizing antibodies. SETTING: The patients were collected from a university hospital infertility clinic. PATIENTS: Sera from 40 infertile women (24 with and 16 without sperm-immobilizing antibodies) and 2 postpartum women as control were used. RESULTS: Of 24 patients' sera with sperm-immobilizing antibodies, 23 (96%) showed significant inhibitory effect, whereas none of 16 patient's sera without sperm-immobilizing antibodies exhibited any inhibitory effect. However, there was no correlation between the antibody titers of sperm-immobilizing antibody and the hemizona index. Among four monoclonal sperm-immobilizing antibodies tested, only one showed a significant inhibitory effect on the sperm-zona tight binding. A human monoclonal antibody derived from an infertile woman with sperm-immobilizing antibodies, whose serum showed an inhibitory effect on HZA, did not inhibit the HZA. CONCLUSIONS: There are at least two kinds of sperm-immobilizing antibodies, one with both activities of sperm immobilization and blocking of sperm-zona tight binding and another with the former activity alone. The vast majority of sperm-immobilizing antibodies reduce zona binding even without the presence of complement.

Animals↗