Assessment Of Sperm Viability Research Articles

Establishment of a rapid, cost-effective, and accurate method for assessing insect sperm viability

High-quality sperm cells are crucial to reproductive success for both males and post-mating females in animals. Sperm viability, defined as the proportion of viable sperm cells, is used as a sperm quality index and this method has provided new insights into research on reproductive strategies. Sperm viability has been assessed by fluorescent staining of sperm cells. However, current staining protocols could potentially underestimate viability due to cell damage caused by cell treatments such as high dye concentration and long time for post-mounting. In this study, we established a method that enables rapid sperm viability assessment, has low sperm cell toxicity, and provides precise results regardless of operator expertise, and cost-effective using sperm cells from an ant, Crematogaster osakensis (Hymenoptera). First, to shorten the time for observation of a sufficient number of sperm cells, the volume per field of view was increased by height elevation between the glass slide and the coverslip, thereby we increased the number of sperm cells in a field of view. Second, to reduce sperm cell toxicity, we optimized the minimum dye concentration and incubation time using acridine orange (AO) and Hoechst in addition to SYBR 14 and propidium iodide (PI), which has been used in most previous studies. We determined the optimal protocol to be 1 µg/mL AO and 150 µM PI without incubation. Besides, we automated counting sperm cells with ImageJ software and combined with manual correction for more accurate results. We employed the improved method for sperm samples from mealworm beetles (Tenebrio molitor) and silkmoths (Bombyx mori). This method, established through our study, will advance research on reproductive strategies, including sperm competition and sperm quality maintenance in females.

МОРФОЛОГИЧЕСКИЕ И ФУНКЦИОНАЛЬНЫЕ ПОКАЗАТЕЛИ СПЕРМАТОЗОИДОВ БЫКОВ ПРИ КРИОКОНСЕРВАЦИИ

The purpose of the study is to analyze the influence of the freezing and thawing cycle on the morphofunctional parameters of bull sperm. The study was conducted at Nizhegorodskoe LLC on breeding work in the Kstov municipal District of the Nizhny Novgorod Region, on the basis of the Department of Physiology and Anatomy of the Institute of Biology and Biomedicine of the Nizhny Novgorod State University named after N.I. Lobachevsky and the Department of Physiology, Animal Biochemistry and Obstetrics of Nizhny Novgorod State Technical University. The object of the study is the sperm production of black-and-white bulls. Semen was diluted with sterile BioXcell medium. Native diluted sperm and sperm after deep freezing were studied. Motility and the average speed of sperm movement were analyzed on a sperm analyzer SA-500 from Biola (Russia). To assess the ultrastructure of spermatozoa, a Hitachi SU8220 electron microscope (Japan) was used. Using a laser interference microscope MIM-340 (Russia, Yekaterinburg), the morphology of spermatozoa was studied in real time without fixation or staining. After cryopreservation of the sperm, there was a decrease in the biological usefulness of sperm, which is confirmed by a decrease in motility by 13.77% (p ≤ 0.05) and the average speed of sperm movement by 12.95% (p ≤ 0.05). Using electron and laser interference microscopy, it was shown that the chromatin of thawed spermatozoa was insufficiently condensed and contained fibrils. After cryopreservation, the position of the acrosome was changed in 6.23% (p ≤ 0.05) of sperm, and the shape of the acrosome was changed in 18.64% (p ≤ 0.05) of cells. After freezing and thawing, 7.01% of sperm showed a decrease in head length, 17.90% - a decrease in body length, and 9.53% - a decrease in sperm tail length. The use of modern methods for assessing sperm viability is of great importance for understanding the processes occurring during sperm cryopreservation and allows us to develop ways to improve the quality of sperm du¬ring freezing and thawing.

3D dynamic observation of human sperm by parallel phase-shifting digital holographic microscopy based on pixelated polarization

Morphology and motility are essential criteria for assessing sperm viability. However, the human sperm head is small (∼3–4 μm) and requires a relatively high-magnification microscope objective, while the sperm flagella (∼45 μm) are poorly visible with complex 3D properties. Microscopic dynamic observation of intact sperm in 3D is challenging. Conventional inspection methods with a limited depth of field are inadequate for this issue. To provide a solution to this critical need, we develop pixelated polarization-based parallel phase-shifting digital holographic microscopy for the 3D dynamic observation of human sperm. Compared to conventional holographic imaging, this approach can effectively separate the object wavefront and avoid image quality degradation while fully exploiting the spatial bandwidth of the camera. We propose the use of the Stokes parameter reconstruction method to reconstruct the object wavefront and investigate the effect of the sampling interval on the system resolution by spectral analysis. The methodology achieves the retrieval of the 3D trajectory and motion parameters of sperm and reconstructs the sperm head orientation and the thin, highly-dynamic flagellum. The system allows for more comprehensive information on sperm motility and morphology, which is significant for male reproductive research. It also has significant potential for 3D dynamic observation of micro-organisms.

Glutathione and selenium nanoparticles have a synergistic protective effect during cryopreservation of bull semen.

In the present study, the synergistic protective effect of co-supplementation of glutathione (GSH) with selenium nanoparticles (SeNPs) on the cryopreservation efficiency of bull semen was analyzed. After collection, the ejaculates of Holstein bulls were subsequently diluted with a Tris extender buffer supplemented with different concentrations of SeNPs (0, 1, 2, and 4 μg/ml), followed by semen equilibration at 4°C and assessment of sperm viability and motility. Subsequently, the ejaculates of Holstein bulls were pooled, split into four equal groups, and diluted with a Tris extender buffer supplemented with basic extender (negative control group, NC group), 2 μg/ml SeNPs (SeNPs group), 4 mM GSH (GSH group), and 4 mM GSH plus 2 μg/ml SeNPs (GSH + SeNPs group). After cryopreservation, motility, viability, mitochondrial activity, plasma membrane integrity, acrosome integrity, concentration of malondialdehyde (MDA), superoxide dismutase (SOD), and catalase (CAT), and ability of frozen-thawed sperm cells to support in vitro embryonic development were evaluated. No side effect of SeNPs concentrations applied in the current study on the motility and viability of equilibrated bull spermatozoa was found. Meanwhile, supplementation of SeNPs significantly promoted the motility and viability of equilibrated bull spermatozoa. Furthermore, the co-supplementation of GSH with SeNPs effectively protected bull spermatozoa from cryoinjury as expressed by promoting semen motility, viability, mitochondrial activity, plasma membrane integrity, and acrosome integrity. Finally, the enhanced antioxidant capacity and embryonic development potential in the frozen-thawed bull spermatozoa cryopreserved by co-supplementation of GSH with SeNPs further confirmed the synergistic protective effect of co-supplementation of GSH with SeNPs on the cryopreservation of bull semen.

P-045 Sperm chromatin structure resilience is related to fertilization and blastocyst rates in ICSI cycles involving both oocyte and sperm donors

Abstract Study question Does the structural maintenance of sperm chromatin have an implication in assisted reproduction outcomes? Summary answer Sperm deprotamination is related to fertilizing capacity. Also, the time needed for the reduction of protamine disulphide bridges is a parameter underlying early embryo development. What is known already How male factor affects embryo development has been a controversial topic for decades, with opposite results. A meta-analysis recently showed that whereas sperm genotoxic damage has an impact on IVF success, its repercussion on ICSI remains unclear. Revealing the factors that may predict embryo development is much warranted to understand the sperm contribution in the ICSI era. Sperm DNA is preferentially protamine-condensed and necessarily needs to be switched to histone-condensed chromatin upon fertilization. This study aims to determine the degree of protamination and the disulphide bond integrity to provide new insights into the influence of chromatin resilience on embryo development. Study design, size, duration The study setting included a public university and a private sperm bank. The design was a blinded retrospective study, including samples from 51 sperm donors that were used for a total of 55 cycles conducted with donated oocytes in the fertility clinic. Sperm quality parameters, including those focused on chromatin structure, were evaluated after 0 min and 240 min post-thawing and compared to embryo outcomes. Participants/materials, setting, methods Sperm samples from donors selected by the germplasm bank were collected and used to fertilize oocytes in double-donation cycles (oocyte donation) with standard intracytoplasmic sperm injection. Cryopreserved samples were used to assess sperm viability (SYBR14/PI), incidence of thiol reduction (Dibromobimane, DBB) and chromatin deprotamination (Chromomycin A3, CMA3) through flow cytometry, at 0 min and 240 min after thawing. Positive controls after incubation with Triton-X100, DTT and DTT+NaCl were used to establish the flow cytometry thresholds. Main results and the role of chance In fresh semen samples, sperm concentration was 34.12±18.13 sperm/mL and progressive motility was 37.49±13.22% (mean±standard deviation). At 0 min and 240 min post-thawing, sperm viability was 24.80±12.12% and 18.65±10.37%, respectively, and the death rate was -1.54±1.24%/hour. Percentages of sperm with reduced thiols were 17.37±11.26% and 11.53±9.16% after 0 min and 240 min post-thawing, the reduction rate being -1.46±2.31%. Percentages of sperm with chromatin deprotamination were 21.12±9.03% and 35.34±14.10% after 0 min and 240 min post-thawing, and the deprotamination rate was 14.22±11.90%/hour. ICSI was conducted with an average of 11.86±7.89 oocytes per sperm sample, of which 8.78±5.95 were fertilized; the mean fertilization rate was 75.77±17.61%. For each sperm sample, 5.98±4.93 blastocysts at day 5 were obtained, leading to an average blastocyst rate of 65.17±22.22%. Interestingly, the deprotamination status at 0 min post-thaw was correlated to fertilization rates (Rs= -0.388; P = 0.005) and the decreasing rate of sperm with reduced thiols was correlated to blastocyst rate (Rs= -0.351; P = 0.012). Reduced thiols and deprotamination were also correlated with each other (Rs= -0.320; P = 0.022). Limitations, reasons for caution The main limitation of the present study was the sample size. More donors are thus needed in order for the promising results found in this study to be confirmed. Wider implications of the findings The research conducted herein has evidenced that the resilience of the sperm chromatin structure is related to embryo development outcomes from ICSI cycles conducted with oocyte donors. Trial registration number N/A

Evaluation of the effects of photostimulation on freeze-thawed bull sperm cells in terms of reproductive potential.

The aim of this study was to determine the time-dependent effectiveness of photo-stimulation against bovine sperm cells using a multi-wavelength LED (Light Emitting Diode). Spermatological parameters were evaluated for viability, acrosome structure and motility. In addition, the effect of photo-stimulation on frozen-thawed sperm cells subjected to in vitro capacitation was evaluated in terms of changes in mitochondrial membrane potential. The study consisted of two separate experiments and a total of 32 sperm samples obtained from separate bulls were used. All sperm samples were obtained from Holstein bulls using an artificial vagina. Semen was diluted to a final concentration of 92 x 106 spermatozoa per ml in 0.25 ml straws. The sperm cells were frozen using the conventional method. Straws were kept in a 37°C water bath for 20 seconds and diluted 1:4 in phosphate buffered saline (PBS) to eliminate the potentially deleterious effect of glycerol, the main permeable cryoprotectant in the freezing medium for bull sperm. This dilution also helped in the evaluation of sperm quality parameters. In the first experiment, whereas the 15-10-15 showed no differences with the control, other treatments such as 10-10-10, 5-5-5, and 3-1-3 exhibited significantly higher percentages of viable spermatozoa at 24h. The results obtained for acrosome integrity were pretty much similar to those observed in the sperm viability assessment. In effect, while the treatment consisting of 15-10-15 had no positive effects, shorter treatments exerted a much more positive effect. The percentages of acrosome-intact spermatozoa in 2-1-2 and 1-1-1 were significantly higher than those obtained in the control. The significant differences in mitochondrial membrane potential were observed at 0, 2, 4 and 24h post-photo-stimulation in all treatments, except 15-10-15. The highest increase in the percentage of spermatozoa exhibiting high mitochondrial membrane potential was found in 10-10-10, 5-5-5 and 3-1-3 treatments. With regard to total and progressive motility, whereas 10-10-10 was the best regime, 5-5-5 and 3-1-3 treatments also had a positive effect. However, 15-10-15 appeared to have a stimulating effect upon progressive motility at 2h and 4h but later declined and showed no significant differences with regard to the control at 24h. In the second experiment, not immediately after thawing but after having been kept at room temperature for up to 24h, it was observed that there was no statistical difference in terms of viability, acrosome integrity and total/progressive motility between photostimulation and the control group. This indicates that photo- stimulation is less able to exert a beneficial effect when post-thawed sperm are not immediately stimulated. As a result it was determined that photo-stimulation at a pattern of 10-10-10, 5-5-5, 3-1-3 and, to a lesser extent 2-1-2, increases the resilience of frozen-thawed bull sperm when applied upon thawing.

Assessment of Sperm Viability and Computer-Assisted Motility Analysis in Budgerigars (Melopsittacus undulatus): Effect of Several In Vitro Processing Conditions.

In order to preserve endangered psittacine species, more basic and applied research in reproductive biology is required. Assisted reproductive technologies such as artificial insemination play an important role in parrots species conservation programs to overcome the problem of infertile eggs and male infertility. The aim of this study was to define an effective in vitro protocol in order to standardize the sperm quality evaluation in psittacines, studying Melopsittacus undulatus as model species. Semen was collected from twenty adult males by massage technique from May to June. Sperm concentration was measured by the spectrophotometric method. Sperm quality (sperm membrane integrity (SMI), motility, and kinetic parameters) was assessed on fresh semen. Three different experimental protocols were performed to compare the effects of various processing conditions on SMI, motility, and kinetic parameters. In protocol 1, test was performed by Lake extender with three different pH, 7.4 versus 8.2 versus 8.4, and two different equilibration temperatures after dilution of fresh semen (4°C versus 25°C). In protocol 2, two dilution rates of semen after collection were valuated, 1 : 3 versus 1 : 4, as well as three different semen storage temperatures (4°C versus 25°C versus 38°C) before sperm motility analysis with the computer-assisted sperm analysis (CASA). In protocol 3, two different Makler chamber temperatures (38 versus 41°C) during motility analysis were tested. A significant progressive improvement in spermatozoa motility and kinetic parameters was registered with pH 8.4. Progressive motility and all kinetic parameters were higher at 4°C equilibration temperature. Straightness (STR) kinetic parameter was better with 1 : 4 dilution rate. Total motile sperm was higher in 41°C Makler chamber. In this study, for the first time, the effects of different processing protocols on psittacines seminal quality analysis were investigated. Significant differences conditioning the effectiveness of analysis protocols have been described.

Curcumin Along With Fe3O4 Nanoparticles Improved Sperm Parameters In Rats With Testicular Ischemia

Background: Ischemic/reperfusion (I/R) in testicular tissue is one reason for the worldwide increase in male infertility. In the present study, we assessed the effects of curcumin and Fe3O4 nanoparticles (NPs) on sperm parameters in rats with I/R damage. Materials and Methods: Forty-eight adult male rats were divided into two groups (n=24 per group): control and torsion/detorsion. The control and torsion/detorsion groups were divided into four subgroups include sham, Fe3O4 NPs, curcumin, and Fe3O4 NPs+curcumin. After the rats were sacrificed, semen was collected from their epididymal tissues to assess sperm viability, motility, concentration, and morphology. Results: Curcumin significantly improved viability, motility, and normal sperm morphology in rats with I/R damage compared to the control group; however, it did not have a significant effect on sperm concentration (P<0.001). Fe3O4 NPs alone decreased all sperm parameters in the control and I/R rats (P<0.001). However, concomitant administration of Fe3O4 nanoparticles with curcumin significantly improved sperm parameters in rats with I/R damage (P<0.001). Conclusion: The increase in all semen parameters in the experimental groups with concomitant use of Fe3O4 NPs plus curcumin indicated that green synthesis of NPs could be recommended for future clinical studies.

Curcumin Along With Fe3O4 Nanoparticles Improved Sperm Parameters In Rats With Testicular Ischemia

Background: Ischemic/reperfusion (I/R) in testicular tissue is one reason for the worldwide increase in male infertility. In the present study, we assessed the effects of curcumin and Fe3O4 nanoparticles (NPs) on sperm parameters in rats with I/R damage. Materials and Methods: Forty-eight adult male rats were divided into two groups (n=24 per group): control and torsion/detorsion. The control and torsion/detorsion groups were divided into four subgroups include sham, Fe3O4 NPs, curcumin, and Fe3O4 NPs+curcumin. After the rats were sacrificed, semen was collected from their epididymal tissues to assess sperm viability, motility, concentration, and morphology. Results: Curcumin significantly improved viability, motility, and normal sperm morphology in rats with I/R damage compared to the control group; however, it did not have a significant effect on sperm concentration (P<0.001). Fe3O4 NPs alone decreased all sperm parameters in the control and I/R rats (P<0.001). However, concomitant administration of Fe3O4 nanoparticles with curcumin significantly improved sperm parameters in rats with I/R damage (P<0.001). Conclusion: The increase in all semen parameters in the experimental groups with concomitant use of Fe3O4 NPs plus curcumin indicated that green synthesis of NPs could be recommended for future clinical studies.

P–102 GM-CSF (granulocyte-macrophage colony-stimulating factor) as a sperm medium supplement improves sperm quality in Oligoastenoteratospermia (OAT) men by activating the PI3K/Akt pathway

Abstract Study question Can GM-CSF as a sperm medium supplement improve sperm quality in OAT men? Summary answer GM-CSF can be used to improve sperm quality in OAT men by activating the PI3K/Akt pathway. What is known already OAT patients have very low sperm parameters, including morphology, count, and motility, which can adversely affect the results of assisted reproduction technologies. It seems the development of sperm media is necessary to improve the sperm parameters of these patients. GM-CSF is a natural growth factor produced by the reproductive organs, culture media supplemented with GM-CSF is widely commercially available and enhances the embryo development and implantation rate. Studies show that this growth factor in the semen of infertile men is lower than that of fertile men. However, there is no study to assess the effect of GM-CSF on sperm quality. Study design, size, duration In the present study, Semen specimens were collected from 20 OAT patients who have male infertility factors, according to WHO criteria. After the swim-up washing procedure, each of the samples is divided into two groups; experiment, and control. In the experimental group, samples are incubated with a medium containing 2 ng/ml GM-CSF for one hour, yet, in the control group, the sperms are incubated without GM-CSF for the same time. Participants/materials, setting, methods The sperm motility was examined with phase-contrast microscopy, Eosin-nigrosin staining method was used to assess sperm viability. The expression of sperm glucose transporters (GLUT 1, 3) was determined using immunofluorescent staining, the ratio of pAkt to total Akt was assessed by the Western blotting method. Image J software was used to quantify results; the data was analyzed by SPSS software. P-value<0.05 was considered statistically significant. Main results and the role of chance As compared to the control group, supplementation with GM-CSF improved sperm progressive motility, enhanced GLUT 1 and 3, and p-AKT/AKT expression (P < 0.05). There was no significant difference between the viability of the control and experimental groups. Limitations, reasons for caution This study needs further investigations, including Real-time PCR for the genes of this signaling pathway which is ongoing. Wider implications of the findings: We showed for the first time that GM-CSF can improve sperm quality by influencing motility and energy metabolism in spermatozoa which can be affected by increasing the phosphorylation of AKT. This growth factor could be an appropriate supplement in sperm media for OAT patients. Trial registration number IRCT20200519047508N1

Effects of reduced glutathione on ram sperm parameters, antioxidant status, mitochondrial activity and the abundance of hexose transporters during liquid storage at 5 ℃

The objective of this study was to evaluate the effects of reduced glutathione (GSH) supplementation on sperm motility, kinematics, mitochondrial activity and the abundance of sperm hexose transporters during liquid storage of ram semen at 5 ℃. Semen samples from eight rams were pooled and diluted with Tris-egg yolk extender supplemented with 0 (control), 50, 100 and 200 mM GSH, and they were assessed at different processing periods (fresh diluted, stored for 24, 48 and 72 h at 5 ℃). Sperm motility and kinematic parameters were analyzed by computer-assisted sperm analysis (CASA). The hypo-osmotic swelling test (HOST) was used to evaluate the functional integrity of sperm membrane. Eosin-nigrosin and JC-1/PI staining methods were used to assess sperm viability and mitochondrial activity, respectively. The antioxidant status of sperm was examined using biological assays. The changes of sperm hexose transporters (GLUT 3, 5 and 8) were determined using western blot analysis. As compared to the control group, supplementation with 100 and 200 mM GSH improved (P ＜ 0.05) sperm total motility, membrane integrity, motion parameters and mitochondrial activity at 72 h of storage, as well as resulted in the higher sperm antioxidant status after storage from 24 to 72 h. The cooling induced a reduction of GLUT 3 and 8, and GSH treatment at 200 mM retarded the gradual decline of these proteins during the prolonged storage time. Our data suggest that GSH can reduce the decline of semen quality by influencing the antioxidant status and energy metabolism of liquid stored ram spermatozoa. The concentration of 200 mM could be appropriate for ram semen during liquid storage at 5 ℃.

Taurine effects on Bisphenol A-induced oxidative stress in the mouse testicular mitochondria and sperm motility.

Objectives:This study was performed to investigate the protective effects of taurine (2-aminoethanesulfonic acid, TAU) on oxidative stress in the isolated mouse testicular mitochondria, mitochondrial membrane potential (MMP), viability and motility of the exposed sperms to the BPA.Methods:We treated epididymal spermatozoa obtained from mice and isolated mouse testicular mitochondria with BPA (0.8 mmol/mL) and various doses of TAU (5, 10, 30 and 50 µmol/L). We used the MTT assay and Rhodamine 123 uptake to assess sperm viability and MMP. We assessed the oxidative stress through measuring ROS (reactive oxygen species), MDA (malondialdehyde), GSH (glutathione), and SOD (super-oxide dismutase) levels in the testicular mitochondrial tissue.Results:BPA significantly elevated ROS, MDA and MMP levels, and markedly reduced SOD and GSH levels in the isolated mitochondria. BPA also considerably impaired spermatozoa viability and motility. Pretreatment with 30 and 50 µmol/L of TAU could considerably suppressed mitochondrial oxidative stress, enhanced MMP, and improved sperm motility and viability.Conclusion:TAU may attenuate the BPA-induced mitochondrial toxicity and impaired sperm motility via decreasing oxidative stress.

Effect of recombinant β-defensin 1 protein on human sperm motility and viability.

The reduction of sperm motility and subsequently reduced ability to undergo capacitation and acrosome reaction are considered as common causes of male infertility. The β-defensin family is a group of well-known secretory proteins with antimicrobial activity that contribute to the process of "sperm maturation" during the passage of spermatozoa in the epididymis when spermatozoa attain its motility. One member of this family is "β-defensin 1" which is present in seminal plasma and spermatozoa. The aim of this study was the incubation of human processed spermatozoa with recombinant β-defensin 1 (500ng/ml) for 1, 2 and 3hr at 37°C under 5% CO2 atmosphere and assessment of sperm viability and motility in 59 semen samples. The analysis of semen samples such as sperm concentration, motility, viability, morphology and semen volume was performed according to the World Health Organization (2010; World health organization laboratory manual for the examination and processing of human semen (p. 287). Geneva, Switzerland: World Health Organization) criteria. The result of the current study shows that the incubation of spermatozoa with recombinant β-defensin significantly maintained percentage of sperm viability and motility compared to processed spermatozoa incubate in the absence of β-defensin in the studied time intervals (p<.05). Therefore, we concluded that recombinant β-defensin 1 protein as an agent with antimicrobial activity can maintain sperm viability and motility in in vitro condition.

Nerve growth factor-β effects on post-thaw bull semen quality: Effects of nerve growth factor-β added to extenders for cryopreservation of electro-ejaculated and epididymal bull semen

Nerve growth factor-β (NGF) is a seminal plasma protein associated with improved sperm membrane integrity and motility in mammalian species. The objective of this study was to compare post-thaw semen quality from both ejaculated and pididymal-collected bull sperm incubated with purified NGF prior to cryopreservation. Semen was obtained from Angus × Simmental crossbred bulls (n = 10) collected by electroejaculation, followed by castration and epididymal sperm collections 3 days later. Semen samples were incubated with extender having 0 ng/mL (CONT), 0.5 ng/mL (LOW), 5 ng/mL (MED), or 50 ng/mL (HIGH) of purified NGF prior to cryopreservation. Sperm motility was assessed in each sample prior to treatment and cryopreservation and at post-thaw. Flow cytometry was used for post-thaw assessment of sperm viability (SYBR-14/PI), acrosome integrity (FITC-PNA/PI), and chromatin stability (acridine orange). Values for post-thaw sperm motility and velocity variables were decreased, while linearity was increased in samples of the HIGH compared with CONT group (P < 0.01), but there were no differences in epididymal samples (P> 0.05). Samples from the HIGH group also had a lesser amplitude of lateral head displacement at 2.5 and 3 h post-thaw (P < 0.01). Post-thaw sperm viability, acrosome integrity, and DNA fragmentation index were not affected by NGF treatment in either ejaculated or epididymal sperm (P> 0.05). In conclusion, supplementation of freezing extender with NGF had minimal effects on post-thaw sperm quality in bulls. Results indicate NGF may have a function in preventing premature sperm hyperactivation in ejaculated, but not epididymal-collected spermatozoa. Fertility studies, both in vitro and in vivo, are warranted to ascertain the relevancy of these findings.

Extending the interval between second vaccination and slaughter: II. Changes in the reproductive capacity of immunocastrated ram lambs

Immunocastration improves the welfare of castrated commercial slaughter lambs; however, the time-point at which this technique influences semen quality and sperm production has not yet been established for various vaccination schedules. Furthermore, the effect of extended intervals between second vaccination and slaughter needs to be investigated regarding continued testosterone suppression in immunocastrated lambs. The effect of extending the interval between second immunocastration vaccination and slaughter from four to six weeks on the reproductive capacity of Dohne Merino lambs was examined. A total of 40 Dohne Merino lambs were stratified according to initial weight (45.4±3.68 kg) and randomly assigned to four treatments that included intact control rams (R), Burdizzo-castrated lambs (B) and lambs immunocastrated with either four (ICS4) or six (ICS6) weeks between second vaccination and slaughter. Blood and semen samples were collected throughout the study period to determine serum testosterone concentrations, evaluate semen quality and assess sperm viability. Semen samples from R showed improvement over the trial. Throughout the collection period, B lambs had low serum testosterone concentrations, poor sperm motility and sperm viability, as expected. However, a slight increase in the percentage of live sperm in semen samples from B lambs towards the end of the collection period indicated poor success rates of the technique in some lambs. Burdizzo-castration also caused testes tissue necrosis and abscessing, indicating physiological stress. Semen appearance scores varied for both immunocastrated treatments, but the mass motility scores decreased over time. The ICS6 lambs showed a consistent and continuous decline in serum testosterone concentrations and sperm viability, with an increased percentage of dead abnormal sperm in the semen samples at the end of the study. The ICS4 treatment was successful in interrupting serum testosterone production and reducing semen quality; however, not as consistently as the ICS6 treatment. Primary immunocastration vaccination influenced serum testosterone concentrations but consistently low levels were only realised for both treatments after secondary vaccination. Although all castration treatments influenced testes size and colour, the six-week vaccination-to-slaughter interval caused a greater decrease in testes cut surface L* (lightness) colour values and in seminiferous tubule circumference. Extending the interval between second immunocastration vaccination and slaughter resulted in a more consistent and reliable influence on reproductive capacity of immunocastrated lambs. Thus, immunocastration is a suitable alternative to Burdizzo-castration regarding the interruption of testosterone production and testis functioning.

Investigations on different Semen Extenders for Cockatiel Semen

The aim of the present study was the modification and evaluation of three different semen extenders for cockatiel semen in order to achieve a long survival time for transport, examination purpose and for potential cryopreservation, respectively. Therefore, individual and pooled semen samples of 30 cockatiels (Nymphicus hollandicus) were investigated for pH and osmolality values and subsequently pH and osmolality values of the semen extenders were adjusted to those values in the semen. Pooled semen samples were then partitioned into four equal parts and diluted with the three different semen extenders in 1:4 and 1:8 dilution. 1 % glucose-Ringer’s solution was used as control, respectively. A total of 64 incremental diluted semen samples were obtained for investigation. Each dilution was investigated regarding sperm motility immediately after dilution and another four times every 30 minutes. Sperm viability was evaluated 0 and 120 minutes after dilution via eosin B-stain on the diluted semen samples and in pure semen samples. Additionally, the fluorescence stain SYBR® Green/propidium iodide was used to assess sperm viability. The results indicate that cockatiel spermatozoa are highly sensitive to variations in pH and osmolality, requiring adjustment of commercial diluents to pH = 7.42 and osmolality = 300 mOsm/kg. Modified Lake diluent maintained higher viability and motility than other diluents tested. Sperm morphology was indicated to be least adversely affected by modified Lake diluent in 1:4 concentration compared to other semen extenders and concentrations used.

Variation in post-thaw sperm quality of white-tailed deer bucks (Odocoileus virginianus) during rut

White-tailed deer farming is a growing industry in the United States, with breeding operations contributing significantly to the industry’s economic impact. Artificial insemination with frozen semen allows for selection and dissemination of valuable genetics, yet surprisingly little is known regarding the best time throughout rut to perform semen cryopreservation. The objective of this study was to compare semen quality following cryopreservation of white-tailed deer bucks collected early in the breeding season (September, n = 6), at peak rut (December, n = 8), and late season (March, n = 7). We hypothesized that post-thaw semen quality would be enhanced at peak rut. Mature bucks were anesthetized with tiletamine-zolazepam and xylazine administered intramuscularly via projector. Semen was collected by electroejaculation and cryopreserved using Optixcell extender. Overall and progressive sperm motilities were assessed for each sample before and after cryopreservation using a computer-aided sperm analyzer. Flow cytometry was used for post-thaw assessment of sperm viability (SYBR-14/PI), acrosome integrity (FITC-PNA/PI), and DNA stability (acridine orange). Analysis of variance was applied to normalized data using a general linear mixed model with buck ID as a random variable, and a Tukey HSD test was performed as needed for post-hoc analysis. Pre-freeze overall and progressive sperm motilities were lowest in March, intermediate in September, and highest in December (p ≤ 0.04). Post-thaw overall and progressive motilities were lowest in September (p ≤ 0.02), but did not differ between December and March (p ≥ 0.12). The DNA Fragmentation Index was lowest in December, intermediate in September, and highest in March (p ≤ 0.05). The percentage of spermatozoa with intact plasma membrane was higher in December than September (p < 0.01), but the percentage of intact acrosomes per sperm with intact plasma membrane was highest in September (p = 0.03). This study confirms that post-thaw semen quality appears to be superior during peak rut (December) in bucks. Though semen collected early or late in rut may present acceptable motility, DNA stability is impaired, which could adversely affect fertility rates. This data suggests that semen cryopreservation during transitional periods should be avoided, though field studies evaluating the translation of these results into satisfactory pregnancy rates are warranted.

Sperm viability assessment in marine invertebrates by fluorescent staining and spectrofluorimetry: A promising tool for assessing marine pollution impact

The viability of spermatozoa is a crucial parameter to evaluate their quality that is an important issue in ecotoxicological studies. Here, a new method has been developed to rapidly determine the viability of spermatozoa in three marine invertebrates: the ascidian Ciona intestinalis, the sea urchin Paracentrotus lividus and the mollusc Mytilus galloprovincialis. This method employed the dual DNA fluorescent staining coupled with spectrofluorimetric analysis. The dual fluorescent staining used the SYBR-14 stained live spermatozoa and propidium iodide stained degenerated cells that had lost membrane integrity. Stain uptake was assessed by confocal microscopy and then the percentage of live and dead spermatozoa was quantified by spectrofluorimetric analysis. The microscopic examination revealed three populations of spermatozoa: living-SYBR-14 stained, dead-PI stained, and dying-doubly stained spermatozoa. The fluorescence emission peak values recorded in a spectrofluorimeter provide the portion of live and dead spermatozoa showing a significant negative correlation. The stain combination was further validated using known ratios of live and dead spermatozoa.The present study demonstrated that the dual DNA staining with SYBR-14 and propidium iodide was effective in assessing viability of spermatozoa in marine invertebrates and that spectrofluorimetric analysis can be successfully employed to evaluate the percentage of live and dead spermatozoa. The method develop herein is simple, accurate, rapid, sensitive, and cost-effective, so it could be a useful tool by which marine pollutants may be screened for spermiotoxicity.

In-Vitro Application of Pentoxifylline Preserved Ultrastructure of Spermatozoa After Vitrification in Asthenozoospermic Patients.

To evaluate the effect of in vitro application of pentoxifylline (PX) on sperm parameters and ultrastructure after vitrification in asthenozoospermic patients. A total of 30 asthenozoospermic semen samples (aged 25-45 years) were divided into four groups before vitrification, after vitrification, control (without PX) and experimental (with PX). In experimental group, each sample was exposed for 30 min to 3.6mmol/l PX and the control group without any treatment apposing in 370C for 30 min. After incubation, the samples were washed and analyzed again. Vitrification was done according to straw method. Eosin-nigrosin and Papanicolaou staining were applied for assessment of sperm viability and morphology, respectively. The samples without PX and post treatment with PX were assessed by transmission electron microscopy (TEM). A significant decrease in sperm motility (P &le; .001), morphology (11.47 &plusmn; 2.9 versus 6.73 &plusmn; 2.01) and viability (73.37 &plusmn; 6.26 versus 54.67 &plusmn; 6.73) was observed post vitrification, but sperm motility (19.85 &plusmn; 4.75 versus 32.07 &plusmn; 5.58, P &le; .001) was increased significantly following application of PX. This drug had no significant (P &gt;.05) detrimental neither negative effect on ultrastructure acrosome, plasma membrane and coiled tail statues of spermatozoa. Vitrification had detrimental effects on sperm parameters, but PX reversed detrimental effects on sperm motility. However, PX had no alteration on ultrastructure morphology of human spermatozoa after vitrification.

Comparison of Centrifugation and Noncentrifugation Methods to Cryopreserve Stallion Epididymal Semen

Most epididymal flushes are performed after a catastrophic injury, acute, or chronic illness and are the last chance to save genetic material from a valuable stallion; this not only prevents test freezing for the particular animal but also means that the starting semen quality is likely poor. This necessitates that the protocol used for epididymal flushes be optimized to achieve the best possible recovery of the least damaged sperm. The objective of this study was to compare the effects of direct flushing of the epididymis with freezing extender to flushing with cooling extender and centrifugation. Epididymides were dissected away from the testes, and each vas deferens was catheterized. For the centrifugation method, the epididymis was flushed using 5 mL of a skim milk–based extender, followed by 20 mL of air, and then, semen was diluted to 50 million/mL before centrifugation and processing. Epididymides used for the noncentrifugation method were flushed directly with a commercial semen freezing extender. Semen was loaded in 0.5-mL straws at 200 million/mL, cooled and frozen. Post-thaw samples were evaluated for total and progressive sperm motility using a computer-automated sperm analyzer. Additionally, post-thaw samples were stained with fluorescent probes and subjected to flow cytometry for assessment of sperm viability, mitochondrial potential, acrosome integrity, and chromatin stability. No significant differences were observed between the two groups for any of the sperm parameters evaluated. In conclusion, although centrifugation does not appear to be detrimental to epididymal sperm, it also does not seem necessary for semen processing.