Motile Fraction Research Articles

P-053 Comparative analysis between microfluidic sperm sorting and Swim-up technique to select spermatozoa with better characteristics in hyper viscous samples

Abstract Study question What is the best technique to select spermatozoa in hyper viscous semen samples? Summary answer Microfluidics is the best technique that allows to select spermatozoa with better seminal characteristics and hyperactivated motility, and less sperm DNA fragmentation. What is known already Density gradient centrifugation and Swim-up (SU) are the two traditional selection methods used during assisted reproduction techniques (ART) to collect the highly motile sperm fraction. Many studies reported that centrifugation increase sperm DNA fragmentation and oxidative status which could affect reproductive outcomes. To overcome the limitations of centrifugation, an alternative approach by using microfluidic-based devices was recently designed. In microfluidic protocol, sample is applied to the device’s inlet port, connected to a lower chamber. This chamber consists of a microporous filter, where the most motile spermatozoa migrate upward through the filter. Study design, size, duration An observational study was conducted on 29 semen samples from patients undergoing routine semen analysis for couple infertility in the Andrology Laboratory of Careggi University Hospital of Florence from January 2023 to January 2024. In these samples we compare two different methods for sperm selection: indirect SU technique and microfluidic devices (MSS). Participants/materials, setting, methods We evaluated seminal parameters (sperm progressive and total motility, viability, and concentration), sperm kinematic parameters by Computer-Assisted Sperm Analysis (C.A.S.A. system), sperm DNA fragmentation by TUNEL/PI assay and sperm oxidative status by CellROX® Orange (which we have recently shown to identify a fraction of viable oxidized spermatozoa with better characteristics (Traini G., et al. 2022)) in 29 normozoospermic and 18 hyper viscous semen samples selected by SU and MSS. Main results and the role of chance In normozoospermic samples, sperm selection with both indirect SU technique and microfluidic devices, ameliorated sperm characteristics compared to not selected samples. Spermatozoa selected by MSS showed statistically significant higher progressive and total motility, viability and concentration compared to those selected by indirect SU. Moreover, an increase in most of kinematic semen parameters (like VAP, VCL and VSL) and hyperactivated motility was observed in MSS selected samples. Also, sperm DNA fragmentation was significantly reduced after MSS selection compared to indirect SU. We evaluated the percentage of viable oxidized spermatozoa by using CellROX® Orange. A significant increase of the percentage of CellROX® Orange positive spermatozoa was observed in most of MSS selected samples. In all 18 hyper viscous samples, the results obtained in normozoospermic samples were confirmed. Indeed, an overall improvement of sperm progressive and total motility, viability and concentration together with an increase in most of kinematic semen parameters and in hyperactivated motility were evidenced in MSS selected spermatozoa respect to those selected by indirect SU. Again, a significant decrease of sperm DNA fragmentation and an increase of the percentage of CellROX® Orange positive spermatozoa, were observed after MSS selection. Limitations, reasons for caution The number of semen samples included in the study is not very elevated. Results obtained in hyper viscous semen samples should be confirmed in a greater number of samples. Wider implications of the findings Our data indicate that MSS selects the sperm fraction with better characteristics and less DNA fragmentation. These results suggest that MSS could improve ART outcomes, particularly for specific categories of patients, including hyper viscous semen samples, for which the selection by SU does not always guarantee good yields. Trial registration number not applicable

Cancer cell migration depends on adjacent ASC and adipose spheroids in a 3D bioprinted breast cancer model

Breast cancer develops in close proximity to mammary adipose tissue and interactions with the local adipose environment have been shown to drive tumor progression. The specific role, however, of this complex tumor microenvironment in cancer cell migration still needs to be elucidated. Therefore, in this study, a 3D bioprinted breast cancer model was developed that allows for a comprehensive analysis of individual tumor cell migration parameters in dependence of adjacent adipose stroma. In this co-culture model, a breast cancer compartment with MDA-MB-231 breast cancer cells embedded in collagen is surrounded by an adipose tissue compartment consisting of adipose-derived stromal cell (ASC) or adipose spheroids in a printable bioink based on thiolated hyaluronic acid. Printing parameters were optimized for adipose spheroids to ensure viability and integrity of the fragile lipid-laden cells. Preservation of the adipogenic phenotype after printing was demonstrated by quantification of lipid content, expression of adipogenic marker genes, the presence of a coherent adipo-specific extracellular matrix, and cytokine secretion. The migration of tumor cells as a function of paracrine signaling of the surrounding adipose compartment was then analyzed using live-cell imaging. The presence of ASC or adipose spheroids substantially increased key migration parameters of MDA-MB-231 cells, namely motile fraction, persistence, invasion distance, and speed. These findings shed new light on the role of adipose tissue in cancer cell migration. They highlight the potential of our 3D printed breast cancer-stroma model to elucidate mechanisms of stroma-induced cancer cell migration and to serve as a screening platform for novel anti-cancer drugs targeting cancer cell dissemination.

Regional abundances of binder of sperm (BSP) proteins are negatively associated with the quality of frozen-thawed bovine spermatozoa.

The localization and abundance of the sperm BSP proteins correlate with in vitro fertility in domestic bulls used in artificial insemination service. Binder of sperm (BSP) proteins, secreted mainly by the accessory sex glands, are the major protein family present in bovine seminal plasma and on the sperm surface after ejaculation. In vivo, BSP proteins facilitate sperm capacitation and sperm reservoir formation; however, their impact on sperm function within the in vitro systems is less clear. Therefore, this biomarker-based study aimed to characterize the localization and abundance of BSP proteins from in vitro processed frozen-thawed bovine spermatozoa. Using image-based flow cytometry and Western blotting, BSP protein localization, abundance, membrane and acrosomal integrity were investigated in the supernatant (nonmotile) and pellet (motile) fractions of gradient-separated bull spermatozoa. Spermatozoa from the supernatant fraction had high enrichment of all BSP proteins investigated (BSP1, BSP3, BSP5; P < 0.05) when compared to the pellet fraction. In the pellet fraction, BSP1 and BSP3 bound predominately to the acrosomal region, whereas BSP5 had a high affinity for the midpiece. However, in the supernatant fraction, BSP proteins predominately coated the entire sperm surface resulting in the loss of regional specificity. High BSP protein abundance in the spermatozoa also correlated with acrosome and membrane damage. Whereas a high abundance of BSP5 correlated with low embryo cleavage rates, high abundance of BSP1 on the sperm head coincided with a high blastocyst rate. Therefore, changes in the quantity and localization of specific BSP proteins could act as potential biomarkers of sperm quality and fertility.

SUMO1 and Defective Spermatozoa Correlate with Endogenous Hydrogen Peroxide and Live Birth Outcome in Intrauterine Insemination Cycles for Unexplained Infertility.

This study aimed to investigate the correlation between hydrogen peroxide (H2O2), small ubiquitin-like modifier molecules (SUMO), and pregnancy outcomes in couples with unexplained infertility (UI) undergoing intrauterine insemination (IUI) treatment. We prospectively collected semen samples from 56 couples with UI and divided the spermatozoa into motile and immotile fractions by density gradient centrifugation (DSC). Immunofluorescence staining was used to examine the immunostaining and localization of nuclear pore complex (NPC), SUMO1, and SUMO2/3 in spermatozoa. We detected H2O2 levels by chemiluminescence methods. We found that H2O2 levels correlated with NPC (neck) (r = 0.400) and NPC (tail) (r = 0.473) in motile sperm fractions. In immotile fractions, H2O2 positively correlated with NPC (tail) (r = 0.431) and SUMO1 (neck) (r = 0.282). Furthermore, the positive NPC (tail) group had a significantly lower live birth rate than the negative NPC group (17.9% = 5/28 vs. 42.9% = 12/28). In conclusion, H2O2 positively correlated with SUMO1 (neck) and NPC (tail) in human spermatozoa. The DSC may partially eliminate defective spermatozoa (positive NPC staining); however, if defective spermatozoa remain in the motile fraction, this scenario is associated with a low live birth rate following IUI treatment.

P-059 Sperm DNA fragmentation (SDF) after cryopreservation and sperm selection: implications for clinical pregnancies and live births after intrauterine insemination with donor sperm

Abstract Study question Can SDF assessment pre-cryopreservation, post-thaw and after post-thaw sperm selection predict clinical outcome in a heterologous intra-uterine donor insemination program (IUI)? Summary answer SDF increased post-cryopreservation in donor sperm and after post-thaw density gradient without affecting clinical pregnancy, live birth and miscarriage rates. What is known already Sperm cryopreservation is effective for preservation of male fertility and facilitates the storage of donor semen, while infectious disease screening can be completed and confirmed negative. Sperm viability and motility are the most vulnerable parameters during the freeze-thaw process. Inherent reactive oxygen species may induce SDF via oxidative stress. Controversial results are reported regarding induction of SDF after cryopreservation due to differences in cryo tolerance, methods of cryopreservation and methods used to evaluate SDF. Sperm selection post-thaw is indispensable to select a normal motile fraction for insemination. Again, results are controversial regarding influence on SDF levels after sperm selection post-thaw. Study design, size, duration This was a prospective, observational study. Between March 2015 and March 2019, eighteen potential sperm donors were screened via a three step plan – semen assessment, medical assessment and serological blood tests. In accordance with the Belgian legislation (2007), a sperm donor was matched to obtain a maximum of 6 pregnancies in acceptor women/couples, allowing for more than one offspring/woman or couple. A total of 106 acceptors were matched for heterologous intra-uterine insemination. Participants/materials, setting, methods Semen samples were collected after 2-7 days abstinence and standard semen parameters analyzed within 60 mins after ejaculation. Within the same time frame SDF test was performed using TUNEL assay both before and after cryopreservation and after a two-step discontinuous density gradient centrifugation post-thaw. Samples were cryopreserved by the conventional slow freezing method using sperm freeze solution. A yield of ≥ 2 M progressive spermatozoa post-thaw after selection was sufficient to contemplate IUI. Main results and the role of chance Mean female age at first cycle was 33.9 ± 4.1 years and donor age 28.5 ± 5.6 years. Out of 429 cycles, 100 (23.3%) resulted in clinical pregnancy. Excluding three ongoing pregnancies, we counted 75 live births (17.6% of cycles or 77.3% of pregnancies), while 21 pregnancies ended in miscarriage (4.9% of cycles or 21.6% of pregnancies) and 1 resulted in stillbirth. Progressive motility (59.3 ± 12.5%) decreased significantly after cryopreservation (30.0 ± 13.2%; p &amp;lt; 0.001), but increased post-thaw after density gradient centrifugation (61.6 ± 16.0%; p &amp;lt; 0.001). On the contrary, SDF (12.0 ± 5.9%) increased post-cryopreservation (26.3 ± 14.5%; p &amp;lt; 0.001) and further increased after sperm selection (34.9 ± 22.1%; p = 0.04). Using multilevel mixed-effects logistic regression (Odds ratio [95%CI]), we found that female age significantly influenced clinical pregnancy (0.911 [0.847-0.981]; p = 0.01), live birth (0.894 [0.834-0.959]; p = 0.002) and miscarriage rates (1.180 [1.033-1.347]; p = 0.015). There was no significant age-adjusted effect of SDF post-thaw after density gradient selection on clinical pregnancy (1.007 [0.994-1.021]; p = 0.30), live birth (1.001 [0.988-1.014]; p = 0.84) or miscarriage (1.021 [0.997-1.046]; p = 0.08). Median time-to-live birth was 4 cycles. Analyses of time-to-live birth with mixed-effects Cox models revealed no significant association with progressive motility; SDF before or after cryopreservation and after sperm selection post-thaw. Limitations, reasons for caution Results concern a small donor population, with high normal semen parameters and should therefore be extrapolated cautiously to subfertile men with normal and subnormal semen parameters. Wider implications of the findings In a donor IUI program with strict selection on conventional sperm parameters, differences in SDF before and after cryopreservation and gradient centrifugation do not change IUI outcomes, although cryopreservation and centrifugation increase SDF. Findings could be useful for the optimization of sperm freezing and selection in different assisted reproductive procedures. Trial registration number not applicable

Seminal cadmium affects human sperm motility through stable binding to the cell membrane.

Environmental pollutants are claimed to be major factors involved in the progressive decline of the fertility rate worldwide. Exposure to the heavy metal Cadmium (Cd) has been associated with reproductive toxicity due to its ionic mimicry. However, the possible direct accumulation of Cd in human sperm cells has been poorly investigated. In this study, we aimed to clarify the possible direct effect of Cd exposure on sperm function through the analysis of its cell accumulation. Semen samples from 30 male subjects residing in high environmental impact areas and adhering to the "Exposoma e Plurifocalità nella Prevenzione Oncologica" campaign for testis cancer prevention were compared with semen samples from 15 males residing in low exposure areas. Semen levels and cell Cd content were quantified by inductively coupled plasma (ICP) spectroscopy. Cell Cd distribution was assessed by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The impact of Cd on sperm function was evaluated by the in vitro exposure to the heavy metal, whilst possible scavenging approaches/agents were assessed. In addition to higher values of semen Cd, exposed subjects showed a reduction in total motile sperm fraction compared to not-exposed controls (59.6% ± 13.6% vs. 66.3% ± 7.3%, p = 0.037). Semen Cd levels were also significantly correlated with SEM-EDS signals of Cd detected on the head and neck of sperm (respectively p = 0.738, p < 0.001 and ρ = 0.465, p < 0.001). A total of 2h of in vitro exposure to 0.5μM Cd was associated with a significant reduction of sperm progressive motility. Scavenging approaches with either hypo-osmotic swelling or 10μM reduced glutathione were ineffective in blunting cell Cd and restoring motility. The reduction of exposure levels appears to be the main approach to reducing the reproductive issues associated with Cd.

Can a sperm selection technique improve embryo ploidy?

Spermatozoa with the highest motility retain a superior genomic integrity, and elevated sperm chromatin fragmentation (SCF) has been linked to a lower ability of the conceptus to develop and implant. Therefore, the utilization of a sperm selection method, such as microfluidic sperm selection (MFSS), is capable of reducing the SCF by yielding the most motile fraction of spermatozoa with the highest embryo developmental competence. What remains unclear, however, is the causal mechanism that linksSCF to an impaired embryo development. To identify a relationship between SCF and an unexpectedly high proportion of embryo aneuploidy, while addressing treatment options. We identified couples with a high incidence of embryo aneuploidy in a previous intracytoplasmic sperm injection (ICSI) cycle with pre-implantation genetic testing for aneuploidy (PGT-A), utilizing spermatozoa selected by density gradient (DG). Terminal deoxynucleotidyl dUTP transferase nick-end labeling (TUNEL) and neutral Comet assays were carried out on the semen specimens to assess total SCF and double-stranded DNA (dsDNA) fragmentation, respectively. These couples underwent subsequent ICSI/PGT-A cycles with MFSS. Total SCF and dsDNA fragmentation were compared between the two sperm selection methods. Embryo aneuploidy, implantation, clinical pregnancy, delivery,and pregnancy loss rates were compared between the couples' historical DG and subsequent MFSS cycles. In 57 couples undergoing 71 ICSI/PGT-A cycles, where DG sperm selection was carried out, a high incidence of aneuploid embryos (74.7%) resulted in poor implantation and no viable pregnancies. Testing for SCF, inclusive of dsDNA breaks, evidenced a SCF of 26.2% and dsDNA break of 3.6% in the raw specimen, that decreased to 18.0% (p < 0.001) and 3.1%, respectively, in the DG processed specimen. Following MFSS, total SCF and dsDNA fragmentation decreased to 1.9% and 0.3%, respectively (p<0.001). The embryo euploidy rate remarkable improved from 25.3% in the DG cycles to 42.9% in the MFSS cycles (p<0.001). The 6.7% implantation rate in the DG cycles increased to 65.5% in the MFSS cycles (p<0.001). Similarly, the clinical pregnancy rate rose from 10.5% (DG) to 64.6% (MFSS), resulting in a 62.5% delivery rate (p<0.001). In couples with a relatively young female partner with a negative infertility workup, and a male partner with semen parameters adequate for ICSI, presenting with a high rate of embryo aneuploidy, an additional subtle male factor component may be the culprit. Thus, it is crucial to assess the SCF and test for the dsDNA breaks, which can eventually contribute to embryo chromosomal abnormalities. Given the inverse relationship between SCF and motility, a selection of the most motile gamete by MFSS enhanced the proportion of spermatozoa with an intact genome, contributing to the generation of moreeuploid embryos that are capable of implanting and yielding increased term pregnancies.

Motile sperm fraction separation from cryopreserved samples in taxonomically distant fishes

Motile sperm fraction separation from cryopreserved samples in taxonomically distant fishes

Chemotaxis may assist marine heterotrophic bacterial diazotrophs to find microzones suitable for N2 fixation in the pelagic ocean.

Heterotrophic bacterial diazotrophs (HBDs) are ubiquitous in the pelagic ocean, where they have been predicted to carry out the anaerobic process of nitrogen fixation within low-oxygen microenvironments associated with marine pelagic particles. However, the mechanisms enabling particle colonization by HBDs are unknown. We hypothesized that HBDs use chemotaxis to locate and colonize suitable microenvironments, and showed that a cultivated marine HBD is chemotactic toward amino acids and phytoplankton-derived DOM. Using an in situ chemotaxis assay, we also discovered that diverse HBDs at a coastal site are motile and chemotactic toward DOM from various phytoplankton taxa and, indeed, that the proportion of diazotrophs was up to seven times higher among the motile fraction of the bacterial community compared to the bulk seawater community. Finally, three of four HBD isolates and 16 of 17 HBD metagenome assembled genomes, recovered from major ocean basins and locations along the Australian coast, each encoded >85% of proteins affiliated with the bacterial chemotaxis pathway. These results document the widespread capacity for chemotaxis in diverse and globally relevant marine HBDs. We suggest that HBDs could use chemotaxis to seek out and colonize low-oxygen microenvironments suitable for nitrogen fixation, such as those formed on marine particles. Chemotaxis in HBDs could therefore affect marine nitrogen and carbon biogeochemistry by facilitating nitrogen fixation within otherwise oxic waters, while also altering particle degradation and the efficiency of the biological pump.

P-063 Multivariate analysis identifies oxidative stress levels and acrosome status of motile spermatozoa as independent predictors of motile sperm hyaluronan binding ability

Abstract Study question Is it possible to predict motile sperm hyaluronan binding ability (HBA) from motile sperm functional parameters? Summary answer Using multivariate analysis, oxidative stress levels and acrosome status of motile spermatozoa, derived from semen swim-up, were identified as predictors of sperm HBA. What is known already Semen analysis is a gold standard practice for fertility evaluation. However, motility and morphology of spermatozoa are not always indicative of the molecular makeup of sperm cells. In this context, several sperm functional tests were developed to enhance our understanding of spermatozoa biology. Interestingly, several studies have shown that the plasma membrane of mature sperm cells contain hyaluronan binding sites. HBA was associated with intact acrosome, decreased DNA damage, and high viability. Nevertheless, it has not been demonstrated yet if hyaluronan binding ability can be predicted solely by swim-up derived- motile spermatozoa functional parameters. Study design, size, duration A prospective study was performed at Al-Hadi Medical Center, beirut, Lebanon, between January and July 2020. Freshly ejaculated semen samples obtained from infertile men with concentration of ≥ 20 x 106/ml and with total sperm motility of ≥ 30% were included. The primary outcome was to assess if the motile sperm functional parameters may influence HBA. A sample size of 54 was calculated using power = 85% and alpha = 5% for multiple linear regression. Participants/materials, setting, methods 54 semen samples were assessed according to WHO guidelines (2010). Thereafter, samples were processed using the semen swim-up technique. Supernatants containing motile spermatozoa were collected for further analysis. In motile spermatozoa-enriched fractions, chromatin integrity was assessed using toluidine blue (TB) staining. Oxidative stress levels were detected using a nitroblue tetrazolium (NBT) test. Acrosome status was determined using triple staining technique. HBA was evaluated via a commercially available hyaluronan binding assay (HBA® Assay). Main results and the role of chance In the motile spermatozoa-enriched fractions, mean ± standard deviations for concentration, progressive motility, non-progressive motility and normal morphology were 26.17±11.48, 76±18.97, 20.94±12.61 and 0.75 ± 1.4, respectively. In addition, mean ± standard deviations for TB + cells, NBT + cells, living spermatozoa with intact acrosome, and HBA were 16.42 ± 13.4, 57.4 ± 9.4, 93.9 ±3.2, and 48.98±11.95, respectively. The values of the HBA had a non-normal distribution; therefore, these values were first linearized by taking the logarithm of the outcome. Afterwards, multiple linear regression (MLR) was used to predict the outcome. The overall regression of the final model was statistically significant (R2 = 0.346), F(4.43) =5.962, p = 0.001. The results of the final MLR model indicated that a unit increase in non-progressive motility (%) (p = 0.002) and NBT + cells (%) (p = 0.009) increased the HBA by 1.505 units and 1.409 units, respectively. However, a unit increase in dead spermatozoa with unreacted acrosome (%) (p = 0.032) and living spermatozoa with reacted acrosome (%) (p = 0.026) decreased the HBA by 1.317 units and 1.342 units, respectively. Limitations, reasons for caution This is an interim study and these results should be taken as preliminary. In order to confirm these findings, further studies including larger sample size and motile spermatozoa derived from semen samples with abnormal parameters (such as severe asthenozoospermia, leukocytospermia, severe oligozoospermia) are required. Wider implications of the findings Several studies indicated that using damaged spermatozoa may affect the intracytoplasmic sperm injection (ICSI) outcomes. In addition, using damaged spermatozoa during fertilization may predispose the offspring to various diseases later in life. These results may be considered as an impetus to reconsider sperm selection during ICSI. Trial registration number Not applicable

New Approaches to Define The Functional Competency of Human Sperm Subpopulations and Its Relationship to Semen Quality.

BackgroundThis study aimed at comparing a comprehensive set of functional and structural sperm characteristics be- tween sperm motility fractions and correlating results to the standard semen parameters. By grouping related variables, our objective was to establish the predictive power of semen parameters and whether they accurately reflect the function- ality of sperm motility fractions or merely a small set of parameters within individual fractions.Materials and MethodsIn this non-invasive experimental study, donor semen samples (n=55) were separated via double density gradient centrifugation, isolating a high (HM) and low motile (LM) sperm fraction. Fractions were evaluated for percentage vitality, chromatin integrity, mature spermatozoa, motility and kinematic parameters, hyper- activation, positive reactive oxygen species, intact mitochondrial membrane potential (MMP) and acrosome reaction.ResultsHM fractions had significantly (P<0.001) enhanced percentages of induced acrosome reaction (HM, 55.6 ± 14.3%, LM, 25.0 ± 16.5%), motility and kinematic parameters, hyperactivation, vitality (HM, 70.4 ± 9.7%, LM, 47.9 ± 10.3%), mitochondrial membrane intactness (HM, 67.2 ± 10.4%, LM, 44.7 ± 15.0%) and mature spermatozoa (HM, 83.4 ± 10.0%, LM, 64.6 ± 8.2%) with intact chromatin (HM, 80.5 ± 8.1%, LM, 71.3 ± 8.0%). Various sperm mor- phology abnormalities correlated with LM fractions’ grouped motility parameters (range, 0.46 to 0.51; range -0.4 to -0.75), whereas combined semen traits of total motility, progressive motility, viscosity and mucus penetration (MPT) correlated with HM fractions’ grouped motility parameters (range, 0.44 to 0.84).ConclusionCollectively, total and progressive motility, viscosity and MPT may represent a reliable grouping of semen parameters for predicting the quality of HM sperm fractions. Separating the same donor semen samples into two signifi- cantly diverse motility sperm fractions could be a potential model in mimicking the qualities of fertile and sub-fertile males’ sperm populations and used for future research on the improvement of sperm subpopulations from males with different fertility statuses.

Gene Expression Alteration of Sperm-Associated Antigens in Human Cryopreserved Sperm.

Background: Sperm-associated antigens (SPAGs) are 18 types of proteins, some of which play important roles in various biological functions associated with assisted reproductive technology outcomes, and are consequently important to the success of fertility programs. Despite the favorable outcomes of fecundity rates among male patients with cancer using cryopreserved sperm, the detrimental impact of freezing on cells has been noted in many studies. Cryopreservation has been thought to have adverse effects on sperm quality through disruptions in the expressions of SPAG genes. This study aimed to evaluate the effects of cryopreservation on the expressions of SPAGs genes and their transcriptome alterations in human sperm. Materials and Methods: A total of 12 normal ejaculations were prepared using the density gradient centrifugation procedure, and the motile sperm fractions were divided into fresh and frozen groups. In the latter, sperm samples were mixed with SpermFreeze® solution as the cryoprotectant. The cryovial of sperm suspension was first held just over nitrogen vapor and then dipped inside liquid nitrogen. After 3 days, the specimens were thawed in tap water and incubated for 2 hours for recovery. Then, RNA from sperm was extracted for SPAG gene expression analysis, using real-time polymerase chain reaction. Results: Our findings showed a decrease in expression of SPAG5 (p-value = 0.009), SPAG7 (p-value = 0.004), and SPAG12 (SNU13/NHP2L1; p-value = 0.039) genes during cryopreservation. Discussion: The results indicate that the freezing procedure could negatively affect gene expression and to some extent proteins in human spermatozoa. Conclusion: The alteration of SPAG expression could provide new information on the molecular correlation between cryopreservation and increased failure in intracytoplasmic sperm injection and in vitro fertilization.

Separation and enrichment of sodium-motile bacteria using cost-effective microfluidics.

Many motile bacteria are propelled by the rotation of flagellar filaments. This rotation is driven by a membrane protein known as the stator-complex, which drives the rotor of the bacterial flagellar motor. Torque generation is powered in most cases by proton transit through membrane protein complexes known as stators, with the next most common ionic power source being sodium. Sodium-powered stators can be studied through the use of synthetic chimeric stators that combine parts of sodium- and proton-powered stator proteins. The most well studied example is the use of the sodium-powered PomA-PotB chimeric stator unit in the naturally proton-powered Escherichia coli. Here we designed a fluidics system at low cost for rapid prototyping to separate motile and non-motile populations of bacteria while varying the ionic composition of the media and thus the sodium-motive force available to drive this chimeric flagellar motor. We measured separation efficiencies at varying ionic concentrations and confirmed using fluorescence that our device delivered eightfold enrichment of the motile proportion of a mixed population. Furthermore, our results showed that we could select bacteria from reservoirs where sodium was not initially present. Overall, this technique can be used to implement the selection of highly motile fractions from mixed liquid cultures, with applications in directed evolution to investigate the adaptation of motility in bacterial ecosystems.

Sperm Nuclei Analysis and Nuclear Organization of a Fertile Boar-Pig Hybrid by 2D FISH on Both Total and Motile Sperm Fractions.

Simple SummaryMammalian hybrids frequently form in nature between closely related species, and the majority are sterile due to the production of chromosomally unbalanced gametes. In Italy, the widespread wild boar has had negative consequences for free-range pig farming, which is considered the best practice for pig welfare and is a common method of farming most autochthonous pig breeds. This study aimed to analyze the sperm DNA integrity, sperm meiotic segregation and nuclear spatial organization in a boar–pig hybrid, for the first time, to evaluate its fertilizing capacity. The results show that the hybrid presented a high frequency (64%) of motile spermatozoa with a regular chromosome composition and a specific spatial distribution. This study underlines how fertile boar–pig hybrids represent a growing problem for conserving autochthonous pig breeds.A wide range of mammalian hybrids has recently been found by chance or through population-screening programs, but studies about their fertilizing capacity remain scarce and incomplete. Most of them are assumed to be sterile due to meiotic arrest caused by the failure of chromosome pairings. In this study, we evaluated both sperm meiotic segregation, by 2D fluorescent in situ hybridization (FISH) analysis, and sperm quality (Sperm Chromatin Structure Assay) by flow cytometer in a fertile boar–pig hybrid (2n = 37,XY) originating from a Nero Siciliano pig breed (Sus scrofa domesticus) and a wild boar (Sus scrofa ferus). Spermatozoa were also separated by a dual-layer (75–60%) discontinuous Percoll gradient, resulting in two fractions with a significantly better overall quality in the motile sperm fraction. These data were confirmed by FISH analysis also, where the frequencies of spermatozoa with a regular chromosome composition were 27% in total sperm fraction and 64% in motile sperm fraction. We also evaluated the nuclear architecture in all counted spermatozoa, showing a chromatin distribution changing when chromosome abnormalities occur. Our results demonstrate that the chromosome pairing has a minimal effect on the sperm segregation and semen quality of a boar–pig hybrid, making it fertile and harmful for the conservation of autochthonous pig breeds.

The impact of cryopreservation on the morphology of spermatozoa in men with oligoasthenoteratozoospermia

The cryopreservation of ejaculate can reduce the viability, motility, and morphological characteristics of the spermatozoa of infertile men. Oligoasthenoteratozoospermia (OAT) is the most common cause of male subfertility. The aim of this study was to evaluate the morphological characteristics and viability of progressive motile sperm fraction before and after cryopreservation, and to determine whether cryopreservation of progressive motile sperm fraction is effective in eliminating morphologically abnormal sperm in men with OAT. An increased proportion of spermatozoa with normal morphology in fresh progressive motile sperm fraction compared with fresh ejaculate has been observed. After cryopreservation, the motility was 65.5 ± 8.8%; the proportion of spermatozoa with normal morphology increased non-significantly compared with freshly prepared motile sperm fraction (35.6 ± 5.5%). Concurrently, the proportion of cryopreserved spermatozoa with head defects increased significantly by 1.7 times (to 38.4 ± 4.7%) and the proportion of almost all morphologically abnormal sperm cells, particularly spermatozoa with multiple abnormalities, was reduced significantly. These data appear to be a novel finding in the context of patients with OAT. Using such spermatozoa for in vitro fertilization leads to a significant decrease in both a number of embryos at the cleavage stage and the blastocysts formation rate. High-magnification sperm morphology examination and selection, IMSI, post-cryopreservation significantly increased the likelihood of successful oocyte fertilization and subsequent embryo development.

Comparative Analysis of Effectiveness of Clomiphene Citrate and Letrozole Combined with Low Dose Human Menopausal Gonadotropin for Controlled Ovarian Stimulation in Intrauterine Insemination Cycles

Objective: To compare the efficacy of clomiphene citrate and letrozole in combination with low dose human menopausal gonadotropin for controlled ovarian stimulation in intrauterine insemination (IUI) cycles.Methods: During January-2018 to December-2019 for intending 496 IUI cycles, controlled ovarian stimulation was performed with either clomiphene or letrozole combined with human menopausal gonadotropin (hMG), in two arms: subjects in one arm (Group A) were with clomiphene and hMG in 222 cycles; those in the second arm (Group B) were with letrozole and hMG in 274 cycles. Pregnancy rate and clinical pregnancy rate of both groups were considered as the primary outcomes.Results: Patient characteristics like female age, indications for IUI, type of IUI, endometrial thickness and total motile fraction (TMF) of spermatozoa of male partners were seen similar in both groups. The letrozole-hMG group (Group B) had significantly higher numbers of cycles with single dominant follicle (P=0.01) and human chorionic gonadotropin (hCG) was more frequently used as the ovulation trigger (P=0.03). Pregnancy rate (18.5% vs. 15.3%, P=0.35) and clinical pregnancy rate (18.5% vs. 15.3%, P=0.35) were similar in groups A and B, respectively.Conclusion: Clomiphene citrate and letrozole combined with low dose human menopausal gonadotropin were equally effective for controlled ovarian stimulation in IUI cycles.

Analysis of meiotic segregation by triple-color fish on both total and motile sperm fractions in a t(1p;18) river buffalo bull.

Chromosomal aberrations are relatively frequent pathologies in both humans and animals. Among them, translocations present a specific meiotic segregation pattern able to give a higher percentage of unbalanced gametes that can induce fertility problems. In this study, the meiotic segregation patterns of 1p, 1q and 18 Bubalus bubalis chromosomes were analyzed in both total sperm fraction and motile sperm fraction of a t(1p;18) carrier and a control bulls by triple-color FISH analysis with a pool of specific BAC probes. The frequencies of each total sperm fraction products in the carrier resulting from alternate, adjacent I, adjacent II and 3:1 segregation were 39%, 20%, 1% and 38%, respectively. On the other hand, the frequencies of each motile sperm fraction products in the carrier resulting from alternate, adjacent I, adjacent II and 3:1 segregation were 93%, 5%, 0% and 2%, respectively. The frequencies of normal sperms in the carrier were 27% and 69% in total sperm fraction and motile sperm fraction, respectively. The frequencies detected in motile sperm fraction were also validated by comparison with bull’s progeny. To our knowledge, this is the first report on the meiotic segregation patterns in motile sperm fractions of B. bubalis bull carrying a chromosomal translocation. These data suggest that translocation has a very limited effect on aneuploidy in the gametes, and therefore, on the reproductive abilities of the bull.

Cryopreservation of human spermatozoa with penetrating and non-penetrating cryoprotectants

Сryopreserved spermatozoa are widely used in infertility treatment by assisted reproductive technologies. However, the spermatozoa survival rate remains low in patients with oligoastenoteratozoospermia. Therefore the development of effective cryopreservation methods for spermatozoa from pathospermia is relevant. The effectiveness of cryopreservation spermatozoa from oligoastenoteratozoospermia man using penetrating and non-penetrating cryoprotectants was compared. Sperm motility, viability and morphological characteristics were evaluated after cryopreservation with glycerol and polyvinylpyrrolidone. The average number of spermatozoa count in fresh ejaculate was (11.0±0.2) mln/ml. After isolation of active motile fraction the number of cells was (3.8±0.3) mln/ml and (84.3±8.4) % from them were motile (group 3). (78.8±6.6) % of spermatozoa cryopreserved with glycerol (group 1) and (41.4±8.1) % cryopreserved with polyvinylpyrrolidone (group 2) remained active motile. The spermatozoa viability after cryopreservation was (82.1±8.6) % and (89.6±8.6) % in group 1 and 2, respectively. Despite the high rate of spermatozoa survival in group 1 the number of motile cells decreased to (27.3±4.8) % after cryoprotectant removing stage. Morphological analysis revealed that the incidence of spermatozoa head abnormalities was (25.97±2.67), (19.21±2.67) and (20.57±1.19) % in group 1–3, respectively. The differences of spermatozoa midpiece and tail abnormalities in the study groups were statistically insignificant. The use of polyvinylpyrrolidone as a cryoprotectant allows preserving 90 % of survived spermatozoa from oligoastenoteratozoospermia men after freeze/thawing. The set of spermatozoa head, neck and midpiece abnormalities is significantly lower after cryopreservation with polyvinylpyrrolidone compared with routine method with glycerol. Two-stage spermatozoa cryopreservation method with polyvinylpyrrolidone is promising for assisted reproductive technologies since spermatozoa can be used immediately after warming for oocyte fertilization without cryoprotectant removing step.

A simple method of human sperm vitrification

Human sperm vitrification is a novel method of sperm freezing which achieves cryopreservation due to ultra-rapid cooling rates that prevent ice-crystal formation. However, sperm vitrification protocols are still largely not standardized for routine clinical use and seldom achieve a post warm sperm survival of 25-35%. The study aim was to validate and optimize a simple method of sperm vitrification that yields a high survival rate of spermatozoa for clinical use. Semen samples from 10 normozoospermic patients were subject to a simple swim-up into pre-warmed gamete handling media. Swim-up specimens were mixed in a 1:1 ratio with 0.5 M sucrose. Swim up specimens were then directly dropped in liquid N2. After a week of storage samples where warmed at 42 degree Celsius and sperm motility and viability was estimated. The mean sperm total motility of the fresh sample after the swim up preparation was 94.3 ± 3.06 %. Upon, vitrification followed by warming the mean percentage of total motile sperm fraction recovered was 74.70 ± 5.60 %. The mean sperm progressive motility of vitrified-warmed spermatozoa was 68 ± 8.47 %. The overall mean percentage of motile sperm recovery was 70.05% of the fresh swim up sample in this study. The overall mean sperm viability as assessed using the HOST vitality test was 77.21 ± 7.52%.•This study presents a simple protocol on the 'droplet method' of sperm vitrification.•Sperm cells vitrified using our modified method show a >70% motility and viability rates compared to the routine 25% to 35% of reported survival with the original sperm vitrification/freezing methodologies. This survival is attributed to a crucial change in the warming step.•This method has the advantage of using no toxic cell permeating cryoprotectant or expensive programmable freezing devices.

Rapid time-stamped analysis of filament motility.

The in vitro motility assay is a valuable tool to understand motor protein mechanics, but existing algorithms are not optimized for accurate time resolution. We propose an algorithm that combines trace detection with a time-stamped analysis. By tracking filament ends, we minimize data loss from overlapping and crossing filaments. A movement trace formed by each filament end is created by time-stamping when the filament either first (filament tip) or last (filament tail) occupies a pixel. A frame number vs. distance curve is generated from this trace, which is segmented into regions by slope to detect stop-and-go movement. We show, using generated mock motility videos, accurate detection of velocity and motile fraction changes for velocities < 0.05 pixels per frame, without manual trace dropping and regardless of filament crossings. Compared with established algorithms we show greatly improved accuracy in velocity and motile fraction estimation, with greatly reduced user effort. We tested two actual motility experiments: (1) adenosine triphosphate (ATP) added to skeletal myosin in rigor; (2) myosin light chain phosphatase (MLCP) added to phasic smooth muscle myosin. Our algorithm revealed previously undetectable features: (1) rapid increase in motile fraction paralleled by a slow increase in velocity as ATP concentration increases; (2) simultaneous reductions in velocity and motile fraction as MLCP diffuses into the motility chamber at very low velocities. Our algorithm surpasses existing algorithms in the resolution of time dependent changes in motile fraction and velocity at a wide range of filament lengths and velocities, with minimal user input and CPU time.