Good Quality Sperm Research Articles

REPRODUCTIVE BEHAVIOR AND MORPHOLOGY ON HORSES (EQUUS CABALLUS) MALES IN NORTH TAPANULI DISTRICT

RAYSWE DUMARIS SIHOMBING, 2018: ''Reproductive Behavior and Morphology in Horses (Equus Caballus) Males in North Tapanuli District ''. Guided by HAMDAN and TRI HESTI WAHYUNI. This study aimed to see reproduction and morphological performance of the stallion in North Tapanuli Regency. This research was conducted in North Tapanuli regency, Silait-lait Village, Hutajulu Village and Siaro Village and Superior Breeding Cattle Hall and Animal Feed (BPTU-HPT) from June to August 2017. The analysis used in this research is quantitative data analysis which includes average, standard deviation and coefficient of diversity.The variable that distinguishes the horse is the part of reproduction which is divided into two, namely the exterior, which includes the diameter of the scrotum and the interior includes the quality of sperm that are tested miscroscopically and macroscopically. Macroscopic tests include volume measurement, viscosity, color, pH. Microscopic tests of motility, concentration, and abnormality. Morphology, including head length, head width, neck length, shoulder height, chest circumference, chest depth, body length, hip width, hip height.The results showed that stallion in North Tapanuli Regency had good sperm quality with gray white color, low concentration level, pH 6.67, motility 80%, concentration 13,76 x 10 ^ 7ml / ejakulat, and abnormality 16, 6% and morphological appearance have mean, standard deviation and high diversity coefficient with head length 62,30 cm, shoulder height 158,84 cm, chest circumference 174,26 cm, chest depth 78,20 cm, body length 169,86 cm , hip height 167.12 cm and hip width 40.01 cm. In conclusion of this study, the morphology and reproduction of horses in North Tapanuli Regency has good weight and posture and good sperm quality used as males in developing horse cattle.

Creatine enhances the duration of sperm capacitation: a novel factor for improving in vitro fertilization with small numbers of sperm.

Why are many sperm required for successful fertilization of oocytes in vitro, even though fertilization occurs in vivo when only a few sperm reach the oocyte? Creatine produced in the ovary promotes efficient fertilization in vivo; however, in vitro, creatine is not contained in the in vitro fertilization (IVF) medium. The IVF medium enables capacitation of sperm. However, the IVF medium does not fully mimic the in vivo environment during fertilization. Consequently, fertilization in vitro is more inefficient than in the oviduct. Follicular and oviductal fluids were collected and then analyzed for creatine and glucose levels. To determine the physiological functions of creatine, the creatine antagonist 3-guanidinopropionic acid (GPA) was injected into hormonally primed mice. Using conventional IVF protocols, sperm were pre-incubated in IVF medium with creatine and then co-cultured with 10 ovulated cumulus-oocyte complexes (1-1000 per oocyte) in 50 μl medium droplets. Glucose and creatine levels were measured using commercial enzymatic assay kits. The effect of creatine in vivo was assessed by mating experiments using mice treated with or without GPA just before ovulation. To assess the functions of sperm incubated in IVF medium containing creatine, we analyzed (1) the motility of sperm using computer-assisted sperm assay, (2) the capacitation level of sperm by western blot analyses, and (3) the condition of sperm acrosomes by peanut agglutinin lectin-FITC staining. Oviductal creatine levels were significantly increased following ovulation. Injecting mice with GPA just before ovulation significantly reduced the number of fertilized oocytes. The addition of creatine to IVF medium enhanced sperm capacitation by increasing ATP levels. Successful fertilization was achieved with as few as five sperm/oocyte in the creatine group, and the number of fertilized oocytes was significantly higher than in the control without creatine (P < 0.01). In the present study, a pharmacological approach, creatine antagonist (GPA) treatment, but not a knockout mouse model, was used to understand the role of creatine in vivo. The role of creatine in fertilization processes can only be shown in a mouse model. A modified IVF technique using creatine-containing medium was developed and shown to markedly improve fertilization with small numbers of sperm. This approach has the potential to be highly beneficial for human assisted reproductive technologies, especially for patients with a limited number of good quality sperm. This work was supported in part by JSPS KAKENHI Grant numbers JP24688028, JP16H05017 (to M.S.), and JP15J05331 (to T.U.), the Japan Agency for Medical Research and Development (AMED) (16gk0110015h0001 to M.S.), and National Institutes of Health (NIH-HD-076980 to J.S.R). The authors have nothing to disclose.

A two-step dilution tris-egg yolk extender containing Equex STM significantly improves sperm cryopreservation in the African wild dog (Lycaon pictus)

Conservation management of endangered African wild dogs (AWD; Lycaon pictus) can benefit greatly from development of sperm freezing and artificial insemination. Previous freezing attempts yielded nearly 0% motile sperm within 2 h of thawing. In this study, two canine freezing protocols were tested: Protocol 1: a one-step dilution in TRIS-20% egg yolk containing 8% glycerol; and Protocol 2: a two-step dilution in TRIS-20% egg yolk containing a final extender concentration of 5% glycerol and 0.5% Equex STM, coupled with a TRIS-citrate-fructose thawing solution. Semen was collected by electroejaculation from n = 24 AWDs, of which eight ejaculates of sufficient quality (four good quality with initial sperm motility of 75.0 ± 4.4% and four poor quality; showing rapid decrease in sperm motility to 3.3 ± 3.3% prior to freezing) were frozen. For good quality samples, motility and sperm motility index persisted for up to 8 h for Protocol 2, and was higher between 2 and 6 h after thawing with a decrease from 4 h of incubation. Motility dropped to nearly 0% after 2 h incubation for Protocol 1. Viability was higher for Protocol 2 throughout the 8 h of incubation, with a decrease after 6 h, compared to 4 h for Protocol 1. Acrosome integrity was higher for Protocol 2 throughout post-thaw incubation, with a decrease after 2 h for both protocols. Protocols did not differ in normal sperm morphology or DNA integrity. Poor quality samples yielded similar results, except for acrosome integrity, which declined for Protocol 2. In conclusion, a two-step dilution in TRIS-egg yolk-glycerol extender containing Equex STM yields significantly improved post-thaw quality and longevity of AWD spermatozoa, making it suitable for sperm banking and artificial insemination initiatives.

Fertilizing capacity of vitrified epididymal sperm from Iberian ibex (Capra pyrenaica)

In this study, we successfully described for the first time a vitrification of epididymal Iberian ibex spermatozoa. Spermatozoa from epididymis were obtained from 15 Iberian ibex. The right epididymis' semen sample was vitrified and the left one was frozen. After thawing/warming, samples were selected by density gradient. Sperm characteristics from each treatment were evaluated. To test the spermatozoa fertilization ability, heterologous IVF was carried out using bovine oocytes. Despite of the observation of a decrease of about 40% for motility sperm between pre-freezing and post-thawing (75.0 ± 5.2 and 45.0 ± 6.0) and pre-vitrification and post-warming (78.2 ± 5.2 and 33.9 ± 6.2) (P < .05), after the washing, an improvement of sperm motility was found when using the vitrification treatment compared to frozen-thawed. Heterologous IVF showed that Iberian Ibex spermatozoa, either frozen-thawed or vitrified-warmed, were equally capable of penetrating ZP intact bovine oocytes, leading to pronuclear formation (%) and hybrid embryo cleavage (%), (31.3 ± 27.2 and 45.1 ± 24.4, respectively). As expected, in the homologous IVF group, higher percentages of penetration, pronuclei formation and cleavage were found compared to heterologous groups using Iberian ibex frozen and vitrified sperm (P < 0,5). The highest pronuclei formation was found after 20 h post insemination in both heterologous IVF groups (30.2 ± 6.7 and 31.7 ± 21.5 thawed and vitrified group). Consequently, the cleavage rate (48 h) followed the same results to homologous and thawed and vitrified groups (76.1 ± 15.9; 31.3 ± 27.2 and 45.1 ± 24.4, respectively) (P < .05). In conclusion, Iberian ibex sperm vitrification is a promising and useful alternative to conventional methods resulting in good quality spermatozoa post-thaw, and an adequate in vitro fertilizing ability.

Characterization of a novel role for the dynamin mechanoenzymes in the regulation of human sperm acrosomal exocytosis.

Does dynamin regulate human sperm acrosomal exocytosis? Our studies of dynamin localization and function have implicated this family of mechanoenzymes in the regulation of progesterone-induced acrosomal exocytosis in human spermatozoa. Completion of an acrosome reaction is a prerequisite for successful fertilization in all studied mammalian species. It follows that failure to complete this unique exocytotic event represents a common aetiology in the defective spermatozoa of male infertility patients that have failed IVF in a clinical setting. Recent studies have implicated the dynamin family of mechanoenzymes as important regulators of the acrosome reaction in murine spermatozoa. The biological basis of this activity appears to rest with the ability of dynamin to polymerize around newly formed membrane vesicles and subsequently regulate the rate of fusion pore expansion. To date, however, the dynamin family of GTPases have not been studied in the spermatozoa of non-rodent species. Here, we have sought to examine the presence and functional significance of dynamin in human spermatozoa. Dynamin expression was characterized in the testis and spermatozoa of several healthy normozoospermic individuals. In addition, we assessed the influence of selective dynamin inhibition on the competence of human spermatozoa to undergo a progesterone-induced acrosome reaction. A minimum of five biological and technical replicates were performed to investigate both inter- and intra-donor variability in dynamin expression and establish statistical significance in terms of the impact of dynamin inhibition. The expression and the localization of dynamin in the human testis, epididymis and mature spermatozoa were determined through the application of immunofluorescence, immunoblotting and/or electron microscopy. Human semen samples were fractionated via density gradient centrifugation and the resultant populations of good and poor quality spermatozoa were induced to capacitate and acrosome react in the presence or absence of selective dynamin inhibitors. The acrosome integrity of live spermatozoa was subsequently assessed via the use of fluorescently conjugated Arachis hypogea lectin (PNA). The influence of dynamin phosphorylation and the regulatory kinase(s) responsible for this modification in human spermatozoa were also assessed via the use of in situ proximity ligation assays and pharmacological inhibition. In all experiments, ≥100 spermatozoa were assessed/treatment group and all graphical data are presented as the mean values ± SEM, with statistical significance being determined by ANOVA. Dynamin 1 (DNM1) and DNM2, but not DNM3, were specifically localized to the acrosomal region of the head of human spermatozoa, an ideal position from which to regulate acrosomal exocytosis. In keeping with this notion, pharmacological inhibition of DNM1 and DNM2 was able to significantly suppress the rates of acrosomal exocytosis stimulated by progesterone. Furthermore, our comparison of dynamin expression in good and poor quality spermatozoa recovered from the same ejaculate, revealed a significant reduction in the amount of DNM2 in the latter subpopulation of cells. In contrast, DNM1 was detected at equivalent levels in both subpopulations of spermatozoa. Such findings are of potential significance given that the poor quality spermatozoa proved refractory to the induction of a progesterone stimulated acrosome reaction. In seeking to identify the regulatory influence of progesterone on DNM2 function, we were able to establish that the protein is a substrate for CDK1-dependent phosphorylation. The functional significance of DNM2 phosphorylation was illustrated by the fact that pharmacological inhibition of CDK1 elicited a concomitant suppression of both DNM2-Ser764 phosphorylation and the overall rates of progesterone-induced acrosomal exocytosis. N/A. This was an in vitro study performed mainly on ejaculated human spermatozoa. This experimental paradigm necessarily eliminates the physiological contributions of the female reproductive tract that would normally support capacitation and acrosomal responsiveness. This study identifies a novel causative link between dynamin activity and the ability of human spermatozoa to complete a progesterone-induced acrosome reaction. Such findings encourage a more detailed analysis of the contribution of dynamin dysregulation as an underlying aetiology in infertile males whose spermatozoa are unable to penetrate the zona pellucida. This research was supported by a National Health and Medical Research Council of Australia Project Grant (APP1103176) awarded to B.N. and E.A.M. The authors report no conflict of interest.

Use of Assisted Reproduction Techniques in Male Pathologies: Molecule Based Sperm Selection Methods

Infertility is a widespread problem that is found in over 15% of couples. In 50 % of the cases, the male factor is the key. In order to improve pregnancy rates in assisted reproductive techniques (ART), new methods to select sperm subpopulations are required. These methods are under constant evaluation, and their possible genetic and epigenetic effects on the offspring must be considered. New concepts such as DNA fragmentation and sperm apoptosis are being introduced in andrology and are considered to develop new techniques. Recently, molecule-based methods have been developed for the purpose of overcoming deficiencies in classical selection methods that involve sperm morphology and movement. One of these methods is physiologic intracytoplasmic sperm injection (PICSI), which selects spermatozoa through their property to bind to hyaluronic acid, a component of the cell-oocyte complexes that acts as a natural selector of spermatozoa. But the top rated method is based on the property of the protein annex in A5 (ANXA V) to bind to phosphatidylserine (PS), a marker of apoptosis. Magnetic-Activated Cell Sorting (MACS) conjugated with ANXA V (MACS-ANXA V) is used to remove apoptotic sperm with exposed PS from a semen sample. The use of MACS-ANX V seems to produce good quality sperm when it is evaluated by in vitro assays. But when MACS-ANXA V is used previous to ART, controversies persist regarding the benefits of sperm selection in reproductive outcomes. In this review, we consider the use of MACS-ANXA V, particularly in cases of male pathologies.

Comparación de 2 métodos de selección espermática sobre la fragmentación del ADN y el potencial de membrana mitocondrial de los espermatozoides humanos: en busca del gameto de oro

IntroductionTo select good-quality sperm for assisted reproductive technology procedures, the best spermatozoa should be elicited. The aim of this study is to compare the impact of sperm selection on human sperm DNA fragmentation and mitochondrial membrane potential by means of density gradient and swim-up techniques. Materials and methodsConventional and functional semen parameters (mitochondrial membrane potential and plasma membrane integrity) in sperm selected by density gradient and swim-up techniques in 14 semen samples were evaluated. ResultsIn the selected neat semen samples, the number of sperm recovered was lower using swim-up as compared to density gradients. By contrast, an increase in progressive motility was observed compared with the initial sample, with no statistically significant difference between both techniques. On the other hand, the swim-up technique was shown to decrease the amount of non-progressive motile sperm recovered, whereas the density gradient technique allowed for a better recovery of the total motile sperm selected. Finally, an increase in the proportion of cells with higher mitochondrial membrane potential and lower DNA fragmentation index was observed. ConclusionThe results of this study demonstrate that sperm selection using the swim-up technique allows for better-quality sperm to be recovered, with a higher sperm cell membrane potential and lower DNA fragmentation. The use of this method is therefore recommended prior to artificial insemination or in vitro fertilisation procedures.

The effect of antioxidant agents' addition and freezing method on quality parameters of frozen thawed ram semen.

The aim of this study was to evaluate the effect of antioxidant agents and freezing methods on the ability of ram sperm to preserve its post-thaw quality characteristics. Six Chios rams were subjected to 52 weekly semen collections. Each ram was used as semen donor for freezing experiments once every 2weeks. Equal number of good quality spermatozoa from each ejaculate (concentration ≥1×109spermatozoa/ml, motility ≥70%, motility score ≥3.5) were pooled. Three equal aliquots of the pooled sample were diluted using three different fractions of a milk-based and glycerol extender (control, quercetin-enriched, α-tocopherol-enriched). Three freezing methods were applied (slow and fast freezing rate in a programmable freezer, vapors of liquid nitrogen) in every aliquot. Sperm aliquots were tested before freezing, immediately after thawing and after 3h of incubation at 37°C. Sperm motility (%) was evaluated microscopically. The percentage of membrane and acrosome-intact spermatozoa (IL%) as well as the percentage of membrane-intact and acrosome-reacted spermatozoa (ARL%) were determined by eosin-nigrosin stain. Furthermore, the percentage of hypo-osmotic swelling (HOS) test-positive spermatozoa was estimated. The results revealed no beneficial effect of the antioxidant treatment on the parameters of post-thaw semen (P>0.05). However, the slow freezing rate method was more beneficial regarding motility, IL, ARL and HOS-positive spermatozoa compared to the other methods. In conclusion, the antioxidant agents used in this study failed to protect sperm against cryopreservation stress; however, the choice of the appropriate freezing method could contribute to the improvement of post-thaw ram sperm quality.

Sperm evaluation of Jungle Cat (Felis chaus) obtained by urethral catheterization (CT) after medetomidine administration

This study aimed to evaluate semen from Jungle Cat (Felis chaus) by urethral catheterization (CT) after medetomidine administration that offers feasible and different approaches to obtaining good quality sperm, especially in wild felids. Accordingly, this method was tested in five Jungle Cats. After general anesthesia with the α2-agonist medetomidine (which also stimulates semen release into the urethra) and ketamine, an abdomen ultrasound was performed to locate dilation of the first segment of the urethra (prostatic urethra). A commercial Tom cat urinary catheter 3–5 (depending on the size of the animal) was advanced into the urethra to reach the semen full dilated primary region of the urethra, so as to allow semen collection into the lumen of the catheter by capillary forces. After retraction, sperm volumes between 69 ± 27.92 yielded motility of 77.13 ± 14.15 (mean ± SD) with a mean sperm concentration of 75.13 ± 17.05 million/ml. The results of this study showed that semen collection in jungle cat is feasible, using this method. This study describes a simple, useful in field, inexpensive method which does not require the training of the animal and is better than other methods. Samples have normal pH, suitable color and consolidation, high concentration and lower contamination with excellent motility in Jungle Cat and potentially, other wild felid species, as an alternative to electro-ejaculation.

Applying data mining techniques for increasing implantation rate by selecting best sperms for intra-cytoplasmic sperm injection treatment

Background and objectiveAspiration of a good-quality sperm during intracytoplasmic sperm injection (ICSI) is one of the main concerns. Understanding the influence of individual sperm morphology on fertilization, embryo quality, and pregnancy probability is one of the most important subjects in male factor infertility. Embryologists need to decide the best sperm for injection in real time during ICSI cycle. Our objective is to predict the quality of zygote, embryo, and implantation outcome before injection of each sperm in an ICSI cycle for male factor infertility with the aim of providing a decision support system on the sperm selection. MethodsThe information was collected from 219 patients with male factor infertility at the infertility therapy center of Alzahra hospital in Rasht from 2012 through 2014. The prepared dataset included the quality of zygote, embryo, and implantation outcome of 1544 injected sperms into the related oocytes. In our study, embryo transfer was performed at day 3. Each sperm was represented with thirteen clinical features. Data preprocessing was the first step in the proposed data mining algorithm. After applying more than 30 classifiers, 9 successful classifiers were selected and evaluated by 10-fold cross validation technique using precision, recall, F1, and AUC measures. Another important experiment was measuring the effect of each feature in prediction process. ResultsIn zygote and embryo quality prediction, IBK and RandomCommittee models provided 79.2% and 83.8% F1, respectively. In implantation outcome prediction, KStar model achieved 95.9% F1, which is even better than prediction of human experts. All these predictions can be done in real time. ConclusionsA machine learning-based decision support system would be helpful in sperm selection phase of ICSI cycle to improve the success rate of ICSI treatment.

Effect of semen preparation technique and its incubation on sperm quality in the Moroccan population.

In in vitro fertilisation (IVF), sperm preparation as critical part and influencing the sperm quality is especially dependent on the chosen technique itself and incubation parameters including temperature and CO2. In this study, we compared firstly density-gradient centrifugation technique (DGC) to the adapted DGC using the sperm pellet of 80% fraction (DGC/80P) in order to improve the sperm yield. Secondly, this study led to evaluate different sperm incubation conditions based on temperature effect (room temperature (RT=23°C) versus 35°C) and in the other hand, with or without 5% CO2 during 24hrs. Based on evaluating sperm conventional parameters and the DNA damage using TUNEL assay, our result showed that DGC/80P increased sperm quality compared to DGC with 25% of improvement. For temperature incubation effect after 24hrs, 35°C increased the DNA damage and decreased the sperm quality while RT could improve sperm motility by 38%. Moreover, the sperm incubation with 5% CO2 after 24hrs realised a negative impact on sperm parameters and its DNA damage. Indeed, for current IVF practice, a good sperm quality can be maintained for several hours at room temperature, while the sperm preparation is processed using the DGC/80P without CO2.

Study on the in vitro fertilizing potential of mithun (Bos frontalis) semen

Semen quality parameters (SQPs) such as motility, viability, total sperm abnormality, integrity of acrosome, plasma membrane and nucleus and vanguard distance travelled by sperm and biochemical profiles such as aspartate amino transaminase (AST), alanine amino transaminase (ALT) and lactate dehydrogenase (LDH) were studied in mithun at post thawed stage. Fifty ejaculates were collected through transrectal massage method from matured bulls and the ejaculates were divided into good and poor quality. The ejaculates were extended with Tris egg yolk citrate glycerol extender and stored in liquid nitrogen. PT seminal, biochemical profiles and zona binding per cent (BP) and binding index (BI) were studied with standard protocols. The results revealed good quality ejaculates has significantly (p&lt;0.05) higher SQPs, BP &amp; BI and has significantly (p&lt;0.05) lower total sperm abnormality, AST, ALT and LDH than in the poor quality ejaculates. PT motility was positively (p&lt;0.05) correlated with SQPs, vanguard distance, BI &amp; BP and negatively correlated (p&lt;0.05) with total sperm abnormality and biochemical profiles. In conclusion, the good quality sperm has higher functional sperm structures and higher intactness of sperm plasma and acrosomal membrane to motile faster in forward direction to reach the site of fertilization and successful fertilization.

Magnetic Activated Cell Sorting performed before double gradient centrifugation improve the recovery of good quality spermatozoa

Magnetic Activated Cell Sorting performed before double gradient centrifugation improve the recovery of good quality spermatozoa

Enhancement of oogenesis/spermatogenesis in meagre Argyrosomus regius using a combination of temperature control and GnRHa treatments

A multiple GnRHa injection method for inducing spawning of high fecundity and quality in meagre was optimized. Specifically, the study (a) examined how long females would continue spawning in response to consecutive, weekly GnRHa injections, if maintained at the natural spawning temperature, and (b) evaluated whether males can produce adequate amounts of good quality sperm for the same period, with the assistance of a GnRHa therapy. Combined with stable temperatures (19–20°C) that are prevalent during the early spawning season (April–May) in the Mediterranean Sea, each weekly GnRHa injection induced ~2 consecutive spawns per week for a period of 17weeks. Fish spawned consistently 2days after treatment and produced high fecundity and egg quality (i.e. fertilization, hatching and early larval development). Maximum mean total fecundity (±S.D.) obtained was 1,415,000±149,000eggskg−1 in 32 spawns, being the highest total season fecundity reported for meagre, and significantly higher than the estimated maximum potential fecundity for the species. At the same time, sperm of consistently high quality (i.e. initial motility, duration of motility and storage survival) was produced in response to treatment with multiple GnRHa implants, though towards the end of the experiment a significant reduction (ANOVA, P≤0.05) in spermatozoa density was observed. This protocol is expected to enhance greatly commercial production of meagre. Statement of relevanceThe present study reports on an optimized protocol for the induction of consistent and repeated spawning in meagre, based on the use of weekly GnRHa injections combined with stable temperatures that are prevalent at the early spawning season in the Mediterranean Sea. This protocol produced eggs of high fecundity and quality (i.e. fertilization, hatching and early larval development) for a period of >4months, and it is expected to enhance greatly commercial production of meagre.

Intracytoplasmic sperm injection into oocytes matured in vitro and early embryonic development in the owl monkey (Aotus lemurinus).

We explored the possibility of employing intracytoplasmic sperm injection (ICSI), involving oocytes and sperm of owl monkeys, to increase the availability of this species for investigations relating to malaria, etc., by increasing the number of animals in our laboratory. Two owl monkeys (a female and a male), raised at the Amami Laboratory of the University of Tokyo, were used. Follicular oocytes surrounded with cumulus cells were cultured in vitro for approximately 25 h and cumulus cells were removed with 0.1 % hyaluronidase. Because of the poor motility of caudal epididymal sperm, sperm were injected without adding polyvinylpyrrolidone to immobilize them. The ICSI procedure was performed by an individual with considerable experience of human ICSI. We were able to produce two owl monkey embryos using ICSI of oocytes that matured to MII stage. Both embryos reached the 10-cell stage at 98 h after ICSI and showed signs of compaction, but failed to cleave further. Although we successfully produced owl monkey embryos after ICSI, the embryos did not develop to the blastocyst stage. Many parameters need to be studied further, including superovulation, selection of culture media, and selection of good quality sperm in order to achieve successful ICSI in the owl monkey.

Frequency of Sperm DNA Fragmentation According to Selection Method: Comparison and Relevance of a Microfluidic Device and a Swim-up Procedure.

Multiple rounds of centrifugation or washing spermatozoa can cause sperm DNA fragmentation (SDF); however, a microfluidic approach to select spermatozoa does not require centrifugation. Reports have suggested that sperm sorting using a microfluidic device is an effective method to select good quality spermatozoa, however, it is not known whether it reduces sperm DNA damage. We investigated whether the frequency of SDF was affected by selection method during sperm processing. Semen samples from ten men with normal, oligozoospermia and asthenozoospermia were split into two groups and sorted using a microfluidic device or by a swim-up method. Subsequently, semen parameters and SDF were measured and analyzed using paired or non-paired Student's t-tests. For samples sorted by the microfluidic device (Sperm Sorter Qualis(®); Menicon, Kasugai, Japan) or the swim-up method, both showed a decrease in SDF. However, the decrease was more significant when the microfluidic device was used. Sorting using the microfluidic device resulted in less SDF than did the swim-up method.

Sperm cleanup and centrifugation processing for cryopreservation.

Fertility rates with artificial insemination are highest with good-quality sperm samples. Therefore, nonviable sperm, cellular debris, and seminal plasma are preferably removed from semen samples prior to use or for preservation. Such compounds are sources where reactive oxygen species are generated during storage or upon cryopreservation, impairing sperm function. In this chapter we describe methods to remove seminal plasma and cellular debris from sperm samples, and for selecting morphologically normal motile sperm. The methods that are described here include: ordinary centrifugation, sperm swim-up, glass wool and Sephadex filtration/adherence, and single-layer as well as discontinuous two-layer iodixanol density gradient centrifugation.

Sperm DNA methylation analysis in swine reveals conserved and species-specific methylation patterns and highlights an altered methylation at the GNAS locus in infertile boars.

Male infertility is an increasing health issue in today's society for both human and livestock populations. In livestock, male infertility slows the improvement of animal selection programs and agricultural productivity. There is increasing evidence that epigenetic marks play an important role in the production of good-quality sperm. We therefore screened for specific or common epigenetic signatures of livestock infertility. To do so, we compared DNA methylation level in sperm DNA from fertile and infertile boars. We evaluated first the global level of sperm DNA methylation and found no difference between the two groups of boars. We then selected 42 loci of interest, most of them known to be imprinted in human or mice, and assessed the imprinting status of five of them not previously described in swine tissues: WT1, CNTN3, IMPACT, QPCT, and GRB10. DNA methylation level was then quantified in fertile and infertile boars at these 42 loci. Results from fertile boars indicated that the methylation level of the selected loci is highly conserved between pig, human, and mice, with a few exceptions, including the POU5F1 (OCT4) promoter and RTL1. Comparison between fertile and infertile boars revealed that one imprinted region, the GNAS locus, shows an increase in sperm DNA methylation in three out of eight infertile boars with low semen quality. This increase in DNA methylation is associated with an altered expression of the genes belonging to the GNAS locus, suggesting a new role for GNAS in the proper formation of functional gametes.

Rescue of germline transmission from chimeras by IVF after sperm analysis.

Successful production of genetically modified mouse lines is dependent on germline transmission (GLT) of mutant alleles from chimeras. When natural mating fails to achieve GLT due to male infertility, sickness, or other problems, sperm can be harvested from chimeras and used for assisted reproductive technologies such as in vitro fertilization (IVF) to attempt to "rescue" GLT. However, a rational, evidence-based approach to determine if such extraordinary efforts should be attempted on a chimera has not been established. Therefore, in the present study we assessed the production, quality and genotype of epididymal sperm harvested from male chimeras generated by blastocyst or morula microinjection of gene targeted embryonic stem (ES) cell clones containing a LacZ expression cassette and that failed to achieve GLT. Results of this analysis enabled us to determine the cause of GLT failure, correlate coat color chimerism with the proportion of LacZ-positive sperm, and test the likelihood of achieving GLT by IVF. In 415 chimeras, 332 (80%) produced no offspring by natural mating ("infertile"), while 83 (20%) produced only wildtype offspring ("fertile"). Of the 332 infertile chimeras, 209 (63%) failed to produce any sperm whatsoever, 48 (15%) had extremely poor quality sperm, and 75 (23%) had good quality sperm. These results indicate that most chimeras that do not achieve GLT by natural mating are infertile, and the primary cause of infertility is failed spermatogenesis. Genotyping of sperm from 519 chimeras revealed a significant positive linear correlation between coat color chimerism and mean percentage of LacZ-positive sperm (R(2) = 0.95). Finally, IVF using good quality, LacZ-positive sperm from fertile and infertile chimeras "rescued" GLT for 19 out of 56 genes. We conclude that an assessment of coat color chimerism together with sperm quality and genotype can better inform the selection of chimeras for IVF to rescue GLT than coat color chimerism alone.

Rotational Dynamics of Optically Trapped Human Spermatozoa

Introduction. Optical trapping is a laser-based method for probing the physiological and mechanical properties of cells in a noninvasive manner. As sperm motility is an important criterion for assessing the male fertility potential, this technique is used to study sperm cell motility behavior and rotational dynamics. Methods and Patients. An integrated optical system with near-infrared laser beam has been used to analyze rotational dynamics of live sperm cells from oligozoospermic and asthenozoospermic cases and compared with controls. Results. The linear, translational motion of the sperm is converted into rotational motion on being optically trapped, without causing any adverse effect on spermatozoa. The rotational speed of sperm cells from infertile men is observed to be significantly less as compared to controls. Conclusions. Distinguishing normal and abnormal sperm cells on the basis of beat frequency above 5.6 Hz may be an important step in modern reproductive biology to sort and select good quality spermatozoa. The application of laser-assisted technique in biology has the potential to be a valuable tool for assessment of sperm fertilization capacity for improving assisted reproductive technology.