Sperm Fractions Research Articles

Automation of the Differential Digestion Process of Sexual Assault Evidence.

Sexual assault evidence samples require the use of a specific process known as a differential digestion to separate sperm from nonsperm cells prior to DNA extraction. An automated differential digestion process was developed using a selective degradation technique, which uses DNase I to digest the remaining nonsperm DNA in the sperm fraction. The use of DNase on pristine samples, as well as aged and degraded samples, was assessed to ensure that the quantity and quality of the sperm DNA were not compromised or adversely affected. Samples processed using the selective degradation technique yielded comparable DNA yield and DNA typing data to the conventional differential digestion process. The automated process utilized 96-well plates for high throughput and incorporated microscope slide preparations for confirmation of sperm. It reduced processing time by about sixfold and was paramount in the elimination of the Oakland Police Department Criminalistics Laboratory's sexual assault kit backlog.

Inferring the presence of spermatozoa in forensic samples based on male DNA fractionation following differential extraction

To address sexual assault kit backlogs some laboratories in North America have implemented ‘Direct to DNA’ (DTD) approaches for the examination of relevant vaginal, oral, rectal and external genitalia swabs from sexual assault examination kits. Using this approach no preliminary serological screening for semen or spermatozoa is performed. Instead, swabs are directly subjected to differential extraction and quantitation using a dual quantification system. Decisions regarding the next steps in processing each sample are typically based on the quantity of male DNA detected, the fraction in which it is detected, and its ratio to the total human DNA in the sample.In the absence of serological results it remains of value in many cases to determine whether spermatozoa are present in the sample and whether the male DNA profile may be attributed to this body fluid. In this study we examine the distribution of male DNA from various body fluids between epithelial and spermatozoa fractions following differential extraction. Based on these results we identified criteria under which a DNA profile can be reliably attributed to spermatozoa.A total of 18 blood samples, 129 saliva samples, and 78 semen samples were processed. The maximum amount of male DNA observed in the sperm fraction of a spermatozoa-free sample was 10.4 ng and the maximum portion of total male DNA observed in the sperm fraction was 7.7%. In contrast, when a sample contained spermatozoa the minimum portion of total male DNA observed in the sperm fraction was 52.6%. This research supports a 50% threshold of male DNA in the sperm fraction following differential extraction as a conservative criterion under which the scientist at the Centre of Forensic Sciences (CFS) may infer that spermatozoa is present in a sample in the absence of serological results. This general threshold is applicable to all sample types (underwear, clothing, swabs, condoms) tested.We further demonstrate that, if the same male DNA profile is represented more prominently in the sperm fraction versus the epithelial fraction, the analyst should not fall into the intuitive trap of inferring the presence of spermatozoa in the sample. Instead, enrichment calculations must be based on the measured quantity of male and total DNA in each fraction and not the male:female DNA ratios observed in the DNA profiles.

Cryopreservation of Low Number of Human Spermatozoa; Which is Better: Vapor Phase or Direct Submerging in Liquid Nitrogen?

Cryopreservation and subsequent survival of semen samples with low numbers of human spermatozoa in assisted reproductive technology (ART) facilities can be challenging. The aim of this study was to compare the quality of warmed human spermatozoa following vitrification using direct submerging (DS) in liquid nitrogen (LN2) or with LN2 vapour (V). Normozoospermic ejaculates were prepared by the swim-up technique and the motile sperm fraction was divided into three groups: (i) fresh (control); (ii) DS methods in LN2 (DS Group); or (iii) cryopreserved in V (Group V). Cryopreservation was performed in a small volume using a Cryotech device. After warming, sperm parameters (motility, viability, acrosome, DNA fragmentation and chromatin integrity) were assessed using cytochemical assays. Progressive motility, viability, chromatin integrity and DNA fragmentation differed significantly after warming when compared with the control. Sperm progressive motility and total motility rates were significantly higher in the DS Group compared to Group V. However, normal morphology, acrosome integrity and DNA damage were not significantly different between two groups. Also, sperm chromatin condensation using chromomycin-A3 (CMA3) and Aniline Blue (AB) staining showed fewer alterations in the DS Group compared to Group V. The rates of spermatozoa with an intact acrosome decreased significantly after thawing from 81.30 ± 6.76% to 68.84 ± 14.70% in the DS Group and to 60.92 ± 8.06% in Group V. Cryopreservation of a small number of spermatozoa with the DS method showed superior outcomes with regard to motility, viability and chromatin configuration.

Enhanced DNA mixture deconvolution of sexual offense samples using the DEPArray™ system

The interpretation of DNA mixtures remains a significant challenge in the analysis of forensic evidence. The ability to selectively identify, collect, and analyze single cells or groups of cells has wide implications in the analysis of forensic samples and the subsequent deconvolution of DNA mixtures, particularly in the processing and interpretation of sexual offense evidence where the deconvolution of heterogeneous sources is essential. Single cell separation technology can be used to address this mixture separation challenge, specifically using the DEPArray™ system from Menarini Silicon Biosystems. We propose that the DEPArray™ will enable enhancements to the standard workflow for forensic biology/DNA analytical laboratories. We have demonstrated that the DEPArray™ workflow will lead to fewer mixture samples, enable purification of sperm and epithelial cell fractions without the need for differential extraction, improve the amplification success rate of samples and improve the interpretation of low template DNA samples. Sperm profiles were identified in 27 of 32 DEPArray™ processed samples, with 26 of 27 (96.2%) yielding single source profiles. In contrast, single source profiles were obtained from 9 of 28 (32.1%) differentially extracted samples. The use of the DEPArray™ also eliminates the need for additional confirmatory tests for the presence of human sperm and permits direct identification of the type and number of cells being analyzed eliminating the need for qPCR-based DNA quantification.

Improving the efficacy of the standard DNA differential extraction method for sexual assault evidence

The efficacy of a DNA differential extraction procedure relies on reducing the amount of non-sperm female DNA carryover into the sperm fraction, while providing a sufficient recovery of male DNA from the sperm cell component. A standard approach to this extraction is to use a mild initial lysis step to digest the female (epithelial cell) component in the mixture, followed by a series of centrifugation and wash steps to further purify the resulting sperm-pellet fraction. This sperm fraction is then digested in the presence of a chemical reducing agent in preparation for DNA extraction. This method has been employed with relatively few changes since its introduction in the mid-1980s, despite numerous attempts to develop new or improved procedures. In this report, we demonstrate that it is possible to improve the efficacy of the standard differential extraction by applying simple modifications that can reduce the amount of female DNA carryover into the sperm fraction, with no adverse effects on the recovery of male DNA. In one modification, the addition of a second mild lysis step at the beginning of the differential extraction procedure improved the average male-to-female DNA ratio in the sperm fraction by 3- to 6-fold. In another modification, a “tube transfer” step was added to move the re-suspended sperm pellet to a new tube for the second mild lysis and subsequent wash steps. With this modification, the average male-to-female DNA ratio in the sperm fraction was improved by 4- to 90-fold, relative to results obtained for the non-modified differential extraction method. These modifications may be accomplished using tools and reagents that are already present in most forensic DNA laboratories, so that implementation should be relatively low-cost and practical.

Endurance training remodels sperm-borne small RNA expression and methylation at neurological gene hotspots

Remodeling of the sperm epigenome by lifestyle factors before conception could account for altered metabolism in the next generation offspring. Here, we hypothesized that endurance training changes the epigenome of human spermatozoa. Using small RNA (sRNA) sequencing and reduced representation bisulfite sequencing (RRBS), we, respectively, investigated sRNA expression and DNA methylation in pure fractions of motile spermatozoa collected from young healthy individuals before, after 6 weeks of endurance training and after 3 months without exercise. Expression of 8 PIWI interacting RNA were changed by exercise training. RRBS analysis revealed 330 differentially methylated regions (DMRs) after training and 303 DMRs after the detraining period, which were, in both conditions, enriched at close vicinity of transcription start sites. Ontology analysis of genes located at proximity of DMRs returned terms related to neurological function at the trained state and, to a much lesser extent, at the detrained state. Our study reveal that short-term endurance training induces marked remodeling of the sperm epigenome, and identify genes related to the development of the central nervous system as potential hot spots for epigenetic variation upon environmental stress.

Viable acrosome-intact human spermatozoa in the ejaculate as a marker of semen quality and fertility status.

Is it possible, in an unbiased and clinical relevant way, to determine the number of viable acrosome-intact human spermatozoa in ejaculates and to use this as a measure of fertility chances? Image cytometry enables easy and unbiased quantification of viable acrosome-intact spermatozoa and it correlates with semen quality and fertility status. The presence of the acrosome and its ability to respond to physiological inducers (e.g. progesterone) in the female reproductive tract at the appropriate time and place is required for fertilization. However, the available assays are labor intensive and therefore not used clinically. Washed semen samples and capacitated swim-up fractions from volunteers were used to develop the assay. Subsequently washed ejaculates from patients in fertility treatment (n = 156), proven fertile men (n = 54) and volunteers (n = 10) were assessed to evaluate the number of acrosome-intact spermatozoa in the ejaculate (acrosomal status) and compared to other semen parameters, fertility status, fertility treatments and pregnancy rates. Image cytometry was used to assess the fluorescence intensity of Pisum sativum agglutinin and Propidium iodide. The assay was validated by inducing the acrosome reaction in swim-up-purified and capacitated spermatozoa with progesterone and ionomycin, and in repeated acrosomal status measurements of washed ejaculates a small coefficient of variation (3.7%) was observed. Men with poor semen quality had fewer viable acrosome-intact spermatozoa in the ejaculate (P = 0.0012; median 32.6% vs. 49.3%). A large proportion (44%) of normozoospermic men from infertile couples had less than the observed median fraction (46%) of viable acrosome-intact spermatozoa in the ejaculate. Furthermore, the total number of viable acrosome-intact spermatozoa was significantly lower among men with male factor infertility compared to fertile men (median 35 vs. 97 mill, P = 1 × 10-7). Men from couples going through one or more ICSI cycles had significant fewer viable acrosome-intact spermatozoa than men from couples who only underwent IUI (P = 0.002; 44.4% vs. 62.0%) and the fraction of viable acrosome-intact spermatozoa appeared better than classical semen parameters in classifying whether or not couples needed ICSI. A positive, although non-significant, tendency toward ongoing pregnancy with an increasing number of viable acrosome-intact spermatozoa was observed (P = 0.2). N/A. Even larger cohorts of infertile couples are needed to substantiate the clinical application of the assay in regard to estimation of fertility potential of an individual. The presented assay makes it possible to measure the number of acrosome competent spermatozoa in an ejaculate in a standardized manner and hence may serve as a new biomarker for male fertility. Few spermatozoa in an ejaculate are acrosome competent and it might be a valuable measure when evaluating male reproductive function. This work was supported by grants from the Innovation Fund Denmark. M.G. and S.K. work at ChemoMetec, which produces the image cytometer used in the study, M.G. hold shares in the company. The other authors have no conflict of interest.

Effect of Phthalates residues in plastic bottled waters on reproductive toxicity and oxidative stress in male rabbits

Phthalates are a genealogy of man-made chemical compounds improved in the last hundred to be employment in the devise of plastics, solvents, and personal care products. They are colorless, odorless, oily liquids that do not evaporate easily and do not. Phthalate esters are widely used as plasticizer. They can migrate from plastic materials to the environment. Exposure to some of these compounds may increase the risk of getting cancer. The experiment was designed to study toxic effects of Di-(2-ethylhexyl) phthalate (DEHP) on semen characteristics, testosterone levels, testicular lipid peroxidation and testicular antioxidants in male New-Zealand white rabbits for 12 weeks. Results obtained showed that DEHP significantly (P<0.05) decreased libido (by increasing the reaction time), ejaculate volume, sperm concentration, total sperm output, sperm motility (%), total motile sperm per ejaculate (TMS), packed sperm volume (PSV), total functional sperm fraction (TFSF), normal and live sperm and semen initial fructose. Also, testosterone levels, body weight (BW), relative weights of the testes (RWT) and epididymis (RWE) were decreased. Thiobarbituric acid-reactive substances and lactate dehydrogenase were increased, while glutathione S-transferase, transaminases and phosphatases were decreased in seminal plasma of rabbits treated with DEHP compared to control. Chemically bind to the material they are added to quality assurance scheme for residue monitoring in water is quite important. Although, one cannot avoid phthalate contamination in bottled waters due to the manufacturing process, but at least special care should be taken regarding their storage conditions.

The Effect of Density Gradient Centrifugation and Magnetic-Activated Cell Sorting with the Combination of Both on Bovine Spermatozoa Kinematics, Viability and Acrosome Status

Conventional and novel spermatozoa separation techniques have their own strength and weaknesses. Both are widely used in assisted reproductive technologies (ARTs). In this study, combinations of two separation methods against single separation methods were evaluated. Freshly ejaculated semen was collected and divided into five groups; control, density gradient centrifugation (DGC), magnetic activated cell sorting (MACS), DGC-MACS and MACS-DGC; based on the sequence of separation. Evaluation of spermatozoa kinematics, viability and acrosome status for each group were done by computer assisted semen analysis (CASA), hypo-osmotic swelling test (HOST) and chlorotetracycline (CTC) staining respectively. Results show that DGC yield the fastest spermatozoa velocity and highest percentage of viable spermatozoa fraction compared to other groups. However, they also produced a high percentage of acrosome-reacted spermatozoa. Spermatozoa isolated through DGC-MACS shows the highest percentage of non-capacitated spermatozoa. However, spermatozoa isolated through DGC-MACS yields slower spermatozoa velocity population and lower percentage of viable sperm compared to spermatozoa isolated through DGC. Isolation of spermatozoa through MACS-DGC yields slower population of spermatozoa velocity with a lower percentage of non-capacitated spermatozoa compared to spermatozoa isolated through DGC-MACS. DGC separation and its combination with MACS had yield different spermatozoa quality. This distinct characteristic is likely suitable for in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) procedure respectively.

Proteomic analysis of good- and poor-quality human sperm demonstrates that several proteins are routinely aberrantly regulated.

Male infertility is a complex condition, and for the most part, all men produce defective spermatozoa, but infertile men have a tendency to produce more. Despite attempts to classify infertility, there is no definitive test. One approach would be to use protein biomarkers; however as yet, we still do not understand proteins that are differentially expressed within defective spermatozoa. As such, we took nine men (fertility status unknown) and used Percoll density gradients to isolate a population of good- and poor-quality sperm. For four of these men, we also obtained multiple ejaculations. The most noticeable differences between the Percoll-isolated fractions were motility and CMA3 staining. While the good sperm fraction produced cells with at least 80% forward progressive motility and low levels of CMA3 staining, the poor-quality sperm demonstrated less than 10% forward progressive motility and higher levels CMA3 staining. Using the technique of sequential window activation of all theoretical mass spectra, we quantified 2774 proteins and found 171 proteins to be significantly more abundant in the good sperm fraction, while 104 proteins were significantly more abundant in the lower sperm fraction (adjusted Benjamini-Hochberg significance of P<0.018, minimum 2-fold difference).

Validation of sampletype I-sep DL for differential extraction and purification with prepfiler express in the automate express DNA extraction system

Genetic profiles obtained from gynaecological swabs or a victim’s underwear usually are imbalanced mixtures of female vs male profile. Performing differential DNA extraction prior to DNA amplification may result in an enriched sperm fraction and a consequently isolated male profile. The aim of this work was to test the ability of Sampletype I-sep DL extraction system to separate epithelial from sperm cells, followed by purification with Prepfiler. Although the I-sep did not always provide an isolated male profile, in almost half of the casework samples resulted in a profile with the male contribution in majority.

Na/K-ATPase regulates bovine sperm capacitation through raft- and non-raft-mediated signaling mechanisms.

Highly dynamic lipid microdomains (rafts) in the sperm plasma membrane contain several signaling proteins that regulate sperm capacitation. Na/K-ATPase isoforms (testis-specific isoform ATP1A4 and ubiquitous isoform ATP1A1) are abundant in bovine sperm plasma membrane. We previously reported that incubation of bovine sperm with ouabain, a specific Na/K-ATPase ligand, induced tyrosine phosphorylation of several sperm proteins during capacitation. The objective of this study was to investigate the roles of lipid rafts and non-rafts in Na/K-ATPase enzyme activity and signaling during bovine sperm capacitation. Content of ATP1A4 and, to a lesser extent, ATP1A1 was increased in raft and non-raft fractions of capacitated sperm, although non-raft enzyme activities of both isoforms were higher than the corresponding activities in rafts from capacitated sperm. Yet, ATP1A4 was the predominant isoform responsible for total Na/K-ATPase activity in both rafts and non-rafts. A comparative increase in phosphorylation of signaling molecules was observed in both raft (CAV1) and non-raft (EGFR and ERK1/2) membrane fractions during capacitation. Although SRC was phosphorylated in both membrane fractions, the non-raft fraction possessed more of this activated form. We also inferred, by immunoprecipitation, that ATP1A4 interacted with CAV1 and EGFR in the raft fraction, whereas interactions of ATP1A4 with SRC, EGFR, and ERK1/2 occurred in the non-raft fraction of ouabain-capacitated sperm; conversely, ATP1A1 interacted only with CAV1 in both fractions of uncapacitated and capacitated sperm. In conclusion, both raft and non-raft cohorts of Na/K-ATPase isoforms contributed to phosphorylation of signaling molecules during bovine sperm capacitation.

Validating Missing Proteins in Human Sperm Cells by Targeted Mass-Spectrometry- and Antibody-based Methods.

The present study is a contribution to the "neXt50 challenge", a coordinated effort across C-HPP teams to identify the 50 most tractable missing proteins (MPs) on each chromosome. We report the targeted search of 38 theoretically detectable MPs from chromosomes 2 and 14 in Triton X-100 soluble and insoluble sperm fractions from a total of 15 healthy donors. A targeted mass-spectrometry-based strategy consisting of the development of LC-PRM assays (with heavy labeled synthetic peptides) targeting 92 proteotypic peptides of the 38 selected MPs was used. Out of the 38 selected MPs, 12 were identified with two or more peptides and 3 with one peptide after extensive SDS-PAGE fractionation of the two samples and with overall low-intensity signals. The PRM data are available via ProteomeXchange in PASSEL (PASS01013). Further validation by immunohistochemistry on human testes sections and cytochemistry on sperm smears was performed for eight MPs with antibodies available from the Human Protein Atlas. Deep analysis of human sperm still allows the validation of MPs and therefore contributes to the C-HPP worldwide effort. We anticipate that our results will be of interest to the reproductive biology community because an in-depth analysis of these MPs may identify potential new candidates in the context of human idiopathic infertilities.

DNA profiling of sperm cells by using micromanipulation and whole genome amplification

The differential extraction method is based on separate lysis of vaginal cells and spermatozoa and was designed to prevent mixed DNA profiles from intimate swabs. However, DNA from the victim can still be present in the sperm fraction, and the suspect’s DNA cannot be identified when only minute amounts of spermatozoa are present. Moreover, differential extraction is not effective when swabs contain sperms from more than one individual. Mixed profiles could ideally be overcome by analysing single spermatozoa. However, current multiplex STR kits are not yet sensitive enough to generate DNA profiles from single cells.The aim of this study was to develop a method that enables DNA profiling of up to a single sperm cell. Spermatozoa were isolated through micromanipulation. Spermatozoa were lysed and their DNA was pre-amplified by whole genome amplification (WGA) to generate sufficient template for PCR. To these ends, several WGA methods were first tested on different amounts of genomic DNA (gDNA) and assessed for allele recovery, allele drop-out (ADO) and allele drop-in (ADI). The best WGA method was selected for use on cell material.The REPLI-g method turned out as the only protocol increasing the sensitivity of DNA profiling. Results of WGA performance on gDNA as well as multiple and single cells will be presented.

Effect of acute Zika virus infection on sperm and virus clearance in body fluids: a prospective observational study

Evidence of human sexual transmission during Zika virus emergence is a matter of concern, particularly in procreation, but to date, kinetics of seminal shedding and the effects of infection on human reproductive function have not been described. To investigate the effects of Zika virus infection on semen and clearance of Zika virus from semen and body fluids, we aimed to study a cohort of Zika virus-infected men. This prospective observational study recruited men presenting with acute Zika virus infection at Pointe-à-Pitre University Hospital in Guadeloupe, French Caribbean, where a Zika virus outbreak occurred between April and November, 2016. Blood, urine, and semen were collected at days 7, 11, 20, 30, 60, 90, and 120 after symptom onset, and semen characteristics, such as total sperm count, sperm motility, vitality, and morphology, and reproductive hormone concentrations, such as testosterone, inhibin, follicle-stimulating hormone, and luteinising hormone, were assessed. At days 7, 11, and 20, semen was processed to isolate motile spermatozoa. Zika virus RNA was detected by RT-PCR using whole blood, serum, urine, seminal plasma, semen cells, and motile spermatozoa fractions. Zika virus was isolated from different sperm fractions on Vero E6 cultures. 15 male volunteers (mean age 35 years [SD 5; range 25-44) with acute Zika virus infection and positive Zika virus RNA detection in blood or urine were enrolled. Total sperm count was decreased from median 119 × 106 spermatozoa (IQR 22-234) at day 7 to 45·2 × 106 (16·5-89·6) at day 30 and 70 × 106 (28·5-81·4) at day 60, respectively, after Zika virus infection. Inhibin values increased from 93·5 pg/mL (IQR 55-162) at day 7 to 150 pg/mL (78-209) at day 120 when total sperm count recovered. In motile spermatozoa obtained after density gradient separation, Zika virus RNA was found in three of 14 patients at day 7, four of 15 at day 11, and four of 15 at day 20, and replication-competent virus was found in the tested patient. Seminal shedding kinetics seemed heterogeneous among patients. Whole blood was the fluid most frequently positive for Zika virus RNA (62 of 92 samples) and three patients remained positive at day 120. Semen alterations early after acute Zika virus infection might affect fertility and could be explained by virus effects on the testis and epididymis. Frequency of shedding and high viral load in semen, together with the presence of replicative virus in a motile spermatozoa fraction, can lead to Zika virus transmission during sexual contact and assisted reproduction procedures. Whole blood seems to be the best specimen for Zika virus RNA detection, diagnosis, and follow-up. Agence de la Biomédecine/Agence Régionale de Santé de la Guadeloupe/Inserm-REACTing.

Scrotal insulation and sperm production in the boar.

Seasonal infertility is a limiting factor in boar fertility, and is increasingly important as climate changes. Spermatogenesis in the boar produces 256 spermatozoa per type A1 spermatogonium, but the process is inefficient such that only 10-30% of these potential spermatozoa are actually produced. Heat further impacts spermatogenesis by reducing the number of specific germ cells produced while increasing the fraction of abnormal sperm. Early studies used whole-animal exposure to simulate seasonal exposure to heat under production settings, but this approach is associated with many confounding factors that make assessment of the mechanisms of heat-induced damage to spermatogenesis difficult. Scrotal insulation provides a better model to investigate the mechanisms and potential mitigation strategies of heat-induce damage. For example, scrotal insulation helped identify a link between short-term heat stress and damage to meiotic germ cells. This outcome is likely due to changes in the integrity of the blood-testis barrier, which induce apoptosis, autophagy and DNA damage in the germ cells. Further understanding how heat damages spermatogenesis, and whether or not this can be repaired, are crucial to mitigating heat effects on boars in production settings.

Apoptosis and the processes of DNA fragmentation in native and cryopreserved human sperm cells with normo- and pathosperma

Cryopreserved human sperm is widely applied in the treatment of infertility using methods of assisted reproductive technologies. Comprehensive studies of the sperm condition after cryopreservation and subsequent cultivation will update the efficiency of the programs based on assisted reproductive technologies. The aim of this study was to investigate the effect of cryopreservation factors on the state of DNA and apoptotic processes in isolated human spermatozoa fractions in normo- and pathospermia. The analysis of DNA fragmentation and the assessment of apoptotic processes (human spermatozoa necrosis) were performed using the sperm chromatin dispersion test and the flow cytometry method. According to our study, sperm cryopreservation has not affected the DNA fragmentation index in normozoospermia and significantly increased it in oligoastenoteratozoospermia. The postcultivation increase of apoptotic and necrotic processes in oligoastenoteratozoospermia gives reason for choosing an alternative technique for oocyte fertilization— intracytoplasmic sperm injection.

Monitoring of libido and semen quality parameters in melatonin‐treated French alpine bucks during the non‐breeding season

The aim of this study was to investigate the effects of exogenous melatonin on libido and semen quality parameters in bucks during the non-breeding season. Twelve bucks of the French alpine breed from 1.5 to 4years of age were assigned into melatonin (MG) and control (CG) groups, with 6 bucks in each group. The experimental period was 3months (March-May), divided into six periods of 15days each. The bucks in the MG group received four melatonin implants at the end of March. Two semen samples were taken from the bucks by artificial vagina once per week and their libido estimated. Volume and spermatozoa concentration, their mass motility and motility, proportion of live and total abnormal and forms with abnormal head and tail were determined in the obtained ejaculate samples. The total number of spermatozoa and functional spermatozoa fraction in the ejaculate was also calculated. The MG bucks had significantly higher mass motility and motility of spermatozoa in the first half of April, and a higher proportion of live spermatozoa in the first and second half of April (p<.05). Differences in libido intensity were not significant. The results indicated that the application of melatonin significantly improved the qualitative parameters of semen in bucks, as seen in increased mass motility, motility of spermatozoa and proportion of live spermatozoa shortly following melatonin insertion. Therefore, the results of the current study are novel regarding the use of melatonin treatment during the non-breeding season to improve the qualitative parameters of ejaculates in bucks.

IN VITRO EFECTS OF SELECTED BIOLOGICALLY ACTIVE COMPOUNDS ON RABBIT SPERMATOZOA MOTILITY BEHAVIOUR

The aim of this study was to evaluate the in vitro effects of selected pure naturally occuring biologically active compounds (resveratrol-RES, quercetin-QUE, curcumin-CUR, epicatechin-EPI, isoquercitrin-ISO) on rabbit sperm motility using the IDENT staining method and the computer-aided sperm (CASA) analysis. Semen samples were collected regularly from 10 male rabbits, pooled, the seminal plasma was removed and the sperm fraction was exposed to different concentrations (1, 5, 10, 50 and 100 μmol/L) of chosen biomolecules. At culture times of 0h, 2h, 4h, 6h and 8h, the spermatozoa motility was assessed using the TOX IVOS II. CASA system and the IDENT fluorescent staining method. The motility assessment revealed different behavior patterns, specific and unique to each of the studied biomolecules. After 8h of in vitro culture, the highest sperm motility was detected in experimental groups subjected to 10 μmol/L RES (P

Adverse effects of leptin on histone-to-protamine transition during spermatogenesis are prevented by melatonin in Sprague-Dawley rats.

This study examines the effect of melatonin on leptin-induced changes in transition of histone to protamine in adult rats during spermatogenesis. Twelve-week-old Sprague-Dawley rats were randomised into control, leptin-, leptin-melatonin-10-, leptin-melatonin-20- and melatonin-10-treated groups with six rats per group. Leptin was given via intraperitoneal injections (i.p.) daily for 42days (60μg/kg body weight). Rats in the leptin- and melatonin-treated groups were given either 10 or 20mgday-1 kg-1 body weight of leptin in drinking water. Melatonin-10-treated group received only 10mg of melatonin day-1 kg-1 body weight in drinking water for 42days. Control rats received 0.1ml of 0.9% saline. Upon completion of the treatment, sperm count, morphology and histone-to-protamine ratio were estimated. Gene expression of HAT, HDAC1, HDAC2, H2B, H2A, H1, PRM1, PRM2, TNP1 and TNP2 was determined. Data were analysed using ANOVA. Sperm count was significantly lower, whereas the fraction of spermatozoa with abnormal morphology, the ratio of histone-to-protamine transition and the expressions of HAT, HDAC1, HDAC2, H2B, H2A, H1, PRM1 were significantly higher in leptin-treated rats than those in controls or melatonin-treated rats. It appears that exogenous leptin administration adversely affects histone-to-protamine transition, which is prevented by concurrent administration of melatonin.