Several studies have highlighted the possibility that radio-frequency electromagnetic fields (RF-EMF) used in mobile phone technology could influence DNA integrity of male germ cells as well as sperm motility. Current knowledge concerning the influence of RF-EMF on male germ cells is extremely limited. In the present study the hypothesis that 900 MHz GSM radiation could induce the activation of stress response in human spermatozoa was investigated. Ejaculated, density purified, human spermatozoa from donors were exposed to 900 MHz GSM mobile phone radiation at specific absorption rate (SAR) levels of 2.0 and 5.7 W/kg and examined at various time points post exposure. Sperm motility and morphology were evaluated by computer-aided sperm analysis (CASA). The ability of RF-EMF exposed sperm to undergo the acrosome reaction was evaluated by flow cytometry. Sperm binding to the zona pellucida of human oocytes was determined by the hemi-zona (HZA) assay. Apoptotic markers, phosphatidylserine (PS) externalization, change in mitochondrial membrane potential (Δψm), reactive oxygen species (ROS) generation, caspase activation and DNA fragmentation were analysed using flow cytometry. Heat shock protein (Hsp) 27 and 70 expression and activity were analyzed using specific antibodies with flow cytometry and Western blot methods. Stress fibre stabilization (F-actin polymerization) was visualized using fluorescent dye labelled phalloidin. No effect was seen on kinematic parameters assessed at SAR 2.0 W/kg, however straight line velocity (VSL) and beat cross frequency (BCF) were significantly altered after exposure at SAR 5.7 W/kg. Sperm shrinkage (decrease in surface area) was observed at both exposure levels. RF-EMF did not influence exposed spermatozoa’s ability to undergo the acrosome reaction. A significant decrease in sperm-zona binding was observed at both exposure levels. RF radiation did not have an effect on any apoptotic markers. ROS generation increased significantly with an increase in SAR (5.7 W/kg). RF-EMF did not induce a stress response in exposed sperm (no activation of Hsp70 and 27 activity). These results cannot be ascribed to heating, as the temperature did not increase by more than 0.2 - 0.3ºC during exposure. The decrease in sperm-zona binding is the result of an alternative non-stress inducible pathway. This study should be replicated at lower SAR levels that would simulate the radiation absorption from carrying the cell phone in a pocket close to the testes. / Thesis (PhD (Reproductive Biology))--University of Pretoria, 2008. / Obstetrics and Gynaecology / unrestricted

A sperm specific and species conserved monoclonal antibody (HS-63) was shown to inhibit in vitro fertilization of mouse oocytes and human sperm penetration to zona-free hamster ova. The sperm antigen (SA-63) which reacts with HS-63 was found to be localized on the sperm acrosome. Following sperm capacitation, this antigen becomes exposed and is shed after the acrosome reaction. SA-63 may be involved in the sperm acrosome reaction during the initial fertilization process. Sperm antigen (SA-63) from mouse (MSA-63) was purified from mouse testes with soluble and detergent extraction procedures followed by immunoaffinity chromatography. The purified MSA-63 antigen was shown to be a group of proteins with a size ranging from 25 Kd to 50 Kd and pIs of about 4.2 when analyzed by two dimensional gel electrophoresis. MSA-63 antigen may be associated with actins in its native form. A proteolytic activity was found in the solution of purified MSA-63 preparation. Purified MSA-63 was used for immunization of mice and rabbits. Following successive immunizations, antisera of high titres were raised and reacted specifically with sperm acre-some. The isoimmune sera from immunized mice exhibited significant inhibition on in vitro fertilization of mouse oocytes. Complementary deoxyribonucleic acid (cDNA) fragments encoding the MSA-63 were cloned from a mouse testis cDNA library by using an immunoscreening method with rabbit antisera against MSA-63 as the detecting probe. When a specific cDNA probe was used for Northern blot analysis, an mRNA of 1.5 Kb in size was detected only in the adult mouse testis, but not in any other somatic tissues. By Southern blot analysis, it was also demonstrated that the gene encoding for SA-63 protein is conserved among different mammalian species. The location of SA-63 antigen gene was determined to be on human chromosome 11 when analyzed with a blot of a human-hamster somatic cell hybrid panel. By DNA sequence analysis, a protein of 28 Kd in size was deduced from the MSA-63 cDNA. The amino acid sequences of trypsin-digested peptide fragments of MSA-63 were used to verify that deduced amino acid sequence from the cDNA. The recombinant fusion proteins containing MSA-63 protein fragment were produced in E. coli and used to immunize female mice. Similar to the original HS-63 monoclonal antibody, the antisera thus produced reacted only with the sperm acrosome and revealed significant inhibition of the in vitro fertilization of mouse oocytes. In the developing mouse testis, the expression of MSA-63 gene was found to be post-meiotic. Protein and mRNA of MSA-63 were not produced until day 20 after birth. / Medicine, Faculty of / Obstetrics and Gynaecology, Department of / Graduate

Orientadora: Profª. Drª. Renata Simões / Coorientador: Prof. Dr. Arnaldo Rodrigues dos Santos Júnior / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biotecnociência, São Bernardo do Campo, 2017. / O Brasil ocupa o segundo lugar mundial como produtor no agronegócio. O país se destaca como um dos maiores exportadores de carne e atende ao mercado internacional exigente com animais geneticamente superiores para crescimento, acabamento de carcaça e precocidade sexual. O rebanho nacional é composto por 80% de gado da raça Nelore (Bos taurus indicus) e 20% restantes abrangem outras raças, dentre elas animais Angus e Wagyu (ambos Bos taurus taurus). O Wagyu tem se destacado devido aos resultados produtivos e de qualidade de carne, porém o exame andrológico desses animais revelou incoerência em relação às características padrões que classificam bons reprodutores. Os touros Wagyu apresentam menor circunferência escrotal e esta característica parece estar relacionada com o menor peso corporal e menor idade à puberdade. Contudo, quando comparado à touros da mesma idade e de outras raças e subespécies, a qualidade seminal e a produção espermática são muito semelhantes. Estas diferenças evidentes entre raças, particularmente as encontradas na raça Wagyu levaram ao objetivo principal deste estudo, que foi avaliar possíveis diferenças nas características espermáticas e hormonais, em touros Wagyu quando comparadas às mesmas características de touros das subespécies Nelore e Angus. Foi realizada avaliação espermática por meio de citometria de fluxo, performance seminal pelas técnicas CASA e TBARS, bem como dosagens séricas dos níveis de testosterona e hormônio luteinizante (LH). Sobre o presente estudo, levantamos a necessidade de mais estudos focados nestas três diferentes raças de gado de corte, com maior número de animais avaliados para de fato compreendermos os aspectos fisiológicos que fazem com que o touro Wagyu seja descrito na literatura como um destaque quanto a precocidade sexual, quando comparado a touros das demais raças. Desta forma poderemos aplicar este conhecimento no melhoramento genético do plantel nacional, otimizando assim a cadeia produtiva e consequentemente, o mercado pecuário atual. / Brazil ranks second in the world as a producer in agribusiness. The country stands out as one of the largest meat exporters and caters to the demanding international market with genetically superior animals for growth, carcass finishing and sexual precocity. The national herd is composed of 80% of Nelore cattle (Bos taurus indicus) and the remaining 20% includes other breeds, including Angus and Wagyu (both Bos taurus taurus). Wagyu has stood out due to the productive and meat quality results, but the andrological examination of these animals revealed incoherence in relation to the standard characteristics that classify good breeding. Wagyu bulls have lower scrotal circumference and this feature seems to be related to lower body weight and younger age at puberty. However, when compared to bulls of the same age and other breeds and subspecies, seminal quality and sperm production are very similar. These differences between breeds, particularly those found in the Wagyu breed, led to the main objective of this study, which was to evaluate possible differences in sperm and hormonal characteristics in Wagyu bulls when compared to the same characteristics of Nelore and Angus subspecies bulls. Sperm evaluation was performed by means of flow cytometry, seminal performance by CASA and TBARS techniques, as well as serum levels of testosterone and luteinizing hormone (LH) levels. On the present study, we raised the need for more studies focused on these three different breeds of beef cattle, with a higher number of animals evaluated to actually understand the physiological aspects that make the Wagyu bull described in the literature as a highlight sexual precocity when compared to bulls of the other races. In this way we can apply this knowledge in the genetic improvement of the national stock, thus optimizing the productive chain and, consequently, the current livestock market.

L’infertilité masculine est actuellement considérée comme un problème majeur qui pose une situation alarmante sur la santé publique. L’oligozoospermie, l’asthénozoospermie et la tératozoospermie sont les trois anomalies les plus connues des spermatozoïdes. Elles affectent, respectivement, la densité, la motilité et la morphologie des spermatozoïdes. Un spermatozoïde anormal est très souvent corrélé à des altérations génétiques et épigénétiques qui peuvent affecter considérablement le transcriptome. Dans ce sens, le séquençage aléatoire du transcriptome entier des spermatozoïdes ou RNA-seq constitue un outil puissant pour caractériser ces maladies. Jusqu’à présent, il n’existe aucune étude exploitant des données RNA-seq chez des hommes présentant de telles anomalies spermatiques. L’objectif principal de notre étude fût d’identifier des profils distincts des modifications du transcriptome de chaque phénotype d’infertilité pour ainsi révéler des gènes-signatures qui tamponnent une spermatogenèse pathologiquePour ce faire, les transcriptomes des spermatozoïdes de 60 sujets infertiles atteints soit d’oligozoospermie, d’asthénozoospermie ou de tératozoospermie ont été comparés à ceux de 20 patients fertiles. Ces analyses supervisées nous ont conduit à identifier: (i) les gènes clés spécifiques aux différentes anomalies des spermatozoïdes (ii) les voies de signalisation associées, (ii) les différents longs ARNs non codants dérégulés dans ces anomalies. Au niveau de l’oligozoospermie, les transcrits de spermatozoïdes dérégulés étaient associées à divers stades de la spermatogenèse, y compris le cycle cellulaire méiotique, l’assemblage du complexe synaptonémal, la cohésion des chromatides sœurs, les processus métaboliques de piRNA, le processus catabolique protéique dépendant de la voie de l’ubiquitine, à la réponse aux dommages de l'ADN et particulièrement le processus de fécondation. Quant à l’asthenozoospermia, la spermatogenèse, l’assemblage du cil, des voies métaboliques reliées à la spermatogenèse, la chimiotaxie et la physiologie des cellules immunitaires ont été significativement dérégulés. De plus, ce qui nous a intéressé au plus était l’analyse des transcrits sous-exprimés qui a permis l’identification de nombreux transcrits associées aux modifications des histones. Nous avons aussi mis en évidence une sous expression des gènes différentiellement exprimés qui définit la tératozoospermie. Cette sous expression est associée au système ubiquitine-protéasome, à l’organisation du cytosquelette, au cycle cellulaire, à la SUMOylation en réponse aux dommages de l'ADN et aux protéines de réparation ainsi qu’à de nombreux modulateurs épigénétiques. Les gènes signature de l'oligozoospermie ont été liés au processus de fécondation et les composants de la matrice extracellulaire, tandis que ceux de la tératozoospermie sont liés à la spermatogenèse et la morphogenèse cellulaire, alors que les gènes signature de l'asthénozoospermie sont impliqués dans l'assemblage du ribosome et du flagelle. En complément de cette étude, nous avons réalisé une étude très globale du paysage épigénétique du sperme des hommes infertiles. Nous avons, ainsi comparé les niveaux des espèces réactives de l’oxygène (ERO), de méthylation de l’ADN, ainsi que l’intégrité de la chromatine dans les spermatozoïdes de 30 individus infertiles avec ceux de 33 individus fertiles. Nos analyses montrent des niveaux élevés d’ERO chez les individus infertiles. Ces niveaux sont d’une part négativement corrélés avec les niveaux de méthylation globale de l’ADN et d’autre part négativement corrélés avec ceux de la 5-hydroxyméthylcytosine et de la 5-formylcytosine (intermédiaire dans le processus de déméthylation active). Ces derniers suggèrent qu’une infertilité associée au stress oxydatif conditionne l’épigénome du sperme. En conclusion, l’ensemble de notre travail apporte des ressources précieuses et originales dans la compréhension des pathologies de sperme. / Male infertility is actually considered as a public alarming health problem. The sperm pathologies spectrum ranges between different phenotypes including oligozoospermia, asthenozoospermia and teratozoospermia depending on the sperm conventional parameters abnormalities. Abnormal sperm is characterized by genetic alterations and epigenetic alterations which can affect the transcriptome extensively. These alterations in RNA profiles are retrospectively indicative of aberrant spermatogenic events. RNA-seq is a powerful tool for comprehensive characterization of whole transcriptome. To date, RNA-seq analysis of sperm from infertile men has not been reported. Our objectives are: (i) recognize key clusters, key pathways and specific gene transcripts for different sperm abnormalities; (ii) catalog the spermatozoal lncRNAs in different sperm pathologies; (iii) identify signature genes which are mechanistically important in the cascade of events driving a pathological spermatogenesis; (iii) portray the global epigenetic landscape in sperm from infertile men. Expression data from 60 sperm samples from 3 groups of infertile men (oligozoospermia, asthenozoospermia, and teratozoospermia) were generated on Illumina HiSeq platform, compared to 20 fertiles, and the resulting gene expression patterns were analyzed for functional enrichment. Our supervised analyses identified numerous differentially expressed genes between fertile and infertile men. In oligozoospermia, the deregulated spermatozoal transcripts were associated with various stages of spermatogenesis including meiotic cell cycle, synaptonemal complex assembly, sister chromatid cohesion, piRNA metabolic process, ubiquitin-dependent protein catabolic process, cellular response to DNA damage stimulus and interestingly fertilization. As for asthenozoospermia, spermatogenesis, cilium assembly, metabolic-related pathways, chemotaxis and immune cell physiology were most significantly differentially expressed. Interestingly, numerous transcripts associated with histone modifications were highly down-regulated. With regards to teratozoospermia, we evidenced sperm-specific differentially expressed genes which are involved in the ubiquitin-proteasome, cytoskeleton organization, the cell cycle pathway, SUMOylation of DNA damage response and repair proteins, as well as many putative epigenetic modulators of gene expression.. We also attempted to identify distinct patterns of gene expression changes that were definite to the different abnormal sperm phenotypes in infertile men relative to controls. Signature genes of oligozoospermia were over-enriched by genes involved in fertilization and extracellular matrix components, while signature genes of teratozoospermia were enriched by genes involved in spermatogenesis and cellular components involved in morphogenesis, whilst signature genes of asthenozoospermia were enriched by genes implicated in ribosome and cilium assembly.We complemented this work by a parallel epigenetic analysis of the global epigenetic landscape in infertile men. We compared the levels of reactive oxygen species (ROS), DNA integrity and global epigenetic parameters in sperm from 33 infertile subjects with abnormal semen parameters compared to fertile individuals. We pointed out that infertile men are characterized by strikingly high levels of reactive oxygen species (ROS) which were in part negatively correlated with the global DNA methylation, and positively correlated with the levels of 5-hydroxymethylcytosine and 5-formylcytosine (active demethylation intermediates). These findings suggest that male infertility associated with oxidative stress shapes the sperm epigenetic landscape. In summary, this original work yielded a transcriptional portrait of sperm abnormalities and provided valuable resources that would further elucidate sperm pathologies.

Nedfrysning och upptining av spermatozoa används frekvent i andrologi-laboratoriet för assisterad reproduktionsteknik och bedömning av spermatozoa. I dagsläget finns det ingen standard hur nedfrysning och upptining av spermatozoa ska ske. I denna studie jämförs två olika processer; ”slow freeze” följt av upptining med G-IVFTM medium, vilken används på RMC Skånes Universitetssjukhus. Kryokonservering med ”pellets” följt av upptining med HTF + 10% HSA medium enligt Martínez-Soto J C m.fl. Två olika upptiningsmetoder används för varje process; först tinas spermatozoa i rumstemperatur i 10 minuter, följt av 10 minuter uppvärmning i 37 °C och precis innan analys tillsätts 37 °C medium. I den andra upptiningensmetoden tillsätts 37 °C medium till det frysta provet och förvaras i värmeskåp, 37 °C i 20 minuter. I studien analyseras effekterna av spermatozoa motilitet och vitalitet. Resultaten visar att med ”slow freeze” och G-IVFTM finns det ingen signifikant skillnad mellan upptiningsmetoderna för både motilitet, p-värde >0,05 och vitalitet, p-värde >0,05. I jämförelse med Martínez-Soto J C m.fl visades ingen skillnad mellan motilitet, p-värde >0,05. Studien visar en positiv effekt på vitalitet jämfört med Martínez-Soto J C m.fl studie, p-värde <0,01. Studien visar att användning av ”slow freeze” med G-IVFTM inte gör någon skillnad på motilitet men har en positiv signifikant påverkan på spermatozoa vitaliteten. Mer studier är nödvändiga för att stärka dessa resultat och överlag behövs mer studier inom området för att utveckla bättre metoder. / Freezing and thawing of spermatozoa are frequently used in the andrology laboratory for assisted reproduction techniques and assessment of spermatozoa. At present, there is no standard on how freezing and thawing of spermatozoa should occur. In this study two different processes are compared; “slow freeze” followed by thawing with G-IVFTM medium, which is used at RMC University Hospital. Cryopreservation with “pellets” followed by thawing with HTF + 10% HSA medium according to Martínez-Soto J C et al. Two different thawing methods are used for each process; first, the spermatozoa are thawed at room temperature for 10 minutes, followed by 10 minutes warming at 37 °C and just before analysis 37 °C medium is added. At the second thawing method, 37 °C medium is added to the sample and stored in a heating chamber, 37 °C for 20 minutes. The study analyzed the effects of spermatozoa motility and vitality. Results show that with “slow freeze” and G-IVFTM there is no significant difference between the two thawing methods for both motility, p-value >0,05 and vitality, p-value >0,05. Comparing with Martínez-Soto J C et al. no difference between motility was shown, p-value >0,05. The study shows a positive effect on vitality compared to Martínez-Soto J C et al, p-value <0,01. The study shows that the use of “slow freeze” with G-IVFTM does not make any difference in motility but has a significant positive effect on the spermatozoa vitality. More studies are necessary to strengthen these results. Overall more research is needed in the area to develop and find a common method.

Introduction: Cryopreservation of human sperm is considered a routine practice in assisted reproduction laboratories. Semen samples are mainly cryopreserved as a back-up for procedures, donor sperm, and validation of samples from human immunodeficiency virus-positive patients. Human immunodeficiency virus semen samples generally result in a low yield of purified spermatozoa after decontamination. These samples need to be cryopreserved for later use. Unlike conventional cryopreservation, vitrification does not use harmful cryoprotectants, thereby potentially reducing sperm damage. Vitrification is not yet common practice for sperm cryopreservation in assisted reproduction. The aim of this study was to establish the feasibility of utilising vitrification as an alternative to current conventional cryopreservation of spermatozoa. Methods: Semen samples were collected from human immunodeficiency virus-negative patients seeking diagnostic assistance from the unit. All samples were processed according to the unit’s standard protocol. For Study 1A (n=10) washed samples were divided and cryopreserved using three different cryopreservation media, and two different freezing protocols. In Study 1B (n=15), washed samples were divided and preserved using cryoprotectant-free vitrification in 100 μl, 300 μl and 500 μl volumes. For Study 2 (n=35) washed samples were split and cryopreserved using cryoprotectant-free vitrification (utilizing the volume that resulted in the highest quality spermatozoa in Study 1B) and conventional slow freezing (using the medium and protocol that resulted in superior quality spermatozoa in Study 1A). Post thawing, motility and kinetic parameters (Studies 1 and 2), viability (Study 1), mitochondrial membrane potential (Study 2), and DNA fragmentation (Study 2) of the two groups were compared. vi Results: Study 1A indicated that cryopreserving spermatozoa using Freezing Medium resulted in the highest quality spermatozoa with regards to motility and viability (p<0.05). Comparing the two preservation protocols, no conclusion could be reached on which protocol yielded superior results (p>0.05). The RBL freezing method is shorter, simpler and requires less equipment, and was therefore deemed the preferred method. Study 1B showed that the larger vitrification volumes (300 μl and 500 μl) yielded better spermatozoa in terms of motility and viability (p<0.05). No significant difference was observed with respect to the 300 μl and 500 μl vitrification volume groups. For practical reasons, 300 μl volumes will provide sufficient sperm for any procedure and, the intermediate volume ensures that more than one straw can be preserved. Study 2 found that cryoprotectant-free vitrification resulted in spermatozoa with significantly higher mitochondrial membrane potential and significantly lower apoptosis post thawing (p<0.05). Discussion: Conventional cryopreservation methods may compromise various sperm parameters and final yield. In this study, cryopreservation and cryoprotectant-free vitrification had equivalent outcomes with respect to sperm motility. However, the latter method yielded superior results in terms of ΔΨ and DNA sperm fragmentation. In conclusion, vitrification is an easy, rapid and more affordable technique that requires no special equipment. Using vitrification for purified sperm samples of patients could potentially result in a better post thaw quality for ART procedures. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Obstetrics and Gynaecology / unrestricted

MSCAGR (Animal Science) / Department of Animal Science / In order to realize many of the potential advantages of AI, storage of semen is necessary. Semen storage is only possible using a system that decreases and/or halts the metabolic processes of the spermatozoa, allowing no significant loss of fertility. Numerous factors affect the success of spermatozoa storage. This study was designed to compare the effects of egg yolk, soybean milk and coconut water in Tris extender using different storage methods for Nguni bull spermatozoa storage. Bull semen was collected from two adult Nguni bulls approximately four years old and kept under similar managerial conditions. Using electro-ejaculator, semen was collected from each bull into a graduated semen collection tube. Macroscopically evaluation of the sample was performed immediately after collection. Only the semen free from contamination was processed. The kinetic properties namely: total spermatozoa motility, and progressive spermatozoa motility were analysed using CASA. Semen sample was stained and spermatozoa morphology and vitality also analysed using CASA. The extended semen was then split into three groups. The first group was stored at room temperature (25 °C). The second group was cooled to 4 °C and stored in the refrigerator. The third group was also cooled to 4 °C for 2 h in the refrigerator, then held in LN2 vapour 5 cm above the surface of LN2 at ~ -80 °C for 10 min and then plunged into LN2 for storage at -196 °C. Different colours of straws and plugging powder were used for identifying each extender. After 3 days of storage at room temperature, in the refrigerator and in LN2, the extended semen was split into three portions and assayed for kinetic properties using the first portion. The second portion was assayed for spermatozoa morphology and the third portion for spermatozoa vitality. The results from the fresh semen extended with all three extenders (TEYE, SBME and COWE), and analysed immediately after dilution at room temperature (25 ºC), showed no significant difference (P > 0.05) in the mean values of the kinetic and morphologic properties and viability, on spermatozoa TM, PM, AR, AT, CT; BT and LS. After three days of storage, there was no significant difference (P > 0.05) in the kinetic morphologic properties and viability of semen stored at room and refrigeration temperature regardless of the extender in use. There were, however, significant differences (P < 0.05) in the TM, PM, AR and DL of the frozen semen samples. For the short storage period of semen used for AI, from this study, it is recommended that semen should be kept at room or refrigeration temperature regardless of the three extenders used. However, for long storage of frozen semen TEYE is recommended. The egg yolk-based extender provided greater preservation of motility and bull spermatozoa integrity during the freezing process than did SBME and COWE.

Beef and milk production industries represent the largest agricultural industries in the United States with a retail equivalent value of approximately $112 billion (USDA, 2008). Infertility is the major problem for mammalian reproduction. In the United States approximately 66% of cows are bred by Artificial Insemination (AI), but only ~50% of these inseminations result in successful pregnancies. Infertility can occur either from male factor (spermatozoon) or female factor (oocyte) and male contributes approximately 40% of cases. Infertility costs the producer approximately $5 per exposed cow for every 1% reduction in pregnancy rate. In spite of its millions of dollars in economic impact, the precise molecular events/mechanisms that determine the fertilizing potential of an oocyte and spermatozoon are not well defined. The thesis of my doctoral dissertation is that proteomics-based “systems biology” modeling of bovine oocyte and spermatozoon can facilitate rapid understanding of fertility. To test this thesis, I needed to first identify the proteins associated with bovine oocyte and its associated cumulus cells, and spermatozoon. The next step was functional annotation of the experimentally confirmed proteins to identify the major functions associated with the oocyte, cumulus cells and spermatozoon, and finally, generate a proteomics based systems biology model of bovine oocyte and cumulus cell communication and male fertility. The results of my dissertation established the methods that provide afoundation for high-throughput proteomics approaches of bovine oocyte and cumuluscell biology and allowed me to model the intricate cross communication between oocyte and cumulus cells using systems biology approaches. Proteomics based systems biology modeling of oocytes and cumulus cells identified the signaling pathways and proteins associated with this communication that may have implications in oocyte maturation. In addition, systems biology modeling of differential spermatozoa proteomes from bulls of varying fertility rates enabled the identification of putative molecular markers and key pathways associated with male fertility. The ultimate positive impact of these results is to facilitate the field of biomedical research with useful information for comparative biology, better understanding of bovine oocyte and spermatozoon development, infertility, biomarker discovery, and eventually development of therapies to treat infertility in bovine as well as humans.

No description available.

Thesis (M.Sc. (Medical Sciences)) -- University of Limpopo, 2021 / Infertility, defined as the inability to conceive following one year of unprotected sexual intercourse, respectively affects 25% of couples globally. Oxidative stress (OS) has been greatly related to the idiopathic cause of infertility and Camellia sinensis contains antioxidants that may enhance reproductive functions. This study focussed on the effects of Camellia sinensis (green and black tea) on human sperm functions in both normal and abnormal samples. Semen samples (n= 59) collected from donors were liquefied, analysed, and classified as normal (n=40) and abnormal (n= 19) using the WHO criteria. Samples were washed and exposed to aqueous leaf extracts of green and black tea (0, 0.4, 4, 40, 405 μg/ml) for 1 hour. Human Tubular Fluid (HTF) served as the control. The respective sperm parameters were analysed (sperm motility, vitality, DNA fragmentation, mitochondrial membrane potential (MMP), capacitation and acrosome reaction (CTC) and reactive oxygen species (ROS). Green and black tea significantly increased vitality, and intact MMP, while it significantly reduced, CTC, and intracellular ROS as well as DNA fragmented spermatozoa in both normal and abnormal samples compared to the control (p<0.05). A significant increase in sperm CTC, ROS, with a decrease in sperm vitality, and intact MMP was observed in the abnormal compared to the normal samples (p<0.05). No significant change in motility was observed between normal and abnormal samples compared to their respective controls, in both green and black tea (p>0.05). Camellia sinensis improved human sperm function in vitro and may be attributed to its antioxidant activity. / National Research Foundation (NRF)