Teses / dissertações sobre o tema "Spermatozoa Physiology"

The role of male germ cell death in spermatogenesis is an important one as it removes dysfunctional or genetically damaged germ cells and is necessary to maintain an optimal germ cell to Sertoli cell ratio. The formation of the bloodtestis barrier requires the elimination of excessive germ cells and a surge of germ cell apoptosis occurs prior to puberty regulating the ratio of germ cells to Sertoli cells. The aim of this study was to evaluate the presence of four apoptotic markers on sperm from patients with various grades of fertility using flow cytometry. Furthermore, any correlations between the apoptotic marker assays and the standard semen analysis results were identified. This study compares early and late parameters of apoptosis with morphological features in spermatozoa in the same samples. The three sample groups were identified as: teratozoospermic [G-pattern] (n=26), teratozoospermic [P-pattern] (n=98) and oligoteratozoospermic [Ppattern] (n=36). Standard semen analysis was conducted on the semen samples according to the WHO guidelines. Four apoptotic marker assays using flow cytometry was applied in this study to examine the apoptotic alterations in ejaculate sperm. These assays included the Annexin-V staining for the determination of phosphatidylserine exposure, APO-Direct to identify DNA fragmentation, caspase-3 to detect expression of this active protease during early apoptosis and Fas expression. For the Annexin-V and caspase-3 assays, statistically significant differences (P<
0.05) were evident between the three groups. No significant differences (P>
0.05) were found between the groups with respect to the APO-Direct assay. A significant difference (P<
0.05) was found when comparing the teratozoospermic [G-pattern] group and the oligoteratozoospermic [P-pattern] group for the Fas assay. A strong positive correlation was evident between the Fas and the caspase-3 assays in the teratozoospermic [G-pattern] group. For the teratozoospermic [P-pattern group] the following positive correlations existed between the APO-Direct and the Fas assays, APO-Direct and caspase-3 assays and between caspase-3 and Fas assays. The only strong positive correlation was between the caspase-3 and APO-Direct assays in the oligoteratozoospermic [P-pattern] group. The presence of spermatozoa showing microscopic features resembling apoptosis has been identified in ten human ejaculate samples per sample group. Electron microscopy was used to identify morphological features of apoptosis in these human sperm samples. Classical apoptosis as observed in diploid cells could be identified in sperm and these included: loose fibrillarmicrogranular chromatin network, presence of vacuoles in the nuclear chromatin, membranous bodies within the vacuoles of the chromatin, partially disrupted nuclear membranes, plasma membrane protuberances and apoptotic bodies containing cytoplasmic vacuoles and dense masses. This study has confirmed that semen samples with abnormal semen parameters exhibit the presence of apoptotic markers in sperm. The identification of apoptotic markers on the sperm suggests that abnormalities occur during their developmental process, however, the exact mechanism thereof remains unclear. These findings may suggest that certain apoptotic markers may be an indicator of abnormal sperm function and possibly indicative of male infertility.

Bibliography: leaves 135-151. A study of chromosomal abnormalities and the localisation of chromosomes in human sperm, especially from men with TSD, using fluorescence in situ hybridization (FISH). The project entailed: 1. development of reliable FISH protocols, 2. determination of basline frequencies of aneuploidy, 3. analysis of chromosomal abnormalities in men with severe TSD and 4. assessment of the localisation of individual chromosomes within the sperm head.

The effects of miticides on the reproductive physiology of queens and drones were examined. The first study examined the effects of Apistan (fluvalinate), Check Mite+ (coumaphos), and Apilife VAR (74% thymol) on sperm production and viability in drones. Drones from colonies treated with each miticide were collected at sexual maturity. Sperm production was determined by counting the number of sperm in the seminal vesicles. Sperm for viability assays was analyzed by dual fluorescent staining. Apilife VAR and coumaphos significantly lowered (P<0.0001) sperm production and coumaphos treatments caused a significant decrease (P<0.0001) in the sperm viability. The effects of miticides on queens was examined by treating queen-rearing colonies and examining the number and viability of sperm in the spermathecae of newly mated queens. Queens from each treatment group were collected after mating and the spermathecae were removed and analyzed. Colonies treated with coumaphos failed to provide viable queens and were excluded. Apilife VAR was found to significantly decrease (P<0.0016) sperm viability. No significant differences in sperm numbers were found between treatments. The effect of miticides on sperm viability over time was also examined. Drones were reared as described, but the spermatozoa were collected as pooled samples from groups of drones. The pooled samples from each treatment were subdivided and analyzed periods of up to 6 weeks. Random samples were taken from each treatment (n = 6 pools) over a period of 6 weeks. The exposure of drones to coumaphos during development significantly reduced sperm viability for all 6 weeks, and caused a large decline in week 6. The potential impacts of these results on queen performance and failure are discussed.
Master of Science in Life Sciences

Thesis (MScMedSc)-- Stellenbosch University, 2013.
ENGLISH ABSTRACT: Preconceptual sex selection is an ethically justifiable process whereby X- and Y-chromosome bearing spermatozoa are isolated prior to fertilization of the oocyte in order to generate either a male or a female offspring. Although various separation techniques are available, none can guarantee 100% accuracy. There are various physiological differences between X- and Y-chromosome bearing spermatozoa which can be used to separate these two populations of sperm. For the purpose of this study, X- and Y-chromosome bearing spermatozoa were separated based on (1) their respective abilities to remain viable when subjected to adverse environments, including extreme pH values, increased temperatures and various hydrogen peroxide (H2O2) concentrations; (2) the ability of Y-chromosome bearing spermatozoa to swim faster and/or more progressively than X-chromosome bearing spermatozoa; and (3) the X-chromosome bearing spermatozoa’s increased size and weight when compared to the Y-chromosome bearing spermatozoa. The efficacy of live and dead cell separation through (i) Magnetic Antibody Cell Separation (MACS) and (ii) a modified swim-up technique was also assessed and compared. Changes in the sex-chromosome ratio of samples were established by double-label fluorescent in situ hybridization (FISH) before and after processing. Sperm motility (CASA) and viability (eosin/nigrosin) was assessed before and after each intervention. Ethical clearance for this study was granted by the Health Research Ethics Committee 1 (Ethics #: S13/04/068). The results indicated successful enrichment of X-chromosome bearing spermatozoa upon incubation in acidic media, increased temperatures, and H2O2. In contrast, Y-chromosome bearing spermatozoa were successfully enriched through a direct swim-up method as well as discontinuous gradient centrifugation. In conclusion, this study demonstrated the potential role for physiological differences between X- and Y-chromosome bearing spermatozoa in the development of preconceptual gender selection through sperm sorting.
AFRIKAANSE OPSOMMING: Prekonsepsie geslagselektering is 'n eties regverdigbare proses waardeur X- en Y- chromosoom draende spermatosoë geïsoleer word voordat bevrugting van die oösiet plaasvind, om óf 'n manlike óf 'n vroulike nageslag te genereer. Alhoewel verskeie skeidingstegnieke beskikbaar is, kan geeneen 100% akkuraatheid waarborg nie. Daar bestaan verskeie fisiologiese verskille tussen X- en Y- chromosoom draende spermatosoë wat skeiding van hierdie twee groepe spermatosoë moontlik kan maak. Vir die doel van hierdie studie is skeidingsmetodes vir die X- en Y- chromosoom draede spermatosoë gebaseer op (1) hul onderskeie vermoëns om lewensvatbaar te bly tydens blootstelling aan ‘n ongunstige milieu, insluitend ekstreme pH waardes, verhoogde temperature en verskeie waterstofperoksied (H2O2) konsentrasies; (2) die vermoë van die Y-chromosoom draende spermatosoon om vinniger en/of meer progressief as X-chromosoom draende spermatosoë te swem; en (3 ) die X-chromosoom draende spermatosoon se verhoogde grootte en gewig in vergelyking met die Y- chromosoom draende spermatosoon. Die effektiwiteit van die (i) Magnetiese Anti-liggaam Sel Skeidingstegniek (MACS) en (ii) 'n aangepaste weergawe van die op-swem tegniek om lewendige en dooie selle te skei is ook bepaal en vergelyk. Veranderinge in die geslagschromosoom verhouding van die monsters is bepaal deur dubbel-etiket fluoresensie in situ hibridisering (FISH) voor en na verwerking. Spermmotiliteit (CASA) en lewensvatbaarheid (eosien/nigrosin) is bepaal voor en na elke intervensie. Etiese goedkeuring vir hierdie studie is verleen deur die Gesondheids-Navorsingsetiekkomitee 1 (Etiese # : S13/04/068). Die resultate dui suksesvolle verryking van X-chromosoom draende spermatosoë deur inkubasie in suur media, verhoogde temperature, en H2O2. Y-chromosoom draende spermatosoë is verryk deur middel van 'n direkte op-swem metode sowel as diskontinue gradiënt sentrifugering . Ten slotte, hierdie studie toon die potensiële rol vir fisiologiese verskille tussen X- en Y- chromosoom draende spermatosoë in die ontwikkeling van prekonsepsie geslagselektering metodes deur skeiding van X- en Y-chromosoom draende sperme.

Thesis (DTech (Biomedical Technology))--Cape Peninsula University of Technology, 2009
Many environmental, physiological, and genetic factors have been shown to impair sperm function through oxidative damage. Oxidative stress (OS) arises as a consequence of excessive reactive oxygen species (ROS) production and/or impaired antioxidant defence mechanisms. The decline in male reproductive health generated considerable public and scientific concerns about the possible role of environmental contaminants. A better understanding of how OS affects sperm function will be beneficial as it might help in the design of new and effective treatment strategies to combat the problem of increasing male subfertility. Studies have suggested that antioxidant nutrients and/or medicines play a protective role in human health. Crude red palm oil (RPO) is known to be the richest natural plant source of antioxidants such as carotenoids, tocopherols and metalloporpheryns. The aims of this study were twofold: (i) To establish an in vivo animal model of OS by exposing rat to organic hydroperoxide such as t-butyl hydroperoxide (tbHP) and cumene hydroperoxide (cHP) through repeated intraperitoneal injections that can be used for studying these effects on testicular tissue, epididymal sperm and sperm function as well as male reproductive parameters in general. (ii) To investigate the effects of a RPO supplemented diet on male reproductive parameters and tissue in animals exposed to OS. In the first part of the study, male Wistar rats aged 10-12 weeks were randomly placed in groups and received standard rat chow (SRC) and water ad lib. Animals were injected intraperitoneally with saline (0.5 ml), t-butyl hydroperoxide (5µM, 10µM, 20µM and 40µM; 0.5 ml) or cumene hydroperoxide cHP (2.5µM, 5µM, 10µM and 20µM; 0.5 ml) over a 60 day period. In the second part, male Wistar rats aged 10-12 weeks were placed randomly in three groups and fed with SRC. Group 1 received no supplement while the food of groups 2 and 3 were supplemented with 2 mL and 4 mL RPO (in 25 gm SRC/day) respectively. Each group was further divided into 3 subgroups and injected intraperitoneally daily with either saline, 10µM cHP or 20µM tbHP respectively. This was done for 5 consecutive days per week over a 60 day period. Sperm concentrations, and motility, lipid peroxidation, superoxide dismutase (SOD), catalase (CAT) and glutathione (GSH) activities as well as apoptosis were assessed.

Includes list of publications by the author. Includes bibliographical references (leaves 103-123) Evaluates the nature of the interactions occurring between semen and cells of the uterus that occur following mating in pigs. Describes a novel ability of porcine seminal plasma to induce dose dependent cell-cell adhesion and mitogenesis amongst peripheral blood lymphocytes in vitro.

Melatonin is a product of the pineal gland and is postulated to play an antigonadotropic role in the reproductive system of mammals. The reproductive system of non-seasonally breeding mammals is believed to be not as responsive to melatonin treatment as that of seasonally breeding mammals. Recently, there has been increasing support from in vivo and in vitro studies, for the hypothesis that melatonin has negative effects on sperm physiology, especially on sperm motility. High and/or low seminal concentrations of melatonin have been associated with abnormalities in human sperm motility and concentration. In this study, I examined the effects of melatonin on the testis, epididymis and sperm physiology, using in vivo and in vitro experiments, in a non-seasonally breeding mammal. Treatment, in vivo, with exogenous melatonin for six weeks did not inhibit testosterone production or spermatogenesis, nor did it affect the mass of the testes and epididymides at dissection, the concentration the morphology of speimatozoa. However, melatonin in vivo had a small, but significant negative effect on sperm motility and sperm motility index. In vitro incubation of spermatozoa Fith melatonin reduced the percentage (%) of forward progressive movement (fpm), increased the % reduction in fpm, reduced the vigor or quality of sperm motility, reduced the sperm motility index, and delayed and/or prolonged the transition of one pattern of sperm motility to the subsequent patterns. Melatonin increased the pH of the culture medium, and the increased pH, and the ethanol utilized as a solvent for melatonin, both negatively affected all the sperm motility parameters that were assessed in my study. The effects of ethanol increased with time, and the effects of pH increased with both time and increasing pH. Melatonin in vitro did not inhibit capacitation and the acrosome reaction, but it delayed the onset and the progression of capacitation and the acrosome reaction. These results suggest that while melatonin did not inhibit spermatogenesis in the Wistar rat, it may influence sperm motility. Therefore, the presence of high concentrations of melatonin in the reproductive fluids may inhibit sperm motility. With further detailed research, melatonin may have a potential use as a contraceptive drug.

Thesis (PhD (Biomedical Sciences. Medical Physiology))--University of Stellenbosch, 2009.
ENGLISH ABSTRACT: In recent years there has been an increase in obesity and diabetes mellitus (DM). These conditions have for a long time been associated with infertility. Obesity is characterized by high levels of circulating leptin and cytokines as well as insulin resistance. Type I DM is associated with low or no insulin whereas, Type II DM is characterised by insulin resistance. As the prevalence of obesity and DM continues to rise, it is likely that the incidence of infertility associated with these pathological conditions will likewise increase. The effects of insulin and leptin on male reproductive function have been reported on the endocrine and spermatogenesis level, but their effects on cellular level of human ejaculated spermatozoa are yet to be elucidated. This study presents data on the role of insulin and leptin on human ejaculated spermatozoa and their interaction with cytokines and nitric oxide. In the first part of the study, we established the suitable concentrations of glucose, insulin and leptin that could be administered to human spermatozoa in vitro. Glucose concentration of 5.6 mM was chosen as the suitable concentration to be administered to human spermatozoa because it has previously been reported in the literature; furthermore, it is within the range of the physiological glucose levels found in the blood of fasting humans. Insulin and leptin concentrations of 10 μIU and 10 nmol were chosen respectively because they gave much improved sperm function and this was within the range of insulin and leptin levels previously measured in human ejaculated spermatozoa. This was followed by investigating the signalling pathway of insulin and its beneficial effects on human spermatozoa function. Endogenous insulin secretion from human ejaculated spermatozoa was blocked by nifedipine and its receptor tyrosine phosphorylation effects were inhibited by erbstatin while phosphatidylinositol 3-kinase (PI3K) phosphorylation activity was inhibited by wortmannin. Exogenous insulin administration significantly increased human sperm motility parameters as well as the sperm ability to acrosome react. The inhibition of endogenous insulin release from spermatozoa as well as the inhibition of the insulin receptor substrate (IRS) tyrosine phosphorylation significantly decreased motility parameters and the ability of spermatozoa to acrosome react. The study also investigated the effects of insulin and leptin on human sperm motility, viability, acrosome reaction and nitric oxide (NO) production. Both insulin and leptin significantly increased sperm motility parameters, acrosome reaction and NO production. The NO production induced by insulin and leptin was via PI3K signalling as evidenced by a reduction in NO levels when PI3K activity was inhibited by wortmannin. To investigate whether insulin and leptin could improve motility parameters of asthernozoospermic and teratozoospermic spermatozoa, the spermatozoa were separated into two fractions by means of a double density gradient technique. The gradient system was able to separate spermatozoa into high morphologically abnormal and less motile spermatozoa similar to that of asthernozoospermic and teratozoospermic patients as well as a more motile fraction. Insulin and leptin significantly increased the motility parameters of spermatozoa from the immature and less motile fraction. The fourth part of the study was aimed at investigating the effects of the cytokines, tumor necrosis factor alpha (TNF-α) and interleukin-6 (IL-6), on human sperm motility, viability, acrosome reaction and NO production. The study shows that TNF-α and IL-6 significantly reduced motility parameters and acrosome reaction in a dose4 and time-dependent manner. These cytokines were also shown to significantly increase NO production from human spermatozoa. The decreased motility parameters induced by these cytokines could be attributed to their ability to induce excessive NO production. It is not yet clear how they inhibit spermatozoa to undergo the acrosome reaction. The fifth part of the study was to investigate the expression and localization of glucose transporter 8 (GLUT8) in human spermatozoa. This study shows that GLUT8 is constitutively expressed and located in the midpiece region of the human spermatozoa. The study also showed that stimulating spermatozoa with insulin led to an increase in GLUT8 expression as well as translocation to the acrosomal region. In the last part of the study we wanted to investigate why the increase in NO generation by spermatozoa due to insulin and leptin stimulation is accompanied with increased sperm function whereas NO increased due to TNF-α and IL-6 stimulation is accompanied with decreased sperm function. We observed that TNF-α and IL-6 not only increased NO production but also ROS production. This study speculates that the decrease in sperm motility and acrosome reaction when TNF-α and IL-6 were administered was due to the concomitant high increase in NO and ROS they induced. In conclusion, this study has established in vitro beneficial effects of insulin and leptin in normozoospermic and asthernozoospermic human sperm function. These hormones influence sperm function via the PI3K signalling pathway in two ways. Firstly, by increasing GLUT8 expression and translocation thereby possibly increasing glucose uptake and metabolism and secondly, by increasing NO production. The study has also established that TNF-α and IL-6 have detrimental effects on human spermatozoa in a dose and time dependent manner. These effects are mediated via their ability to stimulate both NO and ROS production in human spermatozoa. This study reports that GLUT8 is expressed in the midpiece region of human spermatozoa and that insulin stimulation upgrades its expression and leads to its translocation to the acrosomal region.
AFRIKAANSE OPSOMMING: Oor die afgelope jare was daar `n toename in obesiteit en diabetes mellitus (DM). Hierdie toestande word reeds vir ’n geruime tyd geassosieer met onvrugbaarheid. Obesiteit word gekenmerk deur verhoogde sirkulerende vlakke van leptiene en sitokiene sowel as insulien weerstandigheid. Tipe I DM word geassosieer met lae of geen insulien terwyl Tipe II DM gekenmerk word deur insulien weerstandigheid. Soos wat die voorkoms van obesiteit en DM toeneem, is dit waarskynlik dat die insidensie van onvrugbaarheid wat met hierdie patologiese toestande geassosieer word, gevolglik ook sal toeneem. Die effek van insulien en leptien op die manlike voortplantingsfunksie is alreeds aangetoon op endokriene en spermatogenese vlak, maar hul effekte op sellulêre vlak van menslike geëjakuleerde spermatosoë is nog onduidelik. Die studie vertoon data oor die rol van insulien en leptien op die menslike geëjakuleerde spermatosoë en hul interaksie met sitokiene en stikstofoksied (NO). In die eerste gedeelte van die studie, het ons ’n toepaslike konsentrasie van insulien en leptien bepaal wat aan menslike spermatosoë in vitro toegedien kan word. Glukose konsentrasies van 5,6 mM is bepaal as die gepaste konsentrasie om aan menslike spermatosoë toe te dien, omdat dit beter resultate tot gevolg het; verder is dit vergelykbaar met fisiologiese glukose vlakke in die bloed van `n vastende persoon. Insulien en leptien konsentrasies is op 10 μIU en 10 nm onderskeidelik vasgestel, aangesien dit tot beter resultate gelei het, en omdat dit vergelykbaar was met insulien en leptien vlakke wat reeds voorheen in menslike geëjakuleerde spermatosoë gemeet is. Dit was gevolg deur `n ondersoek na die insulien seintransduksie pad en sy voordelige effekte op menslike spermatosoë funksie. Endogene insulien afskeiding deur menslike geëjakuleerde spermatosoë was deur nifedipien geïnhibeer en sy reseptor tirosien fosforilasie effekte was deur erbstatin geïnhibeer terwyl fosfatidielinositol 3-kinase (PI3K) fosforilasie deur wortmannin geïnhibeer is. Eksogene insulien toediening het menslike sperm-motiliteit parameters betekenisvol laat toeneem asook die vermoë van sperme om die akrosoomreaksie te ondergaan. Die inhibisie van endogene insulien afskeiding deur spermatosoë sowel as die inhibisie van die insulien reseptor substraat (IRS) tirosien fosforilasie het die motiliteit parameters en die akrosoomreaksievermoë van spermatosoë verlaag. Die studie het ook die effekte van insulien en leptien op menslike sperm-motiliteit, -lewensvatbaarheid, -akrosoomreaksie en -NO produksie nagevors. Beide insulien en leptien het sperm-motiliteit parameters, -akrosoomreaksie en -NO produksie betekenisvol verhoog. NO produksie is deur insulien en leptien via PI3K seintransduksie geïnduseer, soos bewys deur die verlaging waargeneem in NO vlakke toe PI3K aktiwiteit deur wortmannin geïnhibeer was. Om vas te stel of insulien en leptien die motiliteit parameters van asthenozoospermiese en teratozoospermiese spermatosoë kon verbeter, het ons spermatosoë in twee fraksies met ’n dubbel digtheid gradiënt geskei. Die gradiënt sisteem was daartoe instaat om die spermatosoë in ’n onvolwasse, (morfologies abnormaal en minder motiel - soortgelyk aan dié van asthenozoospermiese en teratozoospermiese pasiënte), sowel as ’n volwasse meer motiele fraksie te skei. Insulien en leptien het die motiliteit parameters van spermatosoë van die onvolwasse en minder motiele fraksie verhoog. Die vierde gedeelte van die studie was daarop gemik om die effekte van die sitokiene tumor nekrose faktor alfa (TNF-α) en interleukin-6 (IL-6) op menslike sperm-motiliteit, -lewensvatbaarheid, -akrosoomreaksie en -NO produksie, te ondersoek. Die studie het getoon dat TNF-α en IL-6 motiliteit parameters en akrosoomreaksie in ’n tyd- en dosis-afhanklike wyse betekenisvol verlaag het. Hierdie sitokiene was ook in staat om NO produksie in menslike spermatosoë te verhoog. Die verlaging in motiliteit parameters wat deur hierdie sitokiene geïnduseer is, kan toegeskryf word aan hul vermoë om die produksie van oormatige hoeveelhede NO te stimuleer. Dit is nog nie duidelik hoe hulle die akrosoomreaksie in spermatosoë kan inhibeer nie. Die vyfde gedeelte van die studie het dit ten doel gehad om die uitdrukking en lokalisering van die glukose transporter 8 (GLUT8) in menslike spermatosoë te ondersoek. Hierdie studie kon aantoon dat GLUT8 konstitutief uitgedruk is en in die middelstuk van die menslike spermatosoë voorkom. Die studie bewys ook dat stimulering van die spermatosoë met insulien tot `n toename in GLUT8 uitdrukking sowel as translokasie na die akrosomale area, lei. In die finale gedeelte van die studie wou ons ondersoek waarom die toename in NO produksie in spermatosoë (as gevolg van insulien en leptien stimulasie) deur `n toename in spermfunksie gekenmerk word, terwyl die toename in NO produksie (as gevolg van TNF-α en IL-6 stimulasie) deur ’n afname in spermfunksie gekenmerk word. Ons het waargeneem dat TNF-α en IL-6 nie alleen NO produksie nie, maar ook reaktiewe suurstof spesies (ROS) produksie verhoog het. Ons vermoed dat die afname in sperm motiliteit en akrosoomreaksie met TNF-α en IL-6 toediening, die gevolg van die gelyktydige verhoging in NO en ROS was. In gevolgtrekking kan ons sê dat hierdie studie die voordelige in vitro effekte van insulien en leptien op asthenozoospermiese en teratozoospermiese menslike spermfunksie aangetoon het. Hierdie hormone beïnvloed spermfunksie via die PI3K seintransduksie pad op twee maniere. Eerstens, deur `n toename in GLUT8 uitdrukking en translokasie, met die gevolg dat glukose opname en metabolisme moontlik verhoog is, en tweedens, deur die toename in NO produksie. Die studie het ook vasgestel dat TNF-α en IL-6 nadelige effekte op menslike spermatosoë in `n dosis- en tyd-afhanklike wyse het. Hierdie effekte vind plaas a.g.v. hul vermoë om beide NO en ROS produksie in menslike spermatosoë te induseer. Die studie toon aan dat GLUT8 uitdrukking in die middelstuk van die menslike spermatosoon voorkom en dat insulien stimulasie GLUT8 uitdrukking opreguleer en tot translokasie na die akrosomale area lei.

The conservation status of the species studied in this thesis (European eel and pufferfish) is currently frail, thus the main goal of this research was to develop, improve and apply several techniques and protocols with the aim of increasing the knowledge about their sperm biology, improving their reproductive performance and even helping future breeding in captivity. The reproductive performance of the males is often assessed through the sperm motion parameters analysed by the CASA system, so first we focused on how to standardize this technique in terms of procedural and biological settings. In this respect, we laid the foundations for applying a standard method to assess sperm quality in fish, making it possible for sperm studies to be compared both intra- and inter-laboratories using the proper CASA settings. Secondly, with the aim of improving the reproductive performance of European eel males, 3 thermal regimes (two of them variable: T10 and T15; and one of them constant: T20) and 3 hormonal treatments (hCG, hCGrec and PSMG) were assessed based on different sperm quality parameters. In the case of the thermal regimes, our results demonstrated that the onset and progression of spermiation are strongly influenced by water temperature, with treatment T20 showing the best results in all the sperm quality parameters. In the case of hormonal treatments, hCGrec produced the best results in all the sperm quality parameters, becoming an economically profitable/viable treatment and an effective alternative to the standard hCG treatment often used to induce spermiation in eel species. A preliminary physiological study regarding the changes to the main ions involved in the fish sperm activation process was carried out. Our results showed that intracellular concentrations of Ca2+ and K+ increased upon eel sperm activation, while pH gradually decreased over time, thus it is likely that all of them play an important role in the initiation of sperm motility in the European eel, as with other marine and freshwater teleosts. In the second part of this thesis, which focuses on the pufferfish, an in-depth study into the sperm of this species was carried out for future application in aquacultural matters. A short-term storage method for pufferfish sperm was developed, enabling us to preserve the sperm quality parameters for a relatively long time period (7 days) compared to fresh sperm samples. Moreover, the effects of both the osmolality and the ion composition of the activation media on the sperm motion parameters were evaluated, concluding that both factors play an essential role in the initiation of sperm motility of pufferfish sperm and probably, in marine fish sperm. Finally, in vitro fertilization trials were developed to assertain how the quantity and quality of male gametes affects the fertilization and hatching rates. We demonstrated that sperm/egg ratio and sperm quality are strongly related factors, suggesting that both should be taken into account as unique interrelated elements. In addition, coefficients of correlation among all the spermatozoa motion parameters provided by a CASA system and fertilization and hatching rates were estimated for the first time in a marine species. Spermatozoa velocities showed the highest coefficients (¿0.80), suggesting that the kinetics of the spermatozoa are a key factor in the fertilization process.
Gallego Albiach, V. (2013). Sperm physiology and quality in two marine teleosts: Anguilla anguilla & Takifugu niphobles [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/34625
TESIS
Premiado

Thesis (MScMedSc)-- Stellenbosch University, 2013.
ENGLISH ABSTRACT: Much has been documented about the detrimental effects of adverse lifestyle factor exposure on the body. Exposure to factors, such as cigarette smoke, have proved to not only be a burden on global health and economy, but have also led to growing concerns about effects on systemic functions such as reproduction. The aim of the present study was to determine the effects of in utero and in vitro nicotine exposure on spermatozoal function and the antioxidant enzyme activity and lipid peroxidation (LPO) status of the male reproductive system. A better understanding of this process is necessary to combat the respective burdens of smoking and male infertility and for the prospective development of treatment strategies. Two experimental models were employed: Wistar rats were exposed to nicotine in utero while human and rat spermatozoa were exposed to nicotine in vitro. In utero studies were achieved by selecting healthy pregnant rats and treating them with 1 mg/kg-bodyweight/day nicotine or 1 ml/kg-bodyweight/day 0.85% physiologic saline throughout gestation and lactation. Male rat pups were selected and sacrificed at each of the following age groups (n=6): 42 days, 84 days and 168 days old. The pups were only exposed to the treatment/saline via placental uptake or lactation. Biochemical analyses of the tissue comprised of measurement of LPO and antioxidant enzyme activity. Results indicated a significant association of maternal nicotine exposure to decreased levels of primary antioxidant enzymes in rat testes. Of particular note was the observation that the treatment group, of which each of the respective antioxidant enzyme levels were significantly less than the control group, was the oldest (d168) rat group. In vitro studies were achieved by collecting sperm samples from healthy human donors (n=12), healthy rats (n=6) and obese rats (n=6). Samples were washed and exposed to different concentrations of high levels of nicotine (Control, 0.1mM, 1mM, 5mM, 10mM) in vitro. Semen parameters such as motility, viability and acrosome reaction were monitored at different time points (30min, 60min, 120min, 180min). Results revealed increasing in vitro nicotine concentrations were associated with decreased viability and acrosomal status of human spermatozoa and decreased progressive motility and viability of rat spermatozoa. Obesity was also associated with decreases in progressive motility and viability of rat spermatozoa. These results indicate that the acute in vitro exposure of spermatozoa to high levels of nicotine could adversely affect semen quality and may be an additive factor to the impediment of male fertility. In utero results reveal maternal nicotine exposure adversely affects male fertility in later life and seems to elicit more detrimental effects on the reproductive system than that of direct nicotine exposure to spermatozoa. Obesity also inhibits parameters of male fertility and these effects are exacerbated by nicotine exposure. The authors believe these adverse effects on the reproductive system to be related to an increased activation of leukocytes, excess production in reactive oxygen species (ROS) and consequent onset of oxidative stress (OS). Nevertheless this study agrees with other studies that nicotine exposure may be an additive factor to the impediment of male fertility.
AFRIKAANSE OPSOMMING: Daar is reeds baie bekend oor die moontlik newe effekte vir die liggaam wat met ‘n ongesonde lewenstyl gepaard gaan. Menslike blootstelling aan sulke faktore, soos sigaret rook, is wêreldwyd ‘n las vir gesondheid en ekonomie en het gelei tot geweldige kommer onder navorsers oor die moontlike komplikasies vir liggaamlike funksies soos voortplanting. Die doel van die betrokke projek was om die effekte van in utero en in vivo nikotien blootstelling op die antioksiderende ensiem aktiwiteit en lipied peroksidasie status van reproduktiewe weefsel en die funksionele parameters van spermatozoa te bepaal. ‘n Beter begrip van hierdie proses is noodsaaklik om die las van rook en vetsug teen te werk en vir die moontlike ontwikkeling van behandelingsstrategieë. Twee eksperimentele modelle is ontwerp: Wistar rotte is in utero blootgestel aan nikotien terwyl mens- en rot- spermatosoë ook in vitro aan nikotien blootgestel is. Vir die in utero studie is gesonde dragtige rotte gedurende swangerskap en laktasie met 1 mg/kgliggaamsgewig/ dag nikotien of 1 ml/kg-liggaamsgewig/dag 0.85% fisiologiese soutoplossing behandel. Manlike welpies is gekies en geoffer op elk van die volgende ouderdomme (n=6): 42 dae, 84 dae en 168 dae. Die welpies is slegs aan nikotien blootgestel deur plasentale opname en laktasie. Biochemiese analise van die testikulêre weefsel het ‘n beduidende assosiasie getoon tussen maternale nikotien blootstelling en verminderde vlakke van die primêre antioksiderende ensieme. Die 168 dag oue groep het ‘n merkbare vermindering getoon tussen kontrole en nikotien weefsel vir elk van die antioksiderende ensieme. Vir die in vitro studie is sperm monsters verkry vanaf gesonde mans (n=12), gesonde rotte (n=6) en vet rotte (n=6). Monsters is gewas en in vitro blootgestel aan verskeie hoë vlakke van nikotien (kontrole, 0.1mM, 1mM, 5mM, 10mM). Seminale parameters soos motiliteit, lewensvatbaarheid en akrosoom status is by verskei tydpunte gemeet (30min, 60min, 120min, 180min). Dit blyk dat verhoging in in vitro nikotien konsentrasies verband hou met verlaagde lewensvatbaarheid en akrosoom status van menslike spermatosoë en verlaagde progressiewe motilteit en lewensvatbaarheid van rot spermatosoë. Vetsug is ook geassosieer met verlagings in progressiewe beweeglikheid en lewensvatbaarheid van rot spermatosoë. In utero resultate openbaar dat maternale nikotien blootstelling manlike vrugbaarheid nadelig beïnvloed in latere lewe en blyk dat dit meer van ‘n nadelige uitwerking op die voortplantingstelsel het as dié van direkte nikotien blootstelling aan spermatosoë. In vitro blootstelling van spermatosoë aan hoë vlakke van nikotien, het wel ook semen kwaliteit nadelig beïnvloed. Vetsug inhibeer ook manlike vrugbaarheids parameters en hierdie effek word vererger deur nikotien blootstelling. Die outeure glo dat hierdie nadelige uitwerking op die voortplantingstelsel verband hou met 'n verhoogde aktivering van leukosiete, oortollige produksie van reaktiewe suurstof spesies en die gevolglike aanvang van oksidatiewe stres bevorder. Hierdie studie stem wel ooreen met ander studies wat nikotien blootstelling bestempel as ‘n bydraende faktor tot die struikelblok van manlike onvrugbaarheid.
Harry Crossley Foundation (South Africa)

The following work demonstrates that paternal diet controls medically important metabolic phenotypes in offspring. We observe transmission of dietary information to the zygote via sperm, and this information evades reprogramming that typically occurs after fertilization. Cytosine methylation is implicated as a major contributor to meiotic epigenetic inheritance in several transgenerational phenomena. Our extensive characterization of the sperm methylome reveals that diet does not significantly affect methylation patterns. However, we find that extensive epivariability in the sperm epigenome makes important contributions to offspring variation. Importantly, coordinate cytosine methylation and copy number changes over the ribosomal DNA locus contributes to variation in offspring metabolism. Thus, rDNA variability acts independently of postadolescent paternal diet to influence offspring metabolism. Therefore, at least two mechanisms exist for epigenetically controlling offspring metabolism: stochastic epivariation and diet acting by an unknown mechanism to further modulate metabolism. This work argues that an offspring's phenotype can no longer be viewed solely as the result of genetic interactions with the developmental environment - the additional influences of paternal environment and inherited epigenetic variability must also be considered. These findings reveal novel contributions to metabolism that could revolutionize how we think about the risk factors for human health and disease.

The following work demonstrates that paternal diet controls medically important metabolic phenotypes in offspring. We observe transmission of dietary information to the zygote via sperm, and this information evades reprogramming that typically occurs after fertilization. Cytosine methylation is implicated as a major contributor to meiotic epigenetic inheritance in several transgenerational phenomena. Our extensive characterization of the sperm methylome reveals that diet does not significantly affect methylation patterns. However, we find that extensive epivariability in the sperm epigenome makes important contributions to offspring variation. Importantly, coordinate cytosine methylation and copy number changes over the ribosomal DNA locus contributes to variation in offspring metabolism. Thus, rDNA variability acts independently of postadolescent paternal diet to influence offspring metabolism. Therefore, at least two mechanisms exist for epigenetically controlling offspring metabolism: stochastic epivariation and diet acting by an unknown mechanism to further modulate metabolism. This work argues that an offspring's phenotype can no longer be viewed solely as the result of genetic interactions with the developmental environment - the additional influences of paternal environment and inherited epigenetic variability must also be considered. These findings reveal novel contributions to metabolism that could revolutionize how we think about the risk factors for human health and disease.

Bibliography: leaves 135-151.
xx, 151, [14] leaves, [15] leaves of plates : ill. (chiefly col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
A study of chromosomal abnormalities and the localisation of chromosomes in human sperm, especially from men with TSD, using fluorescence in situ hybridization (FISH). The project entailed: 1. development of reliable FISH protocols, 2. determination of basline frequencies of aneuploidy, 3. analysis of chromosomal abnormalities in men with severe TSD and 4. assessment of the localisation of individual chromosomes within the sperm head.
Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 2000

Further in vivo functional studies were also performed. The SLC26A3 antibody was injected into the BALB/C mice seminiferous tubules using micropipette. The animals were sacrificed after three days, and CASA, daily sperm production (DSP) were used to evaluate sperm motility and spermatogenesis. The results showed that sperm motility was increased while there was no significant difference between DSP. Our results indicate that SLC26A3 on sperm does not play a dominant role in spermatogenesis, epididymal maturation and sperm motility.
In the first part of study, guinea pig sperm which were incubated in medium with various concentrations of Cl- resulted in varied percentages of capacitated sperm, in a concentration dependent manner. Depleting Cl-, even in the presence of HCO3 -, abolished sperm capacitation and vice versa, indicating the involvement of both anions in the process. Capacitation-associated HCO 3- dependent events, including cAMP production, protein tyrosine phosphorylation and pHi increase also depend on Cl - concentrations. Similar Cl- dependence was observed for sperm hyperactivated motility and sperm-egg fusion. The capacitation-associated events could also be significantly reduced by inhibitors or antibodies of CFTR and SLC26A3, with a more potent effect observed for niflumate, an inhibitor more selective for SLC26A3, over that of DIDS, an inhibitor more selective for SLC4 exchangers. The expression and localization of CFTR and SLC26A3 in guinea pig sperm were also demonstrated using immunostaining and Western blot analysis. Our results indicate that Cl- is required for the entry of HCO3- necessary for sperm capacitation, implicating the involvement of SLC26A3 in transporting HCO3 - with CFTR providing the recycling pathway for Cl- .
In the second part of study, GC-1 spg cell line that expresses SLC26A6 but not SLC26A3 was used as a negative control. The cells and sperm were pretreated with anion exchanger inhibitors and SLC26A3 antibody, and then membrane potential and intracellular calcium were measured. Our results showed that DIDS could inhibit the HCO3- deficiency induced depolarization of GC-1 spg cells as well as the depolarization induced by Cl- or HCO3- deficiency in sperm. Niflumate could inhibit the HCO3- induced [Ca 2+] i increase of the sperm but not GC-1 spg cells. SLC26A3 antibody had no effect on the GC-1 spg cells but it could block the depolarization caused by C--deficiency in sperm.
Our previous study has demonstrated the involvement of Cystic fibrosis transmembrane conductance regulator (CFTR) in transporting bicarbonate necessary for sperm capacitation. However, whether its involvement is direct or indirect remains unclear. The present study is design to investigate: (1) the possibility of a Cl-/HCO3- exchanger, solute carrier family 26, number 3 (SLC26A3), operating with CFTR during sperm capacitation, (2) the role and the underlying mechanisms of SLC26A3 in other sperm post-testicular processes and spermatogenesis.
Taken together, our results demonstrate the involvement of SLC26A3 in sperm function, particularly in transporting HCO3- necessary for sperm capacitation, which appears to be working with CFTR providing the recycling pathway for Cl- in parallel. The present results also provide an explanation to the observed subfertility in patients with SLC26A3 mutations. Further in vitro and in vivo studies also have shown that SLC26A3 does not play a predominant role in spermatogenesis but may affect other post-testicular maturation processes.
Chen, Wenying.
"November 2009."
Adviser: H.C. Chan.
Source: Dissertation Abstracts International, Volume: 72-01, Section: B, page: .
Thesis (Ph.D.)--Chinese University of Hong Kong, 2010.
Includes bibliographical references (leaves 101-109).
Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Electronic reproduction. Ann Arbor, MI : ProQuest Information and Learning Company, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.
Abstract also in Chinese.

Copies of author's previously published articles inserted.
Bibliography: leaves 118-142.
vi, 156, [26] leaves, [22] leaves of plates : ill. (some col.) ; 30 cm.
Title page, contents and abstract only. The complete thesis in print form is available from the University Library.
Thesis (Ph.D.)--University of Adelaide, Dept. of Anatomy and Histology and Dept. of Animal Genetics, 1997?

Copies of author's previously published articles inserted.
Bibliography: leaves 118-142.
vi, 156, [26] leaves, [22] leaves of plates : ill. (some col.) ; 30 cm.
Thesis (Ph.D.)--University of Adelaide, Dept. of Anatomy and Histology and Dept. of Animal Genetics, 1997?

Fertilization is a process that generates the first cell of a new organism. In mammals, fertilization occurs in the female reproductive tract. The male gametes (spermatozoa) are rendered fertilization-competent only after they undergo capacitation and acrosome reaction (AR). The set of physiological changes, characterised by the acquisition of hyperactivated motility, that render the spermatozoa fertilization competent is known as capacitation. Using in vitro models, the complex intracellular signaling events mediating this process are still being understood. This thesis explores the role of protein tyrosine phosphorylation during capacitation using the golden hamster (Mesocricetus auratus) spermatozoa. The knowledge about the molecular components involved in capacitation, apart from enriching our understanding about a basic cellular process could also provide leads in the management of male (in)fertility. A comprehensive review on the perspectives of male reproduction, spermatogenesis, the structural features of a spermatozoon and sperm maturation, relevant to the content of the thesis is provided in Chapter-1 (General Introduction). Molecular mediators that initiate capacitation include cAMP, Ca2+and HCO3- ions. These signalling molecules regulate activities of protein kinases and phosphatases, which control the level of protein phosphorylation in spermatozoa. Capacitation-associated increase in protein phosphorylation, specifically protein tyrosine phosphorylation (PYP) has been demonstrated in a few species such as mouse, rat and human. The unique nature of PYP signaling during sperm capacitation has been exemplified by discoveries of several male germ cell-specific signalling molecules like soluble adenylate cyclase. However,molecular identities of tyrosine-phosphorylated proteins and their functional role during sperm capacitation are yet to be investigated in detail. In this context, the effect of modulating intracellular levels of signaling molecules upstream of protein phosphorylation was sought using pentoxifylline (PF), a cAMP phosphodiesterase inhibitor. Interestingly, PF-induced capacitation was associated with an early induction of tyrosine phosphorylation of proteins (45-80 kDa) localized to the mid piece of the sperm tail. Interestingly, the ultrastructural localization of tyrosine-phosphorylated proteins in the sperm tail by immunoelectron microscopy (IEM) revealed most intense immunolabelling in the fibrous sheath, followed by outer dense fibers (ODFs)and the axoneme. Data pertaining to the effect of PF on sperm capacitation and the associated protein-phosphorylation is presented in Chapter-2. Since PYP was determined to be extremely critical for hyperactivation in spermatozoa, the involvement of protein tyrosine kinases (PTKs) in this process was assessed using a specific PTK inhibitor, tyrphostin A47 (TP-47: EGFR-TK specific). The third chapter deals with the effect of tyrphostins on sperm capacitation and PYP. A dose-dependent inhibition by TP-47 of capacitation and principal piece associated-PYP of ~45-60 kDa proteins was observed. Interestingly, TP-47 treated-spermatozoa exhibited a circular motility pattern; when assessed for kinematic parameters, by computer aided sperm analysis, sperm showed lower values for key kinematic parameters as compared to the controls. While sperm viability in TP-47- treated samples was not affected, the ATP content reduced towards latter (4-5 h) part of culture as compared to the controls. When spermatozoa were treated with two other PTK inhibitors, tyrphostin AG1478 (EGFR-TK specific) and tyrphostin AG1296 (PDGFR-TK specific), they did not show any changes in kinematic parameters or PYP, indicating that the TP-47-effect was compound-specific. The fourth chapter of this thesis involves the molecular analysis of proteins hypo-tyrosine phosphorylated in the presence of TP-47, which started with the enrichment of sperm flagellar proteins that are tyrosine phosphorylated during capacitation, using various detergents. Detergent extractions established that most tyrosine-phosphorylated proteins were non-membranous in nature, which complemented the IEM data. Therefore, phosphoproteome analysis of the untreated and TP-47-treated sperm samples was performed. For this, protein extracts were subjected to 2D-PAGE-phosphotyrosine immunoblots. A 51 kDa spot and two 45 kDa spots, corresponding to the hypo-tyrosine phosphorylated spots, were analyzed by MS/MS. While peptides from the 51 kDa protein matched with tektin-2 (a microtubular protein), those of the 45 kDa spots matched with ODF-2 protein of the sperm flagellum. Validation of the presence of tektin-2 and ODF-2 protein and their tyrosine-phosphorylated forms on sperm capacitation in the hamster spermatozoa has also been performed. In addition to detailing the role of PYP in hamster sperm capacitation, this study revealed the identities of a few of these proteins, whose tyrosine phosphorylated status could be critical for optimal sperm flagellar bending, required for sperm hyperactivation. By understanding causes that lead to altered sperm function, for example, as observed with hamster spermatozoa, new insights could be achieved into molecular regulatory mechanisms that govern sperm function in clinical cases of non-obstructive male infertility in the human.