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Fertilizing Capacity (fertilizing + capacity)
Selected AbstractsAssessing in vivo Fertilizing Capacity of Liquid-Preserved Boar Semen According to the ,Hanover Gilt Model'REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2003F Ardón Contents The goal of this study was to determine the ability of the Hanover gilt model to assess in vivo fertilizing capacity of preserved sperm and to consider whether any modifications to this model were needed. This model evaluates the fertilizing capacity of semen based on the fertilization rate, the rate of normal embryos and the accessory sperm count of 3,5-day embryos. Its distinguishing characteristics are the use of one-time insemination of sperm in reduced numbers, of spontaneously ovulating gilts and of ovulation detection through ultrasound examination of ovaries. Reduced sperm numbers allow for an accurate evaluation of the fertilizing potential of different semen treatments, thereby avoiding the compensatory effect of doses calibrated to maximize fertility. The model's usefulness was assessed in a trial run designed to compare the fertilizing capacity of liquid boar semen diluted into two different extenders. The diluent, the boar and the backflow, had no significant effect on any of the parameters studied. Gilts inseminated less than 24 h before ovulation had a significantly higher (p < 0.01) fertilization rate and accessory sperm cell count (p < 0.05) than those inseminated more than 24 h before ovulation. Very good/good embryos from homogeneous litters (only very good/good embryos were present) had a significantly higher (p < 0.01) accessory sperm count than those from heterogeneous litters (at least one embryo was of a different quality and/or oocytes were present). Both very good/good and degenerated/retarded embryos from heterogeneous litters had low accessory sperm numbers. This suggests that accessory sperm count is significantly related to the quality of the litter, but not to the quality of the embryo within gilts. It can be concluded that the Hanover gilt model is sensitive enough to show fertility differences (in this study, those associated with in vivo ageing of semen), while using relatively few gilts and little time. [source] Sperm function tests and fertilityINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 1 2006R. J. Aitken Summary Traditionally, the diagnosis of male infertility has depended upon a descriptive evaluation of human semen with emphasis on the number of spermatozoa that are present in the ejaculate, their motility and their morphology. The fundamental tenet underlying this approach is that male fertility can be defined by reference to a threshold concentration of motile, morphologically normal spermatozoa that must be exceeded in order to achieve conception. Many independent studies have demonstrated that this fundamental concept is flawed and, in reality, it is not so much the absolute number of spermatozoa that determines fertility, but their functional competence. In the light of this conclusion, a range of in vitro tests have been developed to monitor various aspects of sperm function including their potential for movement, cervical mucus penetration, capacitation, zona recognition, the acrosome reaction and sperm,oocyte fusion. Such functional assays have been found to predict the fertilizing capacity of human spermatozoa in vitro and in vivo with some accuracy. Recent developments in this field include the introduction of tests to assess the degree to which human spermatozoa have suffered oxidative stress as well as the integrity of their nuclear and mitochondrial DNA. Such assessments not only yield information on the fertilizing capacity of human spermatozoa but also their ability to support normal embryonic development. [source] Enzymatic and immunochemical evaluation of phospholipid hydroperoxide glutathione peroxidase (PHGPx) in testes and epididymal spermatozoa of rats of different agesINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 2 2002Federica Tramer Selenium (Se) and selenoproteins such as glutathione peroxidases are necessary for the proper development and fertilizing capacity of sperm cells. Phospholipid hydroperoxide glutathione peroxidase (PHGPx, E.C. 1.11.1.12) is a monomeric seleno-enzyme present in different mammalian tissues in soluble and bound form. Its function, like the other glutathione peroxidases, was originally viewed as a protective role against hydroperoxides, but direct and indirect evidence indicates that it has additional regulatory roles. PHGPx is present in testis cells and sperm cells, and its appearance is hormone regulated. We present here biochemical data, which clearly indicate that the enzyme specific activity in rat is age-dependent during the life-span monitored (from 36 to 365 days), with a maximum at 3 months of age in the testis germ cells and at 6 months of age in the isolated epididymal sperm cells. Western blotting and immunocytochemical analysis by means of anti-PHGPx antibodies show the different distribution and the strong binding of PHGPx in the testes and sperm cell subcellular compartments (nucleus, acrosome, mitochondria and residual bodies) of rats of different age. The presence of the protein exhibits in the testis cells a pattern different from that of the catalytic activity, with a maximum at 6 months of age. The subcellular distribution of PHGPx is qualitatively, but not quantitatively, unchanged during ageing. These different behaviours are compared and discussed. [source] Effect of exogenous DNA on bovine sperm functionality using the sperm mediated gene transfer (SMGT) techniqueMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 8 2010Sebastian Canovas Sperm mediated gene transfer (SMGT) could provide the opportunity to carry out transgenesis on a mass scale using spermatozoa as vectors for exogenous DNA. However, the efficiency of sperm-mediated DNA transfer is still questionable, and the mode of transmission to the egg has not yet been well understood. Our aim was to investigate the capacity of bovine spermatozoa to carry exogenous DNA and its relationship to sperm functionality. We studied these parameters using flow cytometry to measure viability (necrosis and apoptosis) and capacitation status, computer-assisted semen analysis (CASA) to measure motility parameters and in vitro fertilization (IVF) to assess fertilizing capacity. Furthermore, we studied the effect of capacitation status on interaction with exogenous DNA, and the role of heparin supplementation in this process. Bull spermatozoa showed a high capacity to bind DNA quickly and reached a maximum after 30,min, with approximately half of the DNA-bound spermatozoa being viable. Incubation with exogenous DNA induced a decrease in sperm viability and motility and increased the proportion of apoptotic cells, but did not affect the cleavage rate in IVF assay. Heparin increased high-lipid disorder and the number of sperm with DNA bound (viable and dead). In conclusion, this study shows that live spermatozoa can bind exogenous DNA with a slight negative effect in some parameters of sperm function that in our opinion, would not drastically compromise fertility. Mol. Reprod. Dev. 77: 687,698, 2010. © 2010 Wiley-Liss, Inc. [source] Effect of Antioxidants During Bovine In Vitro Fertilization Procedures on Spermatozoa and Embryo DevelopmentREPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2010FS Gonçalves Contents Increased amounts of reactive oxygen species (ROS) during in vitro fertilization (IVF) may cause cytotoxic damage to gametes, whereas small amounts of ROS favour sperm capacitation. The aim of this study was to investigate the effect of antioxidants [50 ,m,-mercaptoethanol (,-ME) and 50 ,m cysteamine (Cyst)] or a pro-oxidant (5 mm buthionine sulfoximine) on the quality and penetrability of spermatozoa into bovine oocytes and on the subsequent embryo development and quality when added during IVF. Sperm quality, evaluated by the integrity of plasma and acrosomal membranes, and mitochondrial function, was diminished (p < 0.05) after 4-h culture in the presence of antioxidants. Oocyte penetration rates were similar between treatments (p > 0.05), but antioxidants adversely affected the normal pronuclear formation rates (p < 0.05). The incidence of polyspermy was high for ,-ME (p < 0.05). No differences were observed in cleavage rates between treatments (p > 0.05). However, the developmental rate to the blastocyst stage was adversely affected by Cyst treatment (p < 0.05). The quality of embryos that reached the blastocyst stage, evaluated by total, inner cell mass (ICM) and trophectoderm cell numbers and ICM/total cell ratio was unaffected (p > 0.05) by treatments. The results indicate that ROS play a role in the fertilizing capacity in bovine spermatozoa, as well as in the interaction between the spermatozoa and the oocytes. It can be concluded that supplementation with antioxidants during IVF procedures impairs sperm quality, normal pronuclear formation and embryo development to the blastocyst stage. [source] OC1 Effects of Cryopreservation on the Expression of Glut-3, Glut-5 and As-A Proteins in Iberian Boar Sperm MembranesREPRODUCTION IN DOMESTIC ANIMALS, Issue 2006S Sancho In order to determine the injure produced in boar spermatozoa through cryopreservation process, we analyzed the expression of the hexose transporters Glut-3 and Glut-5 and the zona pellucida binding protein As-A (P68) in three different steps of the freezing-thawed protocol: at 17°C (fresh BTS-diluted semen, 1 : 2 v/v, step 1), at 5°C (after glycerol addition; step 2), and post-thawing (step 3). All sperm analyses were carried out with immunogold techniques under electronic microscopy. For this study eight healthy post-pubertal Iberian boars were submitted to a collection of twice per week through 3 months, evaluating two ejaculates from each boar. Glut-3 maintains the expression in the acrosome region post-thawing but not along the tail where is reduced. The expression of Glut-5 and As-A is majority located at the post-acrosome region of the spermatozoa at step 1, but in step 2 and step 3 this expression is relocated to sperm tail area. In conclusion, while cryopreservation affects the localization and the expression of Glut-3 and Glut-5, its fertilizing capacity is not significantly reduced. The stabilization of boar semen at 5°C was found to be the most crucial step for sperm survival. [source] Assessing in vivo Fertilizing Capacity of Liquid-Preserved Boar Semen According to the ,Hanover Gilt Model'REPRODUCTION IN DOMESTIC ANIMALS, Issue 2 2003F Ardón Contents The goal of this study was to determine the ability of the Hanover gilt model to assess in vivo fertilizing capacity of preserved sperm and to consider whether any modifications to this model were needed. This model evaluates the fertilizing capacity of semen based on the fertilization rate, the rate of normal embryos and the accessory sperm count of 3,5-day embryos. Its distinguishing characteristics are the use of one-time insemination of sperm in reduced numbers, of spontaneously ovulating gilts and of ovulation detection through ultrasound examination of ovaries. Reduced sperm numbers allow for an accurate evaluation of the fertilizing potential of different semen treatments, thereby avoiding the compensatory effect of doses calibrated to maximize fertility. The model's usefulness was assessed in a trial run designed to compare the fertilizing capacity of liquid boar semen diluted into two different extenders. The diluent, the boar and the backflow, had no significant effect on any of the parameters studied. Gilts inseminated less than 24 h before ovulation had a significantly higher (p < 0.01) fertilization rate and accessory sperm cell count (p < 0.05) than those inseminated more than 24 h before ovulation. Very good/good embryos from homogeneous litters (only very good/good embryos were present) had a significantly higher (p < 0.01) accessory sperm count than those from heterogeneous litters (at least one embryo was of a different quality and/or oocytes were present). Both very good/good and degenerated/retarded embryos from heterogeneous litters had low accessory sperm numbers. This suggests that accessory sperm count is significantly related to the quality of the litter, but not to the quality of the embryo within gilts. It can be concluded that the Hanover gilt model is sensitive enough to show fertility differences (in this study, those associated with in vivo ageing of semen), while using relatively few gilts and little time. [source] The Use of HOS Test to Evaluate Membrane Functionality of Boar Sperm Capacitated in vitroREPRODUCTION IN DOMESTIC ANIMALS, Issue 6 2002D Lechniak Contents The functional and structural integrity of sperm membrane are crucial for the viability of spermatozoa. The commonly used staining test (eosin + nigrosin) for assessing sperm membrane measures only its structural integrity. The hypoosmotic swelling test (HOS) originally developed for human sperm (Jeyendran et al. 1984) has been also applied to several species of domestic animals (bull, pig, horse, dog). The test enables to evaluate the functional status of the sperm membrane. The principle of HOS is based on water transport across the sperm tail membrane under hypoosmotic conditions. It has previously been used to assess the semen quality (Revell and Mrode 1994), to analyse fertilizing capacity (Rota et al. 2000; Perez-Llano et al. 2001) and also to detect viable, immotile cells for ICSI (Intra-cytoplasmic sperm injection) in human (Zeyneloglu et al. 2000). There are two procedures commonly used for sperm capacitation in the pig-sperm washing and incubation before insemination (Nagai 1994). Capacitation involves several changes like removing molecules coating the sperm head membrane, changes in membrane fluidity and intracellular ion concentration (Green and Watson 2001). Thus the membrane integrity as well as functionality may be affected as shown by Harrison (1996). The aim of the present study was to analyse changes in sperm membrane integrity after in vitro capacitation by use of the HOS test. [source] Morphology of Testes from Transgenic Rabbits: Histological and Ultrastructural AspectsANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 1 2010P. Chrenek Summary The aim of this study was to compare morphological characteristics of testes from transgenic (the WAP-hFVIII gene) and non-transgenic rabbits with emphasis on the histological and ultrastructural aspects. Samples of testes from both groups were fixed and embedded into Durcupan ACM for transmission electron microscopy. For histological analysis, semi-thin toluidine blue-stained sections were evaluated under a Jenaval light microscope. Male fertility was tested based on egg fecundity and blastocyst yield; transgene transmission was proved using PCR assay. Spermatogenesis in rabbit testes had not been destroyed both in transgenic and non-transgenic rabbits. No significant differences were found in the occurrence of individual cell organelles of the Sertoli cells in transgenic and non-transgenic rabbits. The ultrastructure of Leydig cells in testes of transgenic and non-transgenic rabbits was rather similar. No differences in the occurrence of individual organelles of Leydig cells between transgenic and non-transgenic males were found. These results were in concert with fertilizing capacity of transgenic spermatozoa. The presented status of organelles in this study indicates functional activity of the analysed cells. [source] Obstructive infertility: changes in the histology of different regions of the epididymis and morphology of spermatozoaANDROLOGIA, Issue 4 2006P. C. Pal Summary In the present study, the effects of prolonged obstruction in different regions of the human epididymis on its histology and on the spermatozoa retained at the site of obstruction were assessed. Men who were confirmed of having obstruction of the epididymis underwent vasoepididymostomy (VEA) for surgical correction of the obstruction. At the time of surgery, fluid from the epididymal tubule above the site of obstruction was aspirated and examined for sperm profile. Epididymal tissue, collected at the site of obstruction, was processed for assessment of histological changes and also used to identify the site of obstruction. Prolonged obstruction of the epididymis has caused degeneration of the epididymal epithelium, gradual decrease in the diameter of the tubule and tubular lumen and increase in the intertubular connective tissue. Sperm aspirated from the caput epididymal fluid showed sluggish pattern of motility only in one out of the six subjects, whereas spermatozoa collected from the cauda epididymal fluid showed rapid linear progressive motility in one of three subjects. A major percentage of spermatozoa in the aspirated fluid showed various types of morphological abnormalities, irrespective of the site of obstruction. These results are discussed in relation to the role of the epididymis in investing spermatozoa with motility and fertilizing capacity. [source] Effects of paternal cigarette smoking on testicular function, sperm fertilizing capacity, embryonic development, and blastocyst capacity for implantation in ratsANDROLOGIA, Issue 2 2004A. Kapawa Summary. We evaluated the effects of paternal smoking on testicular function, sperm fertilizing capacity, embryonic development, and blastocyst capacity for implantation. Rats of group A were exposed to cigarette smoke for 10 weeks. Rats of group B were exposed to the smoke of incense sticks for 10 weeks. Rats of group C served as a control group. Rats of group D were exposed to cigarette smoke for 7 weeks only. Experimental period was 10 weeks in all groups. At the end of the experimental period serum testosterone responses to human chorionic gonadotropin stimulation, andro-gen-binding protein activity in testicular cytosols, epididymal sperm motility, and oocyte fertilization rate, oocyte cleavage rate, and blastocyst development rate after in vitro fertilization (IVF) trials were significantly smaller in group A compared with groups B and C. In contrast, fertilization rate, cleavage rate, and blastocyst development rate after intracytoplasmic sperm injection (ICSI) procedures were not significantly different among groups A, B, C, and D. Both after IVF trials and ICSI techniques, the proportion of the alive offspring to the number of transferred oocytes was significantly smaller in group A than in groups B and C. Cigarette smoke-exposure results in a secretory deficiency of Leydig and Sertoli cells leading to an impaired epididymal sperm maturation process and diminished capacity of spermatozoa to penetrate oocytes. In addition paternal cigarette smoke exposure affects the embryonic ability for implantation. [source] Possible predictive factors for ICSI?ANDROLOGIA, Issue 4 2003Molecular biology techniques in combination with therapeutic testicular biopsies Summary. Applying intracytoplasmic sperm injection (ICSI), the selection of an unsuccessful spermatozoon results in great emotional consequences for the couple. Therefore, there is a need for a prognostic parameter to estimate their chances for successful fertility treatment. This review summarizes both the main reasons for spermatogenic impairment, and possible predictive factors for successful sperm retrieval applying testicular sperm extraction and outcome of ICSI. While basic sperm parameters, aetiology and type of spermatozoa, and serum follicle-stimulating hormone and inhibin levels have been shown to be unrelated to the outcome of ICSI, Y-chromosome microdeletions are known to have a negative influence on the fertilizing capacity of spermatozoa. Recently, a significant correlation has been reported between the protamine-1 to protamine-2 mRNA ratio in haploid spermatids of testicular biopsies and the ability of spermatozoa for successful fertilization of an oocyte. In future, both the outstanding role of the haploid spermatids and the involvement of molecular biological techniques will improve the role of therapeutic testicular biopsies. [source] | |||||||||||||