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Research paper thumbnail of A dynamic assessment of sperm DNA fragmentation versus sperm viability in proven fertile human donors

Fertility and Sterility, 2009

Objective: To analyze any possible dynamic correlation between sperm DNA fragmentation and sperm ... more Objective: To analyze any possible dynamic correlation between sperm DNA fragmentation and sperm viability. Design: The rate of viability loss and the rate of increase of the frequency of sperm cells with fragmented DNA were determined at 0, 1.5, 4.5, and 24.0 hours after thawing samples from donors with proven fertility. Setting: Academic biology and reproductive medicine centers. Patient(s): Fifteen male donors with proven fertility for a maximum of six births at the reproductive medicine center. Intervention(s): None. Main Outcome Measure(s): Sperm DNA fragmentation and viability dynamics expressed as logarithmic coefficients of change.

Research paper thumbnail of Biotechnology and the Conservation of Genetic Diversity

Research paper thumbnail of Peripheral bound membrane proteins are involved in the maintenance of boar sperm viability by oviductal apical plasma membrane preparations in vitro

Research paper thumbnail of Enhanced boar sperm viability with porcine oviductal apical plasma membranes (APM)

Research paper thumbnail of Inter-boar susceptibility to cooling protocols

Research paper thumbnail of Protective effects of glycerol during cold shock in boar spermatozoa. A cryomicroscope study using propidium iodide and Sybr-14

Research paper thumbnail of Assessment of boar sperm function in relation to freezing and storage

Journal of reproduction and fertility. Supplement

The functions necessary for normal fertilization to occur in vivo or in vitro are examined and a ... more The functions necessary for normal fertilization to occur in vivo or in vitro are examined and a rational approach to identifying the main features of a fertilizing spermatozoon are developed. It is concluded that methods for testing the quality of spermatozoa must probe the dynamic changes experienced by the spermatozoa during capacitation or under stressful incubation conditions. Recent developments in the multivariate analysis of sperm motility data are used to illustrate the success that can be achieved by this approach. Ideally, changes in sperm motility characteristics should be correlated with an assessment of capacitation status. However, until the capacitation status of any individual cell can be clearly defined this will remain problematic.

Research paper thumbnail of Towards the development of a genetic resource bank for the Mohor gazelle: putting theory into practice

Research paper thumbnail of Graphical approach to the analysis of fractal dimension for sperm motility

Research paper thumbnail of Oestrogen excretion as a prediction of fertility in an exotic ungulate, the Mohor Gazelle (Gazella dama mhorr)

Research paper thumbnail of Hormonal and behavioural predictors of breeding success in the Mohor gazelle (Gazella dama mhorr)

Research paper thumbnail of Assisted breeding technology in the Marsupialia: Using the koala as a reproductive model

Research paper thumbnail of Sperm motility suppression by porcine oviductal membrane proteins is not caused by inhibition of bicarbonate uptake

Research paper thumbnail of Exposure of spermatozoa to solubilized extracts of he oviductal epithelium apical plasma membrane enhances fertilization in porcine in vitro fertilization

ABSTRACT In vitro production (IVP) of porcine embryos is currently suboptimal compared with IVP i... more ABSTRACT In vitro production (IVP) of porcine embryos is currently suboptimal compared with IVP in species such as mice and cattle. In vitro fertilization (IVF) usually involves the co-culture of oocytes and spermatozoa in a medium droplet. Oocyte quality is the focus of many studies. In vivo, the quality of spermatozoa is as important as the oocyte, and females have many mechanisms to select the highest quality spermatozoa for their oocytes. Oviductal proteins have been shown to affect sperm motility of subpopulations within an ejaculate. The present study was carried out to investigate normal and polyspermic fertilization rates of spermatozoa exposed to oviductal epithelial apical plasma membrane (APM) proteins, a mixture of peripheral proteins extracted by 1 M NaCl from isolated oviductal apical plasma membranes, prior to co-culture with oocytes in IVF. Porcine oocytes were aspirated from ovaries and grade I quality oocytes (cumulus–oocyte complexes with a spherical shape, visible nucleus, even-density cytoplasm, and multiple layers of cumulus cells) were selected and matured for 48 h in TCM-199 supplemented with LH (0.5 µg mL-1), FSH (0.5 µg mL-1), and EGF (10 ng mL-1). Ejaculates were washed through a Percoll gradient to obtain a concentrated pellet. Spermatozoa were diluted in capacitation–fertilization medium in the presence or absence of APM proteins (100 µg mL-1), incubated for 10 min, and then co-cultured with oocytes for 6 h in modified Tween medium B with milk powder medium (Abeydeera and Day 1997 Theriogenology 48, 537–544) supplemented with BSA (0.4%) and sodium bicarbonate (5 mM). Presumptive zygotes were cultured in NCSU23 medium for a further 48 h. The oocytes/zygotes were then fixed and stained with propidium iodide for evaluation by confocal microscopy for fertilization and cleavage (n = 1235 oocytes). Fertilization rates were compared between treatments in a chi-squared test using the Mantel-Haenszel approach. The overall fertilization rate was significantly higher (78 vs. 86%) when spermatozoa were incubated in the presence of APM proteins (P < 0.05), and in the group of fertilized oocytes, polyspermic fertilization (47 vs. 21%) was significantly reduced when spermatozoa were exposed to APM proteins (P < 0.01). However, cleavage rates were not different. These results suggest that exposure of spermatozoa to APM proteins prior to IVF increases the fertilization rate and decreases the incidence of polyspermic penetration.

Research paper thumbnail of Oviductal membrane proteins modulate bicarbonate-induced boar sperm activationresponse

Reproduction in Domestic Animals

Research paper thumbnail of Effects of the heat shock 70 kDa protein 8 (HSPA8) on boar sperm motility

Research paper thumbnail of Postnatal growth in four Pipistrllus kuhli reared in a flight cage

Research paper thumbnail of Boar Reproduction Fundamentals and New Biotechnological Trends

Description based upon print version of record.

Research paper thumbnail of Validation of computer-assisted sperm-motility analysis in the amphibian Silurana tropicalis

Reproduction Fertility and Development

We have developed and validated a computer-assisted sperm-motility assessment (CASA) method for u... more We have developed and validated a computer-assisted sperm-motility assessment (CASA) method for use with the emerging amphibian model Silurana tropicalis. The testicular sperm-activation method was validated by analysing activation replicate coefficients of variation, effects of tracking time settings on velocity distributions and the relative partitioning of differentially motile sperm subpopulations between matched right and left testes. Two major sperm subpopulations were identified using multivariate pattern analysis and their relative frequencies were consistent between samples from matched right and left testes and from randomly drawn subsets of six frogs sampled from the total set of 16 frogs. The power of this approach for detecting treatment effects targeting the hypothalamic–pituitary–­gonadal axis was investigated by injecting a group of frogs with 100 IU human chorionic gonadotrophin (hCG) 2 h before sampling and comparing their sperm-subpopulation frequencies with non-i...

Research paper thumbnail of Do sperm possess a molecular passport? Mechanistic insights into sperm selection in the female reproductive tract

Molecular human reproduction, Jan 9, 2015

Most male mammals produce far more spermatozoa on a daily basis than is strictly necessary for re... more Most male mammals produce far more spermatozoa on a daily basis than is strictly necessary for reproduction and females have evolved mechanisms that prevent all but a small minority from reaching the vicinity of their oocytes. One potential explanation for the stringent selection is that females have developed these mechanisms as a way of avoiding polyspermy as well as exercising post-copulatory choice over the characteristics of the fertilizing spermatozoon. Relatively little is known about how these processes would operate, but here we use evidence from biochemical, molecular and genetic studies of sperm transport in support of a hypothesis proposing that the female reproductive tract can read and interpret a spermatozoon's 'molecular passport' or genetic signature. Such a signature would permit only a highly selected sperm population to reach and fertilize the oocyte. Moreover, the selection criteria might not only be concerned with successful fertilizing ability, but...

Research paper thumbnail of A dynamic assessment of sperm DNA fragmentation versus sperm viability in proven fertile human donors

Fertility and Sterility, 2009

Objective: To analyze any possible dynamic correlation between sperm DNA fragmentation and sperm ... more Objective: To analyze any possible dynamic correlation between sperm DNA fragmentation and sperm viability. Design: The rate of viability loss and the rate of increase of the frequency of sperm cells with fragmented DNA were determined at 0, 1.5, 4.5, and 24.0 hours after thawing samples from donors with proven fertility. Setting: Academic biology and reproductive medicine centers. Patient(s): Fifteen male donors with proven fertility for a maximum of six births at the reproductive medicine center. Intervention(s): None. Main Outcome Measure(s): Sperm DNA fragmentation and viability dynamics expressed as logarithmic coefficients of change.

Research paper thumbnail of Biotechnology and the Conservation of Genetic Diversity

Research paper thumbnail of Peripheral bound membrane proteins are involved in the maintenance of boar sperm viability by oviductal apical plasma membrane preparations in vitro

Research paper thumbnail of Enhanced boar sperm viability with porcine oviductal apical plasma membranes (APM)

Research paper thumbnail of Inter-boar susceptibility to cooling protocols

Research paper thumbnail of Protective effects of glycerol during cold shock in boar spermatozoa. A cryomicroscope study using propidium iodide and Sybr-14

Research paper thumbnail of Assessment of boar sperm function in relation to freezing and storage

Journal of reproduction and fertility. Supplement

The functions necessary for normal fertilization to occur in vivo or in vitro are examined and a ... more The functions necessary for normal fertilization to occur in vivo or in vitro are examined and a rational approach to identifying the main features of a fertilizing spermatozoon are developed. It is concluded that methods for testing the quality of spermatozoa must probe the dynamic changes experienced by the spermatozoa during capacitation or under stressful incubation conditions. Recent developments in the multivariate analysis of sperm motility data are used to illustrate the success that can be achieved by this approach. Ideally, changes in sperm motility characteristics should be correlated with an assessment of capacitation status. However, until the capacitation status of any individual cell can be clearly defined this will remain problematic.

Research paper thumbnail of Towards the development of a genetic resource bank for the Mohor gazelle: putting theory into practice

Research paper thumbnail of Graphical approach to the analysis of fractal dimension for sperm motility

Research paper thumbnail of Oestrogen excretion as a prediction of fertility in an exotic ungulate, the Mohor Gazelle (Gazella dama mhorr)

Research paper thumbnail of Hormonal and behavioural predictors of breeding success in the Mohor gazelle (Gazella dama mhorr)

Research paper thumbnail of Assisted breeding technology in the Marsupialia: Using the koala as a reproductive model

Research paper thumbnail of Sperm motility suppression by porcine oviductal membrane proteins is not caused by inhibition of bicarbonate uptake

Research paper thumbnail of Exposure of spermatozoa to solubilized extracts of he oviductal epithelium apical plasma membrane enhances fertilization in porcine in vitro fertilization

ABSTRACT In vitro production (IVP) of porcine embryos is currently suboptimal compared with IVP i... more ABSTRACT In vitro production (IVP) of porcine embryos is currently suboptimal compared with IVP in species such as mice and cattle. In vitro fertilization (IVF) usually involves the co-culture of oocytes and spermatozoa in a medium droplet. Oocyte quality is the focus of many studies. In vivo, the quality of spermatozoa is as important as the oocyte, and females have many mechanisms to select the highest quality spermatozoa for their oocytes. Oviductal proteins have been shown to affect sperm motility of subpopulations within an ejaculate. The present study was carried out to investigate normal and polyspermic fertilization rates of spermatozoa exposed to oviductal epithelial apical plasma membrane (APM) proteins, a mixture of peripheral proteins extracted by 1 M NaCl from isolated oviductal apical plasma membranes, prior to co-culture with oocytes in IVF. Porcine oocytes were aspirated from ovaries and grade I quality oocytes (cumulus–oocyte complexes with a spherical shape, visible nucleus, even-density cytoplasm, and multiple layers of cumulus cells) were selected and matured for 48 h in TCM-199 supplemented with LH (0.5 µg mL-1), FSH (0.5 µg mL-1), and EGF (10 ng mL-1). Ejaculates were washed through a Percoll gradient to obtain a concentrated pellet. Spermatozoa were diluted in capacitation–fertilization medium in the presence or absence of APM proteins (100 µg mL-1), incubated for 10 min, and then co-cultured with oocytes for 6 h in modified Tween medium B with milk powder medium (Abeydeera and Day 1997 Theriogenology 48, 537–544) supplemented with BSA (0.4%) and sodium bicarbonate (5 mM). Presumptive zygotes were cultured in NCSU23 medium for a further 48 h. The oocytes/zygotes were then fixed and stained with propidium iodide for evaluation by confocal microscopy for fertilization and cleavage (n = 1235 oocytes). Fertilization rates were compared between treatments in a chi-squared test using the Mantel-Haenszel approach. The overall fertilization rate was significantly higher (78 vs. 86%) when spermatozoa were incubated in the presence of APM proteins (P < 0.05), and in the group of fertilized oocytes, polyspermic fertilization (47 vs. 21%) was significantly reduced when spermatozoa were exposed to APM proteins (P < 0.01). However, cleavage rates were not different. These results suggest that exposure of spermatozoa to APM proteins prior to IVF increases the fertilization rate and decreases the incidence of polyspermic penetration.

Research paper thumbnail of Oviductal membrane proteins modulate bicarbonate-induced boar sperm activationresponse

Reproduction in Domestic Animals

Research paper thumbnail of Effects of the heat shock 70 kDa protein 8 (HSPA8) on boar sperm motility

Research paper thumbnail of Postnatal growth in four Pipistrllus kuhli reared in a flight cage

Research paper thumbnail of Boar Reproduction Fundamentals and New Biotechnological Trends

Description based upon print version of record.

Research paper thumbnail of Validation of computer-assisted sperm-motility analysis in the amphibian Silurana tropicalis

Reproduction Fertility and Development

We have developed and validated a computer-assisted sperm-motility assessment (CASA) method for u... more We have developed and validated a computer-assisted sperm-motility assessment (CASA) method for use with the emerging amphibian model Silurana tropicalis. The testicular sperm-activation method was validated by analysing activation replicate coefficients of variation, effects of tracking time settings on velocity distributions and the relative partitioning of differentially motile sperm subpopulations between matched right and left testes. Two major sperm subpopulations were identified using multivariate pattern analysis and their relative frequencies were consistent between samples from matched right and left testes and from randomly drawn subsets of six frogs sampled from the total set of 16 frogs. The power of this approach for detecting treatment effects targeting the hypothalamic–pituitary–­gonadal axis was investigated by injecting a group of frogs with 100 IU human chorionic gonadotrophin (hCG) 2 h before sampling and comparing their sperm-subpopulation frequencies with non-i...

Research paper thumbnail of Do sperm possess a molecular passport? Mechanistic insights into sperm selection in the female reproductive tract

Molecular human reproduction, Jan 9, 2015

Most male mammals produce far more spermatozoa on a daily basis than is strictly necessary for re... more Most male mammals produce far more spermatozoa on a daily basis than is strictly necessary for reproduction and females have evolved mechanisms that prevent all but a small minority from reaching the vicinity of their oocytes. One potential explanation for the stringent selection is that females have developed these mechanisms as a way of avoiding polyspermy as well as exercising post-copulatory choice over the characteristics of the fertilizing spermatozoon. Relatively little is known about how these processes would operate, but here we use evidence from biochemical, molecular and genetic studies of sperm transport in support of a hypothesis proposing that the female reproductive tract can read and interpret a spermatozoon's 'molecular passport' or genetic signature. Such a signature would permit only a highly selected sperm population to reach and fertilize the oocyte. Moreover, the selection criteria might not only be concerned with successful fertilizing ability, but...

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