Search results for " fertilization"
showing 10 items of 167 documents
New molecular markers for the evaluation of gamete quality.
2013
Purpose: Only 30 % of IVF cycles result in a pregnancy, so that multiple embryos need to be replaced, per treatment cycle, to increase pregnancy rates, resulting in a multiple gestation rate of 25 %. The use of new markers in the gamete selection, could reduce the number of the oocytes to be fertilized and embryos to be produced, but the tools to evidence the gamete competence remain unavailable and more studies are needed to identify bio-markers to select the best oocyte and sperm to produce embryos with higher implantation potentiality. Methods: To define oocyte competence, the apoptosis of the surrounding cumulus cells and the oxygen consumption rates for individual oocytes before fertil…
Cholinergic Control of Synchronized Seminal Emissions in Drosophila
2004
0960-9822 (Print) Comparative Study Journal Article Research Support, Non-U.S. Gov't; In many animal species, copulation involves the coordinated release of both sperm and seminal fluid, including substances that change female fertility and postmating behavior. In Drosophila melanogaster, these substances increase female fertility and prevent mating with a second male. By using a PGal4 strain, we targeted together with other cells a dozen cholinergic neurons found only in the male abdominal ganglion (Abg-MAch). Genetic feminization apparently deleted these neurons in males and significantly increased their copulation duration, blocked their fertility in 60% of cases, and only weakly repress…
A mathematical model for the phase of sexual reproduction in monogonont rotifers
2000
Recently, the optimal sex allocation in monogonont rotifers is studied in [1], and, as a closely related question, the relative frequencies of the relevant types of mictic females. The authors focus on the evolution of the age at which young mictic females lose their fertilization susceptibility and they address the threshold age of fertilization that maximizes resting egg production. Assuming that a stationary population is achieved, with stable age distribution, they obtain their results, without knowing the stationary population. Our aim is to study this problem in the framework of the theory of nonlinear age-dependent population dynamics developed by G. F. Webb in [13], which is more ap…
Induced hyperactivity in boar spermatozoa and its evaluation by computer-assisted sperm analysis.
2004
Hyperactivity, a form of sperm motility characterized by vigorous flagellar movements, has been proposed as essential for fertilization in mammals. The objective of the present study was to establish a method for inducing hyperactivityin vitroin boar spermatozoa and to define threshold values to differentiate between hyperactive and non-hyperactive spermatozoa by computer-assisted sperm analysis (CASA) as a prerequisite for analyzing the energy metabolism during hyperactivity. In TALP-HEPES medium, non-frozen boar spermatozoa were stimulated to hyperactivity by 50 μmol l−1Ca2+within 15 min at 37 °C if 5 μmol l−1of the Ca2+ionophore A23187 was present. If 25% seminal plasma was present, boar…
The E-modulus of the oocyte is a non-destructive measure of zona pellucida hardening
2021
Reproduction 162(4), 259-266 (2021). doi:10.1530/REP-21-0122
Occurrence of the interference of sperm-associated antibodies on sperm fertilizing ability as evaluated by the sperm-zona pellucida binding test and …
1997
PROBLEM: This study was performed to evaluate the occurrence as well as the level of the interference of sperm-associated antibodies on fertilization process. METHOD: Motile sperm suspensions from 28 infertile patients with high degree of autoimmunization against the sperm head were tested with the zona pellucida (ZP) binding test and with the sperm penetration assay (SPA) enhanced with TEST-yolk buffer. Both tests were also performed using donor sperm exposed and non-exposed to the patients' circulating sperm antibodies. RESULTS: A low ZP-binding was exhibited by sperm from 50% of patients with normal semen profile. All normozoospermic patients with low ZP-binding showed circulating sperm-…
Effect of genistein added to bull semen after thawing on pronuclear and sperm quality.
2015
The aim of this research was to study the effect of different genistein treatments on bull sperm after thawing on pronuclear formation after in vitro fertilization (IVF) and on different sperm quality variables. Three experiments were performed. In Experiment 1, three treatments (Control, sperm incubation for 1 h at 37 degrees C with or without genistein) and two sperm concentrations during IVF (I or 3 x 10(6) sperm/mL) were evaluated to study the influence of genistein on pronuclear formation (PNF). Sperm incubation for 1 h before IVF reduced PNF regardless of sperm concentration. However, after sperm incubation and with 3 x 10(6) sperm/mL in IVF, the genistein treatment group had greater …
Fetuin-B, a liver-derived plasma protein is essential for fertilization.
2013
SummaryThe zona pellucida (ZP) is a glycoprotein matrix surrounding mammalian oocytes. Upon fertilization, ZP hardening prevents sperm from binding to and penetrating the ZP. Here, we report that targeted gene deletion of the liver-derived plasma protein fetuin-B causes premature ZP hardening and, consequently, female infertility. Transplanting fetuin-B-deficient ovaries into wild-type recipients restores fertility, indicating that plasma fetuin-B is necessary and sufficient for fertilization. In vitro fertilization of oocytes from fetuin-B-deficient mice only worked after rendering the ZP penetrable by laser perforation. Mechanistically, fetuin-B sustains fertility by inhibiting ovastacin,…
Effect of dietary supplementation with a mixture of Vitamins C and E on fertilization of tertiary butyl hydroperoxide-treated oocytes and parthenogen…
2002
The present study aims to analyze the effect of dietary supplementation with a mixture of Vitamins C and E on fertilization and later development of tertiary butyl hydroperoxide (tBH)-treated mouse oocytes and on parthenogenetic activation of freshly ovulated mouse oocytes. We fed hybrid mice a standard diet supplemented or not supplemented with Vitamins C and E from the first day of weaning until the age of 12 weeks. We noted no significant effect of diet on fertilization rate, percentage of total and hatching blastocysts, total number of cells, mitotic index and percentage of apoptotic nuclei at 120 h post-insemination of oocytes incubated for 15 min in the presence of 0, 1, 5 and 10 micr…
The significance of premature luteinization in an oocyte-donation programme
2006
BACKGROUND: Several evidences indicate that premature luteinization (PL) may affect IVF outcome. The primary end-point of the present study was to verify the effect of PL on the pregnancy rate (PR) of our oocytedonation programme. METHODS: PL was defined as serum progesterone ³1.2 ng/ml on the day of HCG. We analysed retrospectively 240 oocyte-donation cycles in which 120 women donated twice, with PL in the first donation cycle and no PL in the following one, acting as its own control. Recipients (n = 240) were divided in two groups according to the presence of PL (n = 120) or not (n = 120). Both groups were compared regarding donor cycle parameters and recipient cycle outcome. RESULTS: The…