Effect of silver nanoparticles on donkey sperm parameters and ultrastructure.

The aim of this study was to determine the effect of silver nanoparticles (AgNPs) on donkey sperm parameters and ultrastructure. AgNPs were synthesized, purified and resuspended in the extender. Nine frozen-thawed donkey sperm samples were exposed to different concentrations of AgNPs (0, 1.

Unveiling the Role of IGF-I in Fertility: Effect of Long-Acting Bovine Somatotropin (bST) on Terminal Follicular Development and Fertility during an Annual Reproductive Cycle in Sheep.

The study aimed to assess the effect of long-acting bST treatment, in a dose that only increases IGF-I plasma concentrations, on ovarian and fertility markers of estrous synchronized ewes that were fed to keep their bodyweight. Three experiments were designed to evaluate this effect: in Experiment 1, 18 ewes were distributed in groups (bST 0, 30, 50 mg) to measure plasma IGF-I and insulin for 15 days; in Experiment 2, 92 ewes (5 replicates) in two groups (0 and 30 mg bST) were synchronized using a 6-day progesterone protocol during the breeding season to assess the effect of bST on follicular and luteal performances, estrous and ovulation, and fertility after mating. In Experiment 3, 50 ewes (3 replicates) were used to repeat the study before but during anestrus.

A Subovulatory Dose of Human Chorionic Gonadotropin (hCG) May Sustain Terminal Follicle Development and Reproductive Efficiency during Anestrus in Sheep.

The study tested the hypothesis that a single administration of hCG supports the LH-dependent phase of terminal follicular development in synchronized sheep during anestrus, using eCG as a functional reference. Using a clinical approach, four experiments were designed to achieve the following: (1) Identify the inhibitory influence of anestrus on reproduction efficiency; (2) Assess the potential of hCG to keep functional blood concentrations after a single dose; (3) Characterize the effect of different doses of hCG on reproductive functional markers; (4) To compare the ability of hCG to that of eCG to support follicular development and fertility based on the same markers. The results showed that anestrus seems to affect follicular and luteal function under LH dependency as FSH-dependent markers are not compromised; hCG maintains higher blood concentrations than controls for at least 48 h; hCG improves follicular development and ovulatory rates compared to controls and at standards comparable to a breeding season; and ewes treated with hCG exhibit similar performance to those treated with eCG.

l-carnitine enhances the kinematics and protects the sperm membranes of chilled and frozen-thawed Peruvian Paso horse spermatozoa.

l-carnitine (LC) transports fatty acids to the mitochondria for energy production, reducing lipid availability for peroxidation through β-oxidation. This research examines the effect of LC supplementation to two skimmed milk-based extenders on the cryosurvival of chilled (5°C) and frozen-thawed Peruvian Paso horse spermatozoa .An initial experiment determined the optimal LC concentration (0, 1, 5, 10, 25, and 50 mM) when added to INRA-96® and UHT (skimmed milk + 6% egg yolk) extenders, using nine ejaculates from three stallions chilled for up to 96 h.

Selection and Conservation of Gametes and Embryos for Improving Assisted Reproductive Technologies.

We are delighted to present this Special Issue, which is dedicated to the paramount subject of gametes and embryo selection and conservation for improving Assisted Reproductive Technologies (ARTs) [...

Effect of Melatonin and Caffeine Supplementation to Freezing Medium on Cryosurvival of Peruvian Paso Horse Sperm Using a Two-Step Accelerating Cooling Rate.

This research examined the antioxidant and cryoprotective effects of melatonin (ME) and caffeine (CAF) supplementation in freezing medium on the cryosurvival of Peruvian Paso horse sperm using a two-step accelerating cooling rate. Twenty ejaculates from four adult and fertile stallions were recovered, initially diluted with INRA-96, and finally frozen with INRA-Freeze with either no supplementation (as control), 1 μM ME, or 2 mM CAF using a two-ramp freezing system content inside a cryogenic-box and liquid nitrogen vapors. The sperm kinematic parameters and integrity of the plasma and acrosomal membranes of fresh semen and cryopreserved samples were evaluated using the CASA system (SCA-Evolution 2018) and PI/fluorescein isothiocyanate-conjugated peanut (Arachis hypogaea) agglutinin double fluorescent test, respectively.

DNA fragmentation of equine cumulus cells from Cumulus-Oocyte complexes submitted to vitrification and its relationship to the developmental competence of the oocyte.

The objectives of this study were to evaluate the effect of vitrification on the DNA fragmentation rate of equine cumulus cells and to assess its relationship to oocyte in vitro maturation (IVM) after vitrification. Cumulus cells (CC) from 14 mares were recovered from COCs, previously submitted to vitrification (VIT) and IVM. The DNA fragmentation rate of the cumulus cells (CC-DF) was assessed using a chromatin dispersion test.

Bicarbonate-Triggered In Vitro Capacitation of Boar Spermatozoa Conveys an Increased Relative Abundance of the Canonical Transient Receptor Potential Cation (TRPC) Channels 3, 4, 6 and 7 and of CatSper-γ Subunit mRNA Transcripts.

Sperm capacitation is a stepwise complex biochemical process towards fertilization. It includes a crucial early calcium (Ca) transport mediated by CatSper channels and Canonical Transient Potential Channels (TRPC). We studied the relative abundance of mRNA transcripts changes of the β, γ and δ subunits and -channels 1, 3, 4, 6 and 7 in pig spermatozoa, after triggering in vitro capacitation by bicarbonate ions at levels present in vivo at the fertilization site.

Hormonal Management for the Induction of Luteolysis and Ovulation in Andalusian Jennies: Effect on Reproductive Performance, Embryo Quality and Recovery Rate.

Two prostanglandins (luprostiol, LUP, and dinoprost, DIN) and two ovulation-inducing agents (human Chorionic Gonadotropin, hCG, and deslorelin, DES) were evaluated for luteolysis and estrus induction, and for ovulation induction, respectively, in embryo donor jennies. Twenty-six fertile Andalusian jennies were used. In Experiment 1, jennies ( = 112 cycles) were randomly treated with either LUP or DIN after embryo flushing.

Sperm morphometry is affected by increased inbreeding in the Retinta cattle breed: A molecular approach.

The effect of inbreeding depression on sperm motility is well documented, but its influence on sperm morphometry has been scarcely examined to date. Here, we combined the use of computer-assisted sperm morphometry analysis (CASMA) with a SNP-based genomic approach to determine and characterize the effect of inbreeding on the sperm shape of a highly inbred cattle population. We determined seven morphometric parameters on frozen-thawed sperm samples of 57 Retinta bulls: length (L, µm), width (W, µm), area (A, µm ), perimeter (P, µm), ellipticity (ELI; L/W), elongation (L-W)/(L + W) and perimeter-to-area shape factor (p2a; P /4 × π × A).

Vitrification of donkey sperm using straws as an alternative to conventional slow freezing.

Cryoprotectant-free vitrification of donkey sperm using 0.25 ml straws has been recently developed, but the obtained results have not been directly compared to conventional slow freezing yet. The aim of this study was to compare sperm quality parameters after cryopreservation using both methods.

Vitrification of Donkey Sperm: Is It Better Using Permeable Cryoprotectants?

Vitrification by direct exposure of sperm to liquid nitrogen is increasing in popularity as an alternative to conventional freezing. In this study, the effect of permeable cryoprotectant agents for donkey sperm vitrification was compared to an extender containing non-permeable cryoprotectants. First, three different concentrations of sucrose (0.

Assessment of Dog Testis Perfusion by Colour and Pulsed-Doppler Ultrasonography and Correlation With Sperm Oxidative DNA Damage.

The assessment of testicular artery blood flow by colour and pulsed-Doppler ultrasonography is an important diagnostic technique to assess vascular perfusion. Recently, it has been suggested as a good predictor of sperm quality. On the other hand, through the alkaline Comet Assay, it is possible to quantify sperm oxidative DNA damage.

The Effect of Different Vitrification and Staining Protocols on the Visibility of the Nuclear Maturation Stage of Equine Oocytes.

In this study, we compared two staining protocols assessing the nuclear chromatin stage of equine oocytes after vitrification using permeable and nonpermeable cryoprotectants. Slaughterhouse-derived oocytes (n = 155) were obtained from a total of 32 mares and in vitro matured in M199 medium for 42 hours at 38.5°C in 5% CO In the first experiment, two concentrations of Hoechst 33342 (HO) were tested (10 μg/mL; P1 and 2.

Comparison of different mathematical models to assess seasonal variations in the longevity of DNA integrity of cooled-stored stallion sperm.

Dynamic assessment of sperm DNA fragmentation (SDF) has shown to give fuller understanding of stallion semen quality; however, there have been limited attempts to use this parameter to investigate seasonal changes in productive functions. The aims of this study were to: (a) establish a reliable mathematical model to describe the longevity of cooled-stored sperm DNA integrity; (b) to examine the effect of seasonal variations on SDF. Ejaculates were cooled to 5°C, and SDF was analysed after 0, 6 and 24 hr of storage.

Vitrification of Large Volumes of Stallion Sperm in Comparison With Spheres and Conventional Freezing: Effect of Warming Procedures and Sperm Selection.

Stallion sperm was vitrified using straws in comparison with spheres and conventional freezing. Vitrification was performed plunging 30 μL of sperm (spheres) or 0.5 mL straws into liquid nitrogen (LN) and conventional freezing using 0.

Low-density lipoproteins and milk serum proteins improve the quality of stallion sperm after vitrification in straws.

Lipids and proteins can be used for sperm vitrification to preserve the integrity of sperm membranes or to increase the viscosity of the medium. This study evaluated the effect of low-density lipoproteins (LDL) and milk serum proteins (Pronexcell) for stallion sperm vitrification. Hippex extender (Barex Biochemical Products, The Netherlands), plus 1% of bovine serum albumin and 100 mM of trehalose, was used as control for sperm vitrification.

Relationship between DNA fragmentation of equine granulosa cells and oocyte meiotic competence after in vitro maturation.

The acquisition of equine oocyte developmental capacity is ensured by the follicular environment, such as granulosa cells, which could reflect the meiotic development potential of immature oocytes. This study evaluated the relationship between DNA fragmentation of granulosa cells, using the chromatin dispersion test, and equine oocyte meiotic development after in vitro maturation. Granulosa cells and cumulus-oocytes complexes (n = 50) were recovered from slaughterhouse-derived ovaries.

Effect of permeable cryoprotectant-free vitrification on DNA fragmentation of equine oocyte-cumulus cells.

DNA fragmentation of cumulus cells could be used as an indicator of oocyte vitrification success as an indirect indicator of the quality of the oocyte. This study was designed to compare the DNA fragmentation of post-mortem equine cumulus cells before or after vitrification in the absence of permeable cryoprotectant agents. Cumulus-oocyte complexes (COCs; n = 56) were recovered from slaughterhouse ovaries and subjected to in vitro maturation (42 hr/38.

Evaluation of DNA Damage of Mare Granulosa Cells Before and After Cryopreservation Using a Chromatin Dispersion Test.

DNA fragmentation of granulosa cells might be related to developmental competence of the equine oocyte. Granulosa cells are commonly stored before DNA fragmentation assessment, but the effect of preservation methods on this parameter remains unexplored. The aim of this study was to evaluate whether or not cryopreservation of granulosa cells affects the DNA damage.

A new molecular screening tool for the detection of chromosomal abnormalities in donkeys.

Chromosomal abnormalities are a major cause of infertility and reproductive problems in equids. Nowadays, their detection is rising due to the use of new diagnostic tools based on molecular markers instead of karyotyping. Reports of this kind of genetic aberrations in domestic donkeys (Equus asinus) are extremely scarce, despite their importance in human activities.

New approach to assess sperm DNA fragmentation dynamics: Fine-tuning mathematical models.

Background: Sperm DNA fragmentation (sDF) has been proved to be an important parameter in order to predict in vitro the potential fertility of a semen sample. Colloid centrifugation could be a suitable technique to select those donkey sperm more resistant to DNA fragmentation after thawing. Previous studies have shown that to elucidate the latent damage of the DNA molecule, sDF should be assessed dynamically, where the rate of fragmentation between treatments indicates how resistant the DNA is to iatrogenic damage.