Zygote最新文献

The secondary metabolites of several plant species, particularly sesquiterpenic lactones (SLs) have been studied by different research groups for over 30 years. This group of metabolites presents numerous biological activities such as antibacterial, antiviral, antiulcer, cell proliferation inhibitor, and oocyte activator with participation in exocytosis processes. This study aims to assess some sperm parameters in epididymal gametes of Chichilla lanigera exposed to increasing concentrations (0 to 2 mM) of DhL for various incubation times from 10 to 40 minutes. We determined the participation of different cell signalling pathways in the induced acrosome reaction. Our results showed an alteration in the progressive motility pattern and cell viability depending on DhL concentration and exposure time of gametes. When analyzing acrosomal status, higher percentages than the negative control were obtained in all tested doses. Both isolated and joint inhibition tests of PKA and phospholipases (PLC and PLA₂) showed a greater participation of PI-PLC. This is the first report concerning the effects of this lactone on the medium of sperm incubation. Consequently, further studies will be necessary to determine the molecular implications of this lactone on the fertilizing potential of the sperm.

Substance use refers to the consumption of drugs that have varying degrees of impact on a persons' physical, mental and emotional well-being. While the adverse health effects of drugs have been extensively documented, further research is needed to understand their impact on fertility. Studies have indicated that substance use affects both the male and female reproductive systems. As substance use is more prevalent among young adults compared with the elderly, it appears that individuals of reproductive age are particularly vulnerable to the reproductive impairments associated with substance use. Although numerous studies have reported detrimental effects of substance use on pregnant women and their foetus during the post-implantation stages, there are limited studies on critical pre-implantation period and gamete stages. In this narrative review, we aimed to focus on the most significant evidence regarding the impact of substances on gametes and pre-implantation embryos.

Human oocyte maturation is a lengthy process that takes place over the course of which oocytes gain the inherent ability to support the next developmental stages in a progressive manner. This process includes intricate and distinct events related to nuclear and cytoplasmic maturation. Nuclear maturation includes mostly chromosome segregation, whereas rearrangement of organelles, storage of mRNAs and transcription factors occur during cytoplasmic maturation.Human oocyte maturation, both in vivo and in vitro, occurs through a process that is not yet fully understood. However, it is believed that the second messenger, cyclic adenosine monophosphate (cAMP), plays a pivotal role in the upkeep of the meiotic blocking of the human oocyte. Relatively high levels of cAMP in the human oocyte are required to maintain meiosis blocked, whereas lower levels of cAMP in the oocyte enable meiosis to resume. Oocyte cAMP concentration is controlled by a balance between adenylate cyclase and phosphodiesterases, the enzymes responsible for cAMP generation and breakdown.In addition to nuclear maturation, the female gamete requires a number of complicated structural and biochemical modifications in the cytoplasmic compartment to be able to fertilize normally. According to ultrastructural studies, during the transition from the germinal vesicle stage to metaphase II (MII), several organelles reorganize their positions. The cytoskeletal microfilaments and microtubules found in the cytoplasm facilitate these movements and regulate chromosomal segregation.The aim of this review is to focus on the nuclear and cytoplasmic maturation by investigating the changes that take place in the process of oocytes being competent for development.

Fungal metabolites are known to have potent and diverse properties such as antiviral, antidiabetic, antitumour, antioxidant, free radical scavenging, and antibacterial effects which can be utilized to treat diseases. In this study, we investigated the functional activity of stereumamide A (StA) derived from a culture broth of Trichaptum fuscoviolaceum during the in vitro fertilization (IVF) of pig oocytes, to determine its effects on sperm penetration. Oocytes matured in vitro were fertilized in the absence or presence of varying concentrations of StA (0-50 μg/ml StA). When StA was directly added into the IVF medium, significantly lower fertilization rates were seen with the 20 or 50 μg/ml StA (2.0-17.5%) treatments compared with those of 10 μg/ml StA or the controls (60.9-62.3%), whereas StA had no influence on the survival of oocytes and spermatozoa throughout the IVF process. For evaluating the control of sperm entry, mature oocytes were pre-incubated in a medium containing 20 μg/ml StA for 1 h, and then IVF was subsequently performed. The incidence of polyspermy was significantly reduced when oocytes were pre-incubated with StA (15.0% vs. 50.4-57.5% in controls). In conclusion, sperm penetration was inhibited in the medium in the presence of StA during IVF, while StA did not affect sperm motility and fertility competence. Fertilization was controlled when mature oocytes were incubated with StA prior to IVF, suggesting the possible use of the fungal metabolite in assisted reproductive technology for humans and animals.

In Assisted Reproductive Technologies (ART), efficient sperm preparation is vital for successful fertilization, with washing media enhancing the process. This pilot study examines the molecular-level impact of a new serotonin-containing sperm-washing medium (Prototype) on sperm motility and ROS metabolism, comparing it with commercially available media (Origio and Irvine). Semen samples from thirty-one individuals underwent preparation using the swim-up method post-semen analysis. Each sample was separately washed with the Prototype, Origio and Irvine mediums. ROS formation was determined through flow cytometric, and AT2R and PRDX2 protein levels, associated with sperm motility, were assessed via Western blot. Statistical evaluation compared the findings among the three outlined media. Significant differences were found among three washing media in terms of total and progressive motility. The Prototype medium showed the highest increase in both total (66%) and progressive motility (59%), while the control group exhibited the lowest increases (41% and 27.7%, respectively). Regarding ROS levels, the prototype (11.5%) and Origio (10.7%) groups demonstrated a notable decrease, contrasting with Irvine (25.8%). Molecular assessment revealed a significant elevation in AT2R protein levels in the prototype medium (59%), compared to other media. Additionally, an increase in PRDX2 protein levels was observed in the prototype medium, although this didn't reach statistical significance. Serotonin-activated washing media for sperm preparation can be a suitable choice for selecting high-quality sperm in ART. A broader molecular analysis with a larger sample size is required to explore the mechanisms and effectiveness of using a serotonin-containing sperm-washing medium in routine ART.

Hydrogen sulfide (H₂S) has been shown to play a significant role in oxidative stress across various tissues and cells; however, its role in sperm function remains poorly understood. This study aimed to investigate the protective effect of GYY4137, a slow-releasing H₂S compound, on sperm damage induced by H₂O₂. We assessed the effects of GYY4137 on motility, viability, lipid peroxidation and caspase-3 activity in human spermatozoa in vitro following oxidative damage mediated by H₂O₂. Spermatozoa from 25 healthy men were selected using a density gradient centrifugation method and cultured in the presence or absence of 10 μM H₂O₂, followed by incubation with varying concentrations of GYY4137 (0.625-2.5 μM). After 24 h of incubation, sperm motility, viability, lipid peroxidation, and caspase-3 activity were evaluated. The results indicated that H₂O₂ adversely affected sperm parameters, reducing motility and viability, while increasing oxidative stress, as evidenced by elevated lipid peroxidation and caspase-3 activity. GYY4137 provided dose-dependent protection against H₂O₂-induced oxidative stress (OS). We concluded that supplementation with GYY4137 may offer antioxidant protection during in vitro sperm preparation for assisted reproductive technology.

L-carnitine has an important role in the control of oxidative stress and lipid β-oxidation during in vitro culture and cryopreservation of ovarian follicles, oocytes and embryos. This substance balances the acetyl-CoA/CoA ratio, maintains glucose metabolism and increases energy production in mitochondria. It also plays a key role in reducing endoplasmic reticulum stress, by transferring palmitate to mitochondria or eliminating it to avoid toxicity. By eliminating reactive oxygen species, L-carnitine increases the percentages of mature oocytes with uniform mitochondrial distribution and improves embryo post-thaw cryotolerance. Therefore, L-carnitine controls lipid β-oxidation and oxidative stress during in vitro culture of ovarian follicles, oocyte maturation, embryonic development and cryopreservation.

The study was conducted on indigenous Tharparkar cow (Bos indicus) to evaluate FSH stimulation on follicular attributes, oocyte recovery and morpho-molecular developmental competence parameters concerning oocyte quality. A total of 20 OPU sessions were performed, which included 10 sessions in each FSH stimulated at the dose of 130 µg divided into four sub-doses and non-stimulated. Findings on the size of follicles having ≥6 mm showed a significantly higher, however an opposite trend was observed in the case of smaller sized follicle (<6 mm) between stimulated and non-stimulated respectively. The stimulated cows had a significantly higher number as well as the percentage of oocytes of Grade A, having a diameter ≥120 µm and BCB^+VE as compared to the non-stimulated cows. The relative mRNA expression profile of GDF9, BMP15, PCNA and BCL-2 genes was higher and BAX was lower in the FSH-stimulated cow. These results indicated that FSH stimulation before OPU in Bos indicus cows has a significant impact on follicle size, oocyte yield, recovery, and their quality with respect to COC's, diameter and BCB^+VE oocytes. Further, a significant increase in the relative mRNA expression levels of GDF9, BMP15 and PCNA genes in the FSH-stimulated group suggests that FSH plays a key role in modulating the expression of these important candidate genes and thus influencing oocyte quality. The higher mRNA expression of BCL-2 genes and concomitantly lower expression of BAX gene in FSH Stimulated cows indicates the protective role of these genes and preventing programmed cell death and thus promoting cell survival, quality and embryo development.

Until a few years ago, it was assumed that oocyte renewal did not take place in the ovary of adult organisms; however, the existence of germline progenitor cells (GPCs), which renew the ovarian follicular reserve, has now been documented in mammals. Specifically, in the adult ovary of bats, the presence of cells located in the cortical region with characteristics similar to GPCs, called adult cortical germ cells (ACGC), has been observed. One of the requirements that a GPC must fulfil is to be able to proliferate mitotically, so the evaluation of cell proliferation in ACGC is of utmost importance in order to be able to relate them to a parental lineage. Currently, there are several methods to determine cell proliferation, including BrdU labelling or the use of endogenous proliferation markers. Thus, the aim of this work was to evaluate the proliferative activity of ACGC in the adult ovary of the bat Artibeus jamaicensis, using different proliferation markers and correlating these with the protein expression of the transcription factor Oct4 and the germ line marker Ddx4. We found that the expression pattern of the proliferation markers BrdU, PCNA, Ki-67 and pH3 occurs at different times of the cell cycle, so co-localization of two or more of these markers allows us to identify proliferating cells. This allowed us to identify ACGC with proliferative capacity in the adult ovary of A. jamaicensis, suggesting that GPCs renew the follicle reserve during the adult life of the organism.

Boric acid (BA) is an important mineral for plants, animals and humans that assists metabolic function and has both positive and negative effects on biological systems. The present study aimed to investigate the effects of different concentrations of BA added to the culture media, the quality and in vitro development potential of mouse embryos. Superovulated C57Bl6/6j female mice were sacrificed ∼18 hours after human chorionic gonadotropin (hCG) injection. Single-cell-stage embryos were collected from the oviduct, divided into experiment groups and cultured in embryo medium with supplemented BA+ in 5% CO₂ at 37 °C until 96 hours at the blastocyst stage. The blastocyst development rates of 0, 1.62 × 10^-1, 1.62 × 10^-2, 1.62 × 10^-3 and 1.62 × 10^-4 µM BA were 51.52%, 73.47%, 77.36% and 81.13%, respectively. The in vitro development rates were significantly higher in the 1.62 × 10^-3 (p < 0.05) and 1.62 × 10^-4 µM BA groups than in the control group (p < 0.001). These results indicated that low BA doses influenced embryo development by positively affecting in vitro development rates, embryo cell numbers, biochemical parameters and development at the molecular level by pluripotent and antioxidant genes. Therefore, BA seems to play an important role on in vitro embryo development.