تخمک

Oocyte culture conditions are critical determinants of the success of in vitro fertilization; therefore, the use of compounds that help preserve oocyte quality in the extracellular environment is essential. Evening primrose seed oil (EPO) is a rich source of potent antioxidants, and its role in modulating cytotoxic reactions has been well documented. The aim of the present study was to investigate the impact of EPO on the quality of oocytes cultured in vitro.

In this experimental study, 35 female Naval Medical Research Institute (NMRI) mice, aged 5 to 6 weeks, were randomly assigned to five groups. To induce ovulation, the mice were injected with gonadotropin hormones, and 48 hours later, they were euthanized via cervical dislocation. Oocytes were extracted from the ovaries and categorized into the following groups: a control group (no treatment), an MO-treated group, an EPO-treated group, a group treated with a 50:50 (v/v) mixture of EPO and MO, and a group treated with a 25:75 (v/v) mixture of EPO and MO. Oocyte viability was assessed by counting under an inverted microscope. The expression levels of growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15) genes were evaluated using quantitative real-time PCR (qRT-PCR). One-way analysis of variance (ANOVA) followed by Tukey’s post-hoc test was used for statistical analysis.

Under EPO treatment, the oocyte viability rate reached 92.3%, representing the highest value observed among all groups. In the EPO-treated group, BMP15 gene expression increased by 1.88 ± 0.06-fold, while GDF9 gene expression increased by 1.36 ± 0.08-fold compared to the control group. In contrast, in the MO-treated group, BMP15 gene expression decreased to 0.52 ± 0.04-fold, and GDF9 gene expression decreased to 0.60 ± 0.02-fold, relative to the control group.

Based on the results, evening primrose oil (EPO) may enhance oocyte viability and quality in the culture medium by preserving the expression of GDF9 and BMP15 genes.

Glyphosate is the most popular broad-spectrum herbicide globally due to the growing demand for glyphosate-resistant crops. Glyphosate exhibits harmful properties, including cytotoxicity, neurotoxicity, and reproductive toxicity. This study aimed to investigate the detrimental effects of glyphosate on ovarian histopathology in mice and the in vitro maturation (IVM) of oocytes following superovulation.

In this study, thirty-two female NMRI mice were randomly divided into the following groups: control, glyphosate, superovulation, and superovulation-glyphosate. Animals received glyphosate (0.5%) continuously through drinking water for three weeks. HMG and HCG were used to induce superovulation. Oocytes were collected from the ampulla, and the quantity and quality of oocytes were analyzed. Then, in vitro maturation (IVM) of oocytes was performed. At the end of the study, ovarian histopathology was analyzed.

Compared to the control group, the glyphosate-treated group exhibited a significant decrease in secondary and Graafian follicles while demonstrating a concomitant increase in atretic follicles (P < 0.05). Additionally, the superovulation-glyphosate group showed fewer germinal vesicle breakdown (GVBD) and MII oocytes than the superovulation group. In the superovulation-glyphosate group, there was a notable reduction in GVBD and MII oocytes following in vitro maturation (IVM).

Glyphosate has the potential to damage ovarian tissue and adversely affect IVM and oogenesis.

To assist save endangered species from extinction and to aid in their care, it is crucial to sustaining their reproductive capacity. The fetus's life and growth processes begin at conception and proceed in accordance with a biological clock's timing. With today's understanding through cryobiology, observing scientific ethics problems and interfering with the clock's operation by stopping its biological time is possible. Practically, it is accomplished by storing the cell at -196 °C, or the temperature of liquid nitrogen, where all metabolic activity ceases. Since 200 years ago, germ cell preservation has been a common practice. Since then, there have been many improvements, particularly for at-risk women. Since then, significant progress has been achieved, and several freezing techniques are being used to preserve ovarian tissue, follicles, and oocytes in women who are at risk of infertility. Different approaches have different levels of success. Among preservation techniques, vitrification performs better and is used more frequently. The cellular configuration of the mammalian oocyte is intricate. This cell's constituent parts are particularly sensitive to osmosis and variations in temperature. For instance, the alterations to the cell membrane that occur during maturation, in vitro fertilization, and the differential between the permeability of water and cryoprotectants can all be mentioned. Oocyte freezing results in a variety of impairments, including a reduction in the quality and viability of cells after thawing.

Recent studies are looking for ways to enhance freezing procedures and raise the caliber of frozen oocytes. The favorable or negative effects of freezing on the oocyte and its potential, or embryo development, are the subject of this review article.

Stress is known to affect many reproductive variables, including gonadotropins and sex steroid levels. Stressors such as crowding can alter the normal function of the ovaries, fallopian tubes, and uterine cycles. In the this study, we investigated the effect of crowding stress on mice oocyte parameters and reproductive organs.

Mice were divided into control, low & high- density crowding stress groups, and kept under stres condition for one month. Superovulation was induced in the mice in all groups by pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG). The mice were sacrificed 15 hours after hCG injection. Grade I and IV oocytes were stained with the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) method after collection and evaluation. Ovarian, fallopian tubes and uterine horns tissues were evaluated after staining with hematoxylin and eosin (H&E). Data were analyzed by ANOVA. p-value ≤0.05 was considered significant.

The number of grade I and the size of grades I and IV oocytes in the high-density crowding stress group were significantly decreased compared to those in the control group. The rate of DNA fragmentation of grade I and IV oocytes in the low and high- density crowding stress groups demonstrated a significant increase compared to that in the control group. The number of monolayer primary follicles and the height of the fallopian tube epithelium significantly decreased in the high- density crowding stress group compared to those in the control group (p≤0.05).

Crowding as an environmental stress can affect DNA fragmentation by inducing irregularities in follicular and oocyte development.

Increasing levels of free radicals in the ova reduce the quality of their fertilization. Investigations have revealed the elevated production of tissue and serum-free radicals in women with polycystic ovary syndrome. Sirtuin-3 is located in mitochondria and plays an important role in the deactivation of free radicals. This study aimed to investigate the expression of the Sirtuin-3 gene in the ova of polycystic ovary syndrome affected mice.

Polycystic ovary syndrome was induced by the injection of estradiol valerate (40 mg/kg) in six NMRI mice (age: six weeks old; weight: 25±5); moreover, six mice were selected as a control group. Following the induction, the structure of the ovaries was examined using the histotechnique, and the serum levels of sex hormones were determined using ELISA. The ova were collected from the ovaries, and their RNA was extracted by a special kit and converted to cDNA. Real-Time PCR was performed to analyze the expression of Sirtuin-3, and the Gapdh gene was selected as an internal control.

In the mice with polycystic ovary syndrome, hydatid cysts were formed in the ovaries. Furthermore, serum FSH hormone levels decreased in the affected mice, while LH and testosterone levels elevated, compared to those in the control mice (P<0.001). The expression of Sirtuin-3 was reduced in the ova of mice with polycystic ovary syndrome, compared to that in healthy mice in the ratio of 0.18 (P<0.05).

The result of the present study showed that the expression of the Sirtuin-3 gene was decreased in the ovum of mice with polycystic ovary syndrome. Moreover, the disrupted expression of the Sirtuin-3 in the ovum can be suggested as one of the causes of reduced quality of the ovum in patients with polycystic ovary syndrome.

Atorvastatin is one of the high blood cholesterol treatment drugs that recently has been shown to have antioxidant effects in the cell. The aim of this study was to investigate the effects of atorvastatin on in vitro growth and quality of immature mouse oocytes.

Oocytes of 40 NMRI mice were removed after stimulation of ovulation and placed in culture medium. The oocytes were divided into two groups of 200 including control (culture medium) and atorvastatin group (culture medium + 2 μM atorvastatin). Then oocyte qualitative parameters of Zona pellucida thickness (ZP), Perivitelline space size (PVS) and egg diameter (OD) were determined using invert microscope and image-J software.

Quantitative parameters of Zona pellucida thickness and oocyte diameter were increased in the atorvastatin group compared to the control group. In the evaluation of oocytes quality, the number of oocytes with +1 score in the atorvastatin and control groups were (70%) and (55.4%) respectively, and the difference between the two group was significant (p≤0.05). The number of polar bodies with +1 score in the atorvastatin and control groups were (36.18%) and (18.5%) respectively (p≤0.05).

The use of atorvastatin has a significant effect on the growth and final quality of immature oocytes in vitro and in the future, it could possibly be used to increase the efficiency of in vitro fertilization

substances can effect on the Hypothalamus-hypophysis-ovary and affect the performance of the Addictive substances can affect the reproductive system and they affect the secretion of gonadotropins. Morphine significantly reduces plasma LH levels in all range groups of men and women. Most illicit drugs and opioids, including morphine, are associated with decreased physical stimulation, decreased libido, decreased ability to reach orgasm (in women), and delayed or stopped ejaculation in men. Morphine can pose a serious threat to fertility and pregnancy by causing abnormal changes in the cell structure and lining of the endometrium. In this study, due to the common use of morphine as a narcotic that leads to addiction and the lack of information on the effect of morphine on ovum in culture medium, the effect of morphine on cell development and its fertility in culture medium has been investigated.

Sixteen female mice with average weight 20-24gm divided into control and treated groups. During three weeks, treated group got access water infected with 0/4 mg/ml morphine sulfate. In order to superovulation, pregnant mare serum gonadotropin injected. Animals sacrificed and ovaries removed. The cumulus-Oocyte complex from the ovaries transferred to medium. After 24 hours, Oocytes containing the first polar body was transferred to in vitro fertilization medium. Male mice was sacrificed and spermatozoids from vas deferens stored in incubator for 2 hours, and then sperms transferred into IVF medium. Finally, the Oocytes observed for second polar body or two cell.

The mean ovarian weight of the control and treatment group was 6.95 mg and 7.2 mg respectively that was not significant. In control group out of 128 metaphase I Ooctytes, 89 metaphase II ovum (69.53%) and in treatment group 99 metaphase II ovum were obtained from 140 metaphase I Oocytes (70.71%) (p = 0.051). Also in control group 29 case positive fertilization from 89 MII Oocytes(32.58%) and in treatment group 31 cases positive fertilization from 99 MII Oocytes(31.31%) was acquired(p=0.051).

It seems that despite its dependence on the animal, morphine does not interfere with the resumption and completion of meiotic division and thus does not impair egg fertility in the culture medium.

Demand for egg donors is growing worldwide. Due to the acute shortage of egg donors worldwide and since donors' satisfaction affect their willingness to re-donate, therefore, this study was conducted with aim of a systematic review of studies on donors' satisfaction with egg donation and willingness to re-donate in Iran and the world.

Comprehensive searches were performed in databases of Magiran, SID, Irandoc, Scopus, Pubmed, ISI as well as Google Scholar search engine from 1990 to 2020. To search the studies, Persian and English keywords including: egg, ovum, oocyte, satisfaction, donor, Re-donation and combining these words with AND and OR operators were used. According to STROBE criteria, the studies which scored above 15 were included in the study. Data analysis was performed qualitatively.

Out of 63 articles found in the databases, 7 articles which met the inclusion criteria were reviewed. All of these articles were of good or average quality.The results of the studies showed that egg donors evaluated the donation experience positively, so that the level of satisfaction was high and many of them were willing to donate eggs again.

Despite the high satisfaction of donors, determining and implementing the methods to improve donor satisfaction leads to better selection and retention of donors.

Telomeres as noncoding hetrochromatic and protective structures contain hexa-nucleutid repeats with rich in guanine at the end of each chromosomes. These structures are conserved during evolution, and their function depends on their length. In somatic cells, telomeres length decreases by each cell division. Shortening of telomere length lead to cell cycle arrest, chromosomes anomalies and cell death. While, telomere length does not short in germ cells and cancer cell due to high activity of telomerase enzyme. Other factors that influenced the telomere length are: 1) parental age at child's birth, 2) gender, 3) family history of cancer, 4) syndromes, 5) smoking, 6) X-radiation, 7) psychological stress, 8) alcohol consumption and 9) improper eating habits. Therefore, we aimed in this review, to discuss the role of telomere length in male germ cells.

For this review, all relevant information were collected via databases including PubMed and Google Scholar during the period 1965-2016.

Normal size of the sperm telomere can be considered as an indicator of semen quality, ability to fertilize and result in formation of good quality embryo and pregnancy.

Examination of telomeric structure especially telomere length could provide a new insight for our understanding of the etiology of human infertility.

It is now more than three decades since the first live birth from oocyte cryopreservation. At present, oocyte cryopreservation has become a major component of Assisted Reproductive technologies (ART). Across the world, there is an increasing demand, especially for so-called ‘social egg freezing’ that allows women to preserve their fertility in anticipation of age-related fertility decline. The purpose of this review article was to investigate the current status of oocyte cryopreservation, common techniques, success rate, clinical applications, the rise of elective oocyte cryopreservation, and future implications. A systematic search was performed using Web of Science and PubMed databases for articles published between January 1980 and December 2015. Keywords used included ‘egg freezing’, ‘oocyte freezing’, ‘oocyte cryopreservation’, ‘oocyte vitrification’, and ‘fertility preservation’. Recently, due to many reasons, including resolving age-related infertility in women the success rate of oocyte cryopreservation by vitrification has risen and IVF pregnancy rates are now similar to those achieved by fresh oocytes, therefore a remarkable increase is seen in oocyte cryopreservation cycles around the world. Oocyte cryopreservation (vitrification), especially social egg freezing is one of the best choices in women and girls with cancer who are at risk of losing fertility due to chemotherapy and radiation therapy, reproductive problems, premature ovaries, and also in women with chronic illnesses.

Diabetes mellitus is a metabolic disease which causes congenital anomalies and misabortion in females. Decrease in follicle growth and maturation and quality of oocytes occur in type 1 diabetes. The antidiabetic effect of Aloe vera is reported by several investigators. In this study, the effects of Aloe vera gel on diabetic mice oocyte were examined.
First, 25 mice were randomly divided into five groups including: control group (normal saline), Aloe vera group (350 mg/kg/day, by gavage), diabetic group (single dose of 190 mg/kg streptozotocin, IP), diabetic receiving Aloe vera (350 mg/kg/day, by gavage), and diabetic receiving insulin (1 IU/day, SC). All animals were superovulated after 3 weeks. Ovulated oocytes were collected from oviduct. Oocyte nuclear maturation and mitochondrial redistribution were investigated by microscopy and immunocytochemical methods.
Diabetes led to a significant increase in spindle defects, chromosome misalignmentm, and mitochondrial redistribution changes (P˂0.05). Aloe vera and insulin administration decreased these defects significantly (P˂0.05). Maturation rate decreased in diabetic mice, but Aloe vera and insulin administration prevented the decrease significantly (P˂0.05).
The results show that diabetes damages oocyte maturation process and reduces maturation rate and oocyte quality which can cause infertility or subfertility, but Aloe vera administration reduced these defects significantly.

As a result of globally increasing trend in infertility, taking advantage of reproductive technology to deal with this issue is recommended. Taking the well-founded claim about Vitamin E as a powerful antioxidant with a protective role in the body, this study was instigated to find the relationship between levels of vitamin E in Follicular fluid and morphology of oocyte along with embryo quality in IVF patients. This cross-sectional analytical study was carried out on oocytes and embryos obtained from 50 women with IVF admitted to Al Zahra Hospital of Rasht city. Patients underwent a similar ovulation stimulation protocol and then ten thousand units of hCG injected. After 36 hours, they underwent Follicle suction and mature oocytes were isolated for fertilization. Vitamin E level was measured and consequently the morphology of oocytes and the quality of embryo were evaluated by means of inverted optical microscopy. Of 50 treated IVF women, 583 oocytes and 275 embryos were examined. No significant relationship was observed between age, BMI, duration or cause of infertility and Vitamin E (P>0/05). At 0.5-1 mg/dl level of vitamin E, there were higher MII oocytes in comparison with other levels (p= 0.014). Despite the mean number of 2PN embryos at this level of vitamin E was more than other levels, this difference was not statistically significant (P=0.872). The results prove the evidence that at 0.5-1mg/dl level of Vitamin E, oocyte morphology and embryo quality were significantly improved.