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Men with diabetes frequently experience spermatogenic dysfunction, which is the most significant sign that diabetes has harmed their ability to reproduce. The effect of various doses of the hydro-alcoholic extract of Nerium oleander leaves on the pituitary-gonadal axis, sperm motility and number, antioxidant system, changes in testicular tissue structure, and spermatogenesis in healthy and diabetic rats has been examined in the current study. Eighty male rats that had been streptozotocin-induced diabetic and healthy were divided into eight groups: (1) control, (2) Nerium (50 mg/kg), (3) Nerium (100 mg/kg), (4) Nerium (200 mg/kg), (5) DM (6) DM+Nerium (50 mg/kg), (7) DM+Nerium (100 mg/kg) and (8) DM+Nerium (200 mg/kg) and were administered orally for 48 days consecutive. Following the studies, analysis of the testicular tissues' antioxidant capacity as well as sperm parameters, Johnsen's scoring and morphometric evaluation, histology, biochemical and stereology studies were performed.The outcomes showed that Nerium 50 and 100 mg/kg considerably enhanced the testicular morphology, sperm parameters, and reproductive organs to varying degrees in diabetic rats. After Nerium 50 mg/kg administration, glutathione peroxidase (GPX) and catalase (CAT) levels in the testicular tissue were increased whereas malondialdehyde (MDA) levels were markedly decreased. Nerium may help protect against diabetic-induced spermatogenic dysfunction in male rats by enhancing the activities of antioxidant enzymes in lower dosages.

Environmental hypoxia adversely affects reproductive health in humans and animals at high altitudes. Therefore, how to alleviate the follicle development disorder caused by hypoxia exposure and to improve the competence of fertility in plateau non-habituated female animals are important problems to be solved urgently. In this study, a hypobaric hypoxic chamber was used for 4 weeks to simulate hypoxic conditions in female mice, and the effects of hypoxia on follicle development, proliferation and apoptosis of granulosa cells, reactive oxygen species (ROS) levels in MII oocyte and 2-cell rate were evaluated. At the same time, the alleviating effect of melatonin on hypoxic exposure-induced oogenesis damage was evaluated by feeding appropriate amounts of melatonin daily under hypoxia for 4 weeks. The results showed that hypoxia exposure significantly increased the proportion of antral follicles in the ovary, the number of proliferation and apoptosis granulosa cells in the follicle, and the level of ROS in MII oocytes, eventually led to the decline of oocyte quality. However, these defects were alleviated when melatonin was fed under hypoxia conditions. Together, these findings suggest that hypoxia exposure impaired follicular development and reduced oocyte quality, and that melatonin supplementation alleviated the fertility reduction induced by hypoxia exposure.

Infertility affects 15% of all couples worldwide and 50% of cases of infertility are solely due to male factors. A decrease in motility in the semen is considered one of the main factors that is directly related to infertility. The use of supplementation to improve the overall sperm quality has become increasingly popular worldwide. The purpose of this study was to evaluate whether sperm motility was affected by the combination of serotonin (5-HT), selenium (Se), zinc (Zn), and vitamins D, and E supplementation. Semen samples were incubated for 75 min at 37°C in medium containing varying concentrations of 5-HT, Se, Zn, vitamin D, and E. 5-HT (200 μM), Se (2 μg/ml), Zn (10 μg/ml), vitamin D (100 nM), and vitamin E (2 mmol) have also been shown to increase progressive sperm motility. Three different mixtures of supplements were also tested for their combined effects on sperm motility and reactive oxygen species (ROS) production. While the total motility in the control group was 71.96%, this was found to increase to 82.85% in the first mixture. In contrast the average ROS level was 8.97% in the control group and decreased to 4.23% in the first mixture. Inclusion of a supplement cocktail (5-HT, Se, Zn, vitamins D and E) in sperm processing and culture medium could create an overall improvement in sperm motility while decreasing ROS levels during the incubation period. These molecules may enhance the success of assisted reproduction techniques when present in sperm preparation medium.

Semen sexing is among one of the most remarkable inventions of the past few decades in the field of reproductive biotechnology. The urge to produce offspring of a desired sex has remained since traditional times. Researchers have tried many methods for accurate semen sexing, but only the flow cytometry method has proved to be effective for commercial utilization. However, there were always concerns about the effects of sexed semen, especially on fertility and the rate of genetic gain. Some concerns were genuine because of factors such as low semen dosage in sexed semen straws and damage to sperm during the sorting process. Various researchers have conducted numerous studies to find out the effect of sexed semen on fertility and, in this article, we reflect on their findings. Initially, there were comparatively much lower conception rates (∼70% of conventional semen) but, with refinement in technology, this gap is bridging and the use of sexed semen will increase over time. Concerning genetic gain with use of sexed semen, a positive effect on rate of genetic progress with the use of sexed semen has been observed based on various simulation studies, although there has been a mild increase in inbreeding.

Spermatogenesis is a developmental process driven by interactions between germ cells and Sertoli cells. This process depends on appropriate gene expression, which might be regulated by transcription factors. This study focused on Rreb1, a zinc finger transcription factor, and explored its function and molecular mechanisms in spermatogenesis in a mouse model. Our results showed that RREB1 was predominantly expressed in the Sertoli cells of the testis. The decreased expression of RREB1 following injection of siRNA caused impaired Sertoli cell development, which was characterized using a defective blood-testis barrier structure and decreased expression of Sertoli cell functional maturity markers; its essential trigger might be SMAD3 destabilization. The decreased expression of RREB1 in mature Sertoli cells influenced the cell structure and function, which resulted in abnormal spermatogenesis, manifested as oligoasthenoteratozoospermia, and we believe RREB1 plays this role by regulating the transcription of Fshr and Wt1. RREB1 has been reported to activate Fshr transcription, and we demonstrated that the knockdown of Rreb1 caused a reduction in follicle-stimulating hormone receptor (FSHR) in the testis, which could be the cause of the increased sperm malformation. Furthermore, we confirmed that RREB1 directly activates Wt1 promoter activity, and RREB1 downregulation induced the decreased expression of Wt1 and its downstream polarity-associated genes Par6b and E-cadherin, which caused increased germ-cell death and reduced sperm number and motility. In conclusion, RREB1 is a key transcription factor essential for Sertoli cell development and function and is required for normal spermatogenesis.

Electromagnetic radiation (EMR) has deleterious effects on sperm motility and viability, as well as oocyte membrane and organelle structure. The aim was to assess the effects of cell phone radiation on preimplantation embryo morphokinetics and blastocyst viability in mice. For superovulation, 20 female mice were treated with intraperitoneal (IP) injections of 10 IU pregnant mare’s serum gonadotropin (Folligon® PMSG), followed by 10 IU of human chorionic gonadotropin (hCG) after 48 h. The zygotes (n = 150) from the control group were incubated for 4 days. The experimental zygotes (n = 150) were exposed to a cell phone emitting EMR with a frequency range 900–1800 MHz for 30 min on day 1. Then, all embryos were cultured in the time-lapse system and annotated based on time points from the 2-cell stage (t2) to hatched blastocyst (tHDyz), as well as abnormal cleavage patterns. Blastocyst viability was assessed using Hoechst and propidium iodide staining. Significant increases (P < 0.05) were observed in the cleavage division time points of t2, t8, t10, and t12 of the experimental group compared with the controls. In terms of blastocyst formation parameters, a delay in embryo development was observed in the experimental group compared with the controls. Data analysis of the time intervals between the two groups showed a significant difference in the s3 time interval (P < 0.05). Also, the rates of fragmentation, reverse cleavage, vacuole formation, and embryo arrest were significantly higher in the experimental group (P < 0.05). Furthermore, the cell survival rate in the experimental group was lower than the control group (P < 0.05). Exposure to EMR has detrimental consequences for preimplantation embryo development in mice. These effects can manifest as defects in the cleavage stage and impaired blastocyst formation, leading to lower cell viability.

Our previous studies have suggested that spastin, which aggregates on spindle microtubules in oocytes, may promote the assembly of mouse oocyte spindles by cutting microtubules. This action may be related to CRMP5, as knocking down CRMP5 results in reduced spindle microtubule density and maturation defects in oocytes. In this study, we found that, after knocking down CRMP5 in oocytes, spastin distribution shifted from the spindle to the spindle poles and errors in microtubule-kinetochore attachment appeared in oocyte spindles. However, CRMP5 did not interact with the other two microtubule-severing proteins, katanin-like-1 (KATNAL1) and fidgetin-like-1 (FIGNL1), which aggregate at the spindle poles. We speculate that, in oocytes, due to the reduction of spastin distribution on chromosomes after knocking down CRMP5, microtubule-kinetochore errors cannot be corrected through severing, resulting in meiotic division abnormalities and maturation defects in oocytes. This finding provides new insights into the regulatory mechanisms of spastin in oocytes and important opportunities for the study of meiotic division mechanisms.

Oocyte cytoplasmic evaluation is based on homogeneity and granular appearance. Our study investigated if a granular cytoplasm, highly heterogeneous, would affect oocyte competence in bovine. In two experiments, bovine cumulus-oocyte complexes (COCs) with homogeneous cytoplasm (control, CC) and granulated cytoplasm (granular, GC) were selected from a regular pool of COCs. Experiment 1 was performed with slaughterhouse ovaries, and Experiment 2 was carried out in Girolando COCs obtained from ovum pick-up. Granular oocytes had higher caspase 3 levels (66.17 ± 11.61 vs 172.08 ± 16.95, P < 0.01) and similar GAP junction activity (5.64 ± 0.45 vs 6.29 ± 0.29). ZAR1 relative mRNA amount was lower in granular oocytes (178.27 ± 151.63 vs 0.89 ± 0.89, P = 0.01) and no effect was detected for MATER, PPP2R1A, ENY2, IGF2R, and BMP15 genes. Despite molecular differences, no detrimental effect was detected on oocyte competence in GC oocytes. Cleavage (Experiment 1: 59.52 ± 7.21% vs 59.79 ± 6.10% and Experiment 2: 68.88 ± 4.82 vs 74.41 ± 5.89%) and blastocyst (Experiment 1: 29.28 ± 4.14% vs 23.15 ± 2.96% and Experiment 2: 21.11 ± 3.28% vs 21.02 ± 6.08%) rates were similar between CC and GC (Experiments 1 and 2, respectively). Post-transfer embryo development revealed that pregnancy (CC: 24.27 ± 9.70% vs GC: 26.31 ± 7.23%) and calving (23.68% vs 33.33%) rates and fetal growth were not affected by the presence of cytoplasmic granules. Our results demonstrated that oocytes with granular cytoplasm present equivalent efficiency for IVF and calf production compared with homogenous cytoplasm oocytes. This could be observed through similar cleavage, blastocyst rates, and fetal growth development. In addition to differences in oocyte gene expression related to oocyte quality, it seems not to affect oocyte developmental competence.

Despite the high level of standardization of the intracytoplasmic sperm injection (ICSI) technique, there are some aspects that deserve special attention and should still be improved. The major drawback of the technique is its invasiveness, as during cytoplasmic aspiration different structures of the oocyte may be lost or damaged. This is partly because the microtools used in ICSI were not specially designed for assisted reproduction but for other medical-biological disciplines. In view of the above caveats, the aim of the study was to compare the results of ICSI with the traditional oocyte-holding pipette and the oocyte-holding pipette without aspiration (PiWA). In total, 155 patients and 1037 oocytes were included in the study. In each ICSI cycle, half of the oocytes were microinjected using a traditional holding pipette and the other half using a PiWA. In result, the PiWA technique produced a significant increase in the fertilization rate: 88.12% (95%CI: 84.62-90.92%); holding pipette: 73.33% (95%CI: 68.72-77.49%). Also, it produced a significant decrease in the embryo degeneration rate compared with the traditional holding pipette [PiWA: 2.07% (95%CI: 1.11-3.8%); holding pipette: 4.51% (95%CI: 3.06-6.59%)]. Pregnancy rate depended on the holding technique used, both in single embryo transfers (n = 59; χ² = 4.608; P-value = 0.032) and double embryo transfers (n = 156; χ² = 4.344; P-value = 0.037); with PiWA presenting a significantly higher pregnancy rate than the traditional holding technique. Based on current evidence and the present results, improvements should focus on decreasing the invasiveness of the microinjection itself by minimizing or avoiding aspiration and cytoplasmic disorganization, as is successfully achieved with PiWA.

The aim of this research was to investigate the effect of Coenzyme Q10 (CoQ10) on the expression of the Transcription Factor A Mitochondrial (Tfam) gene and mtDNA copy number in preantral follicles (PFs) of mice during in vitro culture. To conduct this experimental study, PFs were isolated from 14-day-old National Medical Research Institute mice and cultured in the presence of 50 µm CoQ10 for 12 days. On the 12th day, human chorionic gonadotropin was added to stimulate ovulation. The fundamental parameters, including preantral follicle developmental rate and oocyte maturation, were evaluated. Additionally, the Tfam gene expression and mtDNA copy number of granulosa cells and oocytes were assessed using the real-time polymerase chain reaction. The results revealed that CoQ10 significantly increased the diameter of PFs, survival rate, antrum formation, and metaphase II (MII) oocytes (P < 0.05). Moreover, in the CoQ10-treated groups, the Tfam gene expression in granulosa cells and oocytes increased considerably compared with the control group. The mtDNA copy number of granulosa cells and oocytes cultured in the presence of CoQ10 was substantially higher compared with the control groups (P < 0.05). The addition of CoQ10 to the culture medium enhances the developmental competence of PFs during in vitro culture by upregulating Tfam gene expression and increasing mtDNA copy number in oocyte and granulosa cells.