• Journal of Animal Reproduction and Biotechnology
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• v.35 no.1
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• pp.2-11
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• 2020

Assisted reproductive technologies (ART) merely depend on improving the oocyte maturation and their developmental competence to produce good quality embryos. Oocyte maturation passes through long and complex molecular steps starts from the early embryonic life and ends with sperm fertilization. Oocyte developmental competence can be attained by improving the nuclear and cytoplasmic mechanisms together with some epigenetic maturation. In this review, we highlight the cornerstones of oocyte maturation on both nuclear and cytoplasmic levels. Interfering or supporting these molecular mechanisms would help in the development of novel regulating agents for reproductive performance of humans and livestock species.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.683-697
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• 2023

The threat posed by increased surface temperatures worldwide has attracted the attention of researchers to the reaction of animals to heat stress. Spermatogenesis in animals such as stallions is a temperature-dependent process, ideally occurring at temperatures slightly below the core body temperature. Thus, proper thermoregulation is essential, especially because stallion spermatogenesis and the resulting spermatozoa are negatively affected by increased testicular temperature. Consequently, the failure of thermoregulation resulting in heat stress may diminish sperm quality and increase the likelihood of stallion infertility. In this review, we emphasize upon the impact of heat stress on spermatogenesis and the somatic and germ cells and describe the subsequent testicular alterations. In addition, we explore the functions and molecular responses of heat shock proteins, including HSP60, HSP70, HSP90, and HSP105, in heat-induced stress conditions. Finally, we discuss the use of various therapies to alleviate heat stress-induced reproductive harm by modulating distinct signaling pathways.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.10
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• pp.1348-1357
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• 2011

The objective of this study was to compare the effect of Butylated Hydroxy Toluene (BHT), Pentoxifylline (PTX) and ${\alpha}$-tocopherol (Vit E) on semen quality parameters of Karan Fries bulls. The fortification of extender by various semen additives improves motility as well as fertility of spermatozoa. Split samples of 24 ejaculates of four Karan Fries bulls were extended in extender with or without various additives such as BHT, PTX and Vit E, and performance was evaluated at an interval of 0, 24, 48 and 72 h at refrigerated temperature (4-$7^{\circ}C$). Results of the present study revealed that addition of BHT, PTX and Vit E in extender improved sperm cell function, such as motility, viability, HOST, and acrosome integrity, as compared to the control during liquid storage up to 48 h of preservation at refrigerated temperature. There was no significant (p<0.05) difference between any of the additives up to 48 h of preservation. Overall, the results showed a significant (p<0.05) deterioration in motility after each storage interval. The results showed a significant deterioration in the acrosome integrity and plasma membrane integrity up to 48 h; subsequently, there was not much degradation of both the semen quality parameters. There was a significant increase in spermatozoal tail and total abnormality after each storage interval at refrigerator temperature (4 to $7^{\circ}C$); however, the head and mid-piece abnormalities were almost unaffected. Tail and total abnormality were least in extender fortified with BHT, PTX and Vit E at different hours of incubation as compared to the control. The addition of 1.5 mM BHT, 3.6 mM PTX and 1 mg/ml Vit E in the semen extender has more beneficial effect in terms of semen quality and preservability of spermatozoa.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.137-142
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• 2015

Cryopreservation of boar semen is continually researched in reproductive technologies and genetic resource banking in breed conservation. For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Various researches have been trying to improve the quality of semen post-thawed in boar. Recently, polymorphism (g.158T>C) of phospholipase C zeta (PLCz) gene reported to be significant association with MOT. This study was conducted to evaluate the PLCz gene as a positional controlling for motility and kinematic characteristics of post-thawed boar semen. To results, The g.158 T>C SNP of PLCz was significantly associated with frozen semen motility and kinematic characteristics. g.158 T>C SNP was high significantly associated with MOT, VCL, VSL and VAP (p<0.0001, p=0.0002, p<0.0001 and p<0.0001, respectively). Therefore, we suggest that the intron region of the porcine PLCz, may be used as a molecular marker for Duroc boar post-thawed semen quality, although its functional effect was not defined yet. Whether the association is due to the candidate gene or not require further verification. Thus, it will be of interest to continue association studies in the regions surrounding those genes.

• Journal of Embryo Transfer
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• v.28 no.4
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• pp.325-335
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• 2013

The study was set for one year to measure the effects of concentrate supplementation on reproductive performances and semen quality in indigenous rams. The study was conducted at the Department of Surgery and Obstetrics, Faculty of Veterinary Science, Bangladesh Agricultural University, Mymensingh, Bangladesh during the period from May 2011 to April 2012. Forteen ram lambs (4~5 months) were randomly divided into two equal groups (n=7); supplemented vs control. The animals of control group were maintained on natural grazing. Along with natural grazing the supplemented group was on supplemented feeding. The concentrate supplementation (Wheat bran, Crushed maize, Soy bean meal, Fish meal, DCP powder, Vitamin mineral premix, Salt) was provided @ 300 g/head /day to the supplemented group. Body weight, scrotal circumference, BCS and libido index were measured weekly. Age, body weight and scrotal circumference at puberty were recorded. Semen was collected once in a weak using artificial vagina and chilled at $5^{\circ}C$ for 48h for evaluation. Concentrate supplementation did not influence (p>0.05) body condition score, age, weight, scrotal circumference at puberty and libido index. Final body weight (kg), growth rate (g/d), scrotal circumference (cm) and scrotal growth rate (mm/15d) were significantly (p<0.05) higher in supplemented group of rams compared to control. Volume, concentration, motility and membrane potentiality of spermatozoa were varied significantly (p<0.05) in supplemented and control groups. However, density, mass motility, viability and sperm with normal acrosome, midpiece and tail were not differed insignificantly (p>0.05) in different observation times. It was concluded that concentrate supplementation with free grazing improved weight and scrotal circumference gain and semen production with increased quality in indigenous ram.

• Clinical and Experimental Reproductive Medicine
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• v.46 no.1
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• pp.22-29
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• 2019

Objective: As paternal age increases, the quality of sperm decreases due to increased DNA fragmentation and aneuploidy. Higher levels of structural chromosomal aberrations in the gametes ultimately decrease both the morphologic quality of embryos and the pregnancy rate. In this study, we investigated whether paternal age affected the euploidy rate. Methods: This study was performed using the medical records of patients who underwent in vitro fertilization (IVF) procedures with preimplantation genetic screening (PGS) from January 2016 to August 2017 at a single center. Based on their morphological grade, embryos were categorized as good- or poor-quality blastocysts. The effects of paternal age were elucidated by adjusting for maternal age. Results: Among the 571 total blastocysts, 219 euploid blastocysts were analyzed by PGS (38.4%). When the study population was divided into four groups according to both maternal and paternal age, significant differences were only noted between groups that differed by maternal age (group 1 vs. 3, p= 0.031; group 2 vs. 4, p= 0.027). Further analysis revealed no significant differences in the euploidy rate among the groups according to the morphological grade of the embryos. Conclusion: Paternal age did not have a significant impact on euploidy rates when PGS was performed. An additional study with a larger sample size is needed to clarify the effects of advanced paternal age on IVF outcomes.

• Clinical and Experimental Reproductive Medicine
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• v.47 no.4
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• pp.300-305
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• 2020

Objective: The feasibility of a gonadotropin-releasing hormone agonist (GnRHa) trigger in normal responders is still a matter of debate. The aim of this study was to compare the number of mature oocytes, the number of good-quality embryos, and the live birth rate in normal responders triggered by GnRHa alone, GnRHa and human chorionic gonadotropin (hCG; a dual trigger), and hCG alone. Methods: A retrospective cohort study was conducted at the infertility clinic of a university hospital. Data from 200 normal responders who underwent controlled ovarian hyperstimulation and intracytoplasmic sperm injection with a GnRH antagonist protocol between January 2016 and January 2017 were reviewed. The first study group consisted of patients with cycles triggered by GnRHa alone. The second study group consisted of patients with cycles triggered by both GnRHa and low-dose hCG (a dual trigger). The control group consisted of patients with cycles triggered by hCG alone. Results: The groups were comparable in terms of demographics and cycle characteristics. The numbers of total oocytes retrieved and metaphase II oocytes were similar between the groups. The total numbers of top-quality embryos were 3.2±2.9 in the GnRHa group, 4.4±3.2 in the dual-trigger group, and 2.9±2.1 in the hCG group (p=0.014). The live birth rates were 21.4%, 30.5%, and 28.2% in those groups, respectively (p=0.126). Conclusion: In normal responders, a dual-trigger approach appears superior to an hCG trigger alone with regard to the number of top-quality embryos produced. However, no clinical benefit was apparent in terms of live birth rates.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.113-119
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• 2013

The study focuses on the quality assessment of Black Bengal buck semen preserved at chilled condition. In this in vitro trial, collected semen from Black Bengal bucks was preserved at chilling temperature ($4{\sim}5^{\circ}C$) in tris-glucosecitrate yolk medium of 1:5 ratios for four days. Artificial Vagina (AV) method was utilized to collect semen from buck. General evaluation of semen includes the color, mass activity and density were measured by direct visual examination. However, computer-assisted sperm analysis (CASA) and phase contrast microscopy were used to figure out the motility (%), hyper-activated (HYP) motility (%) and number of abnormal spermatozoa (%) initially, and at every 24 h intervals. The result revealed that spermatozoa preserved at chilling temperature showed significantly (P<0.05) lower motility and HYP motility with the progression of preservation. The number of phenotypically abnormal spermatozoa significantly (P<0.05) increased following preservation. Although significant positive correlation (r=0.945; P<0.05) was existed between % motile and % HYP motile spermatozoa however, the % of morphologically abnormal spermatozoa was negatively correlated with % motile (r=-0.997; P<0.05) and % HYP motile spermatozoa (r=-0.946; P<0.01). Therefore, we concluded that the quality of chilled semen progressively losses its viability and doesn't remain useable after certain period of preservation with respect to its motility and morphology.

• Journal of Embryo Transfer
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• v.30 no.3
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• pp.143-147
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• 2015

Cryopreservation of boar semen is continually researched in reproductive technologies and genetic resource banking in breed conservation. For evaluating the boar semen quality, sperm motility (MOT) is an important parameter because the movement of spermatozoa indicates active metabolism, membrane integrity and fertilizing capacity. Various researches have been trying to improve the quality of semen Post-thawed in boar. Recently, polymorphism (g. 35756 T>C) of Estrogen Receptor 1 (ESR1) gene reported to be significant association with MOT. This study was conducted to evaluate the ESR1 gene as a positional controlling for motility and kinematic characteristics of post-thawed boar semen. To results, The g.35756 T>C SNP of ESR1 was significantly associated with frozen semen motility and kinematic characteristics. The g.35756 T>C SNP was high significantly associated with MOT, VCL, VSL and VAP (p<0.001). The SNP was also significantly associated with ALH (P<0.05). Therefore, we suggest that the g. 35756 T>C polymorphism in the intron 1 region of the porcine ESR1 gene could potentially be applied in frozen semen programs to improve MOT trait, but only after validation in other populations.

• Development and Reproduction
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• v.2 no.2
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• pp.213-221
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• 1998

Intracytoplasmic sperm injection (ICSI) has been widely used to treat couples with infertility due to severely impaired sperm charateristics and for whom conventional in-vitro fertilization (IVF) had failed. The extent to which the morphology of the oocyte at the light microscopy level is related to the results of ICSI vis controversial. In this study, oocytes from 44 patients were reviewed. The ICSI procedure was recorded through CCD camera. The oocytes were divided into five groups according to the presence of cytoplasmic inclusions, the width of perivitelline space (PVS), the presence of cell debris in PVS, the status of first polar body and the flexibility of oolemma. The results showed that the fertilization rate and embryonic development were not associated with the morphological criteria of oocyte. The degeneraton rate of oocytes after ICSI was significantly higher (P<0.001) in the oocytes whose membranes were broken at the moment of insertion (17.7%) than the oocytes whose membranes were broken by aspiration of cytoplasm (1.6%). More oocytes with cytoplasmic inclusions (48.4% vs. 25.1%, p<0.001), wide PVS (35.2% vs. 19.0%, p<0.001), or cell debris in PVS (53.3% vs. 38.4%, p<0.05) were observed in patients with female factor infertility compared to patients with male factor infertility. These results .suggest that the fertilization rate and embryonic development after ICSI are not correlated with oocyte morphology based on the presence of cytoplasmic inclusions, size of PVS, the presence of cell debris in PVS and the status of polar body. And the degeneration rate of oocytes after ICSI was associated with the flexibility of oolemma.