Production Of Bovine Embryos Research Articles

Transcriptomic effects of alginate hydrogel applied to the production of bovine embryos

Transcriptomic effects of alginate hydrogel applied to the production of bovine embryos

Increased in vitro production of bovine embryos resulting from oocyte maturation in the presence of triciribine, a specific inhibitor of AKT

The aim of this study was to evaluate the effect of different concentrations of triciribine, a selective Akt inhibitor, on various aspects of oocyte maturation and on the IVF of bovine embryos. Cumulus-oocyte complexes (COCs) were matured in vitro in medium supplemented with: 0 (control), 1, 5, 10, and 20 μM of triciribine. The nuclear maturation was assessed by staining with acetic orcein, while the cytoplasmic maturation was evaluated by mitochondrial (MitoTracker® Red CMXRos) and lipid droplets distribution (LipidTOX). COCs were fertilized in vitro and cultured for nine days. Cleavage rates, blastocyst production, and hatching rates were determined on days three, seven, and nine of in vitro culture, respectively. Oocytes from COCs treated with 1 μM of triciribine were stained at 3, 6, and 9 h of IVM to determine the inhibitor's involvement in germinal vesicle breakdown. Analysis of variance (ANOVA) of the data was performed and the means were compared using the SNK test at a 5 % significance level. Exposure of COCs to 1, 5, and 10 μM of triciribine did not alter the number of matured oocytes (P < 0.05), a concentration of 20 μM reduced the number of oocytes in MII with a consequent increase in oocytes in MI (P < 0.05). This concentration markedly reduced the number of oocytes with peripheral cortical granules and the rates of cleavage and blastocysts (P < 0.05). On the other hand, when COCs were matured in the presence of 1 μM, there was an increase in the blastocyst rate (P < 0.05), but without altering the timing of meiosis resumption (P < 0.05). It is concluded that the Akt pathway participates in the nuclear and cytoplasmic events of in vitro maturation of bovine oocytes, but through mechanisms that do not interfere with germinal vesicle breakdown. Modulation of Akt activity in bovine COCs during IVM with 1 μM of triciribine increases the in vitro production of bovine embryos.

Putrescine supplementation improves the developmental competence of in vitro produced bovine embryos

The aim of this study was to investigate the effect of putrescine, anti-apoptotic, antioxidant, and a cell proliferation stimulant, on embryo development and quality by supplementing it to in vitro culture medium. In this study, oocytes were obtained from the ovaries of Holstein cattle. Following maturation and fertilization, the presumptive zygotes were randomly assigned to two groups. The first group (Putrescine, n = 435) was supplemented with putrescine at a concentration of 0.5 mM to in vitro culture. The second group (n = 407) was maintained under standard culture conditions without any supplementations to the medium. Following the determination of the developmental stages of the embryos, only those in the blastocyst stage were subjected to differential staining and the cell numbers of the embryos were determined. Moreover, the TUNEL assay was employed to ascertain the extent of cell death and the apoptotic index in the embryos. Additionally, the levels of ROS were determined in the embryos. Furthermore, gene expression analyses were conducted on blastocyst-stage embryos to ascertain the potential of putrescine supplementation in embryo development along specific pathways. Following in vitro culture, the blastocyst formation rate was 44.37 % in the putrescine group and 32.97 % in the control group (P < 0.05). The counts of ICM (60.60 ± 15.79 vs 50.73 ± 16.74), TE (117.70 ± 23.67 vs 94.0 ± 22.46), and TCC (178.30 ± 26.15 vs 144.73 ± 26.86) were found to be statistically higher in blastocysts developing after putrescine supplementation compared to the control group. Furthermore, the number of apoptotic cells (7.69 ± 2.17 vs 9.96 ± 3.99) and the apoptotic index (5.07 % vs 8.01 %) were found to be lower in the putrescine group in comparison to the control group. Nevertheless, it was established that the ROS level in the control group was approximately two-fold higher than in the putrescine group (P < 0.05). The findings also revealed that putrescine up-regulated the gene expression of SOD, GPX4, CAT, BCL2, NANOG and GATA3 while simultaneously down-regulating the BAX expression level. In conclusion, the supplementation of putrescine to the culture medium during in vitro bovine embryo production was found to contribute to the improvement of embryo quality and early embryonic development.

Methodological approaches in vitrification: Enhancing viability of bovine oocytes and invitro-produced embryos.

Cryopreservation of bovine oocytes and embryos is essential for long-term preservation and widespread distribution of genetic material, particularly in bovine invitro embryo production, which has witnessed substantial growth in the past decade due to advancements in reproductive biotechnologies. Among current cryopreservation methods, vitrification has emerged as the preferred cryopreservation technique over slow freezing for preserving oocytes and invitro-produced (IVP) embryos, as it effectively addresses membrane chilling injury and ice crystal formation. Nonetheless, challenges remain and a simple and robust vitrification protocol that guarantees the efficiency and viability after warming has not yet been developed. Furthermore, although slow cooling can easily be adapted for direct transfer, an easier and more practical vitrification protocol for IVP embryos is required to allow the transfer of IVP embryos on farms using in-straw dilution. In addition, the susceptibility of bovine oocytes and embryos to cryoinjuries highlights the need for novel strategies to improve their cryotolerance. This manuscript examines various methodological approaches for increasing the viability of bovine oocytes and IVP embryos during vitrification. Strategies such as modifying lipid content or mitigating oxidative damage have shown promise in improving cryotolerance. Additionally, mathematical modelling of oocyte and embryo membrane permeability has facilitated the rational design of cryopreservation protocols, optimizing the exposure time and concentration of cryoprotectants to reduce cytotoxicity.

Can C-type natriuretic peptide during in vitro maturation or culture influence the development of bovine embryos?

The C-type natriuretic peptide (CNP) plays a central role in regulating the meiotic progression of oocytes into growing follicles in mammals. However, there are few reports examining the relationship between CNP and embryonic development. In our study, different concentrations (50, 100, or 150 nM) of CNP were added during in vitro maturation (IVM) of cumulus-oocyte complexes (COCs) or in vitro culture (IVC) of the bovine embryos (B. taurus indicus). The effects on embryo production and transcript abundance of the 20 genes of greatest interest that are related to metabolism, oocyte maturation, follicular development, cell signaling, oxidative and thermal stress, maternal-fetal interaction, and epigenetic regulation were evaluated. The blastocyst rate was influenced by CNP treatment (P = 0.049). Blastocyst rates were 31.05% (136/438) in the control group, 33.47% (162/484) in the 50 nM treatment group, 35.24% (179/508) in the 100 nM treatment group, and 32.53% (162/498) in the 150 nM treatment group for IVM. Furthermore, with IVC CNP supplementation, blastocyst rates were 28.49% (100/351) at 50 nM, 27.67% (119/430) at 100 nM, and 26.92% (112/416) at 150 nM. Moreover, the expression of RE1 silencing transcription factor (REST), a gene related to pluripotency and to embryonic development, was greater (P = 0.028) in response to 150 nM CNP supplementation in IVM. Finally, we observed for the first time the expression of the CNP receptor (NPR2) in embryos and the possible action of CNP at this stage. In conclusion, our data provide a reference for the improvement of IVM results in the in vitro production of bovine embryos with supplementation with 100 nM CNP, and this is the first study to demonstrate the expression of the CNP receptor (NPR2) in bovine embryos.

Production of bovine embryos by piezo-ICSI using capacitated spermatozoa selected by fluorescence-activated cell sorting (FACS-piezo-ICSI)

Intracytoplasmic sperm injection (ICSI) remains inefficient in cattle. One reason could lie in the injection of oocytes with sperm that have not undergone molecular changes associated with in vivo capacitation and fertilizing ability. This study aimed to enhance the efficiency of bovine intracytoplasmic sperm injection (piezo-ICSI) by employing fluorescent-activated cell sorting (FACS) to select the sperm population before injection based on capacitation markers. First, we evaluated the effects of incubating thawed sperm for 2 hours with different capacitating inductors: heparin, methyl-beta-cyclodextrin (MβCD), and dibutyryl cyclic AMP (dbcAMP), alone or in combinations in a basal capacitating (C) medium (Sp-TALP). Sperm capacitation and quality markers were evaluated by flow cytometry, revealing heparin as the most effective inducer of sperm capacitation changes. It, therefore, this treatment was chosen as the sperm pretreatment for FACS-piezo-ICSI. Two cell populations showing high capacitating levels (Heparin-HCL) and low capacitating levels (Heparin-LCL) of the markers associated with sperm capacitation i(Ca2+) levels and acrosome integrity were selected by FACS and used for sperm injection. Pronuclear formation was significantly higher when ICSI was performed with Heparin-HCL sperm than with Heparin-LCL and the control group (Heparin unsorted) groups (50 %, 10 %, and 20 %, respectively). Furthermore, injecting Heparin-HCL sperm resulted in a higher blastocyst rate (22.5 %) than Heparin-LCL (10 %) and the control group (15.2 %). In conclusion, heparin treatment effectively induced changes associated with sperm capacitation. The combination of Heparin-HCL treatment and FACS enabled precise selection of capacitated sperm before ICSI, enhancing the efficiency of this technology in the bovine species.

A retrospective analysis of conception per embryo transfer in dairy cattle in South Korea

The bovine embryo production industry has seen significant growth over the past two decades, particularly in the production of in vitro produced embryos. This growth, driven by advancements in cryopreservation, in vitro culture mediums, ovum pick-up (OPU) procedures, ultrasonography devices, and embryo transfer (ET) has been notable. Particularly, ET is crucial for disseminating high genetic merit and amplifying foreign breeds by importing frozen embryos. This retrospective study aimed to assess factors affecting conception per embryo transfer (CPET) in Holstein-Friesian cattle in South Korea from October 2008 to July 2022. We evaluated type of embryo breed, type of embryo production (fresh and frozen; in vitro and in vivo production), recipient conditions including estrus type, corpus luteum quality, parity (nulliparous heifers, primiparous, and multiparous cows), and the daily mean temperature-humidity index (THI) as an index for heat stress. Type of embryo breed and estrus had no significant impact on CPET. However, we observed higher CPET in recipients with good quality corpus luteum, nulliparous heifers, and surrogates receiving fresh in vitro and frozen in vivo embryos. Importantly, CPET was not adversely affected by mild heat stress conditions (up to daily mean THI 76), indicating that using frozen in vivo embryos produced by multiple ovulation embryo transfer and fresh in vitro embryos by OPU-ET can help alleviate the subfertility issues in dairy cattle caused by global warming in Korea.

Scoping review of primary studies evaluating Bovine in vitro oocyte maturation and embryo development

We conducted a scoping review to 1) map and categorize published studies reporting interventions during the in vitro production of Bovine embryos and 2) qualitatively summarize the effects of treatments based on hormones, growth factors, sera, and reproductive fluids during oocyte maturation and embryo development. We searched electronic databases using keywords ('Bovine', 'embryo', 'blastocyst', 'oocyte', 'in vitro', 'quality') derived from the PIOS approach of the PRISMA statement. We identified 231 studies published during 2000−2021, with 133 being published between 2012 and 2021. The 231 studies were classified into four treatment categories: culture conditions (28), medium composition (45), bioactive supplements (79), and other additives (79), with 19 subcategories within these categories. A total of 77 studies included hormones, growth factors, sera, and reproductive fluids, among which 53 studies reported a positive effect on embryo production. Hormone-based treatments using melatonin, gonadotropins, and steroids were the most effective, followed by interventions assessing growth factors such as EGF, FGF, IGF-1, and BMP. These treatments improved oocyte competence, cytoplasmic/nuclear maturation, oocyte quality, and blastocyst development. Although free-serum media and synthetic/alternative products can partially or totally replace serum, it is sometimes necessary even at low concentrations. At high concentrations, hormones or growth factors may have detrimental effects on oocyte nuclear maturation, impair embryo development, and decrease embryo survival. Further meta-analyses are needed to estimate the intervention-specific effects. Future research should focus on interventions that have a positive effect and can be used extensively for Bovine production.

In vitro developmental competence of bovine demi-embryos generated by blastomere separation and blastocyst bisection.

The efficiency of bovine invitro embryo production can be significantly improved by splitting embryos at different stages. However, the blastocyst quality of invitro-produced demi-embryos remains unexplored. The objective of this research was to compare embryo developmental rates and quality of bovine demi-embryos produced by two different strategies: (a) embryo bisection (BSEC) and (b) 2-cell blastomere separation (BSEP). To determine demi-embryos quality, we evaluated total blastocyst cell number and proportion of SOX2+ cells. Additionally, the expression of SOX2, NANOG, OCT4, CDX2, IFNT, BAX and BCL genes and let-7a and miRNA-30c Micro RNAs was analysed. BSEP resulted in improved blastocyst development, higher ICM cells and a significantly higher expression of IFNΤ than demi-embryos produced by BSEC. Let-7a, which is associated with low pregnancy establishment was detected in BSEC, while miRNA-30c expression was observed in all treatments. In conclusion, BSEP of 2-cell embryos is more efficient to improve invitro bovine embryo development and to produce good quality demi-embryos based on ICM cell number and the expression pattern of the genes explored compared to BSEC.

Dynamics of transcription is affected by oxygen tension and developmental speed during invitro production of bovine embryos.

This study examines the impact of oxygen tension and embryo kinetics on gene transcription dynamics in pathways crucial for embryonic preimplantation development, including lipid metabolism, carbohydrate transport and metabolism, mitochondrial function, stress response, apoptosis and transcription regulation. Bovine embryos were generated invitro and allocated into two groups based on oxygen tension (20% or 5%) at 18 h post insemination (hpi). At 40 hpi, embryos were categorized into Fast (≥4 cells) or Slow (2 cells) groups, resulting in four experimental groups: FCL20, FCL5, SCL20 and SCL5. Embryo collection also occurred at 72 hpi (16-cell stage; groups FMO20, FMO5, SMO20 and SMO5) and at 168 hpi (expanded blastocyst (BL) stage; groups FBL20, FBL5, SBL20 and SBL5). Pools of three embryos per group were analysed in four replicates using inventoried TaqMan assays specific for Bos taurus, targeting 93 genes. Gene expression patterns were analysed using the K-means algorithm, revealing three main clusters: genes with low relative abundance at the cleavage (CL) and 16-cell morula (MO) stages but increased at the BL stage (cluster 1); genes with higher abundances at CL but decreasing at MO and BL (cluster 2); and genes with low levels at CL, higher levels at MO and decreased levels at BL (cluster 3). Within each cluster, genes related to epigenetic mechanisms, cell differentiation events and glucose metabolism were particularly influenced by differences in developmental kinetics and oxygen tension. Fast-developing embryos, particularly those cultured under low oxygen tension, exhibited transcript dynamics more closely resembling that reported invivo-produced embryos.

An Overview of Reactive Oxygen Species Damage Occurring during In Vitro Bovine Oocyte and Embryo Development and the Efficacy of Antioxidant Use to Limit These Adverse Effects.

The in vitro production (IVP) of bovine embryos has gained popularity worldwide and in recent years and its use for producing embryos from genetically elite heifers and cows has surpassed the use of conventional superovulation-based embryo production schemes. There are, however, several issues with the IVP of embryos that remain unresolved. One limitation of special concern is the low efficiency of the IVP of embryos. Exposure to reactive oxygen species (ROS) is one reason why the production of embryos with IVP is diminished. These highly reactive molecules are generated in small amounts through normal cellular metabolism, but their abundances increase in embryo culture because of oocyte and embryo exposure to temperature fluctuations, light exposure, pH changes, atmospheric oxygen tension, suboptimal culture media formulations, and cryopreservation. When uncontrolled, ROS produce detrimental effects on the structure and function of genomic and mitochondrial DNA, alter DNA methylation, increase lipid membrane damage, and modify protein activity. Several intrinsic enzymatic pathways control ROS abundance and damage, and antioxidants react with and reduce the reactive potential of ROS. This review will focus on exploring the efficiency of supplementing several of these antioxidant molecules on oocyte maturation, sperm viability, fertilization, and embryo culture.

Bovine embryo production in vitro: evolution of culture media and commercial perspectives.

In vitro produced embryos exhibit lower viability compared to their in vivo counterparts. Mammalian preimplantation embryos have the ability to reach the blastocyst stage in diverse culture media, showcasing considerable metabolic adaptability, which complicates the identification of optimal developmental conditions. Despite embryos successfully progressing to the blastocyst stage, adaptation to suboptimal culture environments may jeopardize blastocyst viability, cryotolerance, and implantation potential. Enhancing our capacity to support preimplantation embryonic development in vitro requires a deeper understanding of fundamental embryo physiology, including preferred metabolic substrates and pathways utilized by high-quality embryos. Armed with this knowledge, it becomes achievable to optimize culture conditions to support normal, in vivo-like embryo physiology, mitigate adaptive stress, and enhance viability. The objective of this review is to summarize the evolution of culture media for bovine embryos, highlighting significant milestones and remaining challenges.

Use of platelet-rich plasma on in vitro maturation during bovine embryo production.

One of the crucial aspects to be considered for successful in vitro production (IVP) of embryos is the composition of the various media used throughout the stages of this reproductive biotechnology. The cell culture media employed should fulfill the metabolic requirements of both gametes during oocyte maturation and sperm development, as well as the embryo during its initial cell divisions. Most IVP protocols incorporate blood serum into the media composition as a source of hormones, proteins, growth factors, and nutrients. Numerous studies have suggested Platelet-Rich Plasma (PRP) as a substitute for fetal sera in cell culture, particularly for stem cells. Therefore, the objective of this study is to assess the potential use of PRP as a replacement for fetal bovine serum (FBS) during oocyte maturation for in vitro production of bovine embryos. During in vitro maturation (IVM), cumulus-oocyte complexes (COCs) were allocated into the following experimental groups: Group G1 (IVM medium with 5% PRP); Group G2 (MIV medium with 5% PRP and 5% SFB); Group G3 (MIV medium with 5% SFB); and Group G4 (MIV medium without either PRP or SFB). Subsequently, the cumulus-oocyte complexes were fertilized with semen from a single bull, and the resulting zygotes were cultured for seven days. Cleavage and blastocyst formation rates were assessed on days 2 and 7 of embryonic development, respectively. The quality of matured COCs was also evaluated by analyzing the gene expression of HSP70, an important protein associated with cellular stress. The results demonstrated that there were no significant differences among the experimental groups in terms of embryo production rates, both in the initial cleavage stages and blastocyst formation (except for the G4 group, which exhibited a lower blastocyst formation rate on D7, as expected). This indicates that PRP could be a cost-effective alternative to SFB in the IVP of embryos.

14 Production and transfer of bovine embryos through the hub-and-spoke model: an innovative model to promote embryo transfer technology

14 Production and transfer of bovine embryos through the hub-and-spoke model: an innovative model to promote embryo transfer technology

Clinical Application of Platelet Concentrates in Bovine Practice: A Systematic Review.

Platelet concentrates (PCs) have become widely used in veterinary and human medicine. The PCs consist mainly of supraphysiological concentrations of platelets and, therefore, growth factors (GFs) which are stored within platelet α-granules. Among PCs, Platelet-Rich Plasma (PRP) is characterised by low-density fibrin. Research on the effect of PCs in cattle has surged in recent years; in particular, evidence has shown the positive use of PRP for treating reproductive problems, in vitro production of bovine embryos, sole ulcers and udder diseases. The aim of this report is to critically review, in accordance with the PRISMA guidelines, the available literature reporting clinical application in the bovine practice of PRP. Three bibliographic databases PubMed, Web of Science and Scopus were used for a broad search of "platelet concentrates" OR "PRP" OR "platelet-rich plasma" OR "PRF" OR "platelet-rich fibrin" AND "cows" OR "cattle". From 1196 papers, only six met the inclusion criteria. Two papers described the use of PRP in mastitis, two papers in uterine dysfunction and two papers in ovarian dysfunction. PRP offered a low-cost, easily obtained therapeutic option and showed positive results for these patients. However, given the different pathologies and definitions involved, further studies are necessary to assess its full clinical potential.

THE RESISTANCE OF OOCYTES AND IN VITRO PRODUCED CATTLE EMBRYOS TO CRYOPRESERVATION

In vitro fertilization and production of bovine embryos in vitro is method, which improves utilization of animal reproduction potential. In connection with cryopreservation methods and ability of long-term cryostorage of embryos offers suitable tool for positive influence of endangered species or breeds. In vitro embryo production with subsequent embryo transfer contributes to the improvement of reproduction rates and bypassing some reproduction failure in high productive animal breeding. The method is generally used for in vitro production of transferable bovine embryos. Worldwide about 411 000 of IVP bovine embryos are annually transferred to recipients (IETS, 2013). Most of them were transferred immediately after producing, which is difficult for organization and synchronization of animals. In contrast to this possibility the storage of embryos for later using brings undisputable advantages. In order to protect animal genetic resources and to preserve the gene pool of rare and endangered animals, it is necessary to establish gene banks containing stocks of gametes and embryos of these animals. Optimization of the methods of in vitro production of bovine embryos and increasing their resistance to cryopreservation process is an actual challenge to ensure long-term storage in the gene bank of animal resources. The main goal of this mini-review is to provide general insight into the task of oocyte and embryo resistance to cryopreservation.

Current Advances in Bovine In Vitro Maturation and Embryo Production Using Different Antioxidants: A Review.

In vitro maturation (IVM) is one of the most important steps in in vitro embryo production (IVEP). It is a complicated procedure in which nuclear and cytoplasmatic changes in oocytes appear. In order to carry out the in vitro maturation procedure correctly, it is necessary to provide the oocytes with as close to a natural (in vivo) environment as possible. Many factors contribute to the overall poor quality of in vitro-matured oocytes. One important factor may be oxidative stress (OS). The generation of oxidants, such as reactive oxygen species, is common under culture conditions. The solution for OC treatment and prevention is antioxidants. In the last 5 years, many studies have examined different antioxidants and their effects on in vitro maturation of oocytes and embryo production. The aim of this systematic review was to present the achievements of scientific research in the last five years, in which the effects of many antioxidants were tested on bovine oocyte maturation and embryo production.

Ovum Pick Up (OPU) and in vitro embryo production in pregnant cows (Bos Indicus) at the Bachigualatito rancho, la Trinitaria, Chiapas

With the objective of determining the production, quality and development of bovine embryos (Bos Indicus), oocytes were collected from 14 females distributed in two groups: empty females (T1; n=7) and an experimental group of pregnant females (T2; n=7). The two groups were subjected to Ovum Pick Up (OPU) using disposable 18-gauge needles and a vacuum pressure of 100 mmHg. to later carry out in vitro fertilization (IVF). The study variables were the number of oocyte aspirated and fertilized and the expected embryos. A Wilcoxon test was performed for non-parametric data between two groups, finding no significant differences between treatments P&gt; 0.05. 250 oocytes were recovered by fertilizing out of 190, obtaining a fertilization rate of 77%, reaching a transferrable blastocyst rate of 24% (45/190). In empty females (7), 113 oocytes were obtained, reaching a fertilization rate of 75% (81/113) and 25% transferable blastocysts (18/81). In the 7 pregnant females, 137 oocytes were collected, reaching a fertilization rate of 83% (109/137) and 23% transferable blastocysts (27/109). Follicular aspiration for in vitro fertilization of embryos from pregnant and empty cows is viable without differences between them, but being more variable in pregnant cows.

Effects of anethole supplementation on bovine embryo production and quality

Improvements are necessary to further expand the potential of in vitro embryo production (IVP). Anethole, a natural antioxidant, was shown to be a low-cost alternative with an important role in the gene modulation of oxidative stress, and it can be used to produce higher quality embryos. The aim of this study was to evaluate the anethole effect during in vitro maturation (IVM) on the oocyte nuclear maturation, and then, during IVM and/or in vitro culture (IVC) on the production and quality of bovine embryos. In Experiment 1, cumulus-oocyte complexes (COCs) were matured in IVM medium in the following groups: control group (MC); supplemented with 300 µg/ml anethole (M300); and supplemented with 3,000 µg/ml anethole (M3000). The three groups were matured for 24 h to assess nuclear maturation (metaphase II) and gene expression of cumulus cells (CCs). The group that obtained the best response was M300, which was chosen for Experiment 2, together with MC. In this experiment, maturation was carried out either in IVM medium with 300 µg/ml anethole (M300) or not (MC). Subsequently, the COCs were submitted to in vitro fertilization and then divided into four groups for IVC: MCCC (IVM and IVC controls); MCC300 (control IVM and IVC with 300 µg/ml); M300-CC (IVM with 300 µg/ml and control IVC); and M300-C300 (IVM and IVC with 300 µg/ml anethole each). On the third day (D3) of the culture, cleavage was evaluated, and on D8, the production and classification of blastocysts were assessed. It was observed that 3,000 µg/ml anethole reduced the percentage of COCs that had reached nuclear maturation. The genes GREM1, GSTA1, SOD1, and CAT, related to oxidative stress resistance, and COX2 and HAS, involved in cell metabolism, showed increased abundance in CCs in the anethole presence. Regarding embryo production, the use of 300 µg/ml anethole during IVM and IVC improved the percentage of cleaved embryos. In addition, anethole treatment during IVM and IVC increased the expression of GPX1 gene while decreasing IFNT2α gene in the embryos produced. In conclusion, the addition of 300 µg/ml anethole during IVM modulated the expression of genes related to oxidative stress and oocyte development, and its use during IVM and IVC modulated the gene expression related to embryo quality. However, further studies need to be performed to better understand anethole's impact on embryo development.

Influence of fetal calf serum on the production of bovine embryos in vitro

The aim of the present study was to evaluate the effect of foetal calf serum (FCS) on the production of bovine embryo in vitro. We conducted two experiments: (1) to evaluate the effect of FCS on the production of bovine embryo in vitroand (2) to evaluate the effect of duration of FCS supplementation on the production of bovine embryo in vitro. In experiment 1, we divided mature bovine oocytes after in vitro fertilization into four embryo culture media: CR1aa, CR1aa+FCS, SOFaa, and SOFaa+FCS. Embryos cultured in CR1aa and SOFaa media supplemented with FCS resulted in a higher cleavage and blastocyst formation rates than when cultured in CR1aa and SOFaa without FCS (74.22 and 82.96% vs. 71.6 and 70.62%; 4.11 and 22.31% vs. 16.98 and 34.51%; respectively, p&lt;0.05). The percentage of hatching blastocysts was highest when embryos were cultured in SOFaa medium supplemented with FCS (10.54%; p&lt;0.05). Embryos cultured in the medium with FCS had a higher the average number of cells/blastocyst than the medium without FCS. The SOFaa+FCS group had a higher average number of cells/embryos than the other groups (94.32;p&lt;0.05). In experiment 2, we added FCS to bovine embryo culture in vitro at the following times: 0 h, 48 h, and 120 h after fertilization. The rate of oocyte cleavage, blastocyst formation, and hatching blastocyst rate of the 0-h group were higher than that of 48-h and 120-h groups (82.96 vs 70.5 and 70.24%; 34.51 vs 24.21 and 23.18%; 10.5 vs 6.12 and 4.13%; respectively, p&lt;0.05). However, there was no difference in the average number of cells/blastocysts between the groups. In conclusion, the addition of FCS to embryo culture media improved the efficiency of bovine embryo production in vitro and in vitro bovine embryo quality. The appropriate time to add FCS to bovine embryo culture in vitro was 0 h after fertilization.