87 EVALUATION OF THE NUMERICAL CHROMOSOMAL ABNORMALITIES ON IN VITRO EARLY BOVINE EMBRYOS: EFFECT OF THE CELL CO-CULTURE WITH GRANULOSA CELLS

2014 ◽  
Vol 26 (1) ◽  
pp. 157
Author(s):  
S. Demyda-Peyrás ◽  
M. Hidalgo ◽  
J. Dorado ◽  
M. Moreno-Millan

Chromosomal numerical abnormalities (CNA) were described as a major cause of developmental failures in in vitro-produced (IVP) embryos. It has been described that CNA are influenced by the post-fertilization culture environment of the embryo. Furthermore, it was demonstrated that the use of different culture media affects the CNA rates. The addition of granulosa cells during early embryo development is a well-known procedure to simplify the culture of bovine IVP and cloned embryos. This technique avoids the use of culture environments saturated with N2 (tri-gas chambers). The aim of this study was to determine the effect of the addition of granulosa cells in the chromosomal abnormalities of IVP cattle embryos. Cumulus–oocyte complexes (COC) were matured in TCM-199 medium, supplemented with glutamine, sodium pyruvate, FSH, LH, oestradiol, and gentamicin during 20 h at 38.5°C in a 5% CO2 humid atmosphere. Subsequently, matured oocytes were fertilized in IVF-TALP medium using 1 × 106 spermatozoa mL–1, selected through a Percoll gradient centrifugation. After fertilization, zygotes were divided in 2 groups and cultured in TCM-199 medium for 48 h, with (TCM-GC) or without (TCM) the addition of 1 × 106 granulosa cells. These cells were obtained by centrifuging and washing the follicular fluid remaining from searching dishes and adjusted to the working concentration. After culture, a total of 106 early embryos (72 hpi) were cytogenetically evaluated following our standard laboratory techniques. Embryos showing normal development were individually fixed onto a slide, disaggregated into blastomeres with acetic acid, and stained with Giemsa solution. Chromosomal numerical abnormalities were evaluated by direct observation at 1250× magnification in a brightfield microscope. Percentage of normal diploid embryos (D) and abnormal haploid (H), polyploid (P), or aneuploid (A) embryos were determined. Results were statistically compared between treatments using a Z test for proportions. Results were: D = 81.4%, H = 7.2%, P = 7.2%. and A = 3.6% in TCM and D = 84.3%, H = 3.9%, P = 9.8%, and A = 1.9% in TCM-GC. No significant differences (P > 0.05) were found between culture media in the chromosomal abnormality rates. According to our results, the use of somatic cells in co-culture during embryo development did not influence the appearance of abnormal complements in the produced embryos. This would allow the use of GC as a potential complement to simplify the techniques used in the culture of bovine embryos until Day 3.

2013 ◽  
Vol 25 (1) ◽  
pp. 266
Author(s):  
S. Demyda-Peyrás ◽  
M. Hidalgo ◽  
J. Dorado ◽  
L. De Luca ◽  
E. Genero ◽  
...  

Chromosomal abnormalities were described as a possible cause of embryo failures in cattle, even more so when they are in vitro produced. It has been widely demonstrated that the post-fertilization culture environment affects the frequency of blastomeric aneuploidies. However, the literature concerning the effect of the oocyte maturation techniques on in vitro-produced embryos is scarce. The aim of this study was to determine the effect of homologous bovine follicular fluid (BFF) as a possible replacement for commercial sera in the appearance of chromosomal abnormalities on early IVF-produced embryos. Cumulus–oocyte complexes obtained from ovarian puncture were maturated in modified bicarbonate-buffered TCM-199 media, supplemented with glutamine, sodium pyruvate, FSH, LH, oestradiol, and gentamicin in three different groups. Two treatments were performed: 1) base media supplemented with BFF, obtained aseptically from follicles between 4 and 10 mm in diameter (10 and 20%), and 2) a control group, with base media supplemented with 10% FCS without BFF. After 20 h of culture at 38.5°C in a 5% CO2 humid atmosphere, cumulus–oocyte complexes from both treatments were fertilized in IVF media and then cultured for 72 h in SOF media, according to our laboratory techniques. A total of 152 early embryos were cytogenetically evaluated following our standard laboratory techniques. Developed embryos were individually fixed onto a slide, disaggregated into blastomeres with acetic acid, and stained with Giemsa solution. Chromosomal numerical abnormalities were evaluated in each embryo by direct observation at 1250× magnification using a bright field microscope. Results were statistically compared among treatments by the expected proportion test. No significant differences (P > 0.05) were found between different culture media on the percentages of normal diploid embryos or each kind of numerical abnormality. According to our results (Table 1), the use of homologous follicular fluid as a supplement on the oocyte maturation media did not influence the appearance of abnormal complements in the embryos produced compared with the use of FCS. In conclusion, homologous follicular fluid may be considered a valid serum replacement in the maturation media on IVF-produced bovine embryos. Table 1.Analysis of chromosomal complements of Day 3 in vitro-produced bovine embryos derived from oocytes maturated in culture media with different serum supplementation1


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhi-Qiang Du ◽  
Hao Liang ◽  
Xiao-Man Liu ◽  
Yun-Hua Liu ◽  
Chonglong Wang ◽  
...  

AbstractSuccessful early embryo development requires the correct reprogramming and configuration of gene networks by the timely and faithful execution of zygotic genome activation (ZGA). However, the regulatory principle of molecular elements and circuits fundamental to embryo development remains largely obscure. Here, we profiled the transcriptomes of single zygotes and blastomeres, obtained from in vitro fertilized (IVF) or parthenogenetically activated (PA) porcine early embryos (1- to 8-cell), focusing on the gene expression dynamics and regulatory networks associated with maternal-to-zygote transition (MZT) (mainly maternal RNA clearance and ZGA). We found that minor and major ZGAs occur at 1-cell and 4-cell stages for both IVF and PA embryos, respectively. Maternal RNAs gradually decay from 1- to 8-cell embryos. Top abundantly expressed genes (CDV3, PCNA, CDR1, YWHAE, DNMT1, IGF2BP3, ARMC1, BTG4, UHRF2 and gametocyte-specific factor 1-like) in both IVF and PA early embryos identified are of vital roles for embryo development. Differentially expressed genes within IVF groups are different from that within PA groups, indicating bi-parental and maternal-only embryos have specific sets of mRNAs distinctly decayed and activated. Pathways enriched from DEGs showed that RNA associated pathways (RNA binding, processing, transport and degradation) could be important. Moreover, mitochondrial RNAs are found to be actively transcribed, showing dynamic expression patterns, and for DNA/H3K4 methylation and transcription factors as well. Taken together, our findings provide an important resource to investigate further the epigenetic and genome regulation of MZT events in early embryos of pigs.


2004 ◽  
Vol 16 (2) ◽  
pp. 275
Author(s):  
D. Fischer ◽  
J. Bordignon ◽  
C. Robert ◽  
D. Betts

Environment is crucial for in vitro development of gametes and embryos. The recent progression of culture media towards defined conditions brought to surface the impact of different medium supplements on oocyte and embryo development. In this work we evaluate the effect of various oocyte culture media on bovine oocyte maturation and subsequent embryo development. Bovine cumulus-oocyte complexes were recovered from slaughterhouse ovaries and matured in vitro in either TCM-199 (Gibco) or SOF (Synthetic Oviduct Fluid) media supplemented with BSA (fatty acid-free) or serum (fetal bovine serum). Oocytes from each treatment group were denuded and fixed at 18, 20, 22, 24, 26 and 28h post-maturation (p.m.). Oocyte meiotic progression was monitored in each of the groups (n=28–40 oocytes/group) by immunofluorescence microscopy of chromatin. Oocytes matured in SOF showed a slower rate of meiotic progression when compared to the other groups, with the highest percentage of oocytes reaching the MII stage by 28h p.m. (60.71% SOF-BSA, 71.43% SOF-Serum). The fastest developmental rate was observed in oocytes matured in TCM-serum (77.15% at 24h p.m.) followed by oocytes matured in TCM-BSA (74.29% at 26h p.m.). In order to evaluate the effect of nuclear maturation on chromosome segregation, chromosomal organization of MII oocytes was evaluated by immunofluorescence microscopy within each media group (n=26–31 oocytes/group) at 18, 22 and 26h p.m.. No chromosomal abnormalities were found at 18h p.m.. Both media supplemented with BSA induced lower frequencies of chromosomal abnormalities (0 to 3.23%) and (3.57 to 7.69%) for SOF and TCM, respectively, when compared to their serum-supplemented counterparts (7.14 to 11.54%) and (10 to 10.71%) for SOF and TCM, respectively at 22 and 26h p.m.. Remarkably, the maturation medium and its supplements influenced the speed of blastocyst development. For this experiment, oocytes were matured in TCM-BSA, TCM-Serum, SOF-BSA or SOF-serum, fertilized in vitro in a TALP-base media supplemented with BSA and cultured in SOF-BSA. Blastocyst development was assessed at 7, 8 and 9 days of culture. Cleavage rates were similar between the groups (84–90%), whereas development rates to blastocyst stage varied among treatment groups. Maturation in SOF-BSA induced a delay in blastocyst formation that reached its highest percentage only on day 9 of culture (30.8%); moreover, blastocyst development was carried over until Day 12. When oocytes were matured in the presence of serum, the number of blastocysts did not increase after Day 8 of culture (26.6%, TCM-serum). These results provide evidence of a severe impact of oocyte culture media on the nuclear maturation of oocytes and their subsequent embryonic development after IVF. Moreover, the difference in the rate of oocyte maturation and blastocyst formation emphasizes the necessity for reviewing and adapting current protocols to new systems such as SOF-BSA. [Research funded by NSERC and OMAF of Canada.]


Reproduction ◽  
2016 ◽  
Vol 152 (4) ◽  
pp. R127-R141 ◽  
Author(s):  
Veronica Maillo ◽  
Maria Jesus Sánchez-Calabuig ◽  
Ricaurte Lopera-Vasquez ◽  
Meriem Hamdi ◽  
Alfonso Gutierrez-Adan ◽  
...  

The oviduct is a complex and organized thin tubular structure connecting the ovary with the uterus. It is the site of final sperm capacitation, oocyte fertilization and, in most species, the first 3–4days of early embryo development. The oviductal epithelium is made up of ciliary and secretory cells responsible for the secretion of proteins and other factors which contribute to the formation of the oviductal fluid. Despite significant research, most of the pathways and oviductal factors implicated in the crosstalk between gametes/early embryo and the oviduct remain unknown. Therefore, studying the oviductal environment is crucial to improve our understanding of the regulatory mechanisms controlling fertilization and embryo development. In vitro systems are a valuable tool to study in vivo pathways and mechanisms, particularly those in the oviducts which in livestock species are challenging to access. In studies of gamete and embryo interaction with the reproductive tract, oviductal epithelial cells, oviductal fluid and microvesicles co-cultured with gametes/embryos represent the most appropriate in vitro models to mimic the physiological conditions in vivo.


Reproduction ◽  
2004 ◽  
Vol 128 (3) ◽  
pp. 281-291 ◽  
Author(s):  
Andrea Jurisicova ◽  
Beth M Acton

Human preimplantation embryo development is prone to high rates of early embryo wastage, particularly under currentin vitroculture conditions. There are many possible underlying causes for embryo demise, including DNA damage, poor embryo metabolism and the effect of suboptimal culture media, all of which could result in an imbalance in gene expression and the failed execution of basic embryonic decisions. In view of the complex interactions involved in embryo development, a thorough understanding of these parameters is essential to improving embryo quality. An increasing body of evidence indicates that cell fate (i.e. survival/differentiation or death) is determined by the outcome of specific intracellular interactions between pro- and anti-apoptotic proteins, many of which are expressed during oocyte and preimplantation embryo development. The recent availability of mutant mice lacking expression of various genes involved in the regulation of cell survival has enabled rapid progress towards identifying those molecules that are functionally important for normal oocyte and preimplantation embryo development. In this review we will discuss the current understanding of the regulation of cell death gene expression during preimplantation embryo development, with a focus on human embryology and a discussion of animal models where appropriate.


2013 ◽  
Vol 25 (1) ◽  
pp. 193
Author(s):  
J. Caudle ◽  
C. K. Hamilton ◽  
F. A. Ashkar ◽  
W. A. King

Sexual dimorphisms such as differences in growth rate and metabolism have been observed in the early embryo, suggesting that sex chromosome-linked gene expression may play an active role in early embryo development. Furthermore, in vitro sex ratios are often skewed toward males, indicating that Y-linked genes may benefit development. While little attention has been paid to the Y chromosome, expression of some Y-linked genes such as SRY and ZFY has been identified in the early embryo, and only a few studies have systematically examined early stages. Identification of transcripts of Y-linked genes in the early embryo may provide insights into male development and provide markers of embryonic genome activation in male embryos. The objectives of this study were i) to examine the timing of transcription of 2 Y chromosome-linked genes involved with sperm production and male development, ubiquitin-specific peptidase 9 (USP9Y) and zinc finger protein (ZFY), in in vitro-produced bovine embryos from the 2-cell stage to the blastocyst stage and ii) to determine if USP9Y and ZFY transcripts are present in in vitro-produced embryos arrested at the 2- to 8-cell stages. To examine the chronology of transcription of these genes, pools of 30 embryos for each developmental stage, 2-cell, 4-cell, 8-cell, 16-cell, morula, and blastocyst, were produced by bovine standard in vitro embryo production (Ashkar et al. 2010 Hum. Reprod. 252, 334–344) using semen from a single bull. Pools of 30 were used to balance sex ratios and to account for naturally arresting embryos. Embryos for each developmental stage were harvested and snap frozen. Total RNA was extracted from each pool, reverse transcribed to cDNA and by using PCR, and transcripts of USP9Y and ZFY were detected as positive or negative. In addition pools of 30 embryos arrested at the 2- to 8-cell stage harvested 7 days after IVF were processed and analysed in the same way to determine if transcripts from the Y chromosomes are present in developmentally arrested embryos. Transcripts of USP9Y and ZFY were detected in the pooled embryos from the 8-cell stage through to the blastocyst stage, but none were detected in the 2-cell or 4-cell pools. Transcripts of ZFY were detected in the arrested 2- to 8-cell embryo pool, but transcripts of USP9Y were not detected. Given that these Y genes begin expression at the 8-cell stage, coincident with embryonic genome activation, it was concluded that these genes may be important for early male embryo development. Furthermore, the results suggest that arrested embryos that have stopped cleaving before the major activation of the embryonic genome are still capable of transcribing at least some of these genes. The absence of USP9Y transcripts in the arrested embryos suggests that it may be important for early male embryo development. Funding was provided by NSERC, the CRC program, and the OVC scholarship program.


2009 ◽  
Vol 21 (1) ◽  
pp. 200
Author(s):  
M. Clemente ◽  
A. T. Palasz ◽  
J. de La Fuente ◽  
P. Lonergan ◽  
A. Gutierrez-Adan ◽  
...  

Hyaluronan (HA), which progressively increases during embryogenesis, is a glycosaminoglycan that plays a major role in oocyte/embryo development (Fenderson et al. 1993 Differentiation 54, 85–95). One of the main functions of HA is to participate in the cell proliferation and migration that are controlled by HA receptors, RHAMM and C44, and by the presence of different HA synthases, Has1, Has2, and Has3. All have very distinctive features and functions at different stages of embryo development. The objective of this study was to determine the relative mRNA abundance of HA receptors and synthases in Day 7 and 13 bovine embryos derived in vitro or in vivo. In vitro embryos were produced by standard oocyte maturation and fertilization procedures. Presumptive zygotes were cultured in groups of 25 in 25-μL droplets of synthetic oviduct fluid supplemented with 5% FCS at 39°C, 5% CO2, and 5%O2 with maximum humidity. In vivo blastocysts were collected from superovulated heifers on Day 7 (estrus = Day 0) by uterine flushing and on Day 13 immediately after slaughter by flushing the dissected reproductive tracts. All embryos were frozen in LN2 and stored at –80°C for mRNA extraction. Quantification of transcripts for RHAMM and CD44 receptors and Has2 and Has3 synthases was performed on groups of ten Day 7 blastocysts (3 groups for in vivo or in vitro) and individual Day 13 embryos (7 embryos in vivo or in vitro) by real-time quantitative RT-PCR. Data on differences in transcript abundance were analyzed by ANOVA. The relative abundance of the Has2 and Has3 synthases was similar between in vivo and in vitro embryos, irrespective of their developmental stage. The quantity of CD44 was significantly higher in in vitro compared with in vivo embryos only on Day 7. However, the quantity of RHAMM receptor was higher on Day 13 in in vitro compared with in vivo embryos. When the comparison was done between developmental stages (Day 7 v. Day 13) for in vivo and in vitro embryos, we found that in vivo-produced Day 7 blastocysts expressed significantly more RHAMM receptor than embryos on Day 13. The reverse pattern of expression was shown for CD44 receptor. For in vitro embryos, the only difference observed was for Has3, which was up-regulated on Day 13 compared with Day 7 embryos. In conclusion, the present study demonstrates, for the first time, developmental changes in the abundance of RHAMM and CD44 receptor mRNA and Has2 and Has3 synthase mRNA in in vivo and in vitro bovine-derived embryos on Day 7 and 13. We believe that our results will provide new insight into the potential role of this intriguing multifunctional molecule in bovine early embryo development.


2017 ◽  
Vol 29 (1) ◽  
pp. 201
Author(s):  
S. Demyda-Peyrás ◽  
P. Peral-García ◽  
M. Moreno-Millán

One of the major causes of embryo failure on in vitro-produced cattle embryos is their increased rate of chromosomal abnormalities. It was demonstrated that they can be increased by the pre- and post-environmental conditions of culture, such as the culture media and supplementation and culture atmosphere among others. Furthermore, it was suggested that the percentage of chromosomal abnormalities detected could be used as an indirect methodology to evaluate the embryo stress during culture. The use of oviduct cells in co-culture was employed as a technique that improves the embryo quality in different culture systems in cattle, probably by modulating the variations in the embryo environment or detoxifying the culture media. For that reason, we aimed to determine if the use of an oviducal co-culture system could reduce the percentage of chromosomal abnormalities in in vitro-produced cattle embryos. Oviducal cells were obtained from abattoir oviducts, and plated and cultured in TCM-199 media following standard procedures. Cumulus-oocyte complexes were also obtained from the abattoir and matured in a standard media (TCM199, with glutamine, pyruvate, FSH, LH, and antibiotics) for 20 h (38.5°C, 5% CO2). Matured oocytes were fertilized in IVF-TALP with 1 × 106 spermatozoa/mL (previously selected through a 45–90% Percoll™ gradient) for 18 h using the same conditions. Presumptive zygotes (n = 653) were divided into 2 groups and cultured in the mSof medium for 72 h, with (SOV) or without (SOF) the addition of oviducal cells. In total, 108 embryos were successfully karyotyped following our standard laboratory techniques. Chromosomal numerical abnormalities were evaluated by direct observation at 1250× magnification in a bright-field microscope using a simple Giemsa staining. The percentage of diploid embryos (54/58 in SOV and 47/53 in SOF) and abnormal embryos (4/58 in SOV and 6/53 in SOF) were nonsignificant (P > 0.05; Z-score test for 2 population proportions). Our results suggest that the use of oviducal cells as a co-culture supplementation in in vitro-produced cattle embryos do not improve the percentage of chromosomal abnormalities detected.


Author(s):  
Orhan Örnek ◽  
Yusuf Ziya Güzey

Progesterone plays a key role in the establishment and maintenance of pregnancy in mammalian. Increasing levels of circulating progesterone in the post-conception period are associated with conceptus elongation and high pregnancy rates in cattle. Contradictory results are available on the direct role of progesterone in early embryo development. The objective of this study was to evaluate direct effects of progesterone on in vitro development of cattle embryos. Immature oocytes collected from slaughtered animals and cultured in the presence of different concentrations of progesterone (25, 50, 100 ng/mL) following in vitro fertilization. Cleavage rates in 25 and 50 ng/mL concentrations of progesterone were significantly higher than those in controls and 100 ng/mL. Rate of embryos that reached to the morula stage was similar in all groups. Supplementation of 25 and 50 ng/mL progesterone to the culture media significantly increased blastocyst yield while 100 ng/mL progesterone resulted in a decrease. As a conclusion, we can suggest that progesterone supplementation in in vitro culture may support embryo development at low levels.


2024 ◽  
Vol 84 ◽  
Author(s):  
A. Azam ◽  
R. Ejaz ◽  
S. Qadeer ◽  
S. Irum ◽  
A. Ul-Husna ◽  
...  

Abstract The objective of the current study was to investigate the synergistic impact of α-Tocopherol and α-Linolenic acid (100 µM) on IVM and IVC of Nili Ravi buffalo oocytes. Oocytes were obtained from the ovaries of slaughtered buffaloes within two hours after slaughter and brought to laboratory. Buffalo cumulus oocyte complexes were placed randomly in the five experimental groups included; GROUP 1: Maturation media (MM) + 100 µM ALA (control), GROUP 2: MM + 100 µM ALA + 50μM α-Tocopherol, GROUP 3: MM + 100 µM ALA + 100μM α-Tocopherol, GROUP 4: MM + 100 µM ALA + 200 μM α-Tocopherol and GROUP 5: MM + 100 µM ALA + 300 μM α-Tocopherol under an atmosphere of 5% CO2 in air at 38.5 °C for 22-24 h. Cumulus expansion and nuclear maturation status was determined (Experiment 1). In experiment 2, oocytes were matured as in experiment 1. The matured oocytes were then fertilized in Tyrode’s Albumin Lactate Pyruvate (TALP) medium for about 20 h and cultured in synthetic oviductal fluid (SOF) medium to determine effect of α-Linolenic acid (100 µM) and α-Tocopherol in IVM medium on IVC of presumptive zygotes. To study the effect of α-Linolenic acid (100 µM) in IVM media and increasing concentration of α-tocopherol in the culture media on early embryo development (Experiment 3), the presumptive zygotes were randomly distributed into the five experimental groups with increasing concentration of α-tocopherol in culture media. Higher percentage of MII stage oocytes in experiment 1(65.2±2.0), embryos at morula stage in experiment 2 (30.4±1.5) and experiment 3 (22.2±2.0) were obtained. However, overall results for cumulus cell expansion, maturation of oocyte to MII stage and subsequent embryo development among treatments remain statistically similar (P > 0.05). Supplementation of α-tocopherol in maturation media having α-Linolenic acid and/or in embryo culture media did not further enhance in vitro maturation of oocyte or embryo production.


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