scholarly journals 252A COMPARATIVE EXPRESSION ANALYSIS OF GENES IN PREIMPLANTATION DEVELOPMENTAL STAGES OF BOVINE EMBRYOS PRODUCED IN VITRO OR IN VIVO

2004 ◽  
Vol 16 (2) ◽  
pp. 246 ◽  
Author(s):  
D. Tesfaye ◽  
K. Wimmers ◽  
M. Gilles ◽  
S. Ponsuksili ◽  
K. Schellander

A comparative analysis of mRNA expression patterns between embryos produced under different in vitro and in vivo culture systems allows the isolation of genes associated with embryo quality and investigation of the effect of culture environment on the embryonic gene expression. In this study, expression analysis of four known (PSCD2, TCF7L2, NADH-subunit and PAIP1) genes and one novel transcript, derived from differential display PCR, was performed in in vitro (Ponsuksili et al., 2002, Theriogenology 57, 1611–1624) or in vivo- (Moesslacher et al., 2001 Reprod. Dom. Anim. 32, 37) produced bovine 2-, 4-, 8-, 16-cell, morula and blastocyst stage embryos using real time PCR technology. Poly(A) RNA was isolated from four separate individual embryos from each developmental stage and embryo group (in vitro or in vivo) using Dynabeads mRNA kit (Dynal, Oslo, Norway). After reverse transcription, quantitative PCR was performed with sequence specific primers in an ABI PRISM® 7000 Sequence Detection System instrument (Applied Biosystems, Foster City, CA, USA) using SYBR® Green as a double-strand DNA-specific fluorescent dye. Standard curves were generated for target and endogenous genes using serial dilutions of plasmid DNA. Final quantification was done using the relative standard curve method, and results were reported as relative expression or n-fold difference to the calibrator cDNA (i.e., the blastocyst stage) after normalization with the endogenous control (Histone2a). Data were analyzed using SAS version 8.0 (SAS Institute Inc., NC, USA) software package. Analysis of variance was performed with the main effects being the developmental stage and embryo source (in vitro or in vivo) and their interactions followed by multiple pairwise comparisons using Tukey’s test. No significant difference was observed in the relative abundance of the PSCD2 gene between the two embryo groups. However, its expression was higher (20-fold) (P<0.05) at the 8-cell stage than the other developmental stages among in vitro embryos. Higher expression (P<0.05) of NADH-subunit mRNA was detected in vivo than in vitro at the 2-cell stage of development. The TCF7L2 mRNA was expressed in the in vitro embryos but not in the in vivo ones. PAIP1 mRNA was higher (P<0.05) in in vitro (1500-fold) than in the in vivo embryos (500-fold) at the 2-cell developmental stage compared to the calibrator. The novel transcript was also detected at higher level (P<0.05) in the in vitro than in the in vivo embryos at the 2-cell stage of development. However, the PAIP1 and the novel transcript showed no significant difference in their expression between the two embryo groups beyond the 2-cell developmental stage. Both PAIP1 and the novel transcript were detected only up to 8-cell stage in both embryo groups, suggesting their maternal origin. In conclusion, the variations in the expression of studied genes between in vitro and in vivo may reflect the effect of the two culture systems on the transcriptional activity of early embryos.

2008 ◽  
Vol 20 (1) ◽  
pp. 169 ◽  
Author(s):  
C. E. McHughes ◽  
G. K. Springer ◽  
L. D. Spate ◽  
R. Li ◽  
R. J. Woods ◽  
...  

Identification of transcripts that are present at key development stages of preimplantation embryos is critical for a better understanding of early embryogenesis. To that end, this project had two goals. The first was to characterize the relative abundance of multiple transcripts during several developmental stages, including metaphase II-stage oocytes (MPII), and 2-cell-stage (2-cell), precompact morula (PCM), and in vitro-produced blastocyst-stage (IVTBL) embryos. The second was to characterize differences in the relative abundance of transcripts present in in vivo- (IVVBL), in vitro-, and nuclear transfer-produced (NTBL) blastocysts. It was our hypothesis that the identification of differentially represented transcripts from these stages would reveal not only developmentally important genes, but also genes that might be aberrantly expressed due to embryo production techniques. Individual clusters from a large bovine EST project (http://genome.rnet.missouri.edu/Bovine/), which focused on female reproductive tissues and embryos, were compared using Fisher's exact test weighted by number of transcripts per tissue by gene (SAS PROC FREQ; SAS Institute, Inc., Cary, NC, USA). Of the 3144 transcripts that were present during embryogenesis, 125 were found to be differentially represented (P < 0.01) in at least one pairwise comparison (Table 1). Some transcripts found to increase in representation from the MPII to the 2-cell stage include protein kinases, PRKACA and CKS1, as well as the metabolism-related gene, PTTG1. These same transcripts were also found to decrease in representation from the 2-cell to the PCM stage. RPL15 (translation) and FTH1 (immune function) were both more highly represented in the PCM than in the 2-cell stage. From PCM to IVTBL, we saw an increase in RPS11, another translation-related transcript. When comparing blastocyst-stage embryos from different production techniques, several transcripts involved in energy production (e.g., COX7B and COX8A) were found to be more highly represented in the NTBL than in the IVTBL. COX8A was also more highly represented in the IVVBL than in the IVTBL. By investigating these differentially represented transcripts, we will be able to better understand the developmental implications of embryo manipulation. We may also be able to better develop reproductive technologies that lead to in vitro- and nuclear transfer-derived embryos which more closely follow a normal program of development. Table 1. Differentially represented transcripts between developmental stages


2010 ◽  
Vol 22 (1) ◽  
pp. 238
Author(s):  
I. P. Emanuelli ◽  
B. F. Agostinho ◽  
M. P. M. Mancini ◽  
C. M. Barros ◽  
M. F. G. Nogueira

Embryonic chimeras have been used as a tool to understand embryogenesis and organogenesis, as well as to prove, in vivo, the pluripotency of the embryonic stem cells. One of the techniques used to obtain embryonic chimeras is aggregation, which can be performed with intact or half-embryos and in different stages of the development, produced by in vivo or in vitro systems and in different wells. However, its efficiency tends to reduce when advanced stages, such as morulae and blastocysts, are used. The aim of this work was to evaluate the effect of the treatment with an agglutinating agent (phytohemagglutinin-L; PHA) in the percentage of chimeras produced with IVF bovine embryos. Bovine ovaries (from abattoir) were used to obtain 270 COC that were matured in drops (90 μL) of TCM-199 bicarbonate medium, supplemented with 10% of FCS, and incubated in vitro for 22 to 24 h. The fertilization occurred in TALP-IVF medium, and the COC were maintained in the incubator for 18 h. After fertilization, the presumptive zygotes were transferred to SOF culture medium to in vitro culture. In vitro maturation, fertilization, and culture were performed under 38.5°C, 5% CO2 in air and saturated humidity. The chimerism by aggregation was tested between 2 intact (zona-free) 8- to 16-cell stage embryos in the presence (G1, n = 16) or absence of PHA (G2, n = 14) and between one half-morula and one half-blastocyst with (G3, n = 15) or without PHA (G4, n = 12). The embryos in groups G1 and G3 were treated with PHA in a concentration of 500 μLg mL-1 for 3 min. After PHA treatment, the pairs of embryos were allocated in wells, under previously described culture conditions, until expanded blastocyst stage could be observed (Day 7 of culture). At 24 h of culture, embryonic aggregation pairs were first evaluated to detect only cohesive masses of cells. The results (chimerism rate) were 62.5%, 42.9%, 40.0%, and 25.0%, respectively, for groups G1, G2, G3, and G4. There were no significant differences neither among groups (chi-square, P = 0.252) nor between G1 and G2 (P = 0.464), G3, and G4 (P = 0.683; Fisher’s exact test). Main effects as use of PHA (G1 + G3 v. G2 + G4, P = 0.284) and stage of embryos (G1 + G2 v. G3 + G4, P = 0.183; Fisher’s exact test) were not statistically significant. However, when all groups were compared, the power of the performed test (0.354) was below the desired power of 0.800 (i.e. one must be cautious in over-interpreting the lack of difference among them). In the conditions of this study, it was concluded that the treatment with PHA did not increase the rate of aggregation in the embryonic chimera production, even for half-embryos in advanced stage of development (morulae and blastocysts). Granted by FAPESP, Brazil: 06/06491-2 and 07/07705-9 (MFGN) and 07/04291-9 (MPMM).


2008 ◽  
Vol 56 (2) ◽  
pp. 245-253 ◽  
Author(s):  
Chang-Liang Yan ◽  
Qi-En Yang ◽  
Guang-Bin Zhou ◽  
Yun-Peng Hou ◽  
Xue-Ming Zhao ◽  
...  

The present study was designed to investigate the cryotolerance of in vitro fertilised (IVF) mouse embryos at various preimplantation developmental stages. IVF mouse embryos were vitrified by the open-pulled straw (OPS) method. After warming, embryos were morphologically evaluated and assessed by their development to blastocysts, hatched blastocysts or term. The results showed that a high proportion (93.3–100.0%) of vitrified embryos at all developmental stages were morphologically normal after recovery. The developmental rate of vitrified 1-cell embryos to blastocyst (40.0%) or hatched blastocyst (32.7%) or term (9.3%) was significantly lower than that from other stages (P < 0.05). Vitrified embryos from 2-cell to early blastocyst stage showed similar blastocyst (71.8–89.5%) and hatched blastocyst rates (61.1–69.6%) and could develop to term without a significant loss of survival compared with those of fresh embryos (P > 0.05). Vitrified 2-cell embryos showed the highest survival rate in vivo (50.6%, 88/174), compared with that from other stages (9.3–30.5%, P < 0.05). The data demonstrate that the OPS method is suitable for the cryopreservation of IVF mouse embryos from 2-cell stage to early blastocyst stage without a significant loss of survival. Embryos at the 2-cell stage had the best tolerance for cryopreservation in the present study.


2010 ◽  
Vol 22 (1) ◽  
pp. 231
Author(s):  
C. Y. Choe ◽  
S. R. Cho ◽  
J. K. Son ◽  
S. H. Choi ◽  
C. Y. Cho ◽  
...  

Oxygen consumption has been regarded as a useful indicator for assessment of mammalian embryo quality. This study was carried out to identify whether oxygen consumption rates measured in bovine embryos using SECM can be used as a standard criteria to evaluate bovine embryo quality. Oxygen consumption of bovine embryos at various developmental stages was measured and analyzed using SECM and ANOVA analysis, respectively. We found that the oxygen consumption significantly increased in blastocyst-stage embryos compared to other stage embryos (from 2-cell stage to morula stage), indicating that oxygen consumption reflects the cell number (5.2-7.6 × 1014 mol-1 s-1 v. 1.2-2.4 × 1014 mol-1 s-1, P < 0.05). There was no significant difference between 2-cell-stage embryos and 8-cell-stage embryos. In the morula-stage embryos, the oxygen consumption of in vivo derived embryos was significantly higher than that of in vitro produced embryos (4.0 × 1014 mol-1 s-1 v. 2.4 × 1014 mol-1 s-1, P < 0.05). However, there was no significant difference in consumption of oxygen by in vivo and in vitro derived bovine blastocyst-stage embryos (P > 0.05). Good-quality embryos with grade 1 or 2 showed significantly higher oxygen consumption than grade 3 or 4 embryos. These results showed that SECM could measure oxygen consumption in bovine embryos and the oxygen consumption could reflect embryonic development stage and embryo quality.


1996 ◽  
Vol 8 (6) ◽  
pp. 945 ◽  
Author(s):  
RJ Partridge ◽  
HJ Leese

Bovine embryos produced in vitro from the putative zygote stage to the blastocyst stage, and blastocysts freshly flushed from the uterus, were cultured in a physiological mixture of amino acids. Depletion of amino acids from the medium and, in a few cases, their appearance, was measured by high performance liquid chromatography. Amino acids were depleted at widely differing rates. The depletion of amino acids was higher when embryos at later developmental stages were cultured, implying an increase in amino acid requirement with development. Threonine was the only amino acid to be depleted at all stages of development; depletion increased from 0.18 +/- 0.07 pmol embryo-1 h-1 at the putative zygote stage to 1.96 +/- 0.49 pmol embryo-1 h-1 at the blastocyst stage. Glutamine was depleted at the putative zygote stage and the 4-cell stage (0.76 +/- 0.05 and 0.94 +/- 0.10 pmol embryo-1 h-1 respectively), but was not significantly depleted at the later stages. Alanine was the only amino acid that appeared consistently in the medium and its production increased progressively throughout development. Aspartate, glutamate, threonine and lysine were depleted significantly by blastocysts derived both in vitro and in vivo; the embryos in vivo also depleted arginine, phenylalanine, isoleucine and tyrosine. These results indicate that individual amino acids are depleted at different rates by bovine preimplantation embryos and suggest that amino acid requirements change during development.


2017 ◽  
Vol 29 (1) ◽  
pp. 187
Author(s):  
A. Goldacker ◽  
E. Winn ◽  
J. Z. Current ◽  
B. D. Whitaker

Oviducal fluid has a major role in the maturation of gametes and the process of fertilization. The objective of this study was to determine the effects of oviducal fluid supplementation in vitro, during oocyte maturation and IVF on fertilization characteristics and early embryonic development rates. Oocytes from aspired aspirated mature follicles (3–6 mm diameter) were obtained from a local abattoir. During the last 24 h of maturation, oocytes (n = 1303) were placed into maturation media supplemented either 1% (vol/vol) or 5% (vol/vol) thawed snap-frozen oviducal fluid. Fertilization was performed using pooled frozen-thawed semen from 3 different boars. During IVF, the fertilization medium was supplemented with 1% (vol/vol) or 5% (vol/vol) oviducal fluid. Fertilization characteristics were evaluated 12 h after IVF and rates of embryonic cleavage and blastocyst development were observed at 48 and 144 h after IVF, respectively. Data were analysed using ANOVA with the main effects including treatment, well, and replicate. Chi-square analysis was used to determine percentages of embryos reaching the different developmental stages for each treatment. There were no significant differences in the percentages of oocytes that reached metaphase II by the end of maturation or in sperm penetration rates after IVF. However, oocytes treated with 1% (vol/vol) oviducal fluid during the end of maturation and IVF (33.33 ± 2.61) and 5% (vol/vol) oviducal fluid during maturation (33.33 ± 2.66) or IVF (39.53 ± 3.78) had significantly less (P < 0.05) incidence of polyspermic penetrations and a significantly higher (P < 0.05) incidence of male pronuclear formation (87.50 ± 4.01; 86.67 ± 4.83; 86.05 ± 3.19, respectively) compared with no oviducal fluid supplementation. Oocytes supplemented with 5% (vol/vol) oviducal fluid during maturation and IVF had significantly lower (P < 0.05) incidences of polyspermic penetration (27.91 ± 2.50) and significantly higher (P < 0.05) percentages of embryos reaching the 2-cell stage (81.76 ± 3.72) and blastocyst stage of development (37.74 ± 1.09) by 48 and 144 h, respectively, compared with all other groups. The results of this study suggest that supplementing 5% (vol/vol) oviducal fluid during maturation and IVF improves the success rates of in vitro embryo development in pigs.


2000 ◽  
Vol 8 (3) ◽  
pp. 241-287 ◽  
Author(s):  
GM Jones

The transfer of a blastocyst established the first human clinical pregnancy following in vitro fertilization (IVF). Nine years later Cohen et al. reported pregnancies resulting from the transfer of cryopreserved human blastocysts. However, it was another six years before the first report of births resulting from the transfer of human blastocysts produced in vitro appeared in the medical literature. In the intervening period clinics have opted to transfer embryos at the early cleavage stage to the uterus, despite the fact that in vivo the embryo does not enter the uterus until two to three days later at the morula to blastocyst stage of development. The viability and potential for implantation of blastocysts is high, as indicated by the finding that more than 60% of in-vivo-derived blastocysts, recovered by uterine lavage following artificial insemination of fertile donors, implant and develop into viable fetuses when transferred to recipients. This is in stark contrast to the 10–20% of in-vitro-produced embryos transferred at the early cleavage stage of development that result in a live-birth. This reduction in viability following transfer of in-vitro-derived early cleavage stage embryos may have several possible explanations: (1) a failure of implantation due to poor synchronization between the embryo and the uterine endometrium; (2) a hostile environment in the uterus for early cleavage stage embryos; (3) sub-optimal in vitro culture conditions which result in a reduction in embryo viability; (4) the assumption that all oocytes retrieved in an IVF cycle have an equal ability to develop into viable embryos; and (5) the failure to identify the most viable embryo in a cohort. Certainly, improving culture conditions and laboratory techniques for developing high quality blastocysts routinely in vitro will not only address many of the above questions but will also improve the quality and viability of earlier stages of embryo development.


2006 ◽  
Vol 18 (2) ◽  
pp. 248
Author(s):  
S.-G. Lee ◽  
C.-H. Park ◽  
D.-H. Choi ◽  
H.-Y. Son ◽  
C.-K. Lee

Use of blastocysts produced in vitro would be an efficient way to generate embryonic stem (ES) cells for the production of transgenic animals and the study of developmental gene regulation. In pigs, the morphology and cell number of in vitro-produced blastocysts are inferior to these parameters in their in vivo counterparts. Therefore, establishment of ES cells from blastocysts produced in vitro might be hindered by poor embryo quality. The objective of this study was to increase the cell number of blastocysts derived by aggregating 4–8-cell stage porcine embryos produced in vitro. Cumulus–oocyte complexes were collected from prepubertal gilt ovaries, and matured in vitro. Embryos at the 4–8-cell stage were produced by culturing embryos for two days after in vitro fertilization (IVF). After removal of the zona pellucida with acid Tyrode’s solution, one (1X), two (2X), and three (3X) 4–8-cell stage embryos were aggregated by co-culturing them in aggregation plates followed by culturing to the blastocyst stage. After 7 days, the developmental ability and the number of cells in aggregated embryos were determined by staining with Hoechst 33342 and propidium iodide. The percentage of blastocysts was higher in both 2X and 3X aggregated embryos compared to that of 1X and that of intact controls (Table 1). The cell number of blastocysts also increased in aggregated embryos compared to that of non-aggregated (1X) embryos and controls. This result suggests that aggregation might improve the quality of in vitro-fertilized porcine blastocysts by increasing cell numbers, thus becoming a useful resource for isolation and establishment of porcine ES cells. Further studies are required to investigate the quality of the aggregated embryos in terms of increasing the pluripotent cell population by staining for Oct-4 and to apply improved aggregation methods in nuclear-transferred (NT) porcine embryos. Table 1. Development, cell number, and ICM ratio of aggregated porcine embryos


2017 ◽  
Vol 29 (1) ◽  
pp. 185
Author(s):  
L. R. Madzhie ◽  
M. A. Raseona ◽  
L. P. Nethenzheni ◽  
O. Ajao ◽  
M. L. Mphaphathi ◽  
...  

In vitro fertilization in the straw system might increase the efficiency of fertilization and the quality of blastocyst formation as compared with micro-drops-IVF systems. The aim of the study was to in vitro fertilize mouse oocytes and culture the resulting zygotes in bi-gas incubator and in a goat vagina and compare the in vitro embryo developmental stages in TCM-199 and Ham’s F10 culture media until the blastocyst-stage of development. F1 generations (Balb C × C57) were used to harvest oocytes and spermatozoa. The fresh sperm were capacitated in different incubation methods (bi-gas incubator and in the vagina of a goat). A volume of 2–4 µL of Ham’s F10 containing capacitated sperm (~8 × 106 per mL) were placed into Ham’s F10 fertilization drops under the oil, containing 10 oocytes and penicillamine, hypotaurine, and epinephrine for enhancing sperm motility and penetration of oocytes. The same procedure was used with the TCM-199 medium and IVF drops without oil (both TCM-199 and Ham’s F10) for straw filling. The presumptive embryos in Ham’s F10 and TCM-199 were divided into different groups: first group were cultured in micro-drops, second group the embryos were aspirated in semen straws and placed in the incubator (incubator straws) for culture, and other straws were covered with a sponge and inserted in the vagina of a goat (vaginal straws) for culture. The resulted blastocysts were stained using Hoechst 33528 solution and blastomeres were counted on a fluorescent UV light inverted microscope at 400× magnification (Nikon Eclipse TI, Narishige Co., Ltd., Amityville, NY, USA). The results were analysed by 2 × 2 factorial designs and Student’s t-test was used to separate the mean. There was no statistical difference (P > 0.05) between the media and incubators on the stage of murine embryo development. The overall fertilization rate was 94 to 99%. The incubator straws with Ham’s F10 (80.5%) had the highest rate of embryos that reached the blastocyst stage, followed by incubator straws with TCM-199 (77.0%), and vaginal straws with Ham’s F10 (60.0%) had the lowest rate of embryos that reached the blastocyst stage. The overall mean number of blastomeres in the blastocyst stage of the embryos ranged from 85 ± 9 to 90 ± 9 cells in all receptacles and incubators. It was concluded that the fertilization and culturing of murine embryos are possible in straws incubated in a bi-gas incubator and in the goat vagina as an alternative method of fertilizing oocytes and culturing murine embryos. In addition, Ham’s F10 and TCM-199 can both be used to fertilize oocytes and culture murine embryos until blastocyst formation embryo in vitro, incubated in a bi-gas incubator or in the vagina.


2019 ◽  
Vol 31 (1) ◽  
pp. 198
Author(s):  
E. Hicks ◽  
E. Winn ◽  
B. Whitaker

Elevated levels of reactive oxygen species in the in vitro environment cause oxidative stress, which leads to membrane damage, decreased fertility, and morphological deformities of spermatozoa. Antioxidants, such as quercetin (a polyphenol flavonoid), are often supplemented to reduce the effects of oxidative stress on spermatozoa. Supplementing frozen-thawed boar semen with quercetin improves sperm forward progressive motility, viability and lipid peroxidation up to 10h after thawing. However, the effects of fertilizing with quercetin-supplemented sperm are unknown. Therefore, the objective of this study was to determine the effects of supplementing quercetin (0.25, 0.50, 0.75mM) during the thawing and incubation of frozen-thawed boar semen on oocyte fertilization characteristics (n=400) and subsequent embryonic development (n=1340) at 48 and 144h for cleavage and blastocyst formation, respectively. Oocytes from aspired aspirated mature follicles (3-6mm diameter) were obtained from a local abattoir and matured in medium 199 for 40 to 44h at 38.5°C in an atmosphere of 5% CO2. Fertilization was performed using pooled frozen-thawed semen from 3 different boars, and co-incubation of the sperm (2×105 sperm mL−1) and oocytes (30 oocytes/well) lasted for 6 to 8h at 38.5°C in an atmosphere of 5% CO2. Data were analysed using ANOVA with the main effects including treatment, well and replicate. Chi-squared analysis was used to determine percentages of embryos reaching the different developmental stages for each treatment. There were no differences in penetration rates and male pronuclear formation between treatment groups; however, supplementation of 0.25 (18.18±10.63%), 0.50 (20.93±9.89%) and 0.75mM (18.07±12.02%) quercetin significantly decreased (P&lt;0.05) polyspermic penetration rates compared with no supplementation (40.00±11.34%). Embryos produced from frozen-thawed boar sperm supplemented with 0.25 and 0.50mM quercetin had a significantly higher percentage (P&lt;0.05) of embryos reaching the 2-cell stage of development by 48h after IVF (75.00±7.89%, 68.75±2.23%, respectively) compared with 0.75mM quercetin supplementation (64.62±3.88%) and no supplementation (62.97±4.11%). Supplementation of 0.25 (44.12±6.23%), 0.50 (43.75±7.02%) and 0.75mM (43.08±2.98%) quercetin to the sperm significantly increased (P&lt;0.05) the percentage of embryos reaching the blastocyst stage of development by 144h after IVF compared with no supplementation (28.27±8.07%). These results indicate that supplementing frozen-thawed boar semen with quercetin decreases the incidence of polyspermic penetration and improves early embryonic development in pigs.


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