• Proceedings of the Korean Society of Embryo Transfer Conference
• /
• 2002.11a
• /
• pp.73-73
• /
• 2002

Nuclear transfer (NT) techniques have advanced in the last years, and cloned animals have been produced by using somatic cells in several species including pig. However, it is difficult that the nuclear transfer porcine embryos development to blastocyst stage overcoming the cell block in vitro. Abnormal segregation of chromosomes in nuclear transferred embryos on genome activation stage bring about embryo degeneration, abnormal blastocyst, delayed and low embryo development. Thus, we are evaluated that the correlations of the frequency of embryo developmental rates and chromosome aberration in NT and In viかo fertilization (IVF) derived embryo. We are used for ear-skin-fibroblast cell in NT. If only karyotyping of embryonic cells are chromosomally abnormal, they may difficultly remain undetected. Then, we evaluate the chromosome aberrations, fluorescent in situ hybridization (FISH) with porcine chromosome 1 submetacentric specific DNA probe were excuted. In normal diploid cell nucleus, two hybridization signal was detected. In contrast, abnormal cell figured one or three over signals. The developmental rates of NT and IVF embryos were 55% vs 63%, 32% vs 33% and 13% vs 17% in 2 cell, 8 cell and blastocyst, respectively. When looking at the types of chromosome aberration, the detection of aneuploidy at Day 3 on the embryo culture. The percentage of chromosome aneuploidy of NT and IVF at 4-cell stage 40.0%, 31.3%, respectively. This result indicate that chromosomal abnormalities are associated with low developmental rate in porcine NT embryo. It is also suggest that abnormal porcine embryos produced by NT associated with lower implantation rate, increase abortion rate and production of abnormal fetuses.

• Reproductive and Developmental Biology
• /
• v.31 no.4
• /
• pp.273-278
• /
• 2007

This study was conducted to examine the protein kinase inhibitors, 6-dimethylaminopurine (DMAP) and cycloheximide (CHXM) on the development and chromosome constitution of porcine parthenogenetic embryos. In vitro matured oocytes were activated by electric stimuli (ES) or a combination of ES with culture in 2 mM DMAP or $10{\mu}g/ml$ CHXM for 4 hr. Activated oocytes were cultured in PZM-3 for 6 days. Some 1-cell embryos and blastocysts were fixed by air dry method to analyze the chromosome constitutions and/or total cell number. Blastocyst development of DMAP-treated group (26.7%) was significantly higher (p<0.05) than those of CHXM-treated and ES control groups. Ploidy in 1-cell stage embryos was not different among groups (77.3 to 81.0%), however, proportion of diploid chromosome constitutions was high in DMAP-treated group (61.9%, p<0.05). In the blastocyst stage, proportion of diploid chromosome plates was significantly high in DMAP-treated group (64.2%, p<0.05), and proportion of abnormal chromosome plates was higher in CHXM-treated group (36.6%, p<0.05) than DMAP-treated group (28.3%,). Proportion of embryos with abnormal chromosome constitutions was slightly increased by DMAP (40.0%) and CHXM (42.1%) treatment due to the increasing of mixoploid (47.4 and 52.0%). The present study shows that the DMAP treatment increase the development of porcine parthenotes. However, parthenogenetic activation by ES or combined treatment with ES and DMAP or CHXM detrimentally affects the chromosome constitutions of porcine parthenotes during early embryonic development, leads to increased abnormal ploidy in the blastocyst stage.

• Journal of Embryo Transfer
• /
• v.4 no.1
• /
• pp.41-45
• /
• 1989

Total thirty of flushing were attempted on day 4 to 15 of estrus cycle with S heifers and 9 cows by nonsurgical method. The flushed or recovered rate among flushings was 86.7% (26/30) or 88.5% (23/26), respectively. There was no difference in the recovered rate between heifers (85.7%,6/7) and cows (89.5%, 17119). The embryo was recovered on day 4 to 15 of estrus cycle from the donors in natural heat without any technical difficulties.The I2FG Foley catheter used for pubertal heifers had sometimes plug in it with uterine mucus during flushing of uterine horn. But the problem could be overcomed by pumping the catherter with fluthing solution or by changing the catheter. Three normal embryos were recovered from 3 pubertal (10-11 month old) heifers. The rate of normal and abnormal eggs was 60.9% (14123) and 39.1% (9/23), respectively. The abnormal eggs were on degenerating except one unfertilized egg and were mostly recovered from heifers or cows flushed consecutively during the estrus cycle. The developmental states of normal embryos were l6-cells on day 5, 32-cells on day 6, compacted-morula on day 7, early-to expanded-blastocyst on day 8-to 9, and hatching-to hatched-blastocyst on day 10 to 11 of estrus cycle. The stage of embryos on day 8 to 10 showed varities among donors. On day 8 to 9 of estrus cycle hatching-blas tocyst was recovered from some donors.

• Reproductive and Developmental Biology
• /
• v.37 no.4
• /
• pp.175-183
• /
• 2013

Cathepsin B is abundantly expressed peptidase of the papain family in the lysosomes, and closely related to the cell degradation system such as apoptosis, necrosis and autophagy. Abnormal degradation of organelles often occurs due to release of cathepsin B into the cytoplasm. Many studies have been reported that relationship between cathepsin B and intracellular mechanisms in various cell types, but porcine embryos has not yet been reported. Therefore, this study evaluated the effect of cathepsin B inhibitor (E-64) on preimplantation developmental competence and quality of porcine embryos focusing on apoptosis and oxidative stress. The expression of cathepsin B mRNA in porcine embryos was gradually decreased in inverse proportion to E-64 concentration by using real-time RT-PCR. When putative zygotes were cultured with E-64 for 24 h, the rates of early cleavage and blastocyst development were decreased by increasing E-64 concentration. However, the rate of blastocyst development in $5{\mu}M$ treated group was similar to the control. On the other hand, both the index of apoptotic and reactive oxygen species (ROS) of blastocysts were significantly decreased in the $5{\mu}M$ E-64 treated group compared with control. We also examined the mRNA expression levels of apoptosis related genes in the blastocysts derived from $5{\mu}M$ E-64 treated and non-treated groups. Expression of the pro-apoptotic Bax gene was shown to be decreased in the E-64 treated blastocyst group, whereas expression of the anti-apoptotic Bcl-xL gene was increased. Taken together, these results suggest that proper inhibition of cathepsin B at early development stage embryos improves the quality of blastocysts, which may be related to not only the apoptosis reduction but also the oxidative stress reduction in porcine embryos.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.5
• /
• pp.718-724
• /
• 2007

Considerable attention has been focused on the cloning of mammalian embryos, as a consequence of poor development, in order to enhance the application of genetic engineering. Experiments were conducted to compare the developmental competence of parthenotes and reconstructed (NT) rabbit eggs with fetal fibroblasts (FFs) following various activation regimens. Oocytes and NT eggs were exposed to: electric stimulation (EST, Group 1) and EST followed by 6-dimethylaminopurine (DMAP, Group 2), cycloheximide (CHX, Group 3) or DMAP/CHX (Group 4). Pronuclear (PN) status, cleavage, blastocyst development and the ploidy were assessed. In parthenote groups 1, 2, 3 and 4, the PN formation differed significantly. And, the cleavage and blastocyst rates were 41.7 and 5%, 75.6 and 53.7%, 68 and 36%, 82.1 and 52.6%, respectively, among treatments. Polyploidy was observed in 17.2% of EST plus DMAP and 44.9% of EST plus DMAP/CHX groups. In SCNT groups (Group 1, 2, 3 and 4), the cleavage and blastocyst rates were 28.6 and 7.1%, 58.3 and 29.2%, 56.8 and 24.1%, 64.5 and 27.8%, respectively. The chromosomal composition differed significantly (p<0.05) among treatments. In Group 2 and 3, 53.8% and 81.8% of embryos revealed diploid chromosomal sets, respectively. However, in Group 4, 53.3% of embryos showed abnormal ploidy (mixoploid). Although DMAP or combination with DMAP/CHX resulted in higher in vitro development of rabbit SCNT embryos, higher incidence of chromosomal abnormality may induce problems related to fetal loss of at late stage of development.

• Reproductive and Developmental Biology
• /
• v.31 no.2
• /
• pp.83-90
• /
• 2007

Insulin-like growth factor II (IGF2) and H19 genes are mutually imprinted genes which may be responsible for abnormalities in the cloned fetuses and offspring. This study was performed to identify putative differentially methylated regions (DMRs) of porcine H19 locus and to explore its genomic imprinting in in vitro fertilized (IVF) and somatic cell nuclear transferred (SCNT) embryos. Based on mice genomic data, we identified DMRs on H19 and found porcine H19 DMRs that included three CTCF binding sites. Methylation patterns in IVF and SCNT embryos at the 2-, 4-, $8{\sim}16$-cells and blastocyst stages were analyzed by BS (Bisulfite Sequencing)-PCR. The CpGs in CTCF1 was significantly unmethylated in the 2-cell stage IVF embryos. However, the 4- (29.1%) and $8{\sim}16$-cell (68.2%) and blastocyst (48.2%) stages showed higher methylation levels (p<0.01). On the other hand, SCNT embryos were unmethylayted ($0{\sim}2%$) at all stages of development. The CpGs in CTCF2 showed almost unmethylation levels at the 2-,4- and $8{\sim}16$-cell and blastocyst stages of development in both IVF ($0{\sim}14.1%$) and SCNT ($0{\sim}6.4%$) embryos. At all stages of development, CTCF3 was unmethylated in IVF ($0{\sim}17.3%$) and SCNT ($0{\sim}1.2%$) embryos except at the blastocyst stage (54.5%) of IVF embryos. In conclusion, porcine SCNT embryos showed an aberrant methylation pattern comprised to IVF embryos. Therefore, we suggest that the aberrant methylation pattern of H19 loci may be a reason for increased abnormal fetus after embryo transfer of porcine SCNT embryos.

• Reproductive and Developmental Biology
• /
• v.30 no.2
• /
• pp.125-133
• /
• 2006

This study was conducted to detect the apoptosis incidence in blastocysts and to compare the abundance of Bax, Bcl2L1, VEGF and FGFR2 in in vitro fertilized (IVF), parthenogenetic (PAT) and nuclear transfer (NT) embryos. Oocytes matured for 40 hr were enucleated and reconstructed with confluenced fetal fibroblasts (FFs) derived from a ${\sim}45$ day fetus. Reconstructed eggs were then fused with 2 DC pulses (2.0 kV/cm, $30{\mu}sec$) and cultured with $7.5{\mu}g/ml$ cytochalasin B for 3 hr. Parthenotes (PAT) were produced with the same electric strength and culture for NT eggs. The embryos were cultured in NCSU-23 medium at $39^{\circ}C,\;5%\;CO_2,\;5%\l;O_2$ in air. In 3 runs, set of 10 embryos at the 4-cell to blastocyst stages were used to extract total RNA for analyzing the gene expression patterns of pro-apoptotic (Bax), anti-apoptotic (Bcl2L1), vasculogenesis (VEGF), implantation (FGFR2III) using real-time quantitative PCR. Cleavage and blastocyst rates were significantly higher (P<0.05) in IVF and PAT ($79.3{\pm}8.5\;and\;25.5{\pm}6.1,\;and\;85.0{\pm}6.4\;and\;38.6{\pm}5.5$, respectively)than NT counterparts ($65.1{\pm}5.2\;and\;15.6{\pm}3.0$, respectively). Significantly higher (P<0.05) total cells were observed in IVF controls and PAT ($34.7{\pm}5.8\;and\;38.1{\pm}4.1$) than NT embryos ($24.8{\pm}3.2$). Apoptosis index was significantly lower (P<0.05) in IVF than NT embryos. The Relative abundances (RA) of Bax and VEGF were significantly higher (P<0.05) at blastocyst stage in NT than IVF control. The RA of Bcl2L1 and FGFR2III were significantly higher (P<0.05) at blastocyst stage in IVF than NT. The present study observed the abnormal gene expressions in NT embryos at various developmental stages, suggesting certain clues to find out the cause of the low efficiency of NT to term.

• Journal of Embryo Transfer
• /
• v.15 no.1
• /
• pp.47-56
• /
• 2000

This study was carried out to improve a technique of embryo transfer for twin calves production in Hanwoo cattle. Blastocysts for the donor of embryo transfer were classified into three criteria by accessment of morphology; early blastocyst, blastocyst and expanded blastocyst. Tow embryos were introduced transcervically into utrerine horn either of Hanwoo or Holstein by ipsilaterally or contralaterally to the corpus luteum. Thiry-six out of 57 recipients cows were inseminated by artificially on the next day of estrus, and followed by transfer of embryos into contralaterally. The pregnance rates of recipients following transfer of bovine embryos of day 7, 8 and 9 was 43.5, 18.2 and 8.3%, respectively. These results appeared that these was a significant (P<0.05) difference between on day-7 embryos and day-9 embryos, but not between on day-8 and day-9 embryos. Although there was not significant(P<0.05) difference in the pregnancy rates between the blastocysts(11/25, 44%) and expanded blastocysts(2/19, 10.5%) and between the blastocysts and early blastocysts(2/13, 15.4%), the embryos at blastocyst stage are more suitable than others for obtaining higher rate of pregnancy. There was no significant difference on pregnancy of the embryos transferred prior to presence(6/21, 29%) or absence (9/36, 25%) of artificial insemination. On pregnancy of Holstein, 2(15.4%) out of 13 recipients were pregnant in heifer. Similar Pregnancy rates were obtained between 1∼2 parities and 3∼4 parities by 30% (6/20) and 27.3%(3/11), respectively. Taken together, there was not significant difference in pregnancy rate due to small number of recipients used for this experiment. Both of Hanwoo and Holstein introduced the embryos by contralsterally to the corpus luteum were slightly higher pregnancy rate compare to by ipsilaterally (12/41, 29.3% vs, 3/16, 18.8%). The ratio of production of twin and single calves in Holstein was 20% (9/45) and 2.2% (1/45), respectively. However, in Hanwoo cows both of production of twin and single were similar as 8%. This result suggests that Holstein as recipients was superior to Hanwoo cows for production of twin calves. Out of all 15 pregnant, 12(80%) were produced a total of 22 normal calves in which the others composed of abnormal, as judging as 2(13.3%) for abortion and 1(6.6%) for stillbirth during the pregnant period.

• Clinical and Experimental Reproductive Medicine
• /
• v.44 no.2
• /
• pp.90-95
• /
• 2017

Objective: We investigated whether the insemination method (in vitro fertilization [IVF] or intracytoplasmic sperm injection [ICSI]) affected morphokinetic events and abnormal cleavage events in embryonic development. Methods: A total of 1,830 normal fertilized embryos were obtained from 272 IVF and ICSI cycles that underwent ovum retrieval culture using a time-lapse system (Embryoscope) from June 2013 to March 2015. All embryos were investigated by a detailed time-lapse analysis that measured the developmental events in the hours after IVF or ICSI insemination. Results: No significant differences were observed between the two groups regarding clinical outcomes (p>0.05). ICSI-derived embryos showed significantly faster morphokinetics than those derived from conventional IVF, from the time to pronuclear fading to the time to 6 cells (p<0.05). However, no significant differences were found from the time to 7 cells to the time to expanded blastocyst (p>0.05). There were no differences in abnormal cleavage events between the two groups (p>0.05); they showed the same rates of direct cleavage from 1 to 3 cells, 2 multinucleated cells, 2 uneven cells, and reverse cleavage. Conclusion: The morphokinetics of embryo development was found to vary between IVF- and ICSI-fertilized oocytes, at least until the 6-cell stage. However, these differences did not affect the clinical outcomes of the embryo. Additionally, no significant differences in abnormal cleavage events were found according to the fertilization method.

• Journal of Embryo Transfer
• /
• v.24 no.2
• /
• pp.89-95
• /
• 2009

Successful in vitro embryo production heavily relies on the normal maturation and fertilisation of oocytes. We examined the normal and abnormal fertilisation of zebu cattle oocytes matured in vitro. Immature cumulus oocyte complexes (COCs) from zebu cattle ovaries at slaughter were matured in vitro (IVM) for 24 h. The oocytes were either fixed, stained and examined for nuclear changes or fertilised in vitro (IVF) with Percoll-separated, heparintreated spermatozoa (1.0 ${\times}$ $10^6$/mL) of zebu (n = 7) and crossbred bulls (n = 7). After 18 h of sperm-COCs co-incubation at $39^{\circ}$C with 5% $CO_2$ in humidified air, the presumptive zygotes were fixed, stained and examined for pronuclei. The number of oocytes retrieved per ovary was 5.4 ${\pm}$ 0.7. The percentage of matured oocytes was 73.0. The difference in motility of spermatozoa before and after Percoll seperation was significant (p<0.001). The percentages of normal and abnormal fertilisation (polyspermia and oocytes with one pronucleus) varied significantly depending on individual bulls (p<0.05). A protocol for IVF of IVM oocytes in Bangladeshi zebu cattle is developed. A future study may elucidate the capacity of such IVM-IVF oocytes to develop to the blastocyst stage for transfer to surrogate mother.