• Korean Journal of Animal Reproduction
• /
• v.23 no.4
• /
• pp.293-301
• /
• 1999

This study was to examine whether Hanwoo IVM/IVF/IVC blastocyst can be successfully survived in vitro/in vivo after vitrification and one-step dilution. For vitrification, blastocysts were serially exposed in glycerol (G) and ethylene glycol(EG) mixtures［10% (v Iv) G for 5 min., 10% G plus 20% EG (v/v) for 5 min., and 25% G plus 25% EG (v/v) for 30 sec.］ which is diluted in 10% FBS added D-PBS. And then they were loaded in the straw, placed in cold nitrogen vapor for 3 min. and plunged into L$N_2$(－196$^{\circ}C$). One-step dilution within the straw was done in $25^{\circ}C$ and 36$^{\circ}C$ water for about 5 min. and 3 min., respectively. Recovered embryos after one-step dilution were cultured in cumulus cell mono-layered drop for 48 h or were transferred into recipient cows. When the embryo survival in vitro was assessed to re-expanded and hatched rates at 24 hand 48 h after one-step dilution, the results of vitrified group (85.4, 43.8%) was high, although these results were significantly lower than normal development (100.0, 63.3%) of control group, respectively (P＜0.001, P＜0.05). When in vitro survival of vitrified groups according to developmental stage was compared, the results of fast developed embryos (expanded blastocyst and early hatching blastocyst stage) were significantly higher than those of delayed developed one (early blastocyst stage) after one-step dilution (early hatching: 88.0, 48.0%: expanded: 81.1, 45.3%; early: 66.7, 14.3%) (P＜0.05). Also, in case of in vitro survival of vitrified groups according to embryo age (day 7, 8 and 9), when embryo age was younger, in vitro survival was significantly higher (day 7: 67.3, 34.5%; day 8: 76.9, 40.7%; day 9: 60.9, 23.9%)(P＜0.05). Finally, when in vivo development potential of vitrified and one-step diluted Hanwoo blastocysts was examined, 4 of 8 recipient (50%) cows became confirmed pregnant. These results demonstrated that our vitrification and one-step dilution technique can be applied easily and effectively on field trial without the equipment and embryological skills required for conservative dilution and transfer.

• Clinical and Experimental Reproductive Medicine
• /
• v.23 no.1
• /
• pp.1-6
• /
• 1996

There are a number of problems during the process of culture in vitro on fertilization and embryo development compared to those on in vivo counterparts. And the platelet activating factor (PAF), which is found not only in mammalian spermatozoa but also preembryos, is implicated on reproductive process. To improve the environment of culture on in vitro fertilization and embryo development, coculture using salpingeal epithelial cells has been considered to accept the better result on pregnancy rate. This study was designed to determine if two different culture systems, coculture alone and PAF treated coculture, are positive or negative influence on process of in vitro fertilization and embryo culture in mouse. The cell cleavage rate reached to 2-4 cell stage at 24 hours of culture is 56.81% (50/88) and 48.21%(54/112) respectively, in PAF treated group which is added PAF on coculture and in coculture group. But the rate of cells cleavage was similar in both group after 48 hours of culture. The rate of unfertilization after insemination of oocytes was higher in coculture group(55..53%) than in PAF treated group(42.37%). And in assessment of undeveped embryos, the rate of equalized cell block was similar on both, coculture alone (35.3%)and PAF treated coculture(35.5%). while unequalized cell block was higher rate in PAF treated coculture(19.4%) than coculture alone (11.8%). But the rate of cytoplasmic degeneration of undeveloped embryos was significantly higher in PAF treated coculture than coculture alone. In conclusion, we have observed that PAF treated coculture is superior in the rates of in vitro fertilization and early embryo cell cleavage compared to those in coculture alone, but there is no difference on the rates of embryo develpments, cell degeneration, cell quality in both PAF treated coculture and coculture alone when the embryo cells were continuosly cultured for 48 hours or more.

• Reproductive and Developmental Biology
• /
• v.35 no.3
• /
• pp.281-285
• /
• 2011

In the present study, we identified differentially methylated region (DMR) upstream of Dnmt1o and Dnmt1s gene in early porcine embryos. Porcine Dnmt1o had at least one DMR which was located between -530 bp to -30 bp upstream from transcription start site of the Dnmt1o gene. DNA methylation analyses of Dnmt1o revealed the DMR to be hypomethylated in oocytes, whereas it was highly methylated in sperm. Moreover, the DMR upstream of Dnmt1o was gradually hypermethylated from oocytes to two cells and dramatically changed in the methylation pattern from four cells to BL stages in an in vivo. In an IVF, the methylation status in the DMR upstream of Dnmt1o was hypermethylated from one cell to eight cells, but demethylated at the Morula and BL stages, indicating that the DNA methylation pattern in the Dnmt1o upstream ultimately changed from stage to stage before the implantation. Next, to elucidate whether DNA methylation status of Dnmt1s upstream is stage-by-stage changed in during porcine early development, we analyzed the dynamics of the DNA methylation status of the Dnmt1s locus in germ cell, or one cell to BL cells. The Dnmt1s upstream was highly methylated in one and eight cells, while less methylated in two, four, morula, and BL cells. Taken together, our data demonstrated that DNA methylation and demethylation events in upstream of Dnmt1o/Dnmt1s during early porcine embryos dramatically occurred, and this change may contribute to the maintenance of genomewide DNA methylation in early embryonic development.

• Journal of Embryo Transfer
• /
• v.23 no.2
• /
• pp.101-108
• /
• 2008

This study investigated the developmental ability and gene expression of somatic cell nuclear transfer embryos using ear skin fibroblast cells derived from miniature pig. When miniature pig (m) and landrace pig (p) were used as donor cells, there were no differences in cleavage (79.2 vs. 78.2%) and blastocyst rates (27.4 vs. 29.7%). However, mNT blastocysts showed significantly higher apoptosis rate than that of pNT blastocysts (6.1 vs. 1.7%) (p<0.05). The number of nuclei in pNT blastosysts was significantly higher than that of mNT (35.8 vs. 29.3) (p<0.05). Blastocysts were analyzed using Realtime RT-PCR to determine the expression of Bax-${\alpha}$, Bcl-xl, H19, IGF2, IGF2r and Xist. Bax-${\alpha}$ was higher in mNT blastocyst than pNT blastocyst (p<0.05). There was no difference in Bcl-xl between two NT groups. Bax-${\alpha}$/Bcl-xl was, however, significantly higher in mNT blastocyst compared to pNT. The expression of imprinting genes were aberrant in blastocysts derived from NT compared to in vivo blastocysts. H19 and IGF2r were significantly lower in mNT blastocysts (p<0.05). The expression of IGF2 and Xist was similar in two NT groups. However, imprinting genes were expressed aberrantly in mNT compared to pNT blastocysts. The present results suggest that the NT between donor cells derived from miniature pig and recipient oocytes derived from crossbred pig might affect reprogramming of donor cell, resulting in high apoptosis and aberrant expression patterns of imprinting genes.

• Korean Journal of Animal Reproduction
• /
• v.25 no.1
• /
• pp.9-17
• /
• 2001

To determine the effect of the characteristics of the corpus luteum (CL) and serum metabolites on pregnancy rate following embryo transfer in Hanwoo cow, recipients were synchronized the estrus with CIDR. in vivo or in vitro produced bovine embryos were transferred to synchronized recipients. The characteristics of the CL were checked by rectal palpation and ultrasound. Blood samples were collected from jugular vein at Day 7 and analysed progesterone and serum metabolites. The results obtained from this study were as follows; 1. Total 397 embryos were transferred to recipient and 121 heads out of them were pregnant. The pregnancy rate was 30.5% and slightly differences between farms. 2. There was not significantly different the pregnancy rates between the size of CL and the cavity CL. In the recipients which had more than 2ng/$m\ell$ of serum progesterone level, the pregnancy rates was in higher than others (46.6% vs. 24.4%, 15.0%). 3. The highest pregnancy rate was obtained at 90 to 110mg/㎗ in serum total cholesterol, 14 to 16mg/㎗ in BUN, and 70 to 80mg/㎗ in serum glucose, respectively, and these metabolites in blood could be used as the criteria in the selection of recipient at embryo transfer.

• Biomedical Science Letters
• /
• v.10 no.4
• /
• pp.391-395
• /
• 2004

The demand for the production of gene-defective mice from embryonic stem (ES) cells is increasing to clarify decisive gene function in vivo. Although blastocyst injection is widely used to generate ES cell-mediated knockout mice, coculture method has been alternatively used because of several advantages, such as low cost and simple procedure. Thus, this experiment was designed to demonstrate the feasibility of the coculture method using J1 ES cells, which are known to be efficient for blastocyst injection. Eight-cell embryos were harvested from 2.5 days post-coitum (dpc), denuded with acid tyrode's solution, and transferred onto trypsinized J1 ES cells. Aggregation was carried out following two typical methods, which are simple coculture method and aggregation in groove prepared by aggregation needle. Successfully aggregated-embryos were developed to blastocysts for 24 h and transferred into uterus of pseudo-pregnant foster mother. Chimeric offspring was judged by coat pigmentation. In this study, we could obtain chimeric mice from all the two aggregation methods, but the chimera production efficiencies in coculture using groove were three times higher at least than those in the other group. In conclusion, these observations suggest that coculture method should be available for production of knockout mice from J1 ES cells. Presently, the germ-line transmission rates of the chimeras produced from the two methods are under investigation.

• Environmental Analysis Health and Toxicology
• /
• v.6 no.1_2
• /
• pp.71-82
• /
• 1991

Rat embryos were cultured out of the mother from the head-fold stages, 9.5 days to 11.5 days during which they start to develop the brain, eyes, ears and cardiovascular system etc. We principally did the basic experiment in order to establish the best condition of the rat whole embryo culture in our laboratory. The temperature in the culture system was maintained 37$^{\circ}C$$\pm$0.2$^{\circ}C$ for 48 hrs. The culture was carried out in humidified atmosphere of the air, intially, the bottles were equilibrated with 5% $O_2$,5% $CO_2$, and 90% $N_2$gas mixture. After 22 or 24 and 29 or 30 hrs the cultures were reequilibrated with 20% $O_2$, 5% $CO_2$,75% $N_2$and 40% $O_2$, 5% $CO_2$, 55%$N_2$respectively. Various types of sera were tested and for the purpose of minimizing the quantity of rat serum, artificial medium was also tried and it was determined that rat serum supported normal growth over a period of 48 hrs, based on total growth analysis and structural comparisons with in vivo specimens.

• Reproductive and Developmental Biology
• /
• v.28 no.3
• /
• pp.181-185
• /
• 2004

This study was conducted to examine whether activation treatments, source of oocytes and culture conditions affect in vitro developmental ability of caprine oocytes. Mature Korean native goats were pretreated with intravaginal CIDR for 10 days. The goats were then treated with a single intramuscular injection of 1,000 IU PMSG on Day 8 or twice daily injection of a total of 70 mg FSH for 3 days from Day 8 of CIDR insertion for superovulation. All the goats were injected with 10 mg PGF/sub 2a/ on Day 8 and 400 IU hCG on Day 10 of CIDR. Oocytes were surgically collected by oviduct flushing(in vivo maturation) or direct follicle aspiration(in vitro maturation) through mid-ventral incision at 35 h after hCG injection. Fifteen to twenty oocytes were placed in TCM-199 medium containing 25 mM Hepes and hormones under mineral oil at 39℃ in a humudified atmosphere of 5% CO₂ in air for 22 to 24 h. After maturation, the oocytes were activated by electric stimulation or ionomycin + 6-DMAP. The activated oocytes were then cultured in M16, TCM-199 and mSOF media supplemented with proteins at 39℃ for 6 to 7 days. Activation treatments did not affect cleavage of the oocytes. The cleavage rates were 64.1% (41/64) in oocytes activated by electric stimulation and 76.5% (218/285) in oocytes activated by ionomycin + 6-DMAP. The proportion of development to blastocyst was 15.6% (34/218) in oocytes activated by ionomycin + 6-DMAP, but activation by electric stimulation did not support embryos developed beyond morula stage. There were no differences in the cleavage rates of activated oocytes experiencing in vivo (86.8%, 66/76) and in vitro maturation (69.0%, 127/184). However, the development rate to blastocyst stage was significantly (P<0.05) higher for oocytes matured in vivo (50.0%, 33/66) compared to in vitro (0.8%, 1/127). Culture conditions did not affect the cleavage of -activated oocytes. The cleavage rates were 51.6% (49/95) in M16, 64.3% (18/28) in TCM-199 and 81.0% (145/179) in mSOF, respectively. By contrast, the development rate of activated oocytes to stage was greater (P<0.05) for oocytes cultured in mSOF medium (23.4%, 34/145) than in M16 or TCM-199 (0.0%). Our results suggest that source of oocytes and culture conditions are major factors affecting in vitro development of caprine parthenogenetic oocytes.

• Reproductive and Developmental Biology
• /
• v.34 no.3
• /
• pp.201-205
• /
• 2010

The objective of this study was investigate the superovulation treatment and to relate concentrations of blood urea nitrogen(BUN) in Hanwoo donors. Thirty six, at random stages of the estrous cycle, received a CIDR. Four days later, the animals were superovulated with a total of 28AU FSH (Antorin, 2AU=1 ml) administered twice daily in constant doses over 4 days. On the 3th administration of FSH, CIDR was withdrawn and 25 mg $PGF_2a$ was administered. Cows were artificially inseminated twice after estrous detection at 12 hr intervals. The cows received $100\;{\mu}g$ GnRH at the time of 1st insemination. Embryos were recovered 7 or 8 days after the 1st insemination. Cows with BUN <10, 11~18 and ${\geq}$19 mg/dl had return of estrus of 34.6, 30.5 and 30.4 days respectively. Return of estrus after superovulation treatment was not significantly lower for cows with blood urea nitrogen (BUN) above 10 mg/dl than for cows with BUN below 10 mg/dl. Cows with BUN <10, 11~18 and ${\geq}$19 mg/dl had number of transferable embryos of $3.2{\pm}1.2$, $5.4{\pm}1.9$ and $4.1{\pm}2.1$ respectively.

• Korean Journal of Poultry Science
• /
• v.35 no.3
• /
• pp.241-245
• /
• 2008

Lentiviral vector system is efficient vehicles for the delivery of exogenous genes, and it is generally used in the generation of transgenic chickens. In this study, we used recombinant lentiviral vectors to generate transgenic chicks that express the human superoxide dismutase-3 gene driven by the chicken ovalbumin promoter. It is well known that superoxide dismutases(SODs) are believed to play a crucial role in protecting cells against oxygen toxicity. There are three forms of SOD proteins: cytosolic Cu-Zn SOD, mitochondrial Mn SOD, and extracellular SOD(SOD-3). The recombinant lentivirus containing the human SOD-3 gene was injected into the subgerminal cavity of freshly laid eggs. Subsequently, the embryos were incubated to hatch using phases II and III of the surrogate shell ex vivo culture system. From 341 injected embryos, the 78 chicks hatched after 21 days incubation. The hatched chicks were screened for the human SOD-3 gene by using PCR. Two of 47 male chickens that survived to sexual maturity contained the human SOD-3 gene in their semen. These results showed that our transgenic chicken generation system was completely established.