• Korean Journal of Animal Reproduction
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• v.18 no.2
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• pp.121-126
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• 1994

This study was conducted to examine the condition of activation of the nuclear transplant bovine embryos. In vitro fertilized(IVF) and nuclear transplant embryos(NTs) were co-cultured with bovine oviduct epithelial tissue(BOET). NTs were treated with cycloheximide(CHXM) for 0 to 6 h after electrofusion to investigate the activation conditin of recipient ooplast. Then, the infljence of the CHXM treatment timing on the cleavage and development of NTs were investigated in relation to the nuclear transplant time. The cleavage rates of NTs were increased with the increasing time of the CHXM treatment from 0 to 6 h (54.7 to 91.3%, P<0.01). Similar trend was shown in the development into the morula or blastocyst stage, but very limitted. Activation of enucleated oocytes prior to fusion enhanced development of NTs compared with that post fustion. This result suggests that the frequency of activation of NTs can be greatly enhanced by treating with CHXM for 6 h. The result also suggests that if blastomeres of unknown cell cycle stage are used, activation of enucleated oocytes prior to fusion enhances development of NTs.

• Journal of Embryo Transfer
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• v.11 no.3
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• pp.241-248
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• 1996

This study was conducted to improve the production efficiency of in vitro produced (IVP) embryos in Korean Native cows. The optimal conditions and procedures for in vitro maturation(IVM), in vitro fertilization(IVF) and in vitro culture(IVC) of bovine follicular oocytes and IVP embryos were evaluated. Immature follicular oocytes were collected fiom the follicles of bovine ovaries obtained from abattoirs. The oocytes of Grade I and II for IVM were cocultured with monolayered bovine oviductal epithelial cells(BOEG) or granulosa cells in TCM-199 solution supplemented with follicle stimulating hormone, lutenizing hormone, estradiol-17$\beta$ and heat inactivated fetal calf serum at 39$^{\circ}C$ under 5% $CO_2$ in air for 14 to 24 hours. Most of the oocytes(93%) matured to metaphase II in 24 hours. The cocultured IVM oocytes were fertilized in vitro at significantly(P<0.05) higher rate with BOEC(83.8%) and with granulosa cells(84.6%) than the non-cocultured IVM oocytes(73.6%). The IVM-IVF embryos developed to morula and blastocyst at significantly(P<0.05) higher rate in coculture with BOEC(41.2%) than with granulosa cells(23.1%) or conditioned medium(23.4%).

• Journal of Embryo Transfer
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• v.11 no.3
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• pp.283-289
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• 1996

This study was carried out to determine the sex of genomic and embryonic DNA using polymerase chain reaction(PCR). Bovine specific(216bp) and Y chromosome speicific DNA primers(l4lbp) were synthesized and tested for sexing. Bovine embryos used in this study were produced by in vitro fertilization. Few blastomeres for PCR were bisected by nicromanipulator and demi -embryos were cultured in TCM 199 medium containing 0.1% of solcoseryl. The results obtained were as follows; 1. Average optical density of genomic DNA extracted from blood of Hanwoo was 1.79$\pm$ 0.14. 2. 2. The ratio of the demi-embryos developed to blastocyst was 62.1 and 81.9% in morula and blastocyst, respectively. 3. When DNA of 2~4, 5~10 and more than 11 blastomeres was amplified with Y chromosome specific DNA primer by PCR, appreance rate of Y specific DNA band was 16.7, 46.2 and 40.0%, respectively. At least 5 to 10 blastomeres were required to determine the sex of embryos. 4. The rate of demi-embryos developed to blastocyst was 73.3% in TCM 199 medium supplemented with 0.1% solcoceryl. but 55.6% in control.

• Journal of Embryo Transfer
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• v.32 no.2
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• pp.47-52
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• 2017

As a part of the effort to improve post-transfer survival rate of embryos in Korean black goats, a technique for laparoscopic uterine transfer of blastocysts was carried out. A total of 26 transferrable embryos (morula to expanded blastocysts) were transferred to 13 recipient goats via transabdominal laparoscopic method. In consequence of our hormone protocol, 65% of the recipients (13/20) were found to have synchronized estrus. After confirmation of corpus luteum in each recipient goat, a Babcock laparoscopic forceps was inserted into the lower abdominal cavity to hold a uterine horn and fasten it near the peritoneum without causing injury. Then 7.5cm long 16G IV catheter was inserted directly into the uterine lumen through the abdominal wall. After removal of the stylet of the IV catheter, the embryo transfer tube (identical in size to the stylet and loaded with blastocysts) was inserted into the uterine lumen through the catheter to unload the embryos. Of the 13 estrus synchronized recipients, 9 were transferred blastocysts and 4 were transferred molurae (2 embryos in each recipient) in uterine ipsilateral to the ovary with corpus luteum. Four of the 9 recipients which blastocysts were transferred using this method has been confirmed pregnant (44.4% pregnancy rate).

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.155-161
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• 1996

For a large sclase production of genetically identical or cloned animals, the effect of cryopreservation by vitrification on the post-thaw viability of nuclear transplant rabbit embryos were investigated. The embryos of 16-cell stage were collected from the mated does at 48 hours post-hCG injection, and they were synchronized to G1 phase of 32-cell stage were injected into enucleated recipient cytoplasms by micromanipulation. After culture until 20h post-hCG injection, the nuclear transplant oocytes were electrofused and activated by electrical stimulation. After in vitro culture for 48h, the nuclear transplant embryos developed to morula stage were cryoperserved with EFS solution by vitrification method. The forzen nuclear transplant embryos were thawed and cultured for 72h and the nuclear transplant of blastomeres under a fluorescence microscopy. The in vitro development to blastocyst of intact-fresh and intact-frozen 16-cell embryos was found to be 96.9 and 63.9%, respectively. The in vitro development to blastocyst of nuclear transplant and frozen-thawed nuclear transplant embryos was found to be 74.5 and 42.9%, respectively. Also, their mean blastomere numbers and mean cell cycles/day was 153 and 105, 145 and 1.34, respectively. From the above results it was concluded that the present cryopreservation by vitrification of nuclear transplant rabbit embryos might be useful though was decreased significantly.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.866-871
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• 2007

Testis-specific protein (TSPY) is a Y-specific gene, with up to 200 copy numbers in bulls. In order to make bovine embryo sexing under farm condition more feasible, the possibility of using a non-electrophoretic method to detect the TSPY gene for sexing bovine early embryos was examined. Primers were designed to amplify a portion of the TSPY gene and a common gene as an internal control primer. PCR optimization was carried out using a DNA template from bovine whole blood. Furthermore, embryo samples were diagnosed by this method and the sexing results were contrasted with those of the Loop-Mediated Isothermal Amplification (LAMP) method. The results showed that TSPY was as reliable a sexing method as LAMP. Forty-three morula and blastocyst embryos collected from superovulated donor dairy cattle were sexed by this method, and twenty-one embryos judged to be female embryos were transferred non-surgically to recipients 6 to 8 days after natural estrus. Out of 21 recipients, 9 were pregnant (42.86%) and all delivered female calves. The results showed that the sex predicted by this protocol was 100% accurate. In conclusion, the TSPY gene was a good male specific marker and indicated that a non-electrophoretic method was feasible and accurate to detect the TSPY gene for sexing preimplantation bovine embryos.

• Journal of Veterinary Clinics
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• v.25 no.4
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• pp.289-291
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• 2008

3-year-old female Pitbull terrier dog that had been moved to Republic of Korea was diagnosed with Ehrlichia canis infection. Abnormal findings on a complete blood count (CBC) and serum chemistry profile were moderate anemia, mild thrombocytopenia, hyperproteinemia and hyperglobulinemia. Serologic screening test by a commercial ELISA kit for Ehrlichia canis was positive, and serum antibody titer was markedly high (> 1 : 10240). The morula of Ehrlichia organisms was not detected in buffy coat blood smears. Polymerase chain reaction (PCR) was done using the peripheral blood and the result was negative. Based on the serologic test results and the clinical signs, the dog was diagnosed as ehrlichiosis. The dog responded well to doxycycline and was uneventfully recovered.

• Journal of Life Science
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• v.8 no.5
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• pp.576-581
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• 1998

The present study was carried out to investigate the effect of gonadotropin administration on the timing of ovula-tion, fertlizable life of eggs and cleavage of embryos in rabbit. Mature angora rabbits were primed for superovulation with PMSG 100IU. Eighty hours later, the rabbit were induced to ovulate with HCG 100IU. Ovulation had started at 10hours after HCG injection and finished at about 16hours. Fertilizable life of eggs were lasted for 8hours after ovulation. The most frequent developmental stage observed from the embryos recovered at 24, 48, 72, 96, and 120 hours after HCG injection was 2-ceIL, 16-cell, morula, blastocyst and blastocyst, respectively.

• Journal of Embryo Transfer
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• v.3 no.1
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• pp.38-42
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• 1988

These studies were conducted to investigate the effect of repreated superovulation on embryo production, the effect of the frozen-thawed embryos transferred on the developmental stage and grade, and donor-recipient synchrony on pregnancy rate in Korean native cattle. The results obtained in these studies were as follows: 1. Repeated superovulations in Korean Native Catile were not affected on the number of corpus luteum (CL), embryos recovered and embryos cleaved (range: 4.8 $\pm$ 4.21 to 9.5 $\pm$ 6.50, 1.8 $\pm$ 2.53 to 8.2 $\pm$ 8.04 and 1.6 $\pm$ 2.32 to 4.0 $\pm$ 4.59, respectively). 2. Blastocyst embryos (38.5%) showed higher pregnancy rate than morula (31.6%). 3. The pregnancyrates of cattle transferred with good and fair embryos were 33.3% and 40.4%, respectively. 4. The pregnancy rate when the donors exhibited estrus 12 hours earlier than the recipients (62.5%) was higher than when the donors and recipients exhibited estrus at the same time (33.3%) or when the donors exhibited estrus 12 hours later than the recipients (20.0%).

• Journal of Embryo Transfer
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• v.3 no.1
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• pp.48-52
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• 1988

우수정란의 이식전 성판별이 관한 연구를 수행하기 위하여 GTH와 PGF$_2$$\alpha$투여에 대한 난소반응과 회수난자의 발유단계별 동결융해후 생존성을 조사하였으며, 이식전 수정라느이 성판별을 위하여 H-Y항체 처리후 정상발육 난자의 염색체를 분석하여 다음과 같은 결과를 얻었다. 웅성 비장세포(male, spleen cells)를 면역원으로 mouse와 rat에 투여, 항혈청의 항체를 확인한 결과 mouse에서는 C57 BL계통과 rat에서는 DonRyu 계통이 항체생산능력이 우수하였다. 공란우 87두에 hormone(2500IU PMSG, 25mg PGF$_2$alpha)처리하여 평균 57.8%의 채란유과 두당 4.9개의 난자가 회수되었으며, 전체회수란자(427개)중 moula(162개)와 blastocyst(190개)의 정상발육란자는 82.4%였다. 동결융해후 회수된 난자 (312개)중, 형태적으로 정상인 난자(241개)의 비율은 77.2% 발육단계별 성적은 blastocyst(83.4%)가 morula(71.0%)보다 우수하였다. 항체와 보체(Guinea pig serum)로 처리된 82개의 morula중 15개(18.3%)가 blastocyst로 발육되어 이중 5개(33.3%)가 성이 판별되었으며, 모두 xx형 성염색체를 갖는 자성수정란으로 판명되었다.