This study was performed to investigate the effect of laser-assisted hole in the zona pellucida (ZP) of frozen-thawed ICR mouse embryos on the process of hatching that is critical for expanded blastocysts to implant into endometrium, Vitrification medium, composed of ethylene glycol and sucrose supplemented with 7.5% (w/v) PVP, was used to freeze cell stage embryos recovered from oviducts of superovulated and mated female mice before storing them in . Right after thawing them, a laser beam was shot to make a hole in ZP followed by culturing in KSOM for and examining development to blastocyst and hatching every 12 hr. Laser-treated embryos showed significantly higher hatching rate compared to control (92.9% vs. 22.1%, p<0.05). From around Day 4, blastocysts developed from laser-treated embryos started hatching while the blastocysts of control group failed to hatch showing a lot of shrinkage. This study shows that a laser-assisted hole in ZP improves the hatching rate of blastocysts developed from frozen-thawed, in vitro cultured ICR mouse embryos.

본 연구는 복강경을 이용하여 한국흑염소의 난소를 연속적으로 관찰하여 그 형태적 변화를 확인함으로써 한국흑염소의 성주기를 판정하고 그 결과를 한국흑염소의 수정란 이식시에 활용하고자 하는 목적으로 수행하였다. 제거 2일 후부터 복강경 수술을 통해 난소의 형태적 변화를 관찰하였다. 난소의 크기와 황체의 변화를 관찰하였으며, 황체는 그 성숙과 퇴축 과정에 따라 corpus hemorrhagicum(CH), corpus luteum(CL), corpus albi

본 연구는 체외 성숙된 난자와 동결 융해 정자를 이용한 돼지의 체외 수정 과정에서 난구 세포의 존재가 정자 침투율, 웅성전핵 형성률 그리고 후기배로의 체외 발육에 미치는 영향을 알아보기 위하여 수행되었다. 돼지 난소로부터 난자-난구세포 복합체를 채취하여 eCG/hCG, 10% 돼지 난포액, epidermal growth factor 등이 첨가된 TCM 199 배양액에서 44시간 배양하여 체외 성숙을 유도하였다. 성숙 배양 후 난구 세포를 제거한 난자와

The present study was performed to evaluate the best electric fusion condition in nuclear transfer, Korean Native Cattle fibroblasts were used as nucleic donors. Oocytes from slaughterhouse were matured in vitro for 22 h and enucleated. Each individual cells were transferred into enucleated ocytes and reconstructed embryo were placed into the fusion chamber. In experiment 1, pulse were performed by altering pulse duration at 1. 75kv/cm, 1 time. When pulse duration is 30, fusion and development rates is higher than other conditions. In experiment 2, the effect of different pulse number were studied at the pulse duration 30 and the same pulse intensity. When pulse number was one, fusion rates were higher than other conditions. The fused embryos were moved to culture medium and assessed their development to blastocyst. These results showed that best fusion condition was 30 and one time. And the fibroblasts derived from Han Woo can be reprogrammed by nuclear transplantation and develop subsequently in vitro.

The development potential of bovine somatic cells was evaluated using nuclear transfer. A single donor cell derived from fetus of HanWoo(Korean Native Cattle) was selected and deposited into perivitelline space of each enucleated oocyte before electrical fusion and activation. Nuclei of donor cells starved for 7 days (37%) tended to support the development of reconstitute embryo the blastocyst stage better than those of donor cells starved 3, 14 and 30 days. The cleavage rate was significantly lower(P<0.05) in reconstitute embryos derived from large size donor cells(51.2%), than those from small medium size donor cells(76.6 and 73.5, respectively). The developmental rate to blastocyst of reconstructed embryos from medium size donor cells was higher than those from small and medium size donor cells. This study demonstrates that an appropriate culture period for induction into quiescent stage and the size of donor cells effect on the efficiency of nuclear transfer using cultured bovine cells.

From September 1993 to August 1997, we treated ovarian disorders in 1,782 repeat breeder cows after diagnosis by ultrasound on 35 farms in Kyeong-ki do. The rates of ovarian appearance were 59.8% of CL group, 16.7% of ovarian atrophy or hypofunction, 15.4% of luteal cyst, 4.3% of follicular cyst and 3.7% of follicle group in diagnosis with rectal palpation and ultrasound. The results of treatment for ovarian disorders were 1,316 cows(73.8%) in estrus, 348 cows(19.5%) in non-detected and 118 cows(6.6%) in unidentified. The rates of PGF, GnRH and mineral vitamin complex treatment to estrus were 79.6, 69.2 and 50.3%. Two groups were treated with 5 ml PGF intramuscular injection(I.M.) and 1.5 ml PGF intraovarian injection(I.O.), and the results of 1.5ml PGF I.0. were significantly higher than that of 5ml PGF I.M. in inductiom estrus(p<0.05). The pregnant rates were 29.8% in total repeat breeder cows with ovarian disorders following diagnosis and treatment. In summary, rectal palpation and ultrasonography were proven to be useful tools of diagnosis and treatment in ovarian disorders, and it was also suggested that the response to treatment with PGF I.0. was better than PGF I.M.