Porcine follicular oocytes matured in culture were inseminated with frozen-thawed spermatozoa. When the oocytes were inseminated in the medium with oviductal epithelial cell monolayer, the penetration rates higher in those with (4.1, 31.7, 45.1, 54.5 and 69.4%) than without cells (0, 17.1, 34.8, 45.2 and 58.9%) at 4, 8, 12, 16 and 20 h after insemination. The proportions of polyspermy in penetrated oocytes in medium with or without cells increased with time of examine. In another experiment, the penetration rate was higher without (57.6%) than with (19.6~24.1%) preincubation of spermatozoa for 1~4 h in medium. However, when the oocytes were inseminated with spermatozoa preincubated for 1~2 h, the penetration rates significantly higher (P<0.05) in those with (65.6 and 55.9% for 1 and 2 h) than without (24.1 and 20.6% for 1 and 2 h) oviductal epithelial cell monolayer. On the other hand, the proportions of polyspermy decreased with time of spermatozoa preincubation. These results indicate the significant advantages of the spermatozoa preincubation with oviductal epithelial cell monolayer for 1 and 2 h to maintain penetration potential during in vitro fertilization in the porcine.

The present study was carried out to develop a cloning technology of mouse embryos by nuclear transplantation with electrofusion and to produce cloned offsprings by transfer of reconstituted embryos. A single nucleus from two- and eight-cell embryos was transplanted into the enucleated two-cell embryos by rnicromanipulation. The fusion of nucleus with recipient cytoplasm and the subsequent development of reconstituted embryos in vitro as well as in vivo to term were examined to determine the optimal electrofusion parameters for nuclear transplantation in mouse embryos. The successful enucleation of donor embryos was 84.9 and 83.3% in two- and eight-cell stage, respectively, and the successful injection of nucleus from two- and eight-cell donor embryos into the perivitelline space of enucleated two-cell embryos were 85.1 and 84.7%, respectively. No significant differences were found in enucleation or injection rate between the cell stages of donor embryos. When the blastomeres of intact two-cell mouse embryos were electrofused in 0.3 M mannitol medium(100 sec., 3 pulses), the fusion rate was similarly 93.2, 92.2 and 92.0% in 1.0, 1.5 and 2.0 kV /crn, respectively, but in vitro development to blastocyst of the fused two-cell embryos was significantly(P<0.05) lower in 2.0 kV/cm (63.4%) than in 1.0 kV/cm (91.7%) or 1.5 kV/cm (82.4%). The development in vitro to eight-cell stage of the reconstituted embryos with nucleus from two-cell stage(45.5%) was significantly(P<0.05) higher than that from eight-cell stage blastomeres (16.7%). The number of blastomeres of the intact embryos at blastocyst stage was 50i0.6 and 552.4 in in vitro and in vivo cultured mouse embryos, respectively, but significantly(P<0.05) decreased to 350.7 in nuclear transplanted blastocyst embryos. The conception rate of mice following embryo transfer was 32.1% in the reconstituted two-cell embryos using two-cell donor nuclei, which was comparable to the fresh two-cell embryos(40.6%). However, the rate of development in vivo to term following embryo transfer of the reconstituted two-cell embryos using two-cell donor nuclei (23.5%) was significantly(P<0.05) lower compared with the percentage of two-cell fresh embryos(31.5%).

This study was performed to establish the condition and the methods for the techniques of insertion the isolated blastomere cells into cytoplasm, in order to research the develop-mental ability of bovine embryo blastomere cells in vitro produced. After 24h in vitro ovary maturation with the ovaries from a slaughter house, in vitro fertilization was performed to the vital sperms which their mobility were decided by percoll gradient method, with 2~8 cell stage embryos, the blastomeres were isolated in +. +-free PBS, and following that embedded into agar and alginate solution, respectively. The rates of in vitro develop-ment are as follows ; in agar embedded 11 among 120(9.2%) 1 /2~1 /3 blastomers cleaved and 6 among 93(6.5%) 1 /4~1 /8 blastomeres cleaved. In sodium alginate-embedded 14 among 84(16.7%) 1 /2~1 /3 blastomeres cleaved and 6 among 85(7.1%) 1 /4~1 /8 blastomeres cleaved. In case of Na-alginate, the rate of the cells were better than those of agar. The results suggest that the techniques for embeeding the isolated blastomeres into gel may help cloning of bovine early embryo without nuclear transplantation.

연두금파리의 난세포성숙에 따른 단백질의 변화와 난특이성단백질의 특성을 확인하기 위하여 gel filtration, 전기영동 및 분자량측정, 아미노산과 지방산함량을 측정하여 얻은 결과는 다음과같다. 연두금파리 암컷성충의 난소단백질은 단백질원을 섭식시킨 후 72시간 이후 빠르게 증가하였고, 완전한 성숙이 일어나는 96시간에 최고의 함량을 나타냈다. DEAE-cellulose와 Sephacryl 5-200으로 gel filtration하고 7.5% native polyacrylamide gel에서 전기영동한 결과 난소에서 분리된 특이단백질은 0.4에서 혈림프 및 난소와 다른 밴드가 확인되었으며, 분자량은 110,000 dalton이였다. 분리된 난특이성단백질내 아미노산 조성은 asparagine 외 모두 13종이 검출되었으며, asparagine, glutamic acid와 함께 tyrosine이 특이하게 높게 나타났다. 지방산은 난소와 함께 난특이성단백질에서 palmitic acid의 4종이 분리되었다. 따라서, 연두금파리의 난에는 지방체에서 합성, 분비된 난황단백질이외에 난소에만 존재하는 특이단백질이 있음을 알 수 있다.