• 미생물과산업
• /
• 제26권1호
• /
• pp.2-7
• /
• 2000

1. 양조폐수장, 폐수구의 토양에서 분리한 K-173-10은 초산을 자화하여 L굴루타민산을 24g/l생성하였다. 2. 분리된 균주는 행태학적, 생리학적, 분류학적 특성으로 미루어 보면 Brevibacterium ammoniagenes sp.로 간주된다.

• Journal of Animal Science and Technology
• /
• 제61권4호
• /
• pp.225-233
• /
• 2019

The aim of this study was to produce porcine tetraploid (4N) parthenogenetic embryos using various methods and evaluate their developmental potential. In method 1 (M1), porcine 4N parthenogenetic embryos were obtained by inhibiting extrusion of both first (PB1) and second (PB2) polar bodies; in methods 2 (M2) and 3 (M3), 4N parthenogenetic embryos were obtained by electrofusion of 2-cell stage diploid parthenogenetic embryos derived from inhibition of PB2 or PB1 extrusion, respectively. We found no differences in the rates of cleavage or blastocyst formation or the proportion of 4N embryos among M1, M2, and M3 groups. The different methods also did not influence apoptosis rates (number of TUNEL-positive cells/number of total cells) or expression levels of apoptosis-related BAX and BCL2L1 genes. However, total cell and EdU (5-ethynyl-2'-deoxyuridine)-positive cell numbers in 4N parthenogenetic blastocysts derived from M1 were higher (p < 0.05) than those for M2 and M3 groups. Our results suggest that, although porcine 4N parthenogenetic embryos could be produced by a variety of methods, inhibition of PB1 and PB2 extrusion (M1) is superior to electrofusion of 2-cell stage diploid parthenogenetic embryos derived from inhibition of PB2 (M2) or PB1 (M3) extrusion.

• 한국결정성장학회:학술대회논문집
• /
• 한국결정성장학회 2000년도 Proceedings of 2000 International Nano Crystals/Ceramics Forum and International Symposium on Intermaterials
• /
• pp.179-193
• /
• 2000

Aluminium titanate (Al₂TiO5) with an excellent thermal shock resistant and a low the expansion coefficient was obtained by solid solution with MgO, SiO₂, and ZrO₂ in the Al₂TiO5 lattice or in the grain boundary solution through electrofusion in an arc furnace. However, these materials have low mechanical strength due to the presence of microcracks developed by a large difference in thermal expansion coefficients along crystallographic axes. Pure Al₂TiO5 tends to decompose into α-Al₂O₃ and TiO₂-rutile in the temperature range of 750-1300℃ that rendered it apparently useless for industrial applications. Several thermal shock tests were performed: Long therm thermal annealing test at 1100℃ for 100h; and water quenching from 950 to room temperature (RT). Cyclic thermal expansion coefficients up to 1500℃ before and after decomposition tests was also measured using a dilatometer, changes in the microstructure, thermal expansion coefficients, Young's modulus and strengths were determined. The role of microcracks in relation to thermal shock resistance and thermal expansion coefficient is discussed.

• 한국동물번식학회:학술대회논문집
• /
• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
• /
• pp.6-6
• /
• 2002

This study was conducted to investigate the effect of recipient activation time on the nuclear remodeling, chromatin structure, pronuclear formation and in vitro development of bovine nuclear transfer embryos derived from adult ear skin cells. Somatic cells were transferred to enucleated oocytes after quiescent treatments by serum starvation or culture to confluency. Nuclear transfer embryos were activated with a combination of Ca/sup 2+/-ionophore and cycloheximide at 1, 1.5, 2, 2.5, 3, and 5 h after electrofusion. (omitted)

• 한국동물번식학회:학술대회논문집
• /
• 한국동물번식학회 2002년도 춘계학술발표대회 발표논문초록집
• /
• pp.65-65
• /
• 2002

본 연구는 태아 섬유아세포에 hEPO 를 도입하여 transfedtion된 체세포를 공여핵으로 사용하여 복제수정란을 생산함에 있어서 배반포 발달율을 조사하고자 하였다. 실험에 공시된 공여핵은 임신 30일령의 태아로부터 섬유아 세포를 회수하여 10% FBS 첨가된 ES-DMEM 배지에서 3-4일 동안 배양하여 confluent 를 형성시킨 후 0.25% trypsin을 처리하여 neo-EGFP 와 UPⅢ-hEPO 유전자가 1:9로 함유된 배지에서 electroporation을 실시하였다. (중략)

• 대한의용생체공학회:의공학회지
• /
• 제15권1호
• /
• pp.1-8
• /
• 1994

Electrofusion of cabbage protoplasts was performed with a developed equipment which consists of a parallel wire electrode, a AC field generator, and a pulse generator. Exposure of protoplasts to an alternating current field of 450 KHz causes attraction to each other which leads to chains of protoplasts extending from the electrode. Intra-specific protoplast fusion was effectively induced within the pearl chains by the additional application of a single high-intensity DC square wave pulse of 1 KV/cm for 1-3 msec. To improve the performance, micro fusion electrode fabricated from the semiconductor technology and microcontroller based field an, d pulse generator was proposed. The viability of protoplasts after an application of electric field at optimum condition was reduced by only 5 % compared with that of pre-application. A prototype of fusion electrode, which consists of insulator-structure, was successfully fabricated by using photosensitive polyimide.

• 대한수의학회지
• /
• 제35권1호
• /
• pp.179-185
• /
• 1995

The fusion rates of nuclear transplant embryos with various DC voltage were 55.6-79.2%. The significantly higher fusion rates of nuclear transplant embryos were achieved at the electric field strenght of DC 1.0-2.0kV/cm(72.0-79.2%) than DC 0.75kV/cm(55.6%, P<0.05). No significant differences in the percentage of embryos that cleaved(48.1, 55.4 and 42.6% respectively) and the percentage of cleaved embryos that developed to morulae/blastocyst(1.9, 5.3 and 1.9% respectively) could be found among the three types of in vitro culture system (Granulosa cell, BOEC co-culture and SOF, P>0.01). The age of the recipient cytoplast(30 vs 40hr) had no effect on the fusion rates and the rates of cleavage development(36.9 vs 44.1%, P>0.01).

• 대한수의학회지
• /
• 제33권1호
• /
• pp.151-169
• /
• 1993

The present study was carried out to investigate the best condition for nuclear-cytoplasm fusion and in vitro culture of nuclear transplanted embryos and to investigate the production of nuclear transplanted offsprings. The nuclei from 2-, 4- and 8-cell mouse embryos were transferred into enucleated 2-cell embryos, and the reconstituted embryos were submitted to direct current(DC) pulses at output voltage of 1.0, 1.5 and 2.0 kV/cm for 100, 150 and $200{\mu}$ sec to induce cell fusion. 1. The culture of intact or zona cut 2-cell embryos in the medium supplemented with cytochalasin B($5{\mu}g/m{\ell}$) and colcemide($0.1{\mu}g/m{\ell}$)for 30 and 60 minutes did not affect the development to later stage. 2. The in vitro developmental rates of group A(a nucleus from one of the blastomeres was removed) and B(electrofusion of group A) were significantly lower than that of control group(p<0.01). 3. When nuclear transplanted embryos were submitted to electrofusion, the significantly higher fusion rates of 2-cell donor nuclei were achieved at the electric field strength of DC 1.5kV/cm for 100 and $150{\mu}$ sec, DC 2.0 kV/cm for $100{\sim}200{\mu}$ sec than DC 1.0 kV/cm for 100 and $150{\mu}$ sec(p<0.01). The significantly higher fusion rates of 4-cell donor nuclei were achieved at DC 2.0 kV/cm for 100 and $150{\mu}$ sec than DC 1.0kV/cm for $100{\sim}200{\mu}$ sec(p<0.01). These fusion rates in 8-cell donor nuclei were 88.7~99.3%. 4. The developmental potency to blastocyst in 2- and 4-cell donor nuclei was significantly higher in DC 1.0 and 2.0 kV/cm for $100{\sim}200{\mu}$ sec treated group and DC 2.0 kV/cm for 150 and $200{\mu}$ sec treated group (p<0.01). The developmental potency to blastocyst in 8-cell donor nuclei was significantly higher in DC 2.0 kV/cm for $100{\mu}$ sec treated group than in DC 1.0 kV/cm for $100{\mu}$ sec treated group and DC 2.0 kV/cm for 150 and $200{\mu}$ sec treated group(p<001). 5. The developmental potency to blastocyst after nuclear transplantation was significantly higher in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01). 6. The success rate of nuclear injection into enucleated 2-cell embryos was significantly higher in 2-cell donor nuclei than in 4- or 8-cell donor nuclei(p<0.01). 7. The culture time taken for the nuclear transplanted 2-cell embryos to blastocyst stage was significantly longer in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01). 8. There was no significant difference in the developmental potency of nuclear transplanted embryos within the concentration of EGF at 0 to 15 ng per $m{\ell}$ of BMOC-3 solution. 9. The production rates of offspring after transfer of nuclear transplanted embryos to recipient mouse were significantly higher in 2-cell donor nuclei than in 8-cell donor nuclei(p<0.01).

• 한국가축번식학회지
• /
• 제20권4호
• /
• pp.459-465
• /
• 1997

본 연구는 핵이식의 시기가 융합과 체외발달에 미치는 영향을 조사하고 체외수정 공핵배의 핵과 체외성숙난자간에 전기융합의 최적 통전전압과 통전시간을 결정하기 위하여 시도하였다. 수핵난자는 체외성숙후 25~27시간에 제핵하였고 난자의 추가성숙을 위하여 융합전에 18~20시간 더 배양하였다. 공핵체외수정란은 16~32세포기까지 BOEC와 공배양하였다. 공핵배의 할구 이식시간은 조기핵이식구에서는 체핵후 1~3시간, 자연핵이식구를 체핵후 16~18시간이었다. 융합은 체외성숙후 43~45시간에 행하였다. 융합율은 할구 이식시기에 따라 차이가 없었으나 난할율과 8~16세포기 발달은 자연핵이식구에서 높았다. 융합, 난할 및 상실배 배반포 발달율은 1.0kV/cm보다 0.75kV/cm전압에서 높았으며 0.7kV/cm에서 상실배 배반포율은 17.6%였다. 통전시간에 따라 융합율은 차이가 없었으나 50$\mu$sec와 70$\mu$sec에서 난할율과 상실배-배반포 발달율이 다소 높았다. 본 결과에서 핵이식의 최적시기는 수핵난자의 체외성숙후 42~44시간이었으며 최적 전기융합 조건은 50~70$\mu$sec의 1회 0.75kV/cm임을 알 수 있었다.

• 대한수의학회지
• /
• 제33권3호
• /
• pp.547-554
• /
• 1993

This study was carried out to investigate the best condition for in vitro and in vivo culture after freezing and thawing of nuclear transplant 2 cell embryos. When nuclear transplant embryos were submitted to electrofusion, the significantly higher fusion rates of 2 cell donor nuclei were achieved at the electric field strength of DC 1.5 kV/cm for 100 and $150{\mu}sec$, DC 2.0 kV/cm for 100 and $150{\mu}sec$ than DC 1.0 kV/cm for 100 and $150{\mu}sec$(p<0.01). The significantly higher fusion rates of 4 cell donor nuclei were achievecl at DC 2.0 kV/cm for 100 and $150{\mu}sec$ than DC 1.0 kV/cm for 100 and $150{\mu}sec$(p<0.01). The fusion rates in 8 cell donor nuclei were 94.2~99.3%. The developmental potency to blastocyst in 2 cell donor nuclei was significantly higher in DC 2.0 kV/cm for $150{\mu}sec$ treated group(p<0.01). The significantly higher developmental potency to blastocyst in 4 cell donor nuclei were achieved at the electric field strength of DC 2.0 kV/cm for $150{\mu}sec$ than DC 1.5 kV/cm for 100 and $150{\mu}sec$, DC 2.0 kV/cm for $100{\mu}sec$ treated group(p<0.01). The develop mental potency to blastocyst in 8 cell donor nuclei was significantly higher in DC 2.0 kV/cm for $100{\mu}sec$ treated group(p<0.01). The developmental potency to blastocyst after nuclear transplantation was significantly higher in 2 cell donor nuclei than in 8 cell donor nuclei(p<0.01). When the recovered embryos in normal morphology were cultured in vitro, there were no significant differences in the developmental potency to blastocyst between the freezing methods and the concentrations of cryoprotectant(p<0.01). The production rates of offspring after transfer of nuclear transplant embryos to recipient mouse were no significant difference in 2, 4 and 8 cell donor nuclei.