Since the first success of animal cloning, somatic cell nuclear transfer presented various ideas in many research areas such as regenerative medicine. However, SCNT embryos has poor survival rate. Therefore, numerous researches carried out to enhance the developmental capability of porcine nuclear transfer embryos. Cytochalasin B, demecolcine, latrunculin A, cycloheximide and 6-dimethylaminopurine are efficient chemicals treated in post-activation procedure to increase the efficiency of SCNT. This review study is aim to investigate the effects of these chemicals applied to post-activation in porcine SCNT. Cytochalasin B, demecolcine, latrunculin A are cytoskeletal manuplators inhibit extrusion of pseudo-polar body. Cytochalasin B and demecolcine showed considerably higher blastocyst formation proportion (26-28%) compared to when they are not treated (16%). And when latrunculin A was treated for postactivation, blastocyst formation proportion was increased in SCNT embryos exposed to LA (38%) than those in control (14%). On the other hand, cycloheximide and 6-dimethylaminopurine are protein synthesis and kinase inhibitors. And they help to maintain Ca2+ fluctuation in oocytes. Cleavage and blastocyst rates of NT embryos were increased when they were exposed to CHX (16.9% and 5.4% with no CHX).And 6-DMAP also showed higher blastocyst formation (21.5% compared to 15.7%, control). Although all these chemicals have different mechanisms, they showed developmental competence enhancement in NT embryos. However, there are only few studies comparing each chemical’s post-activation effect. Therefore, further research and study should be conducted to find optimal chemical for improving the efficiency of SCNT.

This study is performed to evaluate the effect of insulin in the porcine parthenogenetic embryo development. In porcine embryo culture, insulin is helpful factor in the process of embryo development. To identify this, insulin is used in pig embryos development. Therefore, this study was performed to investigate the effect of insulin on early embryonic development in pigs. For that, insulin positive or negative (0, 10 ug/mL) was supplemented in the porcine IVM media and then compared two groups divided by the cytoplasm of the black groups and white ring groups based on the distribution of lipid material of the cell cytoplasm in microscope. In maturation rates of porcine oocytes, significant higher black group rates were shown in the insulin positive groups compared with other groups (56.0±2.1 vs 46.2±0.3). In the embryo culture, black groups were showed the significant higher cleavage rates (82.1±0.8, 78.3±0.1 vs 63.2±0.3, 63.4±0.0), and blastocyst formation rates (15.5±3.6, 16.6±0.4 vs 11.7±1.3, 7.4±0.2) regardless of whether the addition of insulin. Also, black groups were showed higher cell number of blastocyst (33.2±2.5, 35.5±2.6 vs 31.2±2.1, 31.3±2.2). In conclusion, supplement of insulin producing black group in vitro maturation, it was effective in vitro maturation and embryonic development of pig embryos.

In the last 10 years, porcine somatic cell nuclear transfer to generate transgenic pig has been performed tremendous development with introduction and knockout of many genes. However, efficiency of porcine somatic cell nuclear transfer is still low and embryo transfer (ET) is one of important step for production efficiency. In porcine ET for production of transgenic cloned pig, we can consider many of points to increase production rates. In respect of seasonality and weather, porcine ET usually is not performed in summer and winter. Cloned transgenic embryos must be transferred into reproductive tracts of recipients where embryos are located after natural fertilization with similar estrous cycle. If cloned embryos with 2∼4 cell stage are transferred, they must be transferred into oviducts in periovulatory stage. Number and deposition sites of transferred cloned embryos are important. And we must compare the methods of ET between surgical and non-surgical ones in respect of production efficiency. Sow recipients after natural estrus is most preferred recipients however its cost is must be considered. Here we will review many of current studies about porcine embryo transfer to increase production efficiency of transgenic pigs and strategies for further studies.

본 논문의 목적은 제1차 세계대전 이후 비슷한 시기에 쓰여진 T. S. 엘리엇의 『황무지와 스티븐 스펜더의 『비엔나가 각각 어떻게 1인칭 대명사를 사용했는지를 탐구함으로써, 유럽의 분열과 정치사회적 탄압 이라는 주제가 각 시에서 어떻게 표현되었는지를 조명하는 것이다. 1인 칭 대명사 사용에 대한 연구는 시인이 “얼마나”, 또 “어떻게” 자신의 시 에 직접 개입하여 (정치적) 메시지를 전달하려 했는지를 알기 위한 중 요한 작업이다. 이 논문에서는 먼저 『황무지속의 1인칭 대명사 “I”의 정체를 찾기 위한 과정이 유럽의 분열이라는 시적 주제를 어떤 방식으 로 표현하고 있는지를 탐구할 것이다. 그 다음, 『비엔나에서의 “we”와 “they”의 병치가 어떻게 사회주의자들을 향한 정치적 탄압 뿐 아니라 동성애자들을 향한 사회적 탄압을 반영하고 있는지에 대하여 논할 것이 다.