역사지진 및 계기지진이 보고되어 앞으로 지진이 발생할 가능성이 있는 한반도 중부지역 중, 충청남도 서부지역 에 분포하는 선형구조와 단층지형을 분석하였다. 단층지형을 기반으로 총 151개의 선형구조가 추출하였다. 당진단층과 예산단층이 위치하는 지역에 단층과 주향이 일치하는 선형구조가 밀집하여 분포하는 반면, 홍성단층이 위치한 지역에는 선형구조의 수가 적으며 단층과 유사한 주향을 갖는 선형구조 또한 잘 인지되지 않는다. 이러한 특징은 넓은 충적층과, 오랜 기간의 풍화와 침식, 그리고 경작으로 인한 지표의 변형 등에 의해 단층을 지시하는 지형증거를 인지하기 어렵기 때문으로 판단된다. 단층으로 판명된 5개의 주요지점에서는 단층안부, 제4기 충적층에 나타나는 경사급변점, 선형곡 등 의 단층지형이 선형구조를 따라 인지되었으며 단층지형이 실제 단층을 잘 지시하는 것으로 나타났다. 한편 선형구조 내 에서 감지된 제4기층의 변위는 단층운동에 의해 직접적으로 형성된 것이 아닌 농경지 정리와 같은 인위적 교란이나 하 천 침식의 영향과 같은 외부요인에 의해 형성되었을 가능성이 있는 것으로 파악되었다. 연구지역에서 인지되는 단층지 형의 유형과 한반도 남동부 지역에서 인지되는 단층지형의 유형에 차이가 나타나는데 이는 단층지형의 유형이 단층종 류에 따라 변화되는 한 예를 보여준다.

Background: Porcine pluripotent stem cells (pPSCs) would provide enormous potential for agriculture and biomedicine. However, authentic pPSCs have not established yet because standards for pPSCs-specific markers and culture conditions are not clear. Therefore, the present study reports comparative pluripotency characteristics in porcine induced pluripotent stem cells (piPSCs) derived from different viral transduction and reprogramming factors [Lenti-iPSCs (OSKM), Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM)]. Methods: Porcine fibroblasts were induced into Lenti-iPSCs (OSKM) and Lenti-iPSCs (OSKMNL) by using Lentiviral vector and Sev-iPSCs (OSKM) by using Sendaiviral vector. Expressions of endogenous or exogenous pluripotency-associated genes, surface marker and in vitro differentiation in between Lenti-piPSCs (OSKM), Lenti-iPSCs (OSKMNL) and Sev-piPSCs (OSKM) were compared. Results: Colonial morphology of Lenti-iPSCs (OSKMNL) closely resembles the naïve mouse embryonic stem cells colony for culture, whereas Sev-iPSCs (OSKM) colony is similar to the primed hESCs. Also, the activity of AP shows a distinct different in piPSCs (AP-positive (+) Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM), but AP-negative (-) LentiiPSCs (OSKM)). mRNAs expression of several marker genes (OCT-3/4, NANOG and SOX2) for pluripotency was increased in Lenti-iPSCs (OSKMNL) and Sev-iPSCs (OSKM), but Sev-iPSCs (OSKM). Interestingly, SSEA-1 of surface markers was expressed only in Sev-iPSCs (OSKM), whereas SSEA-4, Tra-1-60 and Tra-1-81 were positively expressed in Lenti-iPSCs (OSKMNL). Exogenous reprogramming factors continuously expressed in Lenti-iPSCs (OSKMNL) for passage 20, whereas Sev-iPSCs (OSKM) did not express any exogenous transcription factors. Finally, only Lenti-iPSCs (OSKMNL) express the three germ layers and primordial germ cells markers in aggregated EBs. Conclusions: These results indicate that the viral transduction system of reprograming factors into porcine differentiated cells display different pluripotency characteristics in piPSCs.

Background: Pluripotent stem cells (PSCs) including embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) offer the immense therapeutic potential in stem cell-based therapy of degenerative disorders. However, clinical trials of human ESCs cause heavy ethical concerns. With the derivation of iPSCs established by reprogramming from adult somatic cells through the transgenic expression of transcription factors, this problems would be able to overcome. In the present study, we tried to differentiate porcine iPSCs (piPSCs) into endothelial cells (ECs) for stem cell-based therapy of vascular diseases. Methods: piPSCs (OSKMNL) were induced to differentiation into ECs in four differentiation media (APEL-2, APEL-2 + 50 ng/mL of VEGF, EBM-2, EBM-2 + 50 ng/ mL of VEGF) on cultured plates coated with matrigel® (1:40 dilution with DMEM/F-12 medium) for 8 days. Differentiation efficiency of these cells were exanimated using qRT-PCR, Immunocytochemistry, Western blotting and FACS. Results: As results, expressions of pluripotency-associated markers (OCT-3/4, SOX2 and NANOG) were higher observed in all porcine differentiated cells derived from piPSCs (OSKMNL) cultured in four differentiation media than piPSCs as the control, whereas endothelial-associated marker (CD-31) in the differentiated cells was not expressed. Conclusions: It can be seen that piPSCs (OSKMNL) were not suitable to differentiate into ECs in the four differentiation media unlike porcine epiblast stem cells (pEpiSCs). Therefore, it would be required to establish a suitable PSCs for differentiating into ECs for the treatment of cardiovascular diseases.

체세포 복제기술을 이용한 복제가축 생산 기술은 1997년 전 세계적으로 이슈가 되었던 복제 면양 “Dolly”의 탄생을 계기로 여러 나라에서 소, 돼지, 말, 고양이, 개 등 많은 포유류에서 산자 생산에 성 공하였으며 우리나라의 체세포 복제 기술은 기술 선진국 대열에 들어서고 있다. 그러나 복제기술은 아 직까지 높은 유산율과 폐사율 등 해결해야 할 많은 근본적인 문제점 등이 있어 연구해야 할 분야는 적 지 않다고 하겠다. 체세포 복제 동물 생산기술은 당초에는 능력이 우량가축의 생산과 확대 및 조기증식 을 목적으로 이용되고 왔으나, 체세포 내로 우리가 원하는 유전자를 도입시키거나 없애는 기술 (knock-in과 knock-out)의 발달로 바이오장기 생산용 형질전환 복제 돼지의 생산을 목적으로 널리 이 용되고 있다. 또한, 최근에는 멸종위기에 있는 희소동물 유전자원을 멸실 이전에 동결 보존된 체세포를 이용하여 복원에 활용할 뿐 아니라 마약탐지견 생산 등 특수한 목적으로 활용되는 동물을 생산하는 기 술로서 기여하게 된다면 산업적으로 활용할 수 있는 분야가 더욱 확대될 것으로 기대된다. 따라서 체세 포 복제기술은 식용보다는 오히려 다양한 목적으로 복제동물을 생산하게 되면 산업적으로 활용할 수 있 는 가능성이 높을 것으로 기대되고 있다.

The cloning efficiency is extremely low despite successful somatic cell nuclear transfer (SCNT) method producing cloned animals in several mammals. In general, faulty epigenetic modifications underlying the incomplete reprogramming of donor cell nuclei after SCNT mainly results in low cloning efficiency. The nuclear reprogramming process involves epigenetic modifications, such as DNA demethylation and histone acetylation, which may be an important factor in enhancing the cloning efficiency. Recently, the histone deacetylase inhibitors (HDACi), such as trichosatin A (TSA) and m-carboxycinnamic acid bishydroxamide (CBHA), to increase histone acetylation have been used to improve the developmental competence of SCNT embryos. Therefore, we compared the effects of TSA with CBHA on the in vitro developmental competence and pluripotency-related gene expression (Oct4, Nanog and Sox2) in porcine cloned blastocysts and histone acetylation pattern (H3K9ac). The porcine cloned embryos were treated with a 50nM concentration of TSA and 100μM concentration of CBHA during the in vitro early culture (10h) after cell fusion and then were assessed to cleavage rate, development to the blastocyst stage and pluripotency-related gene expression in NT blastocyst also, level of histone acetylation in zygote, 2cell, 4cell stage. As results, Although NT, TSA and CBHA treated NT embryos were not different between all groups for cleavage rates, the developmental competence to the blastocyst stage was significantly increased in CBHA treated embryos (22.7%) compared to that of normal NT and TSA treated NT embryos (8.1% and 15.4%)(p<0.05). In addition, all of pluripotent transcription factors (Oct4, Nanog and Sox2) were expressed in the CBHA treated NT embryos, however, Sox2 and Oct4 were expressed in TSA treated NT embryos and expression pattern of CBHA treated NT embryos is particularly similar to that of IVF embryos. Also, CBHA treated NT embryos were increased in level of histone acetylation (H3K9ac) at the zygote, 2-cell, 4-cell stage compared to those of NT and TSA treated NT embryos. In conclusion, the treatment of CBHA as a histone deacetylase inhibitor significantly increased the developmental competence of porcine NT embryos and pluripotency-related gene expressions(Oct4, Nanog and Sox2) in NT blastocysts and level of histone acetylation (H3K9ac).

Differentiated nuclei can experimentally be returned to an undifferentiated embryonic status after nuclear transfer (NT) to unfertilized metaphase II (MII) oocytes. Nuclear reprogramming is triggered immediately after somatic cell nucleus transfer (SCNT) into recipient cytoplasm and this period is regarded as a key stage for optimizing reprogramming. In a recent study (Dai et al., 2010), use of m-carboxycinnamic acid bishydroxamide (CBHA) as a histone deacetylase inhibitor during the in vitro early culture of murine cloned embryos modifies the acetylation status of somatic nuclei and increases the developmental competence of SCNT embryos. Thus, we examined the effects of CBHA treatment on the in vitro preimplantation development of porcine SCNT embryos and on the acetylated status of histone H3K9 on cloned embryos at the zygote stage. We performed the three groups SCNT: SCNT (NT), CBHA treatment at the porcine fetus fibroblast cells (PFFs) used as donor cells prior to SCNT (CBHA-C) and CBHA treatment at the porcine SCNT embryos during the in vitro early culture after oocyte activation (CBHA-Z). The PFFs were treated with a 15 μM of CBHA (8 h) for the early culture and the porcine cloned embryos were treated with a 100 μM concentration of CBHA during the in vitro early culture (10 h). Cleavage rates and development to the blastocyst stage were assessed. No significant difference was observed the cleavage rate among the groups (82.6%, 76.4% and 82.2%, respectively). However, the development competence to the blastocyst stage was significantly increased in CBHA-Z embryos (22.7%) as compared to SCNT and CBHA-C embryos (8.6% and 4.1%)(p<0.05). Total cell numbers and viable cell numbers at the blastocyst stage of porcine SCNT embryos were increased in CBHA-Z embryos as compared to those in CBHA-C embryos (p<0.05). Signal level of histone acetylation (H3K9ac) at the zygote stage of SCNT was increased in CBHA-Z embryos as compared to SCNT and CBHA-C embryos. The results of the present study suggested that treatment with CBHA during the in vitro early culture (10 h) had significantly increased the developmental competence and histone acetylation level at the zygote stage.

핵이식(NT) 기술을 이용하여 여러 동물 종에서 성공적으로 복제산자가 보고되고 있지만, 아직까지 비효율적인 기술로 남아있다. 본 연구에서는 돼지 체세포 복제 생산 효율성을 증진시키기 위한 방안으로 수핵난자의 품질에 초점을 맞추어 Brilliant cresyl blue (BCB) 염색을 통하여 발육능이 우수한 미성숙 난자를 선발하고, 난자의 감수분열 재개에 관여하는 단백질 합성을 비특이적으로 억제하는 cycloheximide (CHXM)을 이용하여 돼지 난자의 감수분열 재개를 억제시켜 난자의 성숙 동기화를 유도하였다. 또한 핵초기화에 밀접한 영향을 주는 핵막붕괴(NEBD)와 조기염색체응축 (PCC)을 유도하는 MPF의 활성화를 높이기 위하여 단백질 phosphatase 억제제인 caffeine을 첨가하여 수핵난자의 품질을 향상시키고자 하였다. 실험 방법으로는 13 mM BCB 첨가된 배양액에 90분 동안 미성숙난자를 배양하여 BCB 용액의 착색 여부를 구분하여 선발하고, 5 ㎍/ml CHXM를 체외 성숙액에 첨가하여 난자성숙 동기화를 유도하였다. 또한 탈핵 후 탈핵난자를 caffeine을 처리하여 세포주기 관련 단백질의 활성화를 인위적으로 조절하여 체세포복제 수핵난자로 사용하였다. 실험 결과로서 BCB 염색 돼지 미성숙 난자를 대조구와 비교할 때 제2 감수분열 중기(MII)에 도달하는 체외성숙율과 단위발생란의 배반포기까지의 체외 발육율이 유의적으로 증가하는 것이 관찰되었다. 또한 미성숙 돼지 난자의 초기 성숙 (12∼16시간)에 CHXM를 처리하였더니 난자 감수분열 재개가 억제되어 GV기에 핵 성숙이 정지되어 동기화가 유도되었다. GV기에 세포주기 동기화된 난자들은 CHXM를 제거하였을 때 난자 성숙의 진행속도도 일치하는 것이 관찰되었다. 이런 결과는 가장 적합한 탈핵시기인 제1 감수분열 후/말기(AI/TI)에 난자들이 다수 분포하여 대조구에 비하여 높은 탈핵율 (87.9%)을 얻을 수 있었다 (P < 0.05). 덧붙여 5 mM의 caffeine을 돼지 난자에 12시간 처리하였을 때 난자 MPF의 활성화가 증가하는 것이 관찰되었지만 (P < 0.05), 10 mM caffeine 농도를 처리하였을 때 MPF의 활성화가 오히려 감소되어 단위발생란의 배반포기까지의 체외발육에도 악영향을 주는 것이 관찰되었다.

The technique of SCNT is now well established but still remains inefficient. The in vitro development of SCNT embryos is dependent upon numerous factors including the recipient cytoplast and karyoplast. Above all, the metaphase of the second meiotic division (MII)　oocytes have typically become the recipient of choice. Generally high level of MPF present in MII oocytes induces the transferred nucleus to enter mitotic division precociously and causes NEBD and PCC, which may be the critical role for nuclear reprogramming. In the present study we investigated the in vitro development and pregnancy of White-Hanwoo SCNT embryos treated with caffeine (a protein kinase phosphatase inhibitor). As results, the treatment of 10 mM caffeine for 6 h significantly increased MPF activity in bovine oocytes but does not affect the developmental competence to the blastocyst stage in bovine SCNT embryos. However, a significant increase in the mean cell number of blastocysts and the frequency of pregnant on 150 days of White-Hanwoo SCNT embryos produced using caffeine treated cytoplasts was observed. These results indicated that the recipient cytoplast treated with caffeine for a short period prior to reconstruction of SCNT embryos is able to increase the frequency of pregnancy in cow.

Somatic cell nuclear transfer (SCNT) and induced pluripotent stem cell (iPS) experiments have generally demonstrated that a differentiated cell directly converts into a undifferentiated or pluripotent state. In SCNT experiment, nuclear reprogramming is induced by exposure of introduced donor cell nuclei to the recipient cytoplasm of matured oocytes. Although nuclear reprogramming of cells by the ex-ovo methods is not always consistent or efficient, it has been suggested that a combination of nuclear reprogramming technique may improve the efficiency or frequency of normal development of SCNT embryos. Here we hypothesized that treatment of somatic cells with extracts prepared from GV stage sturgeon's oocytes prior to their use as nuclear donors for SCNT will improve subsequent development. We reported a reversible permeabilization protocol with digitonin to deliver sturgeon oocyte exteact (SOE) to porcine fetal fibroblast cell nuclei ex ovo. Porcine fibroblasts were permeabilized by 4 μg/ml of digitonin for 2 min at 4℃ and then incubated in SOE for 7h at 15 18℃ followed by resealing of cell membrane. As results, no difference was observed in the number of fused couplets or the number of fused couplets that cleaved between the extract treated or control group. However, there was a significantly decrease in the percentage of fused couplets that developed to the blastocyst stage in the SOE treated group (p<0.05). Histone acetylation status was determined using an antibody to acetylation at lysine 9 on histone 3 (H3K9Ac). The intensity of H3K9Ac staining in 1-cell stage NT embryos was significantly increased when treated with the SOE (p<0.05), similar to that in 1-cell stage IVF embryos. In addition, porcine NT embryos reconstructed by using donor cell exposed to SOE prior to cell fusion significantly decreased developmental competence to the blastocyst stage but increased pluripotent gene expressions (Sox2, Nanog and Oct3/4) when compared with those in normal NT embryos (p<0.05).

Although somatic cell nuclear transfer (SCNT) has successfully been produced cloned animals in several species, the cloning efficiency is extremely low. It is generally believed that the low cloning efficiency is mainly attributed to faulty epigenetic modifications underlying the aberrant reprogramming of donor cell nuclei in recipient cytoplasm after SCNT. The nuclear reprogramming process involves epigenetic modifications, such as DNA demethylation and histone acetylation, which may be a key factor in improving the cloning efficiency. Recently, the histone deacetylase inhibitors (HDACi), such as trichosatin A (TSA) and m-carboxycinnamic acid bishydroxamide (CBHA), to increase histone acetylation have been used to improve the developmental competence of SCNT embryos. Therefore, we compared the effects of TSA with CBHA on the in vitro developmental competence and pluripotency-related gene expressions (Nanog, Oct3/4 and Sox2) in porcine cloned blastocysts. The porcine cloned embryos were treated with a 50 nM concentration of TSA or a 100 μm concentration of CBHA during the in vitro early culture (10h) after cell fusion and then were assessed to cleavage rate, development to the blastocyst stage and pluripotency-related gene expressions in NT blastocysts. All data was analyzed by chi-square. Following 4-5 replicates (245, 200 and 222 for NT, TSA and CBHA treated NT embryos respectively) there was no difference between normal NT and CBHA treated NT embryos, whereas TSA treated NT embryos was significantly decreased for cleavage rate (p<0.05). The developmental competence to the blastocyst stage in CBHA treated NT embryos (18.9%) significantly increased than that of normal NT and TSA treated NT embryos (9.4% and 11.5%) (p<0.05). In addition, all of pluripotent transcription factors (Nanog, Oct3/4 and Sox2) were highly expressed in the CBHA treated NT embryos, however, Sox2 and Oct3/4 were expressed in TSA treated NT embryos and Sox2 was only expressed in normal NT embryos (p<0.05). In conclusion, the treatment of CBHA as a histone deacetylase inhibitor significantly increased the developmental competence of porcine NT embryos and pluripotency- related gene expressions (Nanog, Oct3/4 and Sox2) in NT blastocysts.