This study was conducted to investigate an effective recipient oocyte and culture system for producing of Hanwoo (Korean native cattle) somatic cell nuclear transfer (SCNT) embryos. Hanwoo ear skin fibroblasts were used as donor cells. In vitro matured Hanwoo or Holstein oocytes were enucleated, and single donor cells were transferred into the perivitelline space of the enucleated oocytes. The couplets were subsequently fused and activated. The reconstructed embryos were cultured in a conventional or sequential culture system. In the former, embryos were cultured in CR2aa medium for eight days; in the latter, embryos were cultured in modified CR2aa-A (mCR2-A) for three days and then further cultured in modified CR2aa-B (mCR2-B) for five days. In the experiment with the recipient oocyte, the rate of embryo development to the blastocyst stage was significantly (p<0.05) higher in Hanwoo recipient oocytes than in Holstein ones (48.8% vs 38.9%). BIastocysts derived from Hanwoo recipient oocytes contained significantly (p<0.05) higher numbers of total cells than those derived from Holstein recipient oocytes (156.0+-68.2 vs 134.7+-54.8)). There was no difference in the mean proportion of apoptotic cells in blastocysts between the sources of recipient oocytes. In the experiment with the embryo culture system, the blastocyst rate was somewhat higher in sequential system than in conventional system (50.0% vs 43.5%), though there was no significant difference. The numbers of total (160.0+-69.0 vs 156.7+-68.4) and apoptotic cells (14.0+-10.4 vs 11.8+-6.4)) were not different between the culture systems. In conclusion, the present study demonstrated that Hanwoo recipient oocytes and the sequential culture system were more effective in supporting the production of Hanwoo SCNT embryos.

수평 배향 액정 모드는 양의 유전율 이방성과 음의 유전융 이방성 액정을 사용한 프린지 필드 스위칭과 양의 유전율 이방성 액정을 사용한 인플래인 스위칭 모드가 대표적이다 . 이 대표적인 세 구동 방식의 화질 특성을 비교하기 위하여 각각의 최척화된 위상지연 값 조건하에서 밝기, 명암대비율과 색 특성을 조사하였다. 그 결과 양액정과 음액정을 사용한 프린지 필드 스위칭 모드가 밝기와 명암대비율 면에 있어서 인플래인 스위칭 모드보다 우수한 특성을 보인다. 또한 양액정을 사용한 프린지 필드 스위 칭 모드는 시야각 방향에서 적은 색 변이 특성을 보인다.

선행 연구에서 poly(styrene sulfonate) (PSS)/poly(diallyldimethylammonium chloride) (PDADMAC) 나노 여과막을 사용하여 불소 이온을 포함한 1가 이온 혼합물을 분리하는 것이 가능함을 보였다. 예를 들면, 다공성 알루미나 지지체에 (PSS/PDADMAC)4PSS 필름을 코팅한 경우 염소/불소 이온의 선택도가 3 이상이었으며 4.8 bar에서 용액의 플럭스가 3.5 m 3 /m 2-day이었다. 그러나, PSS/PDADMAC 이층의 수가 4.5에서 5.5.로 증가하면 염소/불소 이온의 선택도가 1.9로 떨어졌으며, (PSS/PDADMAC)6PSS 필름의 경우에는 염소 이온의 배제율이 급속히 증가하면서 선택도가 1에 가까웠다. 이러한 선택도의 감소 현상은 예상치 못한 것으로서 다른 지지체를 사용하여도 같은 경향을 보이는지 여부는 불분명하였다. 따라서, 본 연구에서는 다공성 알루미나 대신에 분획 분자량이 50kDa인 다공성 polyethersulfone (PES)에 PSS/PDADMAC을 적층하고 불소/염소 이온 혼합물의 나노 여과 특성을 살펴보았다. 그 결과 다공성 알루미나의 경우와 비록 적층 수는 달랐으나 불소 이온의 배제율이 최대가 되는 최적 적층수가 존재하였으며 이로부터 이러한 현상이 지지체에 무관한 일반적인 사실임을 알 수 있었다.

The aim of this study was to examine more effective cryoprotectant for the cryopreservation of mouse preantral follicles. Enzymetically isolated preantral follicles from 12-day-old mice were cryopreserved by a slow freezing protocol with 1.5 M propanediol (PROH), dimethyl sulphoxide (DMSO) or glycerol (GLY) and then grown and matured in vitro for 11 days after thawing. The survival of preantral follicles immediately after freezing and thawing was not different among the PROH (68.2%), DMSO (72.4%) and GLY (72.1%). After grown and matured in vitro, the rates of survival and metaphase II oocytes were 54.9% and 36.6% for PROH which was significantly higher rates (p<0.05) compared with the rates obtained from DMSO (16.9% and 9.0%) and GLY (16.3% and 7.5%). The diameter of metaphase II oocytes from pre antral follicles frozen in PROH (67.4+-1.8 um) was significantly (p<0.05) smaller than that of the fresh preantral follicles (69.1+-2.3 um). The results from the present study revealed that PROH is more suitable cryoprotectant for the cryopreservation of mouse preantral follicles.

It has not been much known about that how much the properties of parental strains appear in the monokaryotic progeny of their basidiospores and the properties of monokaryotic progeny is transferred and expressed after mating with other monokaryotic progeny. To get a basic idea in the evaluation of shiitake strains that are subjectto be used for a breeding program, biochemical properties of monokaryotic strains generated from basidiospores of parental shiitake strains (Sanzo101 and Sanzo108) and hybrid strains generated from cross of these monokaryotic strains were examined. When amylase, avicelase, β-glucosidase, CM-cellulase, pectinase, proteinase, and xylanase were tested against monokaryotic strains generated from forty basidiospores of the two parental strains, No identical patterns of the degree of enzyme activity were observed between monokaryotic strains and parental strains of the two shiitake cultivars. The degree of extracellular enzyme activity also varied among monokaryotic strains of the two shiitake cultivars. Our results showed that dikaryotic parental strains of shiitake mushroom produce basidiospores having very diverse biochemical properties. Biochemical test of monokaryotic strains was useful for the comparative evaluation of parental strains. Biochemical test with hybrid strains formed with the combinational cross of monokaryotic strains that have different degree of extracellular activity showed that the property of monokaryotic strains is not expressed in the hybrid strains according to Mandelian principles. Tests of the ability of using diverse polymeric carbon sources, tolerance to copper and agrochemicals, and antagonistic property to Tricoderma atroviride also showed similar results

Field sequential 액정 디스플레이(FSLCD)는 컬러필터를 사용하지 않아 높은 투과율 특성을 보이고 광 원으로 LED를 사용함으로써 색재현성이 매우 우수하다. 하지만 FSLCD(60Hz 구동)를 실현하기 위해서는 액정의 응답속도가 5ms이하로 고속응답 특성을 보여야 한다. 따라서 본 논문에서는 고속응답 ECB(electrically controlled birefringence) 셀의 최적 구조를 연구하여 5ms 이하의 응답시간을 얻었다. 그리고 ECB 모드에서 높은 구동전압과 시야각을 개선하기 위해 필름 보상을 연구하였다. 판상형 액정필름(discotic film)과 TAC(triacetyl cellulose) 필름의 위상차 값을 최적화함으로써 구동전압을 5V로 낮추고 상하좌우에서 160° 이상(CR>10:1)의 시야각을 실현하였다.

This study was conducted to examine the mRNA expression of apoptosis-related and imprinted genes and methylation pattern of the differentially methylated region (DMR) of H19 gene in day 35 of SCNT pig fetuses. The day 35 of natural mating (control) or cloned (clone) pig fetuses were recovered from uterus. Endometrium from dam and liver from fetus were obtained, respectively. mRNA expression was evaluated by real-time PCR and methylation pattern was analyzed by bisulfite sequencing method. The Bcl-2 mRNA expression in clone was significantly lower than that of control (p<0.05). The mRNA expression of H19 gene in both endometrium and liver was significantly higher in clone than that of control, respectively (p<0.05). The level of IGF-2 mRNA in liver of clone was significantly lower than that of control (p<0.05), whereas the mRNA expression of IGF2-R gene in liver of clone was significantly higher than that of control (p<0.05). The DMR of H19 was lower methylation pattern in clone than that of control. These results suggest that the aberrant mRNA expression of apoptosis-related and imprinted genes and the lower DMR methylation pattern of imprinted gene may be closely related to the inadequate fetal development of cloned fetus.