• Korean Journal of Agricultural Science
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• v.34 no.2
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• pp.135-142
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• 2007

Holstein cows(n=8) were assigned to control diet(n=4) and treatment diet(n=4) containing products of Bromelain(50g/kg) and Zn-methionine (133g/kg). Basal diet was mixed as total mixed rations with 60% concentrate and 40% roughage(rice straw) and fed for 8 weeks. The milk production, somatic cell counts in milk were measured and determined. The results were summarized as follow. Average milk production was higher for cows fed treatment diet(30.2kg/d) than cows fed control diet(29.6kg/d) (P<0.05). The somatic cell counts was significantly lower for cows fed treatment diet ($179.8{\times}10^3/ml$) than cows fed control diet ($260.8{\times}10^3/ml$)(P<0.05). In conclusion, supplementation of both Bromelain and Zn-methionine increased milk production and reduced somatic cell counts in milk.

• Reproductive and Developmental Biology
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• v.31 no.1
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• pp.29-33
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• 2007

This study was conducted to examine the development of in vitro fertilized (IVF) and nuclear transfer (NT) embryos following vitrification IVF and NT embryos developed to the blastocyst stage were equilibrated by 3 steps, vitrified and thawed, and their survival and hatching rates were examined. In IVF embryos, higher survival (82.1%, 96/117) and hatching rates (64.1%, 75/117) were obtained respectively after thawing and culture in expanded blastocysts compared to blastocysts (p<0.05). High survival and hatching rates were also obtained by vitrification of NT blastocysts, especially in expanded and hatching blastocysts (81.1 and 78.3%, respectively). The result of this study shows that IVF and NT blastocysts, especially late stage blastocysts, are successfully cryopreserved by vitrification.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.219-223
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• 2004

Embryogenic calli were induced from petioles of Aralia elata on MS solid medium supplemented with 1.0 mg/L 2,4-D. When embryogenic calli were transferred to MS liquid medium supplemented with 1.0 mg/L 2,4-D, embryogenic cells and embryogenic cell clusters were developed after 2 weeks of culture. Embryogenic cells were filtered through a 250 ${\mu}{\textrm}{m}$ sieve and the passed cells were proliferated and maintained in MS liquid medium supplemented with 1.0 mg/L 2,4-D. Embryogenic cell clusters entrapped on the sieve were transferred to 1/2 MS liquid medium without plant growth regulators, globular-shaped embryos were developed from embryogenic cell clusters after 2 weeks of culture. Numerous early stage somatic embryos could be developed to heart-shaped, torpedo-shaped, cotyledonary embryos and plantlets in 5 L bioreactor. Above results suggest that effective somatic embryo proliferation can be achieved via bioreactor culture systems in Aralia elata.

• Development and Reproduction
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• v.14 no.4
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• pp.253-259
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• 2010

DNA methylation is one of the major epigenetic regulations of gene expression. The DNA methylation patterns are dramatically changed during gametogenesis and embryogenesis, and especially, it has been known that embryonic stem cells show a distinct methylation pattern. In this study, we examined the methylation patterns of imprinting genes, H19, Igf2r, and Snrpn, in stem cells induced from fertilized embryo (fES) and somatic cell nuclear transferred embryo (ntES). The methylation pattern of H19 gene in both fES and ntES were similar. However, the methylation patterns of Igf2r and Snrpn in ntES (hypermethylated) were slightly different from fES cells.

• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.37-37
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• 2003

본 연구실에서는 체세포복제 수정란 이식우의 분만전후 태아와 모체 및 태반과의 내분비적인 관계를 검토하기 위해 복제수정란 이식우의 분만 전후에 있어서, 혈중progesterone 과 TGF-$\beta$$_1$ 수준을 분석한 결과 정상우의 분만직전과 달리 혈중progesterone 및 TGF-$\beta$$_1$ 농도는 감소되지 않고 높은 수준을 그대로 유지되어 복제수정란이식우의 경우 정상적인 분만 signal이 나타나지 않는 것으로 나타났다. 본 연구는 체세포 복제소 수정란 이식우에 있어서 태반조직의 특성을 정상우의 동일한 시기의 태반과 비교 검토하였으며 분만시기에 있어서 태반의 역할을 검토하였다. 태반은 복제란 이식우 및 정상우 임신우를 술을 실시하여 태반을 채취하여 실험에 공시하였다. 정상우의 임신기간중 혈중 progesterone 농도는 임신초기와 중기에 다소 증가되어 유지되다가 임신말기에는 급격한 progesterone의 감소현상과 더불어 분만이 유기되는 것으로 나타났으나 복제우의 경우 분만예정일 직전까지 progesterone의 급격한 감소는 일어나지 않고 높은 농도로 유지되는 현상을 보였다. 이때 제왕절제 수술중 제대근방에 있는 태반궁부를 적출하여 중량을 측정한 결과 정상우의 궁부에 비해 유의적으로 무거웠으며, 이것은 태아의 중량과 정의 상관관계가 있음이 확인되었으며 태아 및 궁부의 중량이 무거울수록 분만 전후의 태아사망율이 높은 것으로 나타났다 이때의 궁부를 조직학적으로 검토한 결과, 복제우의 태반궁부는 정상우의 궁부에 비해 cytotrophoblast 및 syncytiotrophoblast가 적었으며 치밀하지 못한 형태를 확인할 수 있었다. 이때의 태반조직를 이용하여 세포질을 추출하여 단백질양상을 검토한 결과, 정상태반에 비해 복제태반은분자량 90kd, 65kd 및 18kd의 특이단백질이 존재하고 있음을 확인할 수 있었으며 이들 단백질을 HPLC system에 의해 분리한 결과 fraction 2와 3에서 특이한 단백질을 분리하였다. 이와 같이, 복제우의 태반에는 정상적인 임신과 분만을 비롯하여 복제송아지의 생존에 중요한 인자가 관여하고 있을 확인할 수 있었다.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.1-6
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• 1994

Cotyledonary and hypocotyl explants of melon seedlings were cultured on Murashige and Skoog's (MS) medium supplemented with various concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) and benzyladenine (B.A).Up to 22% of cotyledonary explants and 7%, of hypocotyl explants, respectively: Produced somatic embryos through intervening two types of calli: bright yellow compact (BYC) callus and pale-yellow compact (PYC) callus. BYC callus was capable of producing somatic embryos at initial culture, but it became necrotic as subrulhues proceeded. In contrast UC callus was incapable of producing somatic embryos during initial culture (first 6 weeks), but it became bright-yellow friable (BYF) callus with forming a few globular embryos after 2 months of subculture, indicating that the callus turned embryogenic. The embryogenic capacity of BYF maintained for over one year when the callus was sucultured at 4-week interval. Upon transfer onto MS basal medium the callus gave rise to numerous somatic embryos and subsequently converted to plantlets. Plantlets were transplanted to potting soil and grown to maturity in the phyotron.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.105-110
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• 1995

The experiment were carried out to obtain a somatic hybrid through protoplast fusion between P.hybrid and N. sanderae. The isoenzyme pattern he chromosome number and the phonotype were observed for genetic study on the regenerants obtained from the fusion product cultures. Putative somatic hybrids possessed all the bands that appeared in both mother plane. A specific band was found on the top of the banding pattern which was assumed to be a marker band of somatic hybrid between two genera. Aspartate amninotransferase isoenzyme bands which were found in both mother plane were also revealed in the putative somatic hybrids or deleted in the upper part of H. sanderae band pattern. The chromosome number of P.hybrida was 2n=14, while N, sanderae was 2n=18,but the number of the putative somatic hybrids ranged from n=32 to 36. The phonotype of putative somatic hybrids was intermediate of the mother plants.

• Korean Journal of Medicinal Crop Science
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• v.13 no.1
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• pp.57-62
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• 2005

Salt-tolerant transgenic Panax ginseng plants were produced by introducing the SAL1 geue (3'(2'), 5'-bis-phosphate nucleotidase) that confers tolerance to the salts through Agrobacterium tumefaciens co-cultivation. Cotyledon explants of immature ginseng zygotic embryos cultured on Murashige and Skoog medium lacking growth regulators formed somatic embryos directly with below 10%, but the 74% tranformation rate were observed at the treatment of phytohormone with 1.0 mg/l 2,4-D and 0.5 mg/l kinetin. Somatic embryos were initially cultured on MS medium supplemented with 250 mg/l cefotaxime for 3 weeks and subsequently subcultured five times to a medium containing 100 mg/l kanamycin and 250 mg/l cefotaxime. Upon development into the cotyledonary stage, these somatic embryos were transferred to on the medium containing 50 mg/l kanamycin and 10 mg/l gibberellic acid to induce germination and strong selection. Integration of the transgene into the plants was confirmed by polymerase chain reaction with specific primers. The ginseng transformants with well-developed shoots and roots were successfully acclimatized in a greenhouse when they were planted in soil.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.289-291
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• 1999

Hypocotyl explants from 7 days old seedlings of one $F_1$ hybrid cultivar and two pure lines of cucumber formed embryogenic calli at frequencies of up to 8% when cultured on Murashige and Skoog medium (MS) supplemented with 1 mg/L 2,4-D for 3 weeks. Embryogenic calli gave rise to somatic embryos. When slices of somatic embryos were cultured on the same medium for 4 weeks, they formed embryogenic calli. Embryogenic cell suspension cultures were established with embryogenic calli in MS liquid medium with 1 mg/L 2,4-D. Embryogenic potential of cell suspension cultures was maintained by subculturing every seven days. When the level of 2,4-D in the medium was lowered to 0.2 mg/L by diluting with liquid MS basal medium, embryogenic cell suspension cultures underwent development into numerous somatic embryos. When plated onto MS basal medium, over 95% of somatic embryos developed into plantlets. Plantlets were transplanted to potting soil and grown to maturity.

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.85-93
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• 2006

본 연구는 소 형질 전환 체세포 핵이식에서 용이한 탈핵을 위해 demecolcine을 이용할 시 탈핵율과 핵이식란의 발육능을 높이기 위한 최적의 조건을 알아보고자 실시되었다. 도축장 유래 미성숙 난자를 18시간 체외성숙 후 제1극체가 확인된 성숙 난자를 0.1, 0.2, 0.4 및 0.8 ug/ml의 demecolcine이 첨가된 배지에서 1시간 더 처리한 다음 세포막이 돌출되어 있는 난자를 체세포 핵이식에 공여하여 각 군간 배반포로의 발육능을 비교하였다. Demecolcine 처리 후 핵이 포함된 셰포막의 protrusion rates를 각 군간 비교한 결과 0.2, 0.4 및 0.8 ug/ml 군에서 0.1 ug/ml 군보다 유의적으로 높았으며 (82.8, 86.2, 90.4 vs. 70.1%), conventional blind 방법과 비교한 결과 demecolcine를 이용한 군에서 유의적으로 높은 탈핵율을 보였다(75.3 vs. 96.2%; p<0.05). 체세포 핵이식란의 발육능 비교에서는 0.1 및 0.2ug/ml 군에서 대조군과 함께 유의적으로 높은 분할율 및 배반포로의 발육능을 보였다(p<0.05). 결론적으로 소 형질전환 체세포 핵이식을 위한 탈핵시 높은 탈핵율과 배반포로의 발육율을 얻을 수 있는 demecolcine의 적정농도는 0.2ug/ml이라고 사료된다.