• Korean Journal of Plant Taxonomy
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• v.39 no.4
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• pp.247-253
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• 2009

Somatic chromosome numbers for 20 taxa of Korean Artemisia L. were investigated for the purpose of classification. Somatic chromosome numbers of treated taxa were 2n = 16, 18, 34, 36, 50, 52, 54, and therefore their basic chromosome numbers were x = 8, 9, 10, 13, 17. The chromosome number of A. japonica var. angustissima is being reported for the first time in this study. The chromosome numbers of 13 taxa were the same as in previous reports; A. capillaris (2n = 18), A. japonica var. hallaisanensis (2n = 36), A. japonica subsp. littoricola (2n = 36), A. annua (2n = 18), A. carvifolia (2n = 18), A. fukudo (2n = 16), A. keiskeana (2n = 18), A. stolonifera (2n = 36), A. sylvatica(2n = 16), A. selengensis (2n = 36), A. montana (2n = 52), A. lancea (2n = 16), A. sieversiana (2n = 18); however, the chromosome numbers of 6 taxa were different; A. japonica var. japonica (2n = 18, 36 vs 2n = 36), A. sacrorum (2n = 18, 54 vs 2n = 54), A. rubripes (2n = 16, 34 vs 2n = 16), A. indica (2n = 34, 36 vs 2n = 34), A. codonocephala (2n = 18, 50, 54 vs 2n = 50), A. argyi (2n = 34, 36, 50 vs 2n =34). The somatic chromosome numbers of Korean Artemisia are thought to be good characteristics for classifying some taxa such as A. japonica var. japonica, A. sacrorum, A. codonocephala, A. argyi, A. montana, A. sylvatica.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.77-81
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• 1995

When cultured on MS medium supplemented with 0.5 mg/L NAA alone or 1.0 mg/L 2,4-D and 0.5 mg/L BA, immature zygotic embryos of Stewartia koreana formed embryogenic calli and somatic embryos. In investigate effect of sucrose concentration on somatic embryo development, embryogenic calli were transferred to MS basal medium containing 1.5,3, 6 or 9% sucrose. The greatest frequency of somatic embryos was obtained on medium containing 6% sucrose. However addition of 1.5 or 9% sucrose to medium inhibited somatic embryo germination and development into normal plantlet After 5 weeks of hardening culture on medium containing 6% sucrose, somatic embryos were transferred to half strangth MS medium supplemented with 0.1% charcol, wherein these embryo developed into the normal plantlets.

• Journal of Animal Science and Technology
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• v.48 no.1
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• pp.9-14
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• 2006

Milk yield and its quality traits determine the dairy enterprise profitability and sustainability. Milk quality traits including somatic cell counts (SCC) is an upcoming economic challenge for dairy farming community in Korea. This study estimated the effect of parity, stage of lactation (early, mid and late lactation) on SCC, stress (blood cortisol) and immunity (blood IgG, lymphocyte and neutrophil) traits, their heritabilities and genetic correlations between them. SCS and blood neutrophil count were significantly affected by both parity and stage of lactation, however; IgG was affected by only stage of lactation, and blood cortisol and lymphocyte were not affected by both factors. The SCS has shown increasing trend with the parity, however; the difference between first and second parity, second and third parity were not significant. The SCS in early (≤90 days) and late lactation (181≤days) were higher than that of mid lactation (91～180 days). Cortisol concentration in blood was lowest in fourth parity, however; the differences among the first three parties were not significant. The IgG was higher in fourth parity compare with first parity however; all other comparisons were noted non-significant. The IgG concentration was significantly higher in early lactation than those of mid and late lactation. The blood lymphocytes were decreased with increasing parity however the differences beyond second parity were not significant. The neutrophils were increased with the increasing lactation stage however; the difference between early and mid lactation was not significant. Although heritability of SCS was still lower, but it was meaningful value (0.09) and may be considered to improve milk quality. The genetic correlations between SCS and cortisol (-0.96), and lymphocyte (-0.76) were highly negative. Heritability of cortisol was low, however genetic correlations between cortisol and lymphocyte (0.79) was highly positive. IgG with medium heritability was correlated negatively with lymphocyte (-0.88) and neutrophil (-0.98). Lymphocyte was lowly heritable and highly correlated with neutrophil concentration (0.87).This study suggested that cortisol, IgG, lymphocyte and neutrophil being positively genetically correlation with somatic cell score could be used as alternative traits to enhance milk quality in Holstein cattle. Further studies are warranted to estimate genetic relationships between immunological and production traits to increase the genetic merit of Holstein cows for milk yield, to improve animal health and economic viability under intensive management system.

• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.25-29
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• 2007

Plant regeneration system from zygotic embryos (2n=24) of Lilium lancifolium Thunb. via bulblet formation was estabished. Zygotic embryos of Lilium lancifolium formed bulblets and somatic embryos simultaneously when they cultured on MS medium supplemented with low concentration of 2,4-D. The highest frequency of bulblet and somatic embryo formation from zygotic embryos of Lilium lancifolium was 66.7% and 56.7%, respectively. The frequency of bulblet and somatic embryo formation was decreased when they cultured on MS medium over than 1 mg/L of 2,4-D. To regenerate whole plants, somatic embryos formed on zygotic embryos were transferred to MS basal medium. However somatic embryos did not fully converted into plantlets. Further incubation in the light, elongated somatic embryos formed numerous bulblets at the base of somatic embryos. Upon transfer to MS basal medium, bulblets were successfully converted into plantlets after further 4 weeks of culture in the light. After acclimatization, plantets from bulblets were transferred to soil and grown to normal plants in growth chamber (approximately $30\;{\mu}mol\;m^{-2}s^{-1}$, 16/8h photo period, $25^{\circ}C$) The chromosome analysis revealed that plants regenerated from zygotic embryos showed 2n=24. These results indicate that chromosome stability of source tissue is maintained during plant regeneration via bulblet formation.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.229-235
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• 2007

Artificial seeds were produced by encapsulation of somatic embryos of Kalopanax septemlobus and investigated the effects of alginic acid concentration, size of somatic embryos, additives in capsules and nursery seedbeds for germination. The most suitable concentration of alginic acid was 3% for germination of encapsulated seeds. Germination was suppressed at higher concentration more than 3% alginic acid. For germination of artificial seeds, 1/2 MS medium with 0.02% activated charcoal was effective. There was no significant differences on the germination among the different size of somatic embryos. Additives in hydrated capsule was very important for germination and post-germinative growth of artificial seeds. Germination was severly inhibited in hydrated capsule containing only distilled water. Both sucrose and MS medium addition in hydrate capsule was effective for germination of artificial seeds. When artificial seeds were transferred to soilbed, germination rate was high in perlite containing 3% sucrose but very low in perlite with only water. These results indicate that nursery additives in both hydrate capsules and soilbeds was important for germination of artificial seeds in Kalopanax septemlobus.

• Reproductive and Developmental Biology
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• v.39 no.3
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• pp.59-67
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• 2015

Galactose-${\alpha}1,3$-galactose (${\alpha}1,3$-Gal) epitope is synthesized at a high concentration on the surface of pig cells by ${\alpha}1,3$-galactosyltransferase gene (GGTA1). The ${\alpha}1,3$-Gal is responsible for hyperacute rejection in pig-to-human xenotransplantation. The generation of transgenic pigs as organ donors for humans is necessary to eliminate the GGTA1 gene that synthesize $Gal{\alpha}$(1,3)Gal. To prevent hyperacute graft rejection in pig-to-human xenotransplantation, previously, we developed ${\alpha}1,3$-galactosyltransferase gene-knock-out somatic cell by homologous recombination. In this study, we established cell lines of ${\alpha}1,3$-GT knock-out expressing hDAF and hHT gene from minipig fibroblasts to apply somatic cell nuclear transfer. The hDAF and hHT mRNA were expressed in the knock-in somatic cells and ${\alpha}1,3$-GT mRNA was suppressed. However, the knock-in somatic cells were increased resistance to human serum-mediated cytolysis.

• Reproductive and Developmental Biology
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• v.28 no.1
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• pp.1-6
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• 2004

This study was conducted to investigate the effects of donor cell type, individual, passage number and trypsinization time on the in vitro development of bovine somatic cell nuclear transfer embryos. Three cell types (skin, muscle and cumulus cells) and cells from 3 individuals were used for nuclear transfer. Cell were passaged by 5, 15 or 30 times, and cell were trypsinized for 1 or 3 min before injection. Nuclear transfer were performed by conventional fusion method. Development rates to the blastocyst stage were not significantly different among three cell types (16.5∼23.9%) and individuals (16.4∼19.5%). Blastocyst formation rate of cloned embryos reconstituted with cells at passage 30 (5.8%) was significantly lower than those of embryos reconstituted with 5- and 15-passaged cells (25.3 and 23.5%, respectively, P＜0.05). The rate of embryos developed to the blastocyst stage was higher in embryos reconstituted with cells trypsinized for 1 min (30.7%) compared to embryos reconstituted with cells trypsinized for 3 min (P＜0.05). The result of the present study indicates that different donor cell types and individuals used in this study did not affect the development of cloned bovine embryos. However, passage number and trypsinization time of donor cells affect the in vitro development of cloned bovine embryos.

• The Zoological Society Korea : Newsletter
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• v.18 no.1
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• pp.10-15
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• 2001

사람의 체세포가 분열수명에 한계가 있다는 것은 1960년대 초기에 보고되었으며 이것은 artifact가 아니며 세포자신이 가지는 프로그램에 의한 것임이 보고된 것은 최근의 일이다. 그러나 이 프로그램 안에 체세포가 실지로 증식을 정지하는 시기, 모든 세포노화의 타이밍이 어떻게 설정되는가\ulcorner 에 대해서는 아직 알 수 없다. 한편 노화세포가 왜 증식할 수 없는가\ulcorner 에 대해서는 세포주기를 조절하는 유전자에 관한 최근의 연구에 의해 상당부분 밝혀졌다. 또한 분열회수를 인식하는 분열시계의 진행은 세포증식을 억제하는 유전자의 발현을 촉진하여 증식을 정지시킨다. 분열시계를 정지시킨 세포는 기본적으로 무한히 분열하는 것이 가능하다. 분열시계를 정지시키는 주역은 telomerase이다. 정상 세포에서는 생식소(生殖巢)에 존재한다. 대부분의 정상체세포, 세포조직에는 없으나 대부분의 암에서 존재한다. 본 논단에서는 전반부에 노화를 후반부에 암에 관해서 분자세포생물학 차원에서 최근 연구성과를 중심으로 살펴보고자 한다.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.70-70
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• 2002

형질전환 가축을 생산하기 위하여 최근 체세포 복제 기법을 이용하고 있다. 이러한 체세포를 이용한 형질전환 동물의 생산에는 체세포내에 유전자의 도입 효율이 직접적인 영향을 주게 된다. 따라서 본 연구는 세포내 유전자의 transfection 효율을 높이고자 한우의 체세포를 이용하여 여러 가지 조건에서 유전자 도입을 실시하였다. 세포내 유전자 도입 방법은 electroporation (EP) 방법을 이용하였다. 사용한 세포는 소의 귀세포(KbESF), 태아섬유아세포 (KbFF), 그리고 대조구로서 CHO cell을 이용하여 GFP 유전자를 도입하였다. EP는 0.4 cm cuvette을 사용하였고, voltage는 0.25 kV, 그리고 field strength 는 0.625 kV/cm 조건으로 실시하였으며, pulse times은 각각 1, 2, 또는 3회를 사용하였다. KbFF와 KbESF에서는 각각 pulse times을 증가시킬수록 유전자도입 세포수가 증가하였으나 (KbFF: 81, 634, 1,065 cells/$10^{6}$ cells, KbESF: 1,011, 5,567, 15,408 cells/$10^{6}$ cells), CHO cell에서는 pulse times을 증가시킬 수록 오히려 유전자도입 세포수가 감소하였다 (CHO: 1,591, 687, 297 cells/$10^{6}$ cells). 그리고 2주 동안 neo selection을 실시 한 결과 KbFF, KbESF, CHO에서 각각 93, 35, 184 colony가 선발되었으며, 이 중 65.6%, 8.6%, 4.3% 가 GFP 형광 발현 colony로 나타났다. 한편 CHO cell에서 transfection cell수가 감소된 것은 EP의 자극으로 인해 손상된 세포가 많이 발생한 것으로 나타났다. 또한 neo selection에서 선발된 colony중 GFP가 발현되지 않거나 일부만 발현되는 colony들이 많이 발생하였는데, 이것은 세포내 유전자가 transfection되지 않은 세포도 neo selection에서 선발된다는 것을 제시하고 있다. 따라서 체세포를 이용한 형질전환동물 생산을 위해서는 세포내 유전자 도입과 선발 과정에서 나타난 colony에 대하여 보다 엄격한 screen을 하는 것이 필요한 것으로 생각된다.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.167-171
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• 1994

This study was carried out to investigate the possibility of plant regeneration through somatic embryogenesis in suspension culture of Aralia elata S. Callus was induced from the explants of leaf and petiole cultured in the MS media containing 2,4-D and TDZ. More embryogenic calli were formed from petiole and with combination treatment of 24-D and TDZ. The quarter strength MS medium was effective for increasing number of somatic embryos. Mannitol supplemented to the quarter strength MS medium, reduced somatic embryo formation but inositol increased. Normal plantlets(86%) were regenerated from mature somatic embryos in MS basal medium and 50% of those survied when transplanted to the vermiculite in greenhouse.