• 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.

• Korean Journal of Medicinal Crop Science
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• v.14 no.6
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• pp.354-359
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• 2006

Chromosome analysis using mitosis, meiosis and bicolor FISH were carried out in Bupleurum latissimum Nakai, which is one of the endemic plants in Ulleung island of korea. The somatic methaphase chromosomes number of this plant was 2n = 2x = 16 and the chromosome complements consisted of six pairs of metacentrics and two pairs of submetacentrics. The size of chromosomes ranged 2.40${\sim}$4.20 ${\mu}$m and NOR (nucleolus organizer region) chromosome did not observed using conventional staining. In meiosis chromosomes, metaphase-I and anaphase-I were observed. Metaphase-I anaphase-I showed 8 bivalents and chromosomes migration to make two daughter cells. Using bicolor FISH, one pair of 5S and 45S rDNA signals were detected on the centromeric region of chromosome 3 and the end of short of chromosome 2,respectively. We also observed the NOR using 45S rDNA probe.

• Korean Journal of Plant Taxonomy
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• v.35 no.2
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• pp.143-151
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• 2005

Cytological characteristics of Abeliophyllum distichum (Oleaceae), endemic to Korea, was examined. Somatic chromosome numbers was 2n = 28 which corresponds to diploid based on x=14. Chromosome length was varied continuously from $1.00{\mu}m$ to $2.03{\mu}m$. Karyotype of Abeliophyllum distichum was investigated in this study for the first time. The cytological characteristics including basic chromosome number, continuous variation of chromosome length, diploid and karyotype were similar to those of the genus Forsythia, which indicated the close relationship between Abeliophyllum and Forsythia, and consequently the two genera seemed to be included to same tribe.

• Korean Journal of Medicinal Crop Science
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• v.16 no.3
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• pp.161-167
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• 2008

New somatic chromosome numbers and karyotype analyses of 33 medicinal herbs (30 genera, 23 families) in Korea were investigated. The chromosome numbers of 4 taxa, Euryale ferox, Rodgersia podophylla, Cirsium japonicum var. ussurience, Eehinops setifer, showed results that are different from previous reports. Among 33 taxa, 23 taxa were reported for the first time, and karyotype analyses were newly conducted for 2 taxa (Tiarella polyphylla, Crepidiastrum denticulatum) in Korea. In addition, we observed for the first time the new chromosome numbers for 4 taxa distributed evenly over the world (Lindera erythrocarpa, Corylopsis glabrescens var. gotoana, Ardisia crenata, Callicarpa japonica var. luxurians).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.429-433
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• 1996

A Giemsa C-banding method was used for the identification of somatic chromosomes of Korean indigenous maize(Zea mays L.). Two Korean indigenous maize stocks and an American hybrid maize for comparison were examined. Ten deeply stained heterochromatic knobs whose position and size were different between the genotypes, two satellites and interstitial bands were observed. The length of homologous chromosomes compared by the relative lengths of chromosomes presented as a percentage of the length of chromosome 10 were different between the genotypes. The Giemsa method proved to be useful for the identification of somatic chromosomes and for the characterization of different stocks of Korean indigenous maize.

• Korean Journal of Plant Taxonomy
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• v.39 no.3
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• pp.170-180
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• 2009

Somatic chromosome counts and karyotype analyses were carried out for eight taxa of Korean Allium sect. Sacculiferum. The basic chromosome number of sect. Sacculiferum was x = 8, and they could be cytologically divided into two groups, that is, a diploid group (2n = 2x = 16) containing A. thunbergii var. thunbergii, A. thunbergii var. deltoides, A. thunbergii var. teretifistulosum, A. deltoidefistulosum, A. longistylum, A. linearifolium and A. taqueti, and a tetraploid group (2n = 4x = 32) with only A. sacculiferum. All observed chromosomes were classified into metacentric, submetacentric and subtelocentric. The metacentric ones appeared in all treated taxa. One or two pairs of submetacentric chromosomes were observed in most taxa except A. sacculiferum, the unique taxon with subtelocentric chromosomes. All taxa had a pair of homologous chromosomes with satellites, and the B-chromosomes found in A. thunbergii var. thunbergii, A. deltoidefistulosum, A. sacculiferum and A. longistylum, were metacentric or telocentric. The karyotypes of A. longistylum and A. linearifolium were firstly investigated in this study. In conclusion, the somatic chromosome numbers and karyotypes for members of the sect. Sacculiferum were valuable characters in identifying taxa, investigating interspecific relationships and delimiting taxa. In addition, A. thunbergii var. teretifolium, an invalid name (homonym), was renamed as A. thunbergii var. teretifistulosum H. J. Choi & B. U. Oh.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.235-243
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• 2002

This study was designed to examine the ability of the bovine (MII) oocytes cytoplasm to support several mitotic cell cycles under the direction of differentiated somatic cell nuclei of bovine, porcine, mouse and human. Bovine GV oocytes were matured in TCM-199 supplemented with 10% FBS. At 20h after IVM, recipient oocytes were stained with 5 $\mu\textrm{g}$/$m\ell$ Hoechst and their 1st polar body (PB) and MII plate were removed by enucleation micropipette under UV filter. Ear skin samples were obtained by biopsy from an adult bovine, porcine, mouse and human and cultured in 10% FBS added DMEM. Individual fibroblast was anlaysed chromosome number to confirm the specificity of species. Nuclear transferred (NT) units were produced by electrofusion of enucleated bovine oocytes with individual fibroblast. The reconstructed embryos were activated in 5 $\mu$M ionomycin for 5 min followed by 1.9 mM 6-dimethylaminopurine (DMAP) in CR1aa for 3 h. And cleaved NT embryos were cultured in CR1aa medium containing 10% FBS on monolayer of bovine cumulus cell for 8 days. Also NT embryo of 4~8 cell stage was analysed chromosome number to confirm the origin of nuclear transferred somatic cell. The rates of fusion between bovine recipient oocytes and bovine, porcine, mouse and human somatic cells were 70.2%, 70.2%, 72.4% and 63.0%, respectively. Also, their cleavage rates were 60.6%, 63.7%, 54.1% and 62.7%, respectively, there were no differences among them. in vitro development rates into morula and blastocyst were 17.5% and 4.3% in NT embryos from bovine and human fibroblasts, respectively. But NT embryos from porcine and mouse fibroblasts were blocked at 16~32-cell stage. The chromosome number in NT embryos from individual fibroblast was the same as chromosome number of individual species. These results show that bovine MII oocytes cytoplasm has the ability to support several mitotic cell cycles directed by newly introduced nuclear DNA.

• Reproductive and Developmental Biology
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• v.35 no.1
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• pp.105-113
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• 2011

The present study investigated the nuclear remodeling, development potential with telomerase activity and transcription level of X-linked genes (ANT3, HPRT, MeCP2, RPS4X, XIAP, XIST and ZFX) in the bovine somatic cell nuclear transfer (SCNT) embryos using two different fusion and activation methods. Female adult fibroblasts were injected into perivitelline space of in vitro matured oocytes. The oocyte-nucleus complexes were fused and followed by immediately either activated (Group 1), or activated at 1 h post-fusion (hpf) (Group 2), respectively. The incidence of normal premature chromosome condensation (PCC) at 1 hpf was slightly increased in the Group 2, compared to those of Group 1, but there was no significant (p<0.05) difference. The incidence of normal pronucleus (PN) and chromosome spread at 5 and 18 hpf were significantly (p<0.05) higher in the Group 2 than those of Group 1. The cleavage rate to 2-cell stage, developmental rate to blastocyst stage, and the mean number of total and ICM cell numbers were significantly (p<0.05) higher in the Group 2, compared to those of Group 1. Level of telomerase activity was significantly (p<0.05) higher in the SCNT blastocysts of Group 2, compared to those of Group 1. Transcript levels of HPRT, MeCP2 and XIST were not significantly (p<0.05) different between blastocysts of Group 1 and 2. However, transcript level of ANT3, RPS4X, XIAP and ZFX were significantly (p<0.05) up-regulated in the SCNT blastocysts of Group 2, compared to those of Group 1. Taken together, it is concluded that oocyte activation at 1 hpf induces the enhanced developmental potential by efficient nuclear remodeling and subsequent facilitation of the nuclear reprogramming of bovine SCNT embryos.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.106-111
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• 2005

For breeding of a new rootstock for eggplant production, somatic hybrids between two species, Solanum integrifolium and S. sanitwongsei were obtained through protoplast fusion. The former species has been commonly used for rootstock for eggplant production in Japan. Eggplants on these rootstocks are more productive than ungrafted plants, but are susceptible to bacterial wilt caused Ralstonia solanacearum. While the latter species is resistant, the growth of eggplants on this rootstock is rather slow and low yield. Protoplast of both species were isolated from cotyledons, and inactivated with iodoacetamide or UV-irradiation, then fused electrically. The fused products were then cultured. Regenerated plantlets were then transplanted on soil then maintained in a green house. The plants were classified into four groups. Those in the first group showed morphological characters intermediate of the parentalspecies. The plants bore fruit with viable seeds. The plants showed a chromosome number of 2n=48, the sum of those of the parental species, and are suggested to be symmetric fusion products. While plants in the other groupswas less vigorous and showed chromosome number 2n= 68 to 72 suggesting asymmetric fusion products by genomic in situ hybridization(GISH). Isozyme pattern of shikimate dehydrogenase (SKDH; EC 1.1.1.25), isocitrate dehydrogenase (IDH; EC 1.1.1.41) and phosphoglucomutase (PGM; EC 2.7.5.1) showed that 24 regenerated plants in three groups were somatic hybrids. Analysis of random amplified polymorphic DNA (RAPD) showed that 43 S. integrifolium-specific and 57 S. sanitwongsei-specific bands were all found in 24 plants. Both somatic hybrids and its S1 plants were found to be resistant to bacterial wilt, and eggplant grafted these plants using for rootstocks were more productive than grafted mother plants. Now, S1 progenies are used for commercial eggplant production in Osaka Prefecture.

• Korean Journal of Animal Reproduction
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• v.27 no.1
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• pp.53-59
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• 2003

For somatic cell nuclear transfer in Hanwoo, fetal fibroblast cell lines were established from 35, 50, 70 and 90-day fetuses of Korean native cattle. The sex of these fetal fibroblast cells were analyzed by PCR using Y-specific primers and confirmed that two cell lines were female and the other two cell lines were male. Karyotyping of these cell lines indicates that the chromosome numbers of fetal fibroblast cells were not affected by passage number and more than 80% of fetal fibroblast cells have normal chromosome number. To evaluate Go stage in cell cycle of fetal fibroblast cells, Western blotting was performed to detect the expression level of PCNA which is known to be expressed in all cell cycle stages except G$_{0}$ stage. Following serum starvation or confluent culture for 7 days, fetal fibroblast cells were effectively reached to G$_{0}$ stage. The cell cycle was resumed after culture of these Go stage-fetal fibroblast cells with normal medium. These results indicates that fetal fibroblast cells originated from Hanwoo were successfully isolated and culture system and induction of cell cycle of these cells were established for somatic cell nuclear transfer in Hanwoo.woo.