• Genomics & Informatics
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• v.5 no.1
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• pp.32-35
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• 2007

Telomerase reverse transcriptase (TERT) is an enzymatic ribonucleoprotein that prolongs the replicative life span of cells by maintaining protective structures at the ends of eukaryotic chromosomes. Telomerase activity is highly up-regulated in 85-90% of human cancers, and is predominately regulated by hTERT expression. In contrast, most normal somatic tissues in humans express low or undetectable levels of telomerase activity. This expression profile identifies TERT as a potential anticancer target. By using an RNA mapping strategy based on a trans-splicing ribozyme library, we identified the regions of mouse TERT (mTERT) RNA that were accessible to ribozymes. We found that particularly accessible sites were present downstream of the AUG start codon. This mTERTspecific ribozyme will be useful for validation of the RNA replacement as cancer gene therapy approach in mouse model with syngeneic tumors.

• Korean Journal of Plant Taxonomy
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• v.47 no.4
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• pp.304-307
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• 2017

We report somatic chromosome numbers for three species belonging to the Euphorbia pekinensis complex distributed in Far East Asia. In E. pekinensis populations distributed in Korea, 2n = 28 and 56 were found, while the Japanese native E. lasiocaula was also found at 2n = 28 and 56 and the Japanese endemic E. sinanensis was found at 2n = 20. Based on the number of chromosomes, E. lasiocaula distributed in Japan supports treatment as a variety of E. pekinensis rather than as a different species, while E. sinanensis should be recognized as a distinct species rather than as a variety of E. pekinensis. In the same populations of E. pekinensis and E. lasiocaula, diploid and tetraploid individuals were found, and the diversity of these chromosome numbers was consistent with the morphological diversity of these populations, suggesting the future evolutionary potential of this species.

• Journal of Sericultural and Entomological Science
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• v.44 no.2
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• pp.56-58
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• 2002

An autotetraploid, Sawonppong 28 was derived from a thick-leaf and highly productive mulberry variety, Huyeoprok, by colchicine solution treatment on growing point and its characteristics were as follows. The number of somatic chromosomes of the derived variety was 2n=56 of an autotetraploid and green tip sprouting stage was medium budding variety with triangular oval shape and thick leaves contained rich chlorophyll. The length of branches was comparatively short and the number of branches was also small. However the branches were thick and non-budding length percentage at basal part of branch was high and cold hardiness was weak.

• Korean Journal of Plant Taxonomy
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• v.52 no.4
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• pp.214-218
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• 2022

Eleocharis R. Br. (Cyperaceae) is characterized by unbranched culms, one terminal spikelet, bisexual flowers, and bristly perianths, occurring mainly in circumboreal marshes and wetlands. There are about 250 species worldwide, and 15 taxa in Korea have been recognized. Chromosomes in Cyperaceae are known to be holocentric, missing constricted centromeres during cell division. For the first time, we report the chromosome counts of Eleocharis from Korean populations of E. attenuata f. laeviseta (Nakai) H. Hara (2n = 20); E. parvula (Roem. & Schult.) Link ex Bluff, Nees & Schauer (2n = 10); E. ussuriensis Zinserl. (2n = 16); and E. valleculosa var. setosa Ohwi (2n = 16). The populations exhibit variations in their chromosome sizes from ca.1.7 ㎛ to ca. 6 ㎛, categorized as gradient and bimodal karyotypes. The karyotypes observed are congruent with previous phylogenetic groups proposed. To clarify the traditional and phylogenetic classification of Korean Eleocharis, further taxonomic and chromosomal investigations with additional taxon sampling efforts are required.

• Korean Journal of Plant Resources
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• v.20 no.5
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• pp.446-450
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• 2007

Tiarella polyphylla D. Don(Saxifragaceae) is a perennial herb and distributed in China, Japan, Taiwan and Korea. Especially, it only grows in Ulleung island of Korea. It has been using for asthma, bruise and audition troubles with main components of some Triterpenoids and seven oleanolic Saponins. There is only known its chromosomal number rarely and cytogenetic study was not done. From this study, karyotype analysis and chromosomal localization of 5S and 45S rDNAs using bicolor-FISH(fluorescence in situ hybridization) were carried out. The somatic metaphase chromosome number was 2n=2x=14 and the size of chromosomes ranged $1.66{\sim}3.50{\mu}m$. The chromosome complement consisted of four pairs of submetacentrics(chromosomes 1, 2, 3 and 6), two pairs of subtelocentrics(chromosomes 5 and 7) and one pair of telocentrics(chromosome 4). We also observed NOR(nucleolus organizer region) on the chromosome 4. In bicolor-FISH, one pair of 55 and 45S rDNA sites was detected on the centromeric region of chromosome 3 and short arm of chromosome 4, respectively. Bicolor FISH was very useful tool for the localization and identification of rDNAs on the chromosomes in Tiarella polyphylla.

• Korean Journal of Plant Taxonomy
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• v.43 no.2
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• pp.139-145
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• 2013

This study was carried out to determine the karyotype and chromosomal localizations of 45S and 5S rDNAs using FISH in Astragalus koraiensis. The somatic metaphase chromosome number of this species was 2n = 16 with basic chromosome number of x = 8. The karyotype of A. koraiensis was consisted of six pairs of median region chromosomes(chromosome 1, 3, 4, 5, 6, 8) and two pairs of submedian chromosomes(chromosome 2, 7). Based on the FISH, one pair of 45S rDNA site was detected on the centromeric region of chromosome 5. Whereas, two pair of 5S sites were detected on the short arm of chromosome 4 and centromeric region of chromosome 7, respectively. These are quite different patterns from A. membranaceus, A. membranaceus var. alpinus, and A. mongholicus. Although A. koraiensis is considered as Korean endemic species, therefore, it should be conducted out comparative FISH study with A. sikokianus and A. bhotanensis which are very similar to A. koraiensis morphologically.

• Korean Journal of Plant Taxonomy
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• v.39 no.3
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• pp.220-228
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• 2009

C-banded karyotypes of eight taxa of Korean Allium sect. Sacculiferum were examined by means of Giemsa techniques. Each of the taxa had their own characteristic bands. Most of the bands on the somatic metaphase chromosomes were mainly located on the short arm, intercalary region and medium sized chromosomes. In addition, the heterochromatic bands were usually facultative, recognized as two spots, and all investigated taxa had a pair of satellites of heterochromatin. The similarities of total length and number of bands revealed that three varieties of A. thunbergii G. Don have a closer cytological relationship than the others. The C-banding patterns of A. longistylum and A. linearifolium were examined for the first time in this study, and the former was clearly distinguished from the others by the distribution and number of its bands. The proportion of heterochromatic bands suggested that A. thunbergii var. thunbergii is the most primitive, and A. sacculiferum the most advonced, within the section.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.402-407
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• 2003

Karyotype analysis and chromosomal localization of 5S and 45S rDNAs using multi-color fluorescence in situ hybridization (McFISH) technique were carried out in Bupleurum longeradiatum. Somatic metaphase chromosome number was 2n=12. Karyotype was composed of three pairs of metacentrics (No.3, 4 and 6) and three pairs of submetacentrics (No. 1, 2 and 5). The length of somatic prometaphase chromosomes ranges from 2.55 to $5.05{\mu}m$ with total length of $18.15\;{\mu}m$. In FISH experiment, one pair of 5S rDNA signals was detected on the pericentromeric region of chromosome 4 and one pair of 45S rDNA signals was detected on the telomeric region of chromosome 2.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.73-73
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• 2002

Nuclear transfer (NT) techniques have advanced in the last years, and cloned animals have been produced by using somatic cells in several species including pig. However, it is difficult that the nuclear transfer porcine embryos development to blastocyst stage overcoming the cell block in vitro. Abnormal segregation of chromosomes in nuclear transferred embryos on genome activation stage bring about embryo degeneration, abnormal blastocyst, delayed and low embryo development. Thus, we are evaluated that the correlations of the frequency of embryo developmental rates and chromosome aberration in NT and In viかo fertilization (IVF) derived embryo. We are used for ear-skin-fibroblast cell in NT. If only karyotyping of embryonic cells are chromosomally abnormal, they may difficultly remain undetected. Then, we evaluate the chromosome aberrations, fluorescent in situ hybridization (FISH) with porcine chromosome 1 submetacentric specific DNA probe were excuted. In normal diploid cell nucleus, two hybridization signal was detected. In contrast, abnormal cell figured one or three over signals. The developmental rates of NT and IVF embryos were 55% vs 63%, 32% vs 33% and 13% vs 17% in 2 cell, 8 cell and blastocyst, respectively. When looking at the types of chromosome aberration, the detection of aneuploidy at Day 3 on the embryo culture. The percentage of chromosome aneuploidy of NT and IVF at 4-cell stage 40.0%, 31.3%, respectively. This result indicate that chromosomal abnormalities are associated with low developmental rate in porcine NT embryo. It is also suggest that abnormal porcine embryos produced by NT associated with lower implantation rate, increase abortion rate and production of abnormal fetuses.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.83-92
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• 2015

xBrassicoraphanus line BB#5, a new synthetic intergeneric hybrid between Brassica rapa L. ssp. pekinensis and Raphanus sativus L. var. rafiphera induced by N-methyl-N-nitroso-urethane mutagenesis in microspore culture, shows high seed fertility and morphological uniformity. Dual-color fluorescence in situ hybridization (FISH) using 5S and 45S rDNA probes and genomic in situ hybridization (GISH) using B. rapa genomic DNA probe were carried out to analyze the chromosome composition and the meiosis pairing pattern compared to its parental lines. The somatic chromosome complement is 2n = 38, which consists of 17 metacentric and two submetacentric chromosomes with lengths of 2.18 to $5.01{\mu}m$. FISH karyotype analysis showed five and eight pairs of 5S and 45S rDNA loci. GISH meiosis pairing analysis showed that 19 complete bivalents were most frequent and accounted for 42% of the 100 pollen mother cells examined. Based on chromosome number, size, morphology, rDNA distribution, and meiosis pairing pattern, both parental genomes of B. rapa and R. sativus appear to exist in xBrassicoraphanus line BB#5, demonstrating its genome integrity. Such stable chromosome constitutions and meiotic pairing patterns in somatic and meiotic cells are very rare in natural and synthetic intergeneric hybrids. Chromosomal studies and genetic and phenotypic changes in allopolyploids a re discussed. The results p resented h erein will b e usef ul f or f urther g enomic s tudy o f xBrassicoraphanus lines and their improvement as promising new breeding varieties.