• 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 Microbiology
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• v.26 no.4
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• pp.318-323
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• 1988

MAK18 gene of Saccharomyces cerevisiae, needed for M1 replication, was mapped within 2cM of PET3 on chromosome VIII. From 38kb clone pRE66 carrying SPO11 and PET3, we have localized MAK18 gene whose insert is 2.8kb. MAK18 gene is Iocalized on about 9kb distance from PET3 and about 18kb distance from SPO11 on chromosome VIII.

• Microbiology and Biotechnology Letters
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• v.50 no.3
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• pp.436-440
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• 2022

In this study, yeast artificial chromosome Insert (YAC) harboring genes which related xylan metabolism was constructed by using chromosome manipulation technique. For efficient chromosome manipulation, each splitting fragment (DNA module) required for splitting process was prepared and these DNA modules were transformed into Saccharomyces cerevisiae strain YKY164. By two-rounds chromosome splitting, yeast chromosome VII (1,124 kb) was split 887 kb-YAC, 45 kb-mini YAC and 198 kb-YAC and YKY183 strain containing 18 chromosomes was constructed. Splitting efficiency for chromosome manipulation was 50- 78% and expression level of foreign genes on 45 kb-mini YAC and enzyme activity were indistinguishable from that of the YKY164 strain. Furthermore, xylan-degraded products by recombinant enzymes were confirmed and mini-yeast artificial chromosome maintained stable mitotic stability without chromosome loss during 160 generations.

• Journal of Life Science
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• v.26 no.6
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• pp.646-650
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• 2016

The influence of chromosome number on cell growth and cell aging was investigated in various yeast strains that have many artificial chromosomes constructed using a chromosome manipulation technique. Host strain FY833 and the YKY18, YKY18R, YKY24, and YKY30 strains harboring 16 natural chromosomes, 18 chromosomes, 18 chromosomes containing rDNA chromosome, 24 chromosomes, and 30 chromosomes, respectively, were used, and the specific growth rate of each strain was compared. The specific growth rates in the YKY18 and YKY24 strains were indistinguishable from that in the host strain, while those of the YKY18R and YKY30 strains were reduced to approximately 25% and 40% of the host strain level, respectively. Subsequently, the replicative life span was examined to investigate the relationship between the number of chromosomes and cell aging, and the life span was decreased to approximately 14% and 45% of the host strain level in the YKY24 and YKY30 strains, respectively. Moreover, telomere length, well known as a senescence factor, was shorter and more diversified in the strain, showing decreased life span. Therefore, these results suggest the possibility that an increase in the number of chromosomes containing artificial chromosomes caused cell aging, and we expected these observations would be applied to improve industrial strain harboring of versatile and special artificial chromosomes.

• Clinical and Experimental Pediatrics
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• v.48 no.1
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• pp.108-111
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• 2005

Ring chromosome 20 mosaicism [r(20)] is a rare chromosomal anomaly associated with minor dysmorphism, mental retardation, autistic behavior, and intractable epilepsy. The proposed mechanism of ring formation is breakage of both short and long arms of a chromosome with subsequent end-to-end fusion. We encountered an 18-month-old boy who presented with developmental delay and mental retardation with seizure episodes, but showed normal brain magnetic resonance imaging. Chromosome study from peripheral blood showed 46,XY, r(20)(p13q13.3) karyotype. The authors report a case of ring chromosome 20 with mental retardation and epilepsy, with a review of the literature.

• The Korean Journal of Malacology
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• v.13 no.2
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• pp.125-130
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• 1997

The mitotic and meiotic chromosomes of Succineidae snail one species, Oxyloma hirasei(Pilsbry), were investigated by mians of air-drying mithod. The diploid chromosome numbers were n=18, 2n=36. Chromosome complements of this species consist of seven pairs of metacentrics and 11 pairs of submetacentric chromosomes. Spermatogonial metaphase chromosomes range in length from 4.80${\mu}{\textrm}{m}$ for the largest pair to 1.44${\mu}{\textrm}{m}$ for the smallest pair.

• Environmental Mutagens and Carcinogens
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• v.18 no.2
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• pp.109-115
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• 1998

Fluorscence in situ hybridization with chromosome-specific probe has been shown to be a valid and rapid method for detection of chromosome rearrangements induced by chemical and physical agents. This method is useful for quantifying structural aberrations, expecially for stable ones, such as translocation and insertion, which are difficult to detect with conventional method in human lymphocyte. In order to use the FISH method as a biodosimeter for monitoring human population exposed to various chemical and physical agent, baseline level of chromosome rearragement was established. Blood from forty four healthy adults were collected and analysed with whole chromosome-specific probes by human chromosome 1,2 and 4. The frequencies of stable translocation were 2.45 per 100 cell equivalent and those of insertion, color juction, acentric and dicentric were 0.32, 3.28, 0.23 and 0.27 per 100 cell equivalent respectively. The frequencies of chromosome rearragements increased with age in both sexes except for dicenrics. From above result, stable aberrations accumulate with age and it may reflect integrated lifetime exposure of adverse environment.

• Korean Journal of Medicinal Crop Science
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• v.18 no.3
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• pp.186-190
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• 2010

The chromosome number was identified and fluorescence in situ hybridization(FISH) mapping of 5S and 45S rDNAs were conducted for C. minima and C. lanceolata in the genus Codonopsis from Jeju island. In this study, we have confirmed that the somatic metaphase chromosome number determined as 2n=2x=16 was the same as the findings from the previous studies. While the conventional staining method makes it rather difficult to distinguish satellite chromosomes due to high degree of variability, FISH analysis produced the exact number and location of 5S and 45S rDNAs. Both species in the genus Codonopsis have a pair of 5S rDNA and their gene loci were observed on chromosome 3. Although two pairs of 45S rDNAs (one on chromosome 1 and the other on chromosome 8) were identified in both species, the 45S rDNA signals on chromosome 8 in C. minima were significantly weaker than those on chromosome 1. In addition, the 45S rDNA signals on chromosome 1 in C. lanceolata showed that the chromosome is non-homologus. In this study, we have determined cytogenetic characteristics of C. minima and C. lanceolata according to their gene replication patterns.

• Journal of Biomedical Engineering Research
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• v.18 no.3
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• pp.233-241
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• 1997

The research on chromosomes is very significant in cytogenetics since genes of the chromosomes control revelation of the inheritance plasma. The human chromosome analysis is widely used to study leukemia, malignancy, radiation hazard, and mutagen dosimetry as well as various congenital anomalies such as Down's, Klinefelter's, Edward's, and Patau's syndrome. The framing and analysis of the chromosome karyogram, which requires specific cytogenetic knowledge is most important in this field. Many researches on automated chromosome karyotype analysis methods have been carried out, some of which produced commercial systems. However, there still remains much room to improve the accuracy of chromosome classification and to reduce the processing time in real clinic environments. In this paper, we proposed a hierarchical artificial neural network(HANN) to classify the chromosome karyotype. We extracted three or four chromosome morphological feature parameters such as centromeric index, relative length ratio, relative area ratio, and chromosome length by preprocessing from ten human chromosome images. The feature parameters of five human chromosome images were used to learn HANN and the rest of them were used to classify the chromosome images. The experiment results show that the chromosome classification error is reduced much more than that of the other researchers using less feature parameters.

• Journal of Genetic Medicine
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• v.9 no.2
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• pp.101-103
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• 2012

Paracentric inversion of chromosome 18 is a rare cytogenetic abnormality. The vast majority of paracentric inversions are harmless and the offspring of paracentric inversion carriers have only slightly elevated risks for unbalanced karyotypes. However, various clinical phenotypes are seen due to breakpoint variation or recombination. We report a prenatally detected case of familial paracentric inversion of chromosome 18, inv(18)(q21.1q22), with normal clinical features.