• Reproductive and Developmental Biology
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• v.30 no.4
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• pp.263-270
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• 2006

The Chinese Hamster Ovarian cells CHO-K1 are one of the most extensively used cells for the evaluation of gene expression and toxicology. However, these cells are frequently used for biomedical research without consideration of their cytogenetic characteristics. Therefore, we carried out to investigate the karyologic profiles, the frequency and type of chromosome aberration, and the distribution of telomeric DNA on chromosomes of the CHO-K1 cells. The GTG banding and fluorescence in situ hybridization on CHO-K1 cells were performed to characterize the karyotype and the distribution of telomeric DNA The present study revealed that the chromosome modal number of CHO-K1 cells was 2n=20; eight chromosomes appeared to be identical with those of the normal Chinese hamster, whereas the remaining 12 chromosomes were shown to be translocated, deleted, inversed, or rearranged from Chinese hamster chromosomes. The telomeric DNA on CHO-K1 chromosomes was intensively distributed at the centromeres rather than the ends of chromosomes. In addition, three chromosomes had interstitial telomeres and one marker chromosome entirely consisted of telomeric DNAs. The frequency and type of chromosome aberrations in CHO-K1 cells were examined. Of the 822 metaphase spreads, 68 (8.3%) cells resulted in chromosome aberrations of which the chromosome breakage was the most frequently occurred.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.901-910
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• 2003

Using the G-, C-, and NOR-banding techniques, a karyotyping for Korean Native Pig was performed. Blood samples were collected from 50 male Korean Native Pigs that had been bred at the National Livestock Research Institute and then blood cells were prepared from in vitro cultures followed by karyotyping; G-, C-, and NOR-banding patterns of metaphase chromosomes were analyzed. The karyotype of Korean Native Pig is 38, XX or XY which consists of 5 pairs of submetacentric chromosomes(Group I), 2 pairs of acrocentric chromosomes with short p-arm(Group II), 5 pairs of medium metacentric chromosomes(Group III), 6 pairs of acrocentric chromosomes(Group IV) and metacentric X and Y sex chromosomes. On GTG-banding, the Korean Native Pig exhibited a typical and identical banding pattern in each homologous chromosomes. Overall chromosomal morphology and positions of typical landmarks of the Korean Native Pig were virtually identical to those of Committee for the Standardized Karyotype of the Domestic Pig(CSKDP). However, numbers of G-bands of the Korean Native Pig chromosomes were more than those of CSKDP. In chromosomes 1, 3, 5, 6, 7, 8, 13, 14, 15, 16, 17, 18 and X, the Korean Native Pig exhibited more separated bands as compared with CSKDP. In C-banding patterns, although the quantity of heterochromatin was variable in each chromosome, most of the Korean Native Pig chromosomes had heterochromatic C-bands on centromeres. However, the heterochromatic C-band was constantly observed on the whole Y chromosome. In AgNOR staining, the NORs were located at centromeres on the chromosomes 8 and 10. The number of NORs per metaphase ranged from 2 to 4 giving a mean value of 2.13. The number of NORs were distributed on all chromosome pair 10 but not on chromosome 8. The sizes of NORs were also differed between homologous chromosomes 8. Numbers of NORs of Korean Native Pig were significantly higher than those of Yorkshire. The pattern of pig NORs was polymorphic in breeds, individuals and cells, especially on chromosome 8.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.547-554
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• 2004

Telomeres are nucleoprotein structures at the ends of chromosomes consisting of tandem repeat sequences of . (TTAGGG)n. Telomeres serve as guardians of the genome, protect individual chromosomes within the nucleus, and help in meiotic pairing of homologous chromosomes. To investigate the telomere distributions of cattle and pig chromosomes, fluorescence in situ hybridization(FISH) was carried out on metaphase spreads of in vitro fibroblast cultures from Holstein and Landrace using a human telomeric DNA repeat probe. Results indicate that the distinct double spots on both ends of chromosomes of cattle and pigs were observed. In cattle, there was a random variation in the intensity of telomere signals among chromosomes. In pigs, an interstitial telomeric signal was observed on the chromosome 6q1 of all the cells examined. According to quantitative fluorescence in situ hybridization(Q-FISH) analysis, some chromosomes had consistently much more telorneres at one end of chromosomes. In general, both species had consistently much more telomeres at q-end than p-end on most of chromosomes. The relative amount of telomeres on bovine chromosomes was higher than that on pig chromosomes. In additions, Y chromosome had the highest relative amount of telorneres in cattle and pigs.

• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.82-83
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• 1987

The number of chromosomes of the wild mulberry silkworm, Bombyx mandarina, collected in Suwon area in the middle part of Korean peninsula was investigated. The chromosomes were examined after smearing and squashing the testis of the last instar larvae which were at spining stage and the microscopic observation showed that the number of chromosomes of the wild mulberry silkworm was 27.

• Journal of Plant Biology
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• v.39 no.3
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• pp.203-207
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• 1996

On the basis of karyotypic analysis performed by conventional staining and Giemas C-banding technique, cytological relationship was inferred for 21 lines of Paeonia lactiflora Pal. cultivated in Korea. It was very difficult to infer their organized karyotypic classification system using the composition of somatic chromosomes involving sat-chromosomes, relative length of chromosomes, arm ratio and karyotypic formulae by conventional staining. From the distribution and number of Giemsa C-bands on the chromosomes b and c, 21 lines can be subclassified into 5 groups. It seems that the karyotypic polymorphism is observed in 21 lines of cultivated P. lactiflora because peony mainly propagates by outbreeding.

• Journal of Plant Biology
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• v.39 no.3
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• pp.209-214
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• 1996

Cytological characters of ten taxa of the genus Lycoris were investigated to illustrate their chromosomal evolution. The fusion theory was more appropriate than the fission theory. From the viewpoint of the fusion theory L. sanguinea group, diploids with R-shaped chromosomes was the most primitive and they might have diverged into two directions, the diploids with V＋R shaped chromosomes and the triped with V＋R shaped chromosomes via triploids with only R-shaped chromosomes.

• Journal of Plant Biology
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• v.11 no.2
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• pp.31-35
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• 1968

Further study on the frequency and geographical distribution of rye with accessory chromosomes in Korea was carried out in 1996. All of the 15 populations of rye investigated were found to have accessory chromosomes and the frequencies of accessories were ranged from 15 to 54%. The study from 1963 to 1966 shows that the frequency of accessory ranging from 30 to 40% is predominant.

• Korean Journal of Plant Resources
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• v.5 no.1
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• pp.31-35
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• 1992

The somatic chromosome numbers were counted to be 2n = 16 of Codonopsis lanceolata. Chromosomes 2 and 7 of Sokrisan and Koheung II has a hetero satellite on short arm. Chromosome 5 of Bakwoonsan showed homo satllite on short arms. Short arms of chromosomes 1 and 5 has homo satellite and short arms of chromosomes 2 and 7 has hetero satellite of Jilin.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.1
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• pp.35-38
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• 1989

Giemsa C-banded mitotic chromosome prepatations from White Leghorn, New Hampshire and Rhode Island Red inbred lines were compared for frequency of C-band regions on individual chromosomes. Except for autosomes 3, 6, 8 and 9 and W sex chromosomes, C-banding was extremely variable in other macrochromosomes. No divergence for C-band difference between homologous chromosomes of these lines was detected. Approximately 75% of the mitotic metaphase microchromosomes have recognizable C-band regions with the current technique.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.59-63
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• 2007

The chromosome numbers and karyotype of Euphaedusa fusaniana, a kind of Korean land snail are investigated here. From E. fusaniana, chromosome numbers of 28 (n) and 56 (2n) were counted. Euphaedusa fusaniana has 15 pairs of metacentric chromosomes and 13 pairs of submetacentric chromosomes. The mean total length of all chromosomes was $128.7\;{\pm}\;9.93\;{\mu}m$. The maximum length of chromosomes No. 1 was $9.6\;{\pm}\;0.21\;{\mu}m$.