• The Korean Journal of Zoology
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• v.18 no.2
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• pp.71-86
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• 1975

The G-banding patterns of normal and of delayed spiralized chromosomes by BUdR were investigated in three established cell lines of dwarf hamsters. The results obtained were as follows: 1. The number of G-bands appeared in Chinese hamster T-233 cell line was 65. The centromeric dark band was found in No.1 chromosome and weakly stained bands were also observed in part of the centromeric regions of Nos. 2, 3, 8 and $X_2$ chromosomes. Two homologous X chromosomes were found in different banding patterns. Terminal dark bands were shown in No. 1 chromosome. No conspicuous bands appeared in No. 10 chromosome. 2. Eighty four bands appeared in Armenian hamster Y-1249 cell line. Centromeric dark bands were observed in Nos. 5 and 10 chromosomes and moderatly stained bands were also found in near the centromeric region of the long arms of Nos. 7 and 9 chromosomes. Two isomorphic X chromosomes were also distinguished by their banding patterns. 3. In Y-1313 Armenian hamster cell line, the bands were 69. No centromeric dark bands were observed in this cell line, but moderatly stained bands appeared in the centromeric area in the long arm of No. 9 chromosome. The banding patterns of these two cell lines of Armenian hamster were quite different and readily distinguished. Only No. 8 chromosome showed similar G-banding patterns. Although Nos. 5, 7 abd 8 chromosomes revealed the same number of bands in these two cell lines, the location and staining intensity were quite different. 4. Chromosomes of Nos. 1, 2, 6, $X_1$ and $X_2$ in T-233 cell line and of 1, 4, 7, 8, 9, $X_1$ and $X_2$ in both cell lines of Armenian hamster were found to be elongated due to the inhibition of mitotic spiralization by BUdR. G-banding patterns of these chromosomes were found to be identical to those of normal chromosomes in these cell lines.

• Journal of Korean Society of Forest Science
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• v.75 no.1
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• pp.38-45
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• 1986

This study was designed to investigate the karyotype analysis of Juniperus chinensis and its seven varieties, and P. densiflora and P. densiflora for. multicaulis. Following results were obtained. 1. Three varieties, J. chinensis v. kaizuka, J. chinensis v. aureo-variegata and J. chinensis v. procumbens are turned out as tetraploids. 2. Varieties having many long chromosomes and long mean relative length of chromosomes are J. chinensis and J. chinensis v. aureo-globosa, while varieties having short chromosomes are J. chinensis v. horizontalis and J. chinensis v. globosa. 3. Varieties with high mean ratio of long arm length to short arm are J. chinensis v. globosa and J. chinensis v. kaizuka, while a variety with the low mean ratio is J. chinensis v. aureo-globosa. 4. When chromosomes are arranged according to the total length, the most similar variety with J. chinensis was J. chinensis v. sargentii, J. chinensis v. horizontalis, J. chinensis v. globosa and J. chinensis v. aureo-globosa, while the least similar one was J. chinensis v. procumbens. 5. Pinus densiflora for. multicaulis has shorter mean relative length of chromosome than P. densiflora, while the arm ratio of the former is higher than the latter. 6. When chromosomes are arranged according to the total length, six chromosomes showed the same order between the two varieties. 7. P. densiflora for. multicaulis has many chromosomes with secondary constriction.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.247-253
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• 2010

Telomeres are nucleoprotein structures at the ends of chromosomes consisting of DNA sequences arranged in tandemly repeated units $(TTAGGG)_n$. However, this hexamers can also occur at non-telomeric sites in some avians and vertbrate. This study was carried out to present the distribution of telomeric DNA sequences in Korean Native Chicken chromosomes. The fluorescence in situ hybridization technique using a telomeric DNA probe was performed to the metaphase spreads of chicken early embryonic cells. Telomeric DNA signals were detected at the ends of chromosomes including macrochromosomes and microchromosomes. In chicken, surprisingly, chromosome 1 showed very distinct interstitial telomeric DNA hybridization patterns which located two interstitial sites in the p-arm at 1p11 and 1p23, and one in the q-arm at 1q32. In chromosome number 2 and 3 also displayed interstitial telomeric signals (ITS) in the long arms at 2q24 and 3q32, respectively. The pattern of telomeric DNA distribution in Korean Native Chicken chromosomes was in agreement with a previously reported in Gallus domesticus. The relative amount of telomeric DNA sequences in each macrochromosomes ranged from 4.6% to 16.3%. Distribution of telomeric DNAs at the end of p-arm was much more than that of q-arm in almost chicken chromosomes. The distribution of ITS in chicken chromsomes implicate to tandem chromosome fusions that might have occurred during the process of karyotype evolution.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.133-133
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• 2017

Lodging is one of the important constraints in rice production. The lodging destroys the canopy structure, and sharply reduces the capacity of photosynthetic rate and dry matter production. In cereal crops, stem lodging can be classified into two types: stem breaking type and stem bending type. To improve stem lodging resistance, it is important to reveal strong culm traits of superior lodging resistant varieties. There are large varietal differences in parameters associated with the bending moment at breaking (M) and flexural rigidity (FR). The indica variety Takanari possesses large M due to its large section modulus (SM) despite of its small bending stress (BS), while Takanari also has large FR due to its large secondary moment of inertia (SMI) and Young's modulus (YM). To identify quantitative trait loci (QTLs) and the corresponding genes associated with the parameters for M ($=SM{\times}BS$) and FR ($=SM{\times}YM$) should enable to develop lodging resistant varieties, efficiently. In order to identify QTLs for cell wall materials such as cellulose, hemicellulose and lignin associated with BS and YM, a set of Chromosome Segment of Substitution Lines (CSSLs) consisted of 37 lines with chromosome segments of Koshihikari in the genetic background of Takanari were used. Takanari had large M and small BS as compared with Koshihikari. The QTLs for BS were estimated on chromosomes 3, 5, 6, 8, 9, 10, 11 and 12. Koshihikari alleles increased BS in these QTLs. Takanari had a large FR due to its large SMI and YM as compared with Koshihikari. The YM was increased by substitution of the Koshihikari chromosomal segments on chromosomes 2, 10 and 11. Other QTLs estimated on chromosomes 7 and 12 that Koshihikari alleles contributed to the decrease of YM. For lignin, only one major QTL for lignin density was detected on chromosome 11. Hollocellulose densities were increased by the substitution of Koshihikari segments on chromosomes 5 and 11. On the other hand, these were decreased on chromosomes 1 and 3 by substitution of Koshihikari segments. QTLs for cellulose density were estimated on chromosomes 1, 3 and 5 by substitution of Koshihikari segments. For hemicellulose, QTL on chromosome 3 showed that hemicellulose density decreased by the substitution of Koshihikari segment. However, hemicellulose densities on chromosomes 5, 8 and 11 showed the opposite effects. The QTLs for hemicellulose, cellulose, and hollocelulose densities identified on chromosome 5 overlapped with that for bending stress, indicating the positive effect of Koshihikari segment on increasing bending stress. These results suggest that some QTLs for the densities of cell wall materials contribute to increasing bending stress and Young's modulus, and could be utilized to improve the lodging resistance for both types of breaking and bending in rice varieties.

• Korean Journal of Poultry Science
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• v.13 no.2
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• pp.167-172
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• 1986

Chromosome size, number and shape were studied by the centromeric index, the arm ratio and the relative length of chromosome. The chromosomes of 50 early chick embryos which were derived from a pure line of Single Comb White Leghorns were examined. Using a colchicine, hypotonic treatment, fixation and air-drying technique, the clear prometaphase figures were obtained from the whole embryo. The results of the present investigation of chromosome pairs were as follows, 1. Pair 1 and 2; metacentric and submetacentric chromosomes which could be clearly distinguished from each other by size. 2. Pair 3 and 4: acrocentric chromosomes of similar length but the 4th pair had a distinct short arm which was not present in the 3rd. 3, Pair 5; metacentric sex chromosomes, 2 chromosome had relative 5th length but the W chromosome had slightly shorter length than 7th pair of chromosomes. 4. Pair 6; acrocentric chromosomes similar in shape to pair 3 but of little more than half the size. 5, Pair 7 and 8; acrocentric chrocentric but the 7th pairs had a definite short arm. 6. Pair 9; similar length to the 7, 8 pairs but had a medially placed centromere. 7. microchromosomes of 30 pairs ; nearly all acrocentric chromosomes which appeared as paired dots. The total number of diploid was appeared to 72-78. But a number of observations presented the total diploid number in 78 (58%). The inconstancy in number observed in this study was presumably due to the minute size of the microchromosomes. Thus, the modal numbers for the diploid chromosome was at least 78.

• Korean Journal of Plant Taxonomy
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• v.39 no.3
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• pp.193-198
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• 2009

Chromosome analysis using karyotyping and bicolor FISH were carried out for two Maackia species (M. fauriei and M. amurensis) found in Korea. The somatic metaphase chromosome number was 2n = 2x = 18 in both, and the size of these chromosomes ranged from 3.58 to $5.82{\mu}m$. The chromosome complements consisted of two pairs of metacentric (chromosomes 1 and 7), four pairs of submetacentrics (chromosomes 4, 6, 8 and 9) and three pairs of subtelocentrics (chromosomes 2, 3 and 5) in M. fauriei but, chromosomes 4 (subtelocentric) and 7 (submetacentric) of M. amurensis have different morphology. Using bicolor FISH, a pair of 45S rDNA loci were observed for both M. fauriei and M. amurensis, but the number and site of the 5S rDNA signal were different in the two species. M. fauriei has two pairs of 5S signals on chromosomes 7 and 8 but, M. amurensis has four paris on chromosomes 3, 4, 7 and 7. Hence, the 5S rDNA is a useful FISH for Maackia species.

• Journal of Life Science
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• v.11 no.4
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• pp.354-361
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• 2001

Chromosomal characteristics of New Zealane White rabbit was studied at meiosis and mitosis. The meiotic chromosomal preparations were mad with the modified air-drying method and karyotype analysis was performed with the G-banding technique, using isolated mitotic metapase chromosomes of the New Zealand White rabbit. Chromosomes, sex vesicles and centromeres could be classified in the zygotene and the pachytene of the meiosis I. The hair-like processes projecting laterally from the axes of bivalent chromosomes at the mid-to-late pachytene were observed and made the appearance of the lampbrush chromosome structure. Chromosomes could be classified onthe basis of the numbers and locations of chiasma in the diakinesis. Twenty-one autosomal bivalents and a single unequal terminally associated X-Y bivalent were observe during the late prophase and the metaphase of the meiosis I. Most of the bivalent types observed in the New Zealand White rabbit spermatrocytes were 1CH, 1TAl, and 2TA bivalents. The mean chiasma frequency(CF) of the male New Zealand White rabbit was 30.2 and it was found that the CF value tended to decrease through diakinesis and the metaphase I. The karyotype of the New Zealand White rabbit was a male chromosome number of 44(2n=44) comprising 8 pairs of metacentric, 9 pairs of submetacentric, 4 pairs o acrocentric autosomes, metacentric X chromosome and acrocentric Y chromosome.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.64-72
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• 1989

Karyological characteristics were investigated in 3 species of the genus Liobagrus from Korea. The diploid chromosome number in L. andersoni was found to be 28, with 9 pairs of metacentrics and 5 pairs of submetacentric chromosomes, and arm number (AN) was 56. L. mediadiposalis was found with 2n of 42, consisting of 13 pairs of metacentrics and 8 pairs of submetacentric chromosomes (AN=84). In the case of L. obesus 2n was 20, with 20 metacentric chromosomes (AN=40), which was the lowest among the species of the order Siluriformes. Sexual dimorphism or intraspecific polymorphism of the chromosomes was not observed in any species examined.

• The Transactions of the Korea Information Processing Society
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• v.7 no.6
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• pp.1844-1851
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• 2000

In this paper, a metamorphosed genetic algorithm based on the meiosis for human's chromosome is presented. In the algorithm, chromosomes in an individual are divided in half and in the other are divided into other rate. By our definition, they are composed of gametes with X-type chromosomes or Y-type chromosomes or especially M(mutation)-type chromosomes. When tow gametes among them are randomly selected and recombined, the new individual is correspondingly generated. Without reducing the searching space significantly, the global solution can be readily searched by new generated individual. The performance of he presented algorithm is examined and evaluated through proper simulation using test functions.

• 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.