• Korean Journal of Plant Resources
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• v.4 no.2
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• pp.47-49
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• 1991

In an attempt to analyse the variation of chromosome numbers in Cododopsis lanceolate, 28 species of Deo-Deong have been examined for determination of chromosomenumbers. Tlle somatic chromosone numbers were counted to be 2n=16 of C. lanceolata.

• Parasites, Hosts and Diseases
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• v.21 no.1
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• pp.118-124
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• 1983

The distribution, external morphology, radula, chromosome numbers of Planorbidae snails were studied. 1. The specimens were collected at four stations in Nonsangun, Kongjugun, and Daedukgun which are located around Geum river. Three genera and three species of Planorbidae, Hippeutis cantorir Segmentina hemisphaerula and Gyraulus cenvexiusculus, were collected. H. cantori was the most abundant species among the three species. G. convexiusculus was the least abundant one. 2. Each species could be identified on the basis of its external characteristic, since the periphery of each species has a peculiar shape. H. cantori was the largest one among the three species. 3. The radula formula of each species was very similar to other species. The size of radula was proportional to the size of shell. The radula formulae of H. cantori, S. hemisphaerula, and G. convexiusculus were 29 : 1 : 29, 23 : 1 : 23, and 16 : 1 : 16 respectively. The difference of radula formula could be found in the total numbers of laternal and marginal teeth. 4. The haploid chromosome number of H. cantori was eighteen (n=18), S. hemisphaerula and G. convesiusculus were assumed to be same in their chromosome numbers (n: 18).

• Korean Journal of Microbiology
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• v.20 no.3
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• pp.134-146
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• 1982

This experiment was designed to elucidate the life cycle of 7 species (Rh.nigricans, Rh. delemar, Rh.oryzae, Rh.acidus, Rh.tritici, Rh. formosaensis and Rh. japonicus) in genus Rhizopus isolated from Korean soil, so as to seize the appropriate stage for detecting their chromosomal number and nuclear size under the method of thin layer slide culture using modified Rogers(1965a) medium. The results are summarized as the folowings ; 1. The haploid chromosome number are found 16 in Rh. japonicus are 8, respectively. 2. Comparing the 7 species of Rhizopus with each other, it may be concluded that the basic haploid chromosome number of genus Rhizopus distributed in Korean soil are 8 and that Rh. nigricans is double of the basic hapolid chromosome number (n = 16). Besides them, the other two species (Rh. tritici and Rh. formosaensis) are believed aneuploids.

• Journal of Genetic Medicine
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• v.11 no.1
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• pp.16-21
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• 2014

A 31-year-old woman, who was pregnant with twins, underwent chorionic villus sampling because of increased nuchal translucency in one of the fetuses. Cytogenetic analysis showed a normal karyotype in the fetus with increased nuchal translucency. However, the other fetus, with normal nuchal translucency, had a derivative X chromosome (der(X)). For further analysis, fluorescence in situ hybridization (FISH) and additional molecular studies including fragile X analysis were performed. FISH analysis confirmed that the Y chromosome was the origin of extra segment of the der(X). The X-chromosome breakpoint was determined to be at Xq27 by FMR1 CGG repeat analysis, and the Y-chromosome breakpoint was determined to be at Yq11.23 by the Y chromosome microdeletion study. To predict the fetal outcome, the X-inactivation pattern was examined, and it revealed non-random X inactivation of the der(X). To the best of our knowledge, the identification of an unbalanced Xq;Yq translocation at prenatal diagnosis has never been reported. This study was performed to identify precise breakpoints and the X-inactivation pattern as well as to provide the parents with appropriate genetic counseling.

• Korean Journal of Animal Reproduction
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• v.15 no.2
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• pp.87-95
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• 1991

The chromosome analyses of blood culture were made of 11 Korean native and 53 crossbred males between the Korean native cattles(K) and Charolais(C), which consisted of $K\times$K, $C\times$K, $C\times$CK, CK$\times$CCK and Charolais synthetic males(CK$\times$CCK or CCK$\times$CK). 1. The diploid(2n=60, XY) Charolais synthetic male has the 29 pairs of acrocentric autosomes, a single large submetacentric X and a small metacentric Y chromosome. 2. The numbers of G-band of karyotype in these males were a few differences in the 8 pairs of autosomes(chromosome 2, 4, 5, 6, 9, 11, 19 and 26) compared to those of purebred Korean native ones. G-banding qualities were not matched in chromosome 16, 19 and 29 with the Korean native males and also in chromosome 14, 20 and 22 with other domestic cattles. 3. The G-banding pattern between chromosome 4-6-7 and 24-25-27 was alomost similar together and the possibilityof misidentification was greater in the G-banded preparations. 4. 1/29 Robertsonian translocation and other abnormalities were not observed among 11 Korean native and 53 crossbred males. This result is considered in relation to limited data and further investigation based on larger samples may be necessary for definite conclusion.

• Journal of Plant Biology
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• v.33 no.4
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• pp.237-242
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• 1990

Geographical distribution of diploid plant with AA genome (2n=16) and allotetraploid with AABB genome (2n=34) of Scilla scilloides Complex from Korea has been studied. The composition and frequencies of B chromosomes ere also investigated. Plants with AABB genome were predominant over AA genome plants. A mixed population of AA and AABB genome plants was found for the first time. Aneuploid plants have not been found. Chromosomes of AA genome were composed of three pairs of metacentric, two pairs of submetacentric, two pairs of subtlocentric and one pair of telocentric chromosomes, whereas BB genome was four pairs of metacentric and five pairs of subtelocentric chromosomes. B chromosomes were classified into two categories, isochromosome (F) and chromosome fragment (f). The frequencies of B chromosomes were 43% in AA genome plants and 44% in AABB genome plants. The number of B chromosome ranged from 1 to 3 and 1 to 7 in AA and AABB genome plants, respectively. B chromosome combinations were F and F+f in AA genome plants and F, F+f and f in AABB genome plants.

• Journal of Environmental Health Sciences
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• v.16 no.1
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• pp.55-65
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• 1990

This study was carried out to investigate the effects on sister chromatid exchanges (SCEs) and chromosome aberrations in PHA or LPS stimulated mouse spleen and bone marrow lymphocytes after an acute whole body irradiation. Frequencies of sister chromatid exchanges were significantly increased with the increased dose(from zero to 400tad) but there was no differences between B-cell and T-cell. By times, the maximum induced SCE levels was observed at 12 hours after irradiation and then returned to base level at one day in 100rad group and three day in 400rad group. There was a significant difference in chromosome aberration with increasing exposure. X-ray irradiated chromosome aberration was long lived relative to SCE. This results show that counting the incidence of SCE may not provide a sensitive system for detecting X-ray exposure.

• Animal cells and systems
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• v.16 no.3
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• pp.183-189
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• 2012

It has been suggested that chromatin is organized into the stable structures that provide fundamental units of chromosome architecture in interphase mammalian cells. The stable structures of chromatin can be visualized as replication foci when replicating DNA is labeled with thymidine analogs. Previously, we showed that the chromosome territory expanded after BAF53 knockdown. In this study, we found that BAF53 is required for the formation of replication foci. DNA replication was not impaired in BAF53 knockdown cells, suggesting that the decrease in the number of replication foci is due to disintegration of replication foci, but not suppression of DNA replication. The attractive forces that maintain structural integrity of replication foci could be disrupted by BAF53 knockdown, and it may be responsible, at least in part, for the expansion of chromosome territories after BAF53 knockdown.

• Clinical and Experimental Reproductive Medicine
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• v.26 no.3
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• pp.467-474
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• 1999

Objectives: Cytogenetic investigations were carried out on 770 women with primary (n=560) and secondary amenorrhea (n=210) to determine the frequency of chromosomal or genetic causes of amenorrhea. Materials and Methods: In 770 women with primary amenorrhea (n=560) and secondary amenorrhea (n=210), chromosomal analysis were performed. Results: 1) The most prevalent age group is 16-20 years of age group with primary amenorrhea and 26-30 years of age group with secondary amenorrhea. 2) Out of 560 cases of primary amenorrhea, 343 cases (61.3%) had the normal chromosome constitution and 217 cases (38.7%) had the abnormal chromosome constitution including 46,XY. 3) In 217 cases of abnormal chromosome of primary amenorrhea, 57 cases (26.3%) had 45,X and 34 cases (15.8%) had the 46,XY, 24 cases (11.0%) had 45,X/46,X,i (Xq), 23 cases (10.6%) had 45,X/46,X,+mar and 14 cases (6.6%) had 45,X/46,XY. 4) Out of 210 cases of secondary amenorrhea, 181 cases (86.2%) had the normal chromosome constitution and 29 cases (13.8%) had the abnormal chromosome. 5) In 29 cases of abnormal chromosome of secondary amenorrhea, 7 cases (24.1%) had 45,X/46, X,i (Xq), 4 cases (13.8%) had 45,X/46,XX. Conclusion: High percentage of chromosomal abnormalities was diagnosed in primary amenorrhea and most of them were sex chromosome anomalies. In secondary amenorrhea, the prevalence was lower than primary amenorrhea, so a preselection of patients with secondary amenorrhea for cytogenetic investigations seems to be necessary.

• Journal of Genetic Medicine
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• v.3 no.1
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• pp.5-10
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• 1999

This is a case report of 46,XY female phenotype (46,XY karyotype, no pubic hair, blind vagina and absence of uterus)in an 18-year-old patient. To confirm whether a Y chromosome has a structural abnormality, fluorescent in situ hybridization (FISH) with the chromosome X/Y cocktail probe was simultaneously performed, and the six loci [PABY, RPS4Y(sy16, sy17), ZFY, DYS14] on the short arm, one locus (DYZ3) on the centromere and one locus (DYZ1) on the long arm were amplified by polymerase chain reaction (PCR). The probes used FISH hybridized to centromere of the X chromosome and heterochromatin region (Yq12) of the Y chromosome, and all PCR related Y chromosome showed positive band like normal male. From the results obtained, it seemed that the Y chromosome from the 46,XY female was structurely normal. Especially, the SRY gene has been equated with the mammalian testis-determining factor, and absence or point mutation in the SRY gene causes XY female. To detect the point mutations of SRY sequences, single-strand conformation polymorphism (SSCP) assay was used. Our results confirm that this patient has no mutation in the SRY gene on the Y chromosome.