• Korean Journal of Plant Taxonomy
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• v.39 no.1
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• pp.24-28
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• 2009

The chromosome morphology of two Korean Lactuca (L. indica, L. triangulata) is reported herein. The chromosome number and karyotype of a naturalized plant, L. scariola are reported for the first time. The basic chromosome number was x = 9. Polyploid forms were not recorded. The karyotypes of L. indica, L. scariola, and L. triangulata were 2 n = 18 = 2 m+ 7 sm, 2 n = 18 = 1 m + 6 sm+ 2 st, 2 n = 18 = 2 m + 5 sm+ 2 st, respectively. Both L. indica and L. triangulata had satellites at the ends of their short arms. The haploid genome lengths of L. indica, L.scariola, and L. triangulata were $56.3{\mu}m$, $35.3{\mu}m$, and $72.5{\mu}m$ respectively. Each chromosome length of naturalized L. scariola was $2.7-5.2{\mu}m$; the smallest among Korean Lactuca. The chromosome lengths of L. indica and L. triangulata were $4.7-7.6{\mu}m$ and $2.9-7.9{\mu}m$, respectively. The karyotype of L. scariola differed from that of L.indica and L.triangulata both of which belong to sect. Tuberosae. Therefore, L. scariola is thought to belong to sect. Lactuca subsect. Lactuca.

• Journal of Preventive Medicine and Public Health
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• v.22 no.1 s.25
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• pp.116-124
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• 1989

To assay the cytogenetic toxicity of $NiCl_2,\;K_2Cr_2O_7CdCl_2,\;and\;HgCl_2$, the frequencies of sister chromatid exchanges(SCEs) and chromosomal aberrations were observed in the metaphase chromosomes of the human lymphocytes which were cultured with above materials. The frequencies of SCEs are dose-dependently increased by all materials in this experiment. Chromosomal aberrations, especially gap and break, are increased by the nickel and chromic compounds, while not significantly increased by the cadmium and mercurial compounds. This results indicate the dose dependent relationship between the frequencies of SCEs and the concentrations of the heavy metals, but the increasing rates of the SCEs induced by the heavy metals are less sensitive than other mutagens or carcinogens which were confirmed.

• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.243-249
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• 2004

The cytokinesis-block micronucleus (CBMN) assay in combination with FISH technique using chromosome-specific centromeric probes for chromosome 1 and 4 was performed in mitogen stimulated human lymphocytes which were exposed to x-radiation to identify different sensitivity of chromosomes to the induction of micronuclei(MN) and aneuploidy by radiation. The frequencies of micronucleated cytokinesis-blocked(MNCB) cells and MN in binucleated lymphocytes(BN) increased with the increase in radiation dose. A significant induction of aneuploidy of chromosome 1 and 4 were found. The frequency of aneuploidy of chromosome 1 and 4 in the control were 9 per 2,000 BN cells and this increased to 47 and 71 following irradiation at a dose of 1 and 2 Gy, respectively. The induction of aneuploidy of chromosome 1 was higher than that of chromosome 4. The frequency of aneuploid BN cells with MN exhibiting positive centromere signal for either chromosome 1 and/or 4 increased in a dose dependent manner, and that for chromosome 1 is higher than that for chromosome 4. Among the total induced MN in irradiated lymphocytes, smaller proportion of MN exhibit centromeric signal of chromosome indicating that radiation-induced MN are mainly originated from chromosomal breakage rather than chromosomal non-disjunction. These results suggest that x-radiation can induce aneuploidy and supports the finding that chromosome vary in their sensitivity to aneuploidy induction by x-irradiation.

• The Korean Journal of Zoology
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• v.23 no.4
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• pp.203-218
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• 1980

Unscheduled DNA synthesis, chromosome aberrations, sister chromatid exchanges and DNA replication inhibition induced by the combined treatments with ara-C and UV-light or MMS in $HF_1$, CHO and $HelaS_3$ cells were studied, and the results obtained were as follows: (1) Ara-C was found to inhibit UV-or MMS-induced unscheduled DNA synthesis and the inhibitory effect of ara-C was more remarkable in its post-treatment. (2) Ara-C enhanced the rate of chromosome aberrations induced by MMS or UV-light. Post-treatment with ara-C exhibited the synergistic effect on MMS-induced chromosome aberrations mainly by increases of chromatid deletions. (3) Contrarily, ara-C did not increase the rate of sister chromatid exchanges, particularly in the pre-treatment with MMS, although it was found to induce sister chromatid exchanges. (4) The rate of DNA synthesis was declined immediately after are-C treatment and then recovered. The combined treatments with ara-C and UV-light or MMS showed that the initial response on replication inhibition was similar to that of ara-C, but later responses were similar to that of UV-light or MMS treated group.

• Clinical and Experimental Reproductive Medicine
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• v.37 no.1
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• pp.25-31
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• 2010

Objective: X inactivation is the silencing one of the two X chromosomes in female mammals for gene dosage on the X-chromosome between female and male. X inactivation is controlled by X inactive-specific transcript (XIST) gene, untranslated RNA. XIST is expressed only from the inactive X (Xi), not expressed from the active X (Xa). The Xist promoter is methylated on the silent Xist allele on the Xa in somatic cells, and less methylated on the Xist-expressing Xi. We investigated the difference of XIST methylation pattern of the promoter and 5'-region of XIST from male (XY) and female (XX) subjects. Methods: The direct quantification of XIST methylation is required for clinical application of normal XX and XY blood. Methylation percentage of eight CpG sites (-1696, -1679, -1475, -1473, -1469, +947, +956, +971) of XIST gene were diagnosed by pyrosequencing. Results: We directly quantitated the methylation percentage of the promoter and 5'-end of XIST by pyrosequencing. The average methylation percentages at CpG6-8 sites (+947, +956, +971) were 45.2% at CpG6, 49.9% at CpG7, and 44.2% at CpG8 from normal female and normal male were 90.6%, 96.7%, 87.8%, respectively. Nether CpG 1-5sites (-1696, -1679, -1475, -1473, -1469) had any effect on XX and XY. Conclusion: This method is sensitive for quantifying the small percentage change in the methylation status of XIST, and may be used for diagnosis.

• 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 Plant Resources
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• v.30 no.2
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• pp.213-218
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• 2017

Rice is the staple food of at least half of the world's population. Due to global warming, the weather is difficult to forecast nowadays. Therefore, it is necessary to breed various breeding to respond to such changes in the environment. This study was conducted to analyze the QTL about plant form, culm length, ear number and ear length by using 120 lines by anther culture, a cross between the Indica variety Cheongcheong and Japonica variety Nagdong. DNA marker was selected on the QTLs gene, and the following results were obtained. CNDH (Cheongcheong Nagdong Doubled Haploid) lines frequency distribution table curves about culm length, ear number and ear length exhibited showed a continuous variation close to a normal distribution. QTL analysis result, on culm length qPlL1-1 and qPlL1-2 were detected on the chromosome 1 and qPlL5 was detected on the chromosome 5. However, on ear length qPL2, qPL3 and qPL10, were detected on the chromosome 2, 3 and 10, while on ear number qPN1-1 and qPN1-2 were detected on the chromosome 1, qPN9 was detected on the chromosome 9. The QTLs related to culm length was found to chromosomes 5 and LOD scores were 3.81. The QTLs related to ear length was found to chromosomes 2 and 3 LOD scores were 7.13 and 3.20. The QTLs related to ear number was found to chromosome 9 and LOD scores were 4.27. Twenty two (22) Japonica cultivars and 12 Indica cultivars were analyzed polymorphisms, using selected 9 markers from the result about plant form analysis. RM5311, RM555 and RM8111 about the culm length, the ear length and number of ear were selected on the standard of Cheongcheong and Nagdong. Each rate of concordances about the culm length, the ear length and number of ear are 44.11%, 41.17% and 44.11%.

• Journal of Korean Society of Forest Science
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• v.80 no.4
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• pp.383-392
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• 1991

The genetic variation of Pinus densiflora and Pinus thunbergii by Giemsa C-banding was investigated and the results were as follows : 1. From Karyotype analysis of P. densiflora and P. thunbergii by Giemsa C-banding, somatic chromosome numbers of both species were 2n=24. 2. Chromosome of P. densiflora was M-type in arm ratio and they were no variation among individuals but variation in number and position of the secondary constriction and telomere banding among individuals. 3. P. thunbergii showed also M-type in arm ratio of chromosome, however, there was no variation in both number and position of the secondary constriction among individuals. 4. From chromosome C-banding, bands were appeared in the position of centromere and the secondary constriction in both P. densiflora and P. thunbergii. 5. In P. densiflora, the bands were shown on the secondary-constriction in chromosome No. 3, 4 and 7 of all individuals and the bands of the secondary constriction in chromosome No. 1, 2 and 5 showed variation among individuals. In chromosome No. 9, 10 and 11, the bands were shown in telomere and showed variation among individuals. 6. In P. thunbergii, the bands were shown on the secondary constriction in chromosome No. 2, 3, 7 and 8, and were shown no variation among individuals. There was no band on telomere. 7. The genetic variation by C-banding were shown in P. densiflora among individuals but no in P. thunbergii, and were shown on the secondary constriction in chromosome No. 4 of Pinus densiflora and in clnromosome No. 8 of Pinus thunbergii. These are the difference between the two species by C-banding.

• Korean Journal of Plant Taxonomy
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• v.33 no.3
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• pp.279-293
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• 2003

Somatic chromosomes about 13 taxa of Korean Euphorbia L. was investigated to estimate its taxonomic significance. Somatic chromosome numbers of treated taxa were 2n= 12, 20, 22, 28, 40, 42, 56, therefore basic chromosome numbers of those were x=6, 7, 10, 11. The chromosome numbers of E. pallasii Turcz. (2n=20), E. hylonoma Hand.-Mazz (2n=20.), E. fauriei H. L$\acute{e}$v. & Vaniot ex H. L$\acute{e}$v (2n=28) and E. jolkini Boiss. (2n=28) were determined for the first time in this study. The chromosome numbers of four taxa were same as previous ones; E. sieboldiana Moor. & Decne. (2n=20), E. ebracteolata Hayata (2n=20), E. humifusa Willd. ex Schlecht. (2n=22). But those of six taxa were different; E. esula L (2n= 16, 20, 60, 64 vs 2n=20), E. helioscopia L. (2n=12, 42 vs 2n=42), E. lucorum Rupr. (2n=28, 40 vs 2n=56), E. pekinensis Rupr. in Maxim. (2n=24 vs 2n=28, 56), E. maculata L. (2n=28, 42 vs 2n=12), E. supina Raf. (n=7 vs 2n=40). E. ebracteolata, E. pallasii and E. hylonoma were distingushcd from the other taxa by the chromosome numbers, size and satellites, E. maculata, E. humifusa, E. supina had the different basic and somatic chromosome numbers in spite of the similar morphological. anatomical and palynological chracters. The chromosomal character of Korean Euphorbia was supported the Ma and Hu's systems, and as above results, it was found to be a good character in delimiting above sections and estimating relationships for some species.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.3
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• pp.179-187
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• 2006

Objectives: The risk of aneuploidies of embryos increases in advanced maternal age or parental karyotype abnormality and it results in poor reproductive outcomes such as recurrent spontaneous abortion (RSA) or repeated implantation failure (RIF). Preimplantation genetic diagnosis for aneuploidy screening (PGD-AS) can be applied for better ART outcome by selecting chromosomally normal embryos. The aim of this study is to evaluate the clinical outcome of PGD-AS and which group can get much benefit from PGD-AS among the patients expected to have poor reproductive outcome. Methods: In 42 patients, 77 PGD cycles were performed for aneuploidy screening. Patients were allocated to 3 groups according to the indication of PGD-AS: group I-patients with old age (${\geq}37$) and RIF more than 3 times (n=11, mean age=42.2 yrs.), group II-patients with RSA (${\geq}3$ times) associated with aneuploid pregnancy (n=19, mean age=38.9 yrs.), group III-parental sex chromosome abnormality or mosaicism (n=18, mean age=29.6 yrs.) including Turner syndrome, Klinefelter syndrome and 47, XYY. PGD was performed by using FISH for chromosome 13, 16, 18, 21, X and Y in group I and II, and chromosome X, Y and 18 (or 17) in group III. Results: Blastomere biopsy was successful in 530 embryos and FISH efficiency was 92.3%. The proportions of transferable embryos in each group were $32.5{\pm}17.5%$, $23.0{\pm}21.7%$ and $52.6{\pm}29.2%$ (mean ${\pm}$ SD), respectively, showing higher normal rate in group III (group II vs. III, p<0.05). The numbers of transferred embryos in each group were $3.9{\pm}1.5$, $1.9{\pm}1.1$ and $3.1{\pm}1.4$ (mean ${\pm}$ SD), respectively. The clinical pregnancy rates per transfer was 0%, 30.0% and 20.0%, and it was significantly higher in group II (group I vs. group II, p<0.05). The overall pregnancy rate per transfer was 19.6% (10/51) and the spontaneous abortion rate was 20% (2/10) of which karyotypes were euploid. Nine healthy babies (one twin pregnancy) were born with normal karyotype confirmed on amniocentesis. Conclusion: Our data suggests that PGD-AS provides advantages in patients with RSA associated with aneuploidy or sex chromosome abnormality, decreasing abortion rate and increasing ongoing pregnancy rate. It is not likely to be beneficial in RIF group due to other detrimental factors involved in implantation.