• Development and Reproduction
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• v.15 no.3
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• pp.187-195
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• 2011

X chromosome inactivation (XCI) is a process that enables mammalian females to ensure the dosage compensation for X-linked genes. Investigating the mechanism of XCI might provide deeper understandings of chromosomal silencing, epigenetic regulation of gene expressions, and even the course of evolution. Studies on mammalian XCI conducted with mice have revealed many fundamental findings on XCI. However, difference of murine and human XCI necessitates the further investigation in human XCI. Recent success in reprogramming of differentiated cells into pluripotent stem cells showed the reversibility of XCI in vitro, X chromosome reactivation (XCR), which provides another tool to study the change in X chromosome status. This review summarizes the current knowledge of XCI during early embryonic development and describes recent achievements in studies of XCI in reprogramming process.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.92-92
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• 2003

Accurate analysis of nuclear status is needed when biopsied-blastomeres are used for embryo sexing. In this study, the nuclear status of blastomeres derived from 8- to 16-cell stage IVF bovine embryos was analyzed to evaluate the representative of single blastomere for embryo sexing. When 55 embryos were analyzed by PCR following biopsy, the coincident rate of sex determination between biopsied-single blastomere and matched blastocyst by PCR was 80 %. Karyotyping of biastomeres in 8- 16-cell stage bovine embryos was conducted to assess chromosome status of IVF embryos. To establish karyotyping of blastomeres, concentrations of vinblastine sulfate and duration of exposure time for metaphase plate induction with 8- to 16-cell stage bovine embryos were tested. The most effective condition for induction of metaphase plate (>45%) was 1.0 ug/ml vinblastine sulfate treatment for 15 h. In 22 embryos under the condition, only 8 embryos out of ten that had a normal diploid chromosome complement showed a sex-chromosomal composition of XX or XY (36.4%) and 2 diploid embryos showed mosaicism of the opposite sex of XX and XY in blastomeres of embryo (9.1%). One haploid embryo contained only one X-chromosome (4.5%). Four out of the other 11 embryos having a mixoploid chromosomal complement contained haploid blastomere with wrong sex chromosome (18.2%). These results suggested that morphologically normal bovine embryos derived from IVF had considerable proportion of mixoploid and sex-chromosomal mosaicism which could be the cause of discrepancies of the sex between biopsied-single blastomere and matched blastocyst by PCR analysis.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.329-337
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• 2012

Considerable attention has been given to the accuracy of HER-2 testing and the correlation between the results of different testing methods. This interest reflects the growing importance of HER-2 status in the management of patients with breast cancer. In this study the detection of HER-2 gene and centromere 17 status was evaluated using dual-colour primed in situ labelling (PRINS) in comparison with fluorescence in situ hybridization (FISH). These two methods were evaluated on a series of 27 formalin fixed paraffin embedded breast carcinoma tumours, previously tested for protein overexpression by HercepTest (grouped into Hercep 1+/0, 2+ and 3+). HER-2 gene amplification (ratio${\geq}2.2$) by PRINS was found in 3:3, 6:21 and 0:3 in IHC 3+, 2+ and 1+/0 cases, respectively. Comparing FISH and IHC (immunohistochemistry), showed the same results as for PRINS and IHC. Chromosome 17 aneusomy was found in 10 of 21 IHC 2+ cases (47.6%), of which 1 (10%) showed hypodisomy (chromosome 17 copy number per cell${\leq}1.75$), 7 (70%) showed low polysomy (chromosome 17 copy number per cell=2.26 - 3.75) and 2 (20%) showed high polysomy (chromosome 17 copy number per cell ${\geq}3.76$). The overall concordance of detection of HER-2 gene amplification by FISH and PRINS was 100% (27:27). Furthermore, both the level of HER-2 amplification and copy number of CEN17 analysis results correlated well between the two methods. In conclusion, PRINS is a reliable, reproducible technique and in our opinion can be used as an additional test to determine HER-2 status in breast tumours.

• The Zoological Society Korea : Newsletter
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• v.12 no.2
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• pp.130.2-130
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• 1995

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1995.10b
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• pp.306.2-306
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• 1995

No Abstract, See Full Text

• Korean Journal of Medicinal Crop Science
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• v.14 no.2
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• pp.96-100
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• 2006

Regions of allelic loss on chromosomes in many tumors of human and some experimental animals are generally considered to harbor tumor-suppressor genes involved in tumorigenesis. Allelotype analyses have greatly improved our under-standing of the molecular mechanism of radiation lymphomagenesis. Previously, we and others found frequent loss of heterozygosity (LOH) on chromosomes 4, 11, 12, 16 and 19 in radiation-induced lymphomas from several $F_1$, hybrid mice. To examine possible contributions of individual tumor-suppressor genes to tumorigenesis in p53 heterozygous deficiency, we investigated the genome-wide distribution and status of LOH in radiation-induced lymphomas from $F_1$ mice with different p53 status. In this study, we found frequent LOH (more than 20%) on chromosomes 4 and 12 and on chromosomes 11, 12, 16 and 19 in radiation-induced lymphomas from $(STS/A{\times}MSM/Ms)F_1$ mice and $(STS/A{\times}MSM/Ms)F_1-p53^{KO/+}$ mice, respectively. Low incidences of LOH (10-20%) were also observed on chromosomes 11 in mice with wild-type p53, and chromosomes 1, 2, 9, 17 and X in p53 heterozygous-deficient mice. The frequency of LOH on chromosomes 9 and 11 increased in the $(STS/A{\times}MSM/Ms)F_1-p53^{KO/+}$ mice. Preferential losses of the STS-derived allele on chromosome 9 and wild-type p53 allele on chromosome 11 were also found in the p53 heterozygous-deficient mice. Thus, the putative tumor-suppressor gene regions responsible for lymphomagenesis might considerably differ due to the p53 status.

• Genomics & Informatics
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• v.2 no.3
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• pp.113-120
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• 2004

• Interdisciplinary Bio Central
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• v.1 no.1
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• pp.4.1-4.7
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• 2009

Introduction: Histone modifications and DNA methylation are the major factors in epigenetic gene regulation. Especially, revealing how histone modifications are related to DNA methylation is one of the challenging problems in this field. In this paper, we address this issue and propose several plausible mechanisms for precise controlling of DNA methylation status at CpG islands. Materials and Methods: To establish the regulatory relationships, we used 38 histone modification types including H2A.Z and CTCF, and DNA methylation status at CpG islands across chromosome 6, 20, and 22 of human CD4+ T cell. We utilized Bayesian network to construct regulatory network. Results and Discussion: We found several meaningful relationships supported by previous studies. In addition, our results show that histone modifications can be clustered into several groups with different regulatory properties. Based on those findings we predicted the status of methylation level at CpG islands with high accuracy, and suggested core-regulatory network to control DNA methylation status.

• Korean Journal of Plant Taxonomy
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• v.31 no.4
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• pp.311-319
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• 2001

In order to evaluate taxonomic status of Latcuca hallaisanensis H. $L{\acute{e}}v$., an endemic species of the Jeju-do Island, we investigated fruit wall structure and chromosome morphology. The fruit wall structure had 10-11 obtuse costae in the transverse section. The costa was wholly occupied by libriform fiber cells, and the underlying fibersclereid tissue was only one to three cells layers thick. Also, the intercosta lacked fiber-sclereid layers. Somatic chromosome numbers and karyotype of Latcuca hallaisanensis were recorded for the first time. This diploid species (2n=10) with the same basic number of x=5 has the total chromosome length $23.3{\mu}m$ and the length of each chromosome falls in $1.9{\mu}m-2.9{\mu}m$. It possess the karyotype complement i.e., 3sm+2st and a characteristic chromosome pair (No. 1 and 2) with a secondary constriction at the distal portion of the short arms. The overall similarity in external morphology (involucre, achene etc), chromosome morphology as well as in fruit wall anatomy between Lactuca hallaisanensis and Crepidiastrum s. lat. clearly indicated that this species should be treated as Crepidiastrum, rather than Lactuca.

• Korean Journal of Ichthyology
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• v.9 no.2
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• pp.228-234
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• 1997

This study was carried out to confirm the taxonomical status by comparison of morphological and chromosomal charateristics and cross breeding in the two types of black and yellow body color of Korean mandarin fish, Siniperca sherzeri from Han River, Korea. Black and yellow types of Korean mandarin fish were similar in having 90-98 lateral line scale pores, 13 dorsal fin rays and XII XIII spines, 9 anal fin rays and 15 pectoral fin rays, but yellow type was differ from blacks type by yellow body color pattern. Diploid chromosome and arm number (fundamental number, NF) of the two types were the same to 2n=48 and NF=52. Karyotypes in the two types are consisted of 2 pairs submetacentric chromosome and 22 pairs of acro and/or telocentric chromosome. The black type females of Siniperca scherzeri were artificially crossed with yellow type males and black type males, respectively. The progenies from each cross breeding produced the normal individuls that possessed with parent types in the body color pattern. These data suggest that two types of Korean mandarin fish were same species, and yellow type was mutant by albino.