• Journal of Life Science
• /
• v.19 no.4
• /
• pp.449-456
• /
• 2009

Murine Neuro-2a (N2a) cells have been widely used for the investigation of neuronal differentiation, trophic interaction and neurotoxic effects of various compounds and their associated mechanisms. N2a cells have many genomic variations such as gains or losses in DNA copy number, similar to other neuroblastoma cells, and no systematic or high-resolution studies of their genome-wide chromosomal aberrations have been reported. Presently, we conducted a systematic genome-wide determination of chromosomal aberrations in N2a cells using a high-throughput, oligonucleotide array-based comparative genomic hybridization (oaCGH) technique. A hidden Markov Model was employed to assign each genomic oligonucleotide to a DNA copy number state: double loss, single loss, normal, gain, double gain and amplification. Unlike most neuroblastoma cells, Mycn amplification was not observed in N2a cells. In addition, these cells showed gain only in the neuron-derived neurotrophic factor (NF), while other neurotrophic factors such as glial line-derived NF and brain-derived NF presented normal copy numbers. Chromosomes 4, 8, 10, 11 and 15 displayed more than 1000 aberrational oligonucleotides, while chromosomes 3, 17, 18 and 19 displayed less than 20. The largest region of gain was located on chromosome 8 and its size was no less than 26.7 Mb (Chr8:8427841-35162415), while chromosome 4 had the longest region of single deletion, with a size of 15.1 Mb (Chr4:73265785-88374165).

• Journal of Life Science
• /
• v.14 no.6 s.67
• /
• pp.1023-1027
• /
• 2004

The RAD3 gene of Saccharomyces cerevisiae is essential for the incision step of UV-induced excision repair. An yeast RAD3 gene has been previously isolated by functional complementation. In order to identify the RAD3 homologous gene from fungus Coprinus cinereus, we have constructed cosmid libraries from electrophoretically separated chromosomes of the C. cinereus. The 13 C. cinereus chromosomes were resolved by pulse-field gel electrophoresis, hybridized with S. cerevisiae RAD3 DNA, and then isolated RAD3 homologous DNA from C. cinereus chromosome. The RAD3 homolog DNA was contained in 3.2 kb DNA fragment. Here, we report the results of characterization of a fungus C. cinereus homolog to the yeast RAD3 gene. Southern blot analysis confirmed that the C. cinereus chromosome contains the RAD3 homolog gene and this gene exists as a single copy in C. cinereus genome. When total RNA isolated from the C. cinereus cells were hybridized with the 3.4 kb PvuII DNA fragment of the S. cerevisiae RAD3 gene, transcripts size of 2.8 kb were detected. In order to investigate whether the increase of the amount of transcripts by DNA damaging agent, transcript levels were examined after treating agents to the cells. The level of transcripts were not increased by untraviolet light (UV). This result indicated that the RAD3 homologous gene is not UV inducible gene. Gene deletion experiments indicate that the HRD3 gene is essential for viability of the cells and DNA repair function. These observations suggest an evolutionary conservation of other protein components with which HRD3 interacts in mediating its DNA repair and viability functions.

• Journal of Genetic Medicine
• /
• v.10 no.2
• /
• pp.99-103
• /
• 2013

Purpose: This study was designed to determine the frequency and echocardiographic findings of 22q11.2 deletions in fetuses with cardiac defects on fetal ultrasound or familial backgrounds of 22q11.2 deletions. Materials and methods: We retrospectively reviewed the medical and ultrasonographic records of 170 fetuses that underwent fluorescence in situ hybridization (FISH) analysis for chromosome 22q11.2 deletions between February 2001 and April 2013. Results: Among 145 fetuses with cardiac defects, six (4.1%) had 22q11.2 deletions. Deletions of 22q11.2 were detected in 6 (5%) of the 120 fetuses with conotruncal defects: 5 (8.9%) of 56 with tetralogy of Fallot (TOF) and 1 (5.9%) of 17 with double outlet right ventricle (DORV). No deletions were found in cases of pulmonary atresia, truncus arteriosus, right aortic arch, or transposition of the great arteries. No 22q11.2 deletions were found in non-conotruncal cardiac malformations. Among 25 fetuses with familial backgrounds of 22q11.2 deletions, one (4%) had a maternally inherited 22q11.2 deletion with no cardiac findings. Conclusion: Knowledge of the frequency and echocardiographic findings of 22q11.2 deletions might be helpful for prenatal genetic counseling. It is advisable to perform FISH analysis for 22q11.2 deletions in pregnancies exhibiting conotruncal cardiac defects such as TOF or DORV.

• Korean Journal of Head & Neck Oncology
• /
• v.9 no.1
• /
• pp.25-32
• /
• 1993

The nodular hyperplasia of the thyroid is a common thyriod disease. Nodular hyperplasia does rarely progress to thyroid cancer. The differentiation of a nodular hyperplasia from a neoplasm may be simple or difficult, both clinically and anatomically. The papillary carcinoma of the thyroid is the most common type of thyroid malignancies. There were few studies about cytogenetic observation in thyroid cancer. But only one case of banding observation in nodular hyperplasia have been reported. In order to compare the chromosomal changes in the thyroid cancer and the noncancerous thyroid disease, we performed cytogenetic analysis in two papillary carcinoma and two nodular hyperplasia after cell culture. The chromosomal pattern of the nodular hyperplasia found was very heterogenous but no clonal abnormaly in both cases was observed. Case I : A modal chromosomal number was in 42-46 range. Chromosome 8, 19, 21. 22 were commonly lost. 9 structural anomalities among 51 analysed cells were observed but they were not clonal. Case II: A modal chromosomal number was 43. Chromosome 17 and 19 were commonly lossed. Common cytogenetic characters of this two nodular hyperplasia are hypodiploidity and very heterogenous chromosomal pattern. The result about the papillary carcinoma are as follow. In one case some numerical and structural chromosomal changes were observed. But they were not clonal abnormality. In another case the chromosomal pattern found was very heterogenous with a clonal abnormality of del(11)(q23). The modal number was 46. The del(11)(q23) a chromosomal change in papillary carcinoma of the thyroid have previously been reported(Eva Olah et al. 1989). We suggest that 11q deletion may be important role to pathogenesis of papillary carcinoma of the thyroid. According to this results, we could not find out specific differences about chromosomal changes and any relationship between the papillary carcinoma and the nodular hyperplasia.

• Journal of Genetic Medicine
• /
• v.2 no.1
• /
• pp.35-39
• /
• 1998

Duchenne/Becker muscular dystrophy are the major neuromuscular disorders with X-linked recessive inheritance. Preimplantation diagnosis of sex determination has been generally used to avoid male pregnancies with these diseases. However, in order to determine if the embryo is normal, carrier or affected regardless of the sex, there is a need for a combined analysis of specific exon on dystrophin gene as well as sex determination of embryo using the same biopsied blastomere. If the exon deletion is not determinable, further diagnosis of carrier or patient can be performed by haplotype analysis. In this study, we applied the primer extension preamplification (PEP) method, which amplifies the whole genome, in 40 cases of single amniocyte and 40 cases of chorionic villus cell. We analysed haplotypes using two (CA)n dinucleotide polymorphic markers located at the end of 5' and 3' region of the dystrophin gene. Exon 46 of dystrophin gene and DYZ3 on chromosome Y were chosen as a target sequence for coamplification PCR. Upon optimizing the conditions, the amplification rates were 91.25% (73/80) for haplotypes (92.5% in amniocyte, 90% in chorionic villus cell) and 88.75% (71/80) for coamplification (85% in amniocyte, 92.5% in chorionic villus cell). The result of the study indicates that haplotypes analysis and coamplification of dystrophin and Y-specific gene using PEP can be applied to prenatal and preimplantation diagnosis in Duchenne/Becker muscular dystrophy making it possible to determine if the fetus is a carrier or an affected one.

• Clinical and Experimental Pediatrics
• /
• v.52 no.6
• /
• pp.701-704
• /
• 2009

SmithMagenis syndrome (SMS) is a rare disorder with multiple congenital anomalies caused by a heterozygous interstitial deletion involving chromosome 17p11.2, where the retinoic acid-induced 1 (RAI1) gene is located, or by a mutation of RAI1. Approximately 90% of the patients with SMS have a detectable 17p11.2 microdeletion on fluorescence in-situ hybridization (FISH). SMS is characterized by mental retardation, distinctive behavioral features, craniofacial and skeletal anomalies, speech and developmental delay, and sleep disturbances. Although there are some intervention strategies that help individuals with SMS, there are no reported specific interventions for improving the outcome in children with SMS. Here, we report two cases of SmithMagenis syndrome.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.2
• /
• pp.415-424
• /
• 2010

The purpose of this study was to investigate the relationship between the global regulatory mechanism known as quorum sensing and expression of virulence factors in Escherichia coli O157:87. A nonpolar luxS deletion was introduced into the chromosome of strain CI03J, a human clinical isolate from South Korea, to create the ${\Delta}luxS$ mutant strain ML03J. Phenotypic characterization of wild-type and mutant strains demonstrated that ML03J had no obvious growth or metabolic defects on 0.2% glucose LB medium, produced a functionally defective flagellum, and could not utilize sorbose; the biological significance of sorbose utilization is unknown. Omics-based analysis revealed the involvement of LuxS in the transcriptional activation of several flagella/chemotaxisrelated genes (flhD; fliA, C, D, S, Z; and cheA, Y, Z), repression of glutamate-dependent acid resistance genes (gadAB), and expression of virulence factors including Shiga toxin, hemolysin, and SepD within the LEE pathogenicity island.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.35 no.1
• /
• pp.1-6
• /
• 2009

DNA double-strand breaks (DSBs) occur commonly in the all living and in cycling cells. They constitute one of the most severe form of DNA damage, because they affect both strand of DNA. DSBs result in cell death or a genetic alterations including deletion, loss of heterozygosity, translocation, and chromosome loss. DSBs arise from endogenous sources like metabolic products and reactive oxygen, and also exogenous factors like ionizing radiation. Defective DNA DSBs can lead to toxicity and large scale sequence rearrangement that can cause cancer and promote premature aging. There are two major pathways for their repair: homologous recombination(HR) and non-homologous end-joining(NHEJ). The HR pathway is a known "error-free" repair mechanism, in which a homologous sister chromatid serves as a template. NHEJ, on the other hand, is a "error-prone" pathway, in which the two termini of the broken DNA molecule are used to form compatible ends that are directly ligated. This review aims to provide a fundamental understanding of how HR and NHEJ pathways operate, cause genome instability, and what kind of genes during the pathways are associated with head and neck cancer.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.8 no.1
• /
• pp.133-138
• /
• 1997

Prader Willi Syndrome(PWS) was first recognized and reported by Prader-Willi. The etiology of the syndrome is not fully understood, but 50-70% of the patients show small deletion in chromosome 15. Manifested symtoms vary according to developmental age. In early life, hypotonia, areflexia, feeding difficulties, hypothermia, microgenitalia, hypoplastic scrotum, cryptochordism were observed. But in several years, hypotonia disappears, and polyphagia, decreased satiety, psychomotor retardation, obesity, hypogonadism and short stature become main problems. Behavioural problems including temper and aggressive outbursts, stealing food, hoarding food, and self excoriating skin picking, trichotillomania are more prominent during adolescence and young adulthood. Also, irritable, depressed mood are described. Lots of psychological and behavioural problems explain the reason why psychiatrists have managed and reported this syndrome. However, there has been no official report of PWS in our country. So authors report the clinical characteristics and issues in management of a patient with PWS.

• Toxicological Research
• /
• v.18 no.2
• /
• pp.129-138
• /
• 2002

The mouse lymphoma assay (MLA) has been recently validated as a sensitive and specific test system to determine the genotoxic potential for a chemical. The objective of this study is to evaluate the utility of MLA for detecting mutagens. Especially, to compare MLA with the in vitro chromosomal aberration test (CA), we performed MLA using the microwell method with three chemicals (hydroxyurea, theophylline and amino acid copper complex), which were reportedly positive in the CA. In cell treated with hydroxyurea, anti-neoplastic agent that blocks DNA replication, evidence of a positive response was obtained without S9 mix for 4 h and 24 h. In addition, analysis of colony size distribution at concentration that gave an elevated mutant fraction showed that hydroxyurea induced a high proportion of small type colonies, indicating that hydroxyurea-induced mutation is associated with large chromosomal deletion. Conversely, negative MLA result was obtained for theophylline, which was wed as central nervous system stimulator. Although theophylline increased the mutant frequency at concentration of 1250 $\mu\textrm{g}$/$\textrm{m}{\ell}$ with S9 mix for 4 h, a concentration-related increase in mutant frequency was not observed. The MLA result of amino acid copper complex was considered equivocal because the positive result was obtained at concentration showing 10% or less RS or RTG. Thus, among 3 CA-positive chemicals, positive MLA result was obtained for one. The other two chemicals were negative and equivocal. However MLA, which evaluates mutagenic potential of chemicals through colony formation by cell grouth, may provide a higher predictivity of carcinogenesis than CA.