• Mycobiology
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• v.42 no.1
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• pp.46-51
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• 2014

A degenerated strain of Pleurotus eryngii KNR2312 was isolated from a commercial farm. Random amplified polymorphic DNA analysis performed on the genomic DNA of the normal and degenerated strains of this species revealed differences in the DNA banding pattern. A unique DNA fragment (1.7 kbp), which appeared only in the degenerated strain, was isolated and sequenced. Comparing this sequence with the KNR2312 genomic sequence showed that the sequence of the degenerated strain comprised three DNA regions that originated from nine distinct scaffolds of the genomic sequence, suggesting that chromosome-level changes had occurred in the degenerated strain. Using the unique sequence, three sets of PCR primers were designed that targeted the full length, the 5' half, and the 3' half of the DNA. The primer sets P2-1 and P2-2 yielded 1.76 and 0.97 kbp PCR products, respectively, only in the case of the degenerated strain, whereas P2-3 generated a 0.8 kbp product in both the normal and the degenerated strains because its target region was intact in the normal strain as well. In the case of the P2-1 and P2-2 sets, the priming regions of the forward and reverse primers were located at distinct genomic scaffolds in the normal strain. These two primer sets specifically detected the degenerate strain of KNR2312 isolated from various mushrooms including 10 different strains of P. eryngii, four strains of P. ostreatus, and 11 other wild mushrooms.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.10
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• pp.5229-5232
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• 2012

The incidence of malignant melanoma increases with age. One significiant effect of aging processes is an accumulation of oxidative damage in the genetical material. In this study, the relationship between malignant melanoma and damage in chromosomes and proliferative effectiveness of human peripheral lymphocytes were investigated by the micronucleus (MN) technique. A total of 15 malignant melanoma patients and appropriately matching 15 healthy controls were involved in the study. MN frequencies and proliferative indexes (PI) after non toxic levels of hydrogen peroxide treatment were also measured to determine damaging effect of oxidative stress in genome in addition to measuring the spontenous levels of micronuclei and PI. The patient group had a significantly higher rate of spontaneous MN than the control group (p<0.01). After treatment with $H_2O_2$, MN frequencies in the patient group was significantly decreased (p<0.01) although there was no difference between the treated and untreated results of control group (p=0.29). There was also difference (p<0.01) between the MN frequencies of the patient and the control group either in the spontaneous levels or in the $H_2O_2$ treated groups. The same significant difference persisted when the PI values were compared between patient and control groups. Increase in the MN frequency in patients could mean the alterations in the chromosomal structure which may lead to the chromosome instability and therefore genetic susceptibility to cancer. This increased number of micronuclei can also be used for cytological marker in identifying high risk cases for malignant melanoma.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5391-5397
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• 2012

Background: Neuroblastoma (NB), like most human cancers, is characterized by genomic instability, manifested at the chromosomal level as allelic gain, loss or rearrangement. Genetics methods, as well as conventional and molecular cytogenetics may provide valuable clues for the identification of target loci and successful search for major genes in neuroblastoma. We aimed to investigate AURKA and MYCN gene rearrangements and the chromosomal aberrations (CAs) to determine the prognosis of neuroblastoma. Methods: We performed cytogenetic analysis by G-banding in 25 cases [11 girls (44%) and 14 boys (66%)] and in 25 controls. Fluorescence in situ hybridization (FISH) with AURKA and MYCN gene probes was also used on interphase nuclei to screen for alterations. Results: Some 18.4% of patient cells exhibited CAs., with a significant difference between patient and control groups in the frequencies (P<0.0001). Some 72% of the cells had structural aberrations, and only 28% had numerical chnages in patients. Structural aberrations consisted of deletions, translocations, breaks and fragility in various chromosomes, 84% and 52% of the patients having deletions and translocations, respectively. Among these expressed CAs, there was a higher frequency at 1q21, 1q32, 2q21, 2q31, 2p24, 4q31, 9q11, 9q22, 13q14, 14q11.2, 14q24, and 15q22 in patients. 32% of the patients had chromosome breaks, most frequently in chromosomes 1, 2, 3, 4, 5, 8, 9, 11, 12, 19 and X. The number of cells with breaks and the genomic damage frequencies were higher in patients (p<0.001). Aneuploidies in chromosomes X, 22, 3, 17 and 18 were most frequently observed. Numerical chromosome abnormalities were distinctive in 10.7% of sex chromosomes. Fragile sites were observed in 16% of our patients. Conclusion: Our data confirmed that there is a close correlation between amplification of the two genes, amplification of MYCN possibly contributing significantly to the oncogenic properties of AURKA. The high frequencies of chromosomal aberrations and amplifications of AURKA and MYCN genes indicate prognostic value in children with neuroblastomas and may point to contributing factors in their development.

• Journal of Life Science
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• v.19 no.10
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• pp.1463-1467
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• 2009

Telomeres, comprised of tandem repeats of TTAGGG sequences, are special nucleoprotein structures that protect and stabilize chromosome ends. These structures form the crux of the telomere concept of aging, senescence and genomic instability. The classic terminal restriction fragment (TRF) analysis to quantify the amount of telomeric DNA is disadvantageous in species containing ultra long telomeres like in mice (100Kb). In this study, we used a more sensitive quantitative fluorescence in situ hybridization (Q FISH) technique to quantify telomeric DNA, and used it as a biological aging marker in mice. 12 litters each of Senescence-Resistant (SAMR1) and -Prone (SAMP1) known as senescence accelerated mouse strains were purchased from Central Lab, Animal Inc. We quantified the amount of telomeric DNA using telomere specific DNA probes on the two strains of male mice at 8 weeks, 18 weeks and 26 weeks of age. The amount of telomeric DNA correlated with aging and age associated changes in body and organ weight between SAMR1 and SAMP1 strains of mice. These data suggest the usefulness of the amount of telomeric DNA as a biological aging marker in human aging studies.

• Journal of Life Science
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• v.16 no.6
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• pp.1036-1043
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• 2006

The transformation-associated recombination (TAR) cloning technique allows selective isolation of chromosome regions or genes from complex genome. The procedure requires knowledge of relatively small genomic sequences that reside adjacent to the chromosome region of interest. This method involves homologous recombination during spheroplast transformation between genomic DNA and a TAR vector that has 5' and 3' gene targeting sequences (hooks). To examine whether TAR cloning can be applied to the isolation of gene homologues, we chose the HPRT genes from human and mouse genome. As results, the yield of positive clones for HPRT gene from human and mouse genome when using a TAR vector containing mHPRT hook or hHPRT hook was almost same level. Analysis of the gap regions in mHPRT revealed that they contain abnormalities that could result in instability of the sequences. In conclusion, we were able to use the TAR cloning technology to isolate gene homologue (orthologue) from nonidentical genome. Moreover, the use of the TAR cloning system may accelerate work on closing the remaining gaps in mammalian genome to achieve the goal of annotation of all mammalian genes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.1
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• pp.1-6
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• 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 Genetic Medicine
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• v.1 no.1
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• pp.27-31
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• 1997

Steroid 21 hydroxylase deficiency is a major cause of congenital adrenal hyperplasia (CAH) and is caused by genetic impairment of the gene (CYP21B). In the human genome, CYP21B is located within the MHC class III region on the short arm of chromosome 6. Most of the genes in this region are highly polymorphic and crowded. Also the CYP21B gene is accompanied by its pseudogene (CYP21A) and tandemly arranged with two genes of fourth component of complement. This highly complex gene cluster in this area may predispose genetic instability of CYP21, i.e. mutations. In this study, tried to investigate the frequency of duplication and deletion of CYP21 and patterns of the genetic alterations of these genes.We also compared the genetic alteration in normal subjects with those of the CAH patients. The results showed that 15% of the normal korean population have duplication or deletion of CYP21. There was one normal subject with heterozygous deletion of CYP21B. Of the 5 CAH patients examined, 2 were found to show abnormal patterns. One was a large-scale gene conversion and the other a gene conversion associated with deletion involving both CYP21B and C4 locus II gene. Through this study, we carne to the conclusion that the duplication or even deletion of CYP21 and C4 might be quite a common event in the Korean population and these rearrangements must be regarded as polymorphisms. It could contribute to a high incidencs of CAH by providing a genetic pool of instable CYP21.