• Asian Pacific Journal of Cancer Prevention
• /
• 제16권17호
• /
• pp.7929-7933
• /
• 2015

Background: The incidence of breast cancer in India is on the rise and is rapidly becoming the number one cancer in females, pushing the cervical cancer to the second position. Most of the predisposition to hereditary breast and ovarian cancer has been attributed to inherited defects in two tumor suppressor genes BRCA1 and BRCA2. Alterations in these genes have been reported in different populations, some of which are population-specific mutations showing founder effects. Two specific mutations in the BRCA1 (185delAG) and BRCA2 (6174delT) genes have been reported to be of high prevalence in different populations. The aim of this study was to estimate the carrier frequency of 185delAG and 6174delT mutations in eastern Indian breast cancer patients. Materials and Methods: We selected 231 histologically confirmed breast cancer patients from our tertiary cancer care center in eastern India. Family history was obtained by interview or a self-reported questionnaire. The presence of the mutation was investigated by allele specific duplex/multiplex-PCR on genomic DNA extracted from peripheral blood. Results: A total of 231 patients (age range: 26-77 years), 130 with a family history and 101 without were screened. The two founder mutations 185delAG in BRCA1 and 6174delT in BRCA2 were not found in any of the subjects. This was confirmed by molecular analysis. Conclusions: Our findings suggest that these BRCA mutations may not have a strong recurrent effect on breast cancer among the eastern Indian population. The contribution of these founder mutations to breast cancer incidence is probably low and could be limited to specific subgroups. This may be particularly useful in establishing further pre-screening strategies.

• 식물분류학회지
• /
• 제45권3호
• /
• pp.254-261
• /
• 2015

분비나무와 구상나무의 계통지리적 유연관계 파악을 위하여 16개 지역의 구상나무와 분비나무 집단에 대하여 미토콘드리아 DNA(nad5 intron 4, nad5 intron 1 지역)를 이용한 유전적 분석을 수행하였다. 그 결과 총 7 지역의 유전자 변이가 확인되었으며, 4개의 반수체형이 확인되었다. 개체군 내 평균 유전다양성($H_S$)은 0.098, 전체 유전다양성($H_T$)은 0.620으로 관찰되었으며, 개체군 간 분화값은 $G_{ST}=0.841$, $N_{ST}=0.849$로 확인되었다. 조사 개체의 지리적 위치에 따라 일본지역을 제외하고 3개의 그룹(북부지역, 중부지역, 남부지역)으로 나누었다. 북부지역과 남부지역은 대부분 각각 M1, M2 단일의 반수체형을 가지며, 중부지역은 북부지역과 남부지역의 분포경계에 위치하면서 유전자 유입으로 인해 유전 다양성 ($H_T=0.654$) 이 가장 높게 나타난 것으로 판단된다. 현재 남부지역의 단일의 반수체형(M2) 분포는 빙하기 때 북부지역에서 남하한 개체군들이 지리적 격리를 통해 분화하게 되고 빙하기 이후 다시 중부지역까지 분포 확장된 결과로 추측된다.

• 환경생물
• /
• 제22권1호
• /
• pp.66-74
• /
• 2004

한국에 분포하고 있는 개구리 속에 대한 염기서열을 결정하고 상호 비교하여 종간 유전적 변이 정도를 밝히고자 한국산 개구리 속 6종과 일본산 개구리 속 1종에 대한 미토콘드리아 165 rDNA를 분석하였으며, Gene-bank에 수록된 일본산 산개구리류 3종도 함께 비교 분석하여 총 437 bp의 염기서열을 결정하였다. 산개구리류 7종에 대한 similarity는 91.3∼97.3％이며, 참개구리류는 96.1∼97.3％로 나타났다. 또한, 참개구리류와 옴개구리류의 genetic distance가 참개구리류와 산개구리류보다 더 가깝게 나타났다. Neighbor-joining분석에서 참개구리류와 산개구리류로 2개의 cluster를 형성하였는데, 이 중산개구리류는 총 3개의 subcluster를 형성하였다. 또한, 참개구리는 내륙지방과 도서지방에 분포하는 집단이 각각 나눠지는 것은 지리적 격리에 의한 결과라고 사료된다. Maximum-likelihood분석도 NJ 분석 결과와 매우 유사하게 나타났으나 옴개구리(R. rugosa)는 NJ와 ML분석에서 서로 상반된 결과를 나타냈다. 이는 한국산 옴 개구리가 남부지역과 기타 지역에서 유전적 차이가 크게 나타나며, 일본 집단과 외부 특징에서 차이를 보이는 등 문제점을 가지고 있기 때문에 보다 다양한 연구가 이루어져야 올바른 해석 이 가능하리라 판단된다.

• Animal cells and systems
• /
• 제8권4호
• /
• pp.289-294
• /
• 2004

Bupleurum latissimum is a narrowly endemic and endangered plant, restricted to only two small populations on steep cliffs of a small island, Ulleung Island, in Korea. The genetic diversity and population differentiation in the two remnant populations of the species were investigated using RAPD (random amplified polymorphic DNA) analysis. The Neis gene diversities were 0.146 in the smaller population of 45 individuals, and 0.151 in the larger population of 61 individuals. The genetic variation was not significantly different between these two populations. Genetic diversity within populations was not low considering the very small size of populations. Analysis of molecular variance (AMOVA) revealed higher variation within populations (65.9%) than genetic differentiation between them (34.1%). B. latissimum revealed higher population differentiation than other outbreeding species. The differentiation of the populations corresponded to low gene flow (Nem = 0.482). The cluster and principal coordination analyses provide strong support for high population differentiation, showing that all individuals of the two populations have built up population-specific clusters. Although gene flow between the two populations of B. latissimum was limited, they have preserved relatively high levels of genetic variation.

• Plant Biotechnology Reports
• /
• 제4권3호
• /
• pp.201-211
• /
• 2010

We present a highly effective T-DNA inserted gene screening method as part of a reverse genetics model system using the Chinese cabbage (Brassica rapa L. spp. pekinensis). Three-step two-dimensional (2D) matrix strategies are potentially accurate and useful for the identification of specific T-DNA inserted mutants from a large population. To construct our Chinese cabbage model, we utilized a forward genetics screening approach for the abnormal phenotypes that were obtained from transgenic plants of Brassica rapa generated with Agrobacteria tumefaciens containing the pRCV2 vector. From one transgenic plant with an abnormal phenotype, we observed that the st1 gene (which is related to senescence-associated process proteins) contained a T-DNA fragment, and that its expression level was decreased. This T-DNA insert was then used as a control to construct an effective screening pool. As a result, the optimum template concentration was found to be 0.1-1 ng in our PCR strategy. For other conditions, positive changes to the Gibbs free energy prevented the formation of oligo dimers and hairpin loop structures, and autosegment extension gave better results for long fragment amplification. Using this effective reverse genetics screening method, only 23 PCR reactions were necessary to select a target gene from a pool of 100 individual DNAs. Finally, we also confirmed that the sequence we obtained from the above method was identical to the flanking sequence isolated by rescue cloning.

• Asian Pacific Journal of Cancer Prevention
• /
• 제14권11호
• /
• pp.6929-6933
• /
• 2013

Background: Multiple etiologies have been hypothesized for prostate cancer, including genetic defects and infectious agents. A recently reported gamaretrovirus, xenotropic murine leukemia virus-related virus (XMRV) has been reported to be detected in prostate cancer. However, this virus has not been detected in similar groups of patients in other studies. Herein, we sought to detect XMRV in prostate cancers and benign controls in Sanandaj, west of Iran. Materials and Methods: In a case-control study, genomic DNA was extracted from formalin fixed and paraffin embedded prostate tissues from a total of 163 Iranian patients. We developed a conventional and a nested PCR assay using primers targeting to an env specific sequence of XMRV. PCR assays were carried out on 63 prostate cancers and 100 benign prostate hyperplasias. Results: Beta-actin sequences were successfully detected in the DNA extracts from all prostate tissues, confirming DNA extraction integrity. We did not detect XMRV in samples either from prostate cancers or benign prostate hyperplasias using XMRV specific primers. Conclusions: We conclude that in our population XMRV does not play a role in genesis of prostate cancer.

• Animal cells and systems
• /
• 제5권2호
• /
• pp.153-156
• /
• 2001

A key aspect of genomic research in the “post-genome era”is to associate sequence variations with heritable phenotypes. The most common variations in the human genome are single nucleotide polymorphisms (SNPs) that occur approximately once in every 500 to 1,000 bases. Although analyzing the phenotypic outcome of these SNPs is crucial to facilitate large-scale association studies of genetic diseases, detection of SNPs from an extended number of human DNA samples is often difficult, labor-intensive and time-consuming. Recent development in SNP detection methods using DNA microarrays and mass spectrophotometry has allowed automated high throughput analyses, but such equipments are not accessible to many scientists. In this study, we demonstrate that a simple PCR-based method using primers with a mismatched base at the 3'-end provides a fast and easy tool to identify known SNPs from human genomic DNA in a regular molecular biology laboratory. Results from this PCR amplification of specific alleles (PASA) analysis efficiently and accurately typed the Q576R polymorphism of human IL4 receptor from the genomic DNAs of 29 Koreans, including 9 samples whose genotype could not be discerned by the conventiona1 PCR-SSCP (single strand conformation polymorphism) method. Given the increasing attention to disease-associated polymorphisms in genomic research, this alternative technique will be very useful to identify SNPs in large-scale population studies.

• Asian Pacific Journal of Cancer Prevention
• /
• 제16권2호
• /
• pp.541-549
• /
• 2015

Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer (BC) with higher metastatic rate and both local and systemic recurrence compared to non-TNBC. The generation of reactive oxygen species (ROS) secondary to oxidative stress is associated with DNA damage, chromosomal degradation and alterations of both hypermethylation and hypomethylation of DNA. This study concerns differential methylation of promoter regions in specific groups of genes in TNBC and non-TNBC Saudi females in an effort to understand whether epigenetic events might be involved in breast carcinogenesis, and whether they might be used as markers for Saudi BCs. Methylation of glutathione S-transferase P1 (GSTP1), T-cadherin (CDH13), Paired box protein 5 (PAX5), death associated protein kinase (DAPK), twist-related protein (TWIST), DNA-binding protein inhibitor (ID4), High In Normal-1 (HIN-1), cyclin-dependent kinase inhibitor 2A (p16), cyclin D2 and retinoic acid receptor-${\beta}$ ($RAR{\beta}1$) genes was analyzed by methylation specific polymerase chain reaction (MSP) in 200 archival formalin-fixed paraffin embedded BC tissues divided into 3 groups; benign breast tissues (20), TNBC (80) and non-TNBC (100). The relationships between methylation status, and clinical and pathological characteristics of patients and tumors were assessed. Higher frequencies of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 hypermethylation were found in TNBC than in non-TNBC. Hypermethylation of GSTP1, CDH13, ID4, DAPK, HIN-1 and PAX5 increased with tumor grade increasing. Other statistically significant correlations were identified with studied genes. Data from this study suggest that increased hypermethylation of GSTP1, ID4, TWIST, DAPK, PAX5 and HIN-1 genes in TNBC than in non-TNBC can act as useful biomarker for BCs in the Saudi population. The higher frequency of specific hypermethylated genes paralleling tumor grade, size and lymph node involvement suggests contributions to breast cancer initiation and progression.

• 한국발생생물학회지:발생과생식
• /
• 제10권4호
• /
• pp.227-238
• /
• 2006

한반도의 동쪽에 위치해 있는 삼척(venus clam from Samcheok; VCS)과 원산(venus clam from Wonsan; VCW) 지역에서 채취된 민들조개(Gomphina aequilatera)에서 genomic DNAs(gDNAs)를 분리 추출하였다. 증폭산물은 primer agarose 전기영동법에 의해서 생성되었고, EtBr에 의해서 염색된 이후에 자외선에 의해서 확인되었다. 150 bp에서 2,400 bp에 해당되는 shared loci, polymorphic 및 specific loci를 얻기 위해서 BION-21, BION-23, BION-25, BION-27, BION-29, BION-31 및 BION-33와 같은 7개의 primer를 사용하였다. 본 연구에서 7개의 primer는 VCS 민들조개 집단에서 147개의 polymorphic loci(147/954 loci, 15.41%)와 VCW 집단에서 274개의 polymorphic loci(274/996 loci, 27.51%)를 확인하였다. 이것은 VCS 민들조개 집단에서 보다 VCW 집단에서 더 높은 유전적 변이를 나타내고 있다는 것을 제시하고 있다. 특히 BION-21 primer에 의해서 나타난 700 bp는 민들조개 2개 집단에서 공통적으로 확인되었으며, 이러한 것은 집단이나 종을 확인할 수 있는 marker로서 활용이 가능할 것이다. 이러한 특이한 primer는 개체, 종 및 집단에서 서로 다른 DNA 다형성을 나타내며, 개체나 집단을 확인하는 데 유용하다는 것을 알 수 있다. 2개 민들조개 집단의 개체들을 비교해 보았을 때 SAMCHEOK no. 03와 WONSAN no. 22에서 가장 긴 유전적 거리(0.696)를 나타내었다. 3개의 genetic groupings and dendrogram을 포함한 complete linkage cluster analysis을 통해서 볼 때 지리적 거리가 있었지만 삼척과 원산 2 민들조개 집단의 개체 정체성과 다소 가까운 친척관계를 확인시켜 주었다. 분자적인 표지인자로부터 얻어진 종내 분류와 clustering analyses은 패각 크기, 패각 형태 및 패각 색깔과 같은 형태적인 형질을 기초한 재래적인 종 분류를 지원하고 있다. 따라서 위에서 언급된 바와 같이 RAPD 분석은 VCS 민들조개 집단이 VCW 집단과 어느 정도 차이가 있다는 것을 확인시켜 주었다.

• Genomics & Informatics
• /
• 제12권1호
• /
• pp.42-47
• /
• 2014

Asian populations contain a variety of ethnic groups that have ethnically specific genetic differences. Ethnic variants may be highly relevant in disease and human differentiation studies. Here, we identified ethnically specific variants and then investigated their distribution across Asian ethnic groups. We obtained 58,960 Pan-Asian single nucleotide polymorphisms of 1,953 individuals from 72 ethnic groups of 11 Asian countries. We selected 9,306 ethnic variant single nucleotide polymorphisms (ESNPs) and 5,167 ethnic variant copy number polymorphisms (ECNPs) using the nearest shrunken centroid method. We analyzed ESNPs and ECNPs in 3 hierarchical levels: superpopulation, subpopulation, and ethnic population. We also identified ESNP- and ECNP-related genes and their features. This study represents the first attempt to identify Asian ESNP and ECNP markers, which can be used to identify genetic differences and predict disease susceptibility and drug effectiveness in Asian ethnic populations.