• Asian-Australasian Journal of Animal Sciences
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• 제33권1호
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• pp.12-23
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• 2020

Objective: The objective of a conservation program is to maintain maximum genetic diversity and preserve the viability of a breed. However, the efficiency of a program is influenced by the ability to accurately measure and predict genetic diversity. Methods: To examine this question, we conducted a simulation in which common measures (i.e. heterozygosity) and novel measures (identity-by-descent probabilities and parental genomic components) were used to estimate genetic diversity within a conserved population using double-labeled single nucleotide polymorphism markers. Results: The results showed that the accuracy and sensitivity of identity-by-state probabilities and heterozygosity were close to identity by descent (IBD) probabilities, which reflect the true genetic diversity. Expected heterozygosity most closely aligned with IBD. All common measures suggested that practices used in the current Chinese pig conservation program result in a ~5% loss in genetic diversity every 10 generations. Parental genomic components were also analyzed to monitor real-time changes in genomic components for each male and female ancestor. The analysis showed that ~7.5% of male families and ~30% of female families were lost every 5 generations. After 50 generations of simulated conservation, 4 male families lost ~50% of their initial genomic components, and the genomic components for 24.8% of the female families were lost entirely. Conclusion: In summary, compared with the true genetic diversity value obtained using double-labeled markers, expected heterozygosity appears to be the optimal indicator. Parental genomic components analysis provides a more detailed picture of genetic diversity and can be used to guide conservation management practices.

• Asian-Australasian Journal of Animal Sciences
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• 제33권10호
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• pp.1558-1565
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• 2020

Objective: The objective of this study was to characterize the number of loci affecting growth traits and the distribution of single nucleotide polymorphism (SNP) effects on growth traits, and to understand the genetic architecture for growth traits in Hanwoo (Korean cattle) using genome-wide association study (GWAS), genomic partitioning, and hierarchical Bayesian mixture models. Methods: GWAS: A single-marker regression-based mixed model was used to test the association between SNPs and causal variants. A genotype relationship matrix was fitted as a random effect in this linear mixed model to correct the genetic structure of a sire family. Genomic restricted maximum likelihood and BayesR: A priori information included setting the fixed additive genetic variance to a pre-specified value; the first mixture component was set to zero, the second to 0.0001×σ²_g, the third 0.001×σ²_g, and the fourth to 0.01×σ²_g. BayesR fixed a priori information was not more than 1% of the genetic variance for each of the SNPs affecting the mixed distribution. Results: The GWAS revealed common genomic regions of 2 Mb on bovine chromosome 14 (BTA14) and 3 had a moderate effect that may contain causal variants for body weight at 6, 12, 18, and 24 months. This genomic region explained approximately 10% of the variance against total additive genetic variance and body weight heritability at 12, 18, and 24 months. BayesR identified the exact genomic region containing causal SNPs on BTA14, 3, and 22. However, the genetic variance explained by each chromosome or SNP was estimated to be very small compared to the total additive genetic variance. Causal SNPs for growth trait on BTA14 explained only 0.04% to 0.5% of the genetic variance Conclusion: Segregating mutations have a moderate effect on BTA14, 3, and 19; many other loci with small effects on growth traits at different ages were also identified.

• Asian Pacific Journal of Cancer Prevention
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• 제17권5호
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• pp.2625-2628
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• 2016

ABCC11 is reported to be associated with breast cancer. However, whether ABCC11 polymorphisms relate to breast cancer risk remains unclear. This study aimed to evaluate any association of a single nucleotide polymorphism (SNP), rs17822931, in ABCC11 with breast cancer in Koreans. Genomic DNA samples of 170 women with breast cancer and 100 controls were assessed for SNP rs17822931 of ABCC11 by single-strand conformation polymorphism (SSCP) and DNA sequencing. A 27-bp deletion (${\Delta}27$) of ABCC11 was analyzed by PCR amplification. The genotype of SNP rs17822931 was confirmed to be AA in all samples from breast cancer patients and ${\Delta}27$ was found in none of the samples. Our finding indicated that the SNP rs17822931 in ABCC11 is not associated with breast cancer. However, this study does provide information on fundamental genetic aspects of ABCC11 with regard to breast cancer risk in Koreans.

• 대한의생명과학회지
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• 제8권1호
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• pp.39-46
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• 2002

Amplified fragment length polymorphism (AFLP) is a recently developed PCR-based high resolution fingerprinting method that is able to generate complex banding patterns which can be used to delineate intraspecific genetic relationships among bacteria. In this study, we have modified and evaluated a PCR-based technique, amplified fragment length polymorphism (AFLP) analysis, for use in fingerprinting strains of Staphylococcus aureus. Single-enzyme amplified fragment length polymorphism (SE-AFLP) analysis was used to perform strain identification of Staphylococus aureus. By careful selection of AFLP primers, it was possible to obtain reproducible and sensitive identification to strain level. AFLP fingerprinting of 5 reference strains of Staphylococcus aureus and 65 strains of Staphylococcus aureus that were isolated from food sources of different area and diverse genomic types of Staphylococcus aureus were recognized. As a result of this study, we found that the AFLP patterns of Staphylococcus aureus isolated from Seoul, Taejeon and Gwang-Ju indicated the close relation with genetic similarity. The main purpose of this study was to find an alternative and reliable fingerprinting method to study the overall genetic diversity, using Staphylococcus aureus species as an example, and observed if the method can be successfully applied to all staphylococcal species.

• Genomics & Informatics
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• 제9권2호
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• pp.64-68
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• 2011

Monomelic amyotrophy (MA), also known as Hirayama disease, occurs mainly in young men and manifests as weakness and wasting of the muscles of the distal upper limbs. Here, we sought to identify a genetic basis for MA. Given the predominance of MA in males, we focused on candidate neurological disease genes located on the X chromosome, selecting two X-linked candidate genes, androgen receptor (AR ) and ubiquitin-like modifier activating enzyme 1 (UBA1). Screening for genetic variants using patients' genomic DNA revealed three known genetic variants in the coding region of the AR gene: one nonsynonymous single-nucleotide polymorphism (SNP; rs78686797) encoding Leu57Gln, and two variants of polymorphic trinucleotide repeat segments that encode polyglutamine (CAG repeat; rs5902610) and polyglycine (GGC repeat; rs3138869) tracts. Notably, the Leu57Gln polymorphism was found in two patients with MA from 24 MA patients, whereas no variants were found in 142 healthy male controls. However, the numbers of CAG and GGC repeats in the AR gene were within the normal range. These data suggest that the Leu57Gln polymorphism encoded by the X-linked AR gene may contribute to the development of MA.

• 식물조직배양학회지
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• 제24권2호
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• pp.113-117
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• 1997

Simple sequence repeats (SSR)는 진핵생물체에 널리 산재되어 있으며, 큰 다형현상을 나타내고, polymerase chain reaction (PCR)으로 쉽게 분석된다. 이 연구의 목적은 서로 다른 Chlamydomonas reinhardtii계통간의 다형현상과 Chlamydomonas의 SSR 좌위에서의 유전양상을 결정하는데 있었다. C. reinhardtii의 genomic DNA library를 만들어 $^{32}$P로 라벨링한 (AC)$_{11}$ probe를 이용하여 (CA/GT)n 반복서열을 가지는 clone을 선택하기위해 screen하였다. 선택된 clone을 sequencing하여 (CA/GT)n sequence에 인접한 PCR primer set를 제조하였다. PCR은 여러 C. reinhardtii 계통의 SSR 좌위를 증폭하기 위하여 사용하였다. 그 좌위는 및몇 C. reinhardtii 계통에서 다형현상을 보였다. 그러나 그 좌위에서 C. reinhardtii의 6계통중 4계통만 DNA가 PCR 증폭을 하였고 2계통은 증폭을 하지 않았다. C. reinhardtii와 C. smithii의 교배로 생긴 4배체에서 2:2의 분리비를 보여주었는데, 이는 단순한 멘델의 유전양상을 나타낸다. 이러한 결과로 미루어 SSR 다형현상은 Chlamydomonas의 개체 식별, 개체군 연구, 연쇄 분석, 그리고 유전자 지도 작성을 하는데 유용할 것이다.다.

• 분석과학
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• 제17권1호
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• pp.53-59
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• 2004

현재 일반적으로 많이 사용되는 single strand conformation polymorphism (SSCP)나 denaturing gradient gel electrophoresis (DGGE)같은 돌연변이 검출법은 많은 시간과 비용, 그리고 노동력이 소모된다는 단점과 실험자의 실험에 대한 숙련도에 의해 실험 결과가 달라지는 한계점을 가지고 있다. 이런 단점들을 보완하기 위하여 ion-pair reversed phase chromatography (IP-RPC)방식을 이용한 denaturing high performance liquid chromatography (DHPLC)방법을 사용하여 기관지 천식 (bronchial asthma)을 조절하는 베타2-교감신경수용체 유전자의 돌연변이를 검출하였다. 80명의 천식 환자의 혈액에서 genomic DNA를 추출하여 중합효소연쇄반응 (polymerase chain reaction)을 이용해 증폭하고, 그 산물을 SSCP와 DHPLC로 분석하였다. 그 결과, 베타2-교감신경수용체 유전자에서 SSCP는 80명의 sample 가운데 19개 (23.75%)의 돌연변이를 검출하였고, DHPLC는 25개 (31.25%)의 변이를 검출하였다. 돌연변이 검출법으로 DHPLC 분석법이 SSCP보다 더 빠르고 효과적인 방법임을 확인하였다.

• Genomics & Informatics
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• 제8권3호
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• pp.138-141
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• 2010

Together with single nucleotide polymorphism (SNP), copy number variations (CNV) are recognized to be the major component of human genetic diversity and used as a genetic marker in many disease association studies. Affymetrix Genome-wide SNP 5.0 is one of the commonly used SNP array platforms for SNP-GWAS as well as CNV analysis. However, there has been no report that validated the accuracy and reproducibility of CNVs identified by Affymetrix SNP array 5.0. In this study, we compared the characteristics of CNVs from the same set of genomic DNAs detected by three different array platforms; Affymetrix SNP array 5.0, Agilent 2X244K CNV array and NimbleGen 2.1M CNV array. In our analysis, Affymetrix SNP array 5.0 seems to detect CNVs in a reliable manner, which can be applied for association studies. However, for the purpose of defining CNVs in detail, Affymetrix Genome-wide SNP 5.0 might be relatively less ideal than NimbleGen 2.1M CNV array and Agilent 2X244K CNV array, which outperform Affymetrix array for defining the small-sized single copy variants. This result will help researchers to select a suitable array platform for CNV analysis.

• 농업과학연구
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• 제44권4호
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• pp.495-503
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• 2017

Genotyping-by-sequencing (GBS) is an outstanding technology for genotyping and single nucleotide polymorphism (SNP) discovery compared to next generation sequencing (NGS) because it can save time when analyzing large-scale samples and carries a low cost per sample. Recently, studies using GBS have been conducted on major crops and, to a greater extent, on fruit crops. However, many researchers have some problems due to low GBS efficiency resulting from low quality GBS libraries. To overcome this limitation, we developed an efficient GBS library construction method that regulates important conditions such as restriction enzymes (RE) digestion and a PCR procedure for grapevine. For RE digestion, DNA samples are digested with ApeKI (3.6U) at $75^{\circ}C$ for 5 hours and adapters are ligated to the ends of gDNA products. To produce suitable PCR fragments for sequencing, we modified the PCR amplification conditions; temperature cycling consisted of $72^{\circ}C$ (5 min), $98^{\circ}C$ (30 s), followed by 16 cycles of $98^{\circ}C$ (30 s), $65^{\circ}C$ (30 s), $72^{\circ}C$ (20 s) with a final extension step. As a result, we had obtained optimal library construct sizes (200 to 400 bp) for GBS analysis. Furthermore, it not only increased the mapping efficiency by approximately 10.17% compared to the previous method, but also produced mapped reads which were distributed equally on the19 chromosomes in the grape genome. Therefore, we suggest that this system can be used for various fruit crops and is expected to increase the efficiency of various genomic analysis performed.

• Animal Bioscience
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• 제37권4호
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• pp.555-566
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• 2024

Objective: This study aimed to assess the genetic parameters and accuracy of genomic predictions for twenty-four linear body conformation traits and overall conformation scores in Korean Holstein dairy cows. Methods: A dataset of 2,206 Korean Holsteins was collected, and genotyping was performed using the Illumina Bovine 50K single nucleotide polymorphism (SNP) chip. The traits investigated included body traits (stature, height at front end, chest width, body depth, angularity, body condition score, and locomotion), rump traits (rump angle, rump width, and loin strength), feet and leg traits (rear leg set, rear leg rear view, foot angle, heel depth, and bone quality), udder traits (udder depth, udder texture, udder support, fore udder attachment, front teat placement, front teat length, rear udder height, rear udder width, and rear teat placement), and overall conformation score. Accuracy of genomic predictions was assessed using the single-trait animal model genomic best linear unbiased prediction method implemented in the ASReml-SA v4.2 software. Results: Heritability estimates ranged from 0.10 to 0.50 for body traits, 0.21 to 0.35 for rump traits, 0.13 to 0.29 for feet and leg traits, and 0.05 to 0.46 for udder traits. Rump traits exhibited the highest average heritability (0.29), while feet and leg traits had the lowest estimates (0.21). Accuracy of genomic predictions varied among the twenty-four linear body conformation traits, ranging from 0.26 to 0.49. The heritability and prediction accuracy of genomic estimated breeding value (GEBV) for the overall conformation score were 0.45 and 0.46, respectively. The GEBVs for body conformation traits in Korean Holstein cows had low accuracy, falling below the 50% threshold. Conclusion: The limited response to selection for body conformation traits in Korean Holsteins may be attributed to both the low heritability of these traits and the lower accuracy estimates for GEBVs. Further research is needed to enhance the accuracy of GEBVs and improve the selection response for these traits.