• Journal of Animal Science and Technology
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• 제52권5호
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• pp.357-366
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• 2010

한우의 유전체 전장의 정보를 Illumina BeadArray$^{TM}$ Bovine SNP50 assay를 이용하여 단일염기다형 현상을 조사한 결과, 유전적 다양성을 보이는 좌위가 약 32,567 좌위 이상에서 다양성을 보이고 있었으며 약 5,554 좌위에서 다양성이 조사되지 않았다. 이는 조사된 자료의 가계집단의 수가 크게 제한되었기 때문에 기인될 수 있으며 또 다른 원인으로는 한우 종축집단의 크기가 작을 수 있다는 현상을 반증한다고 사료된다. 유전분석의 기초가 되는 혈통기록에 의한 개체간 혈연관계를 유전체 정보에 의한 혈연관계와 비교하여 본 결과, 유전체 정보에 의한 혈연관계의 크기가 혈통기록에 의한 혈연관계보다 좀 더 정확하게 추정될 수 있다는 장점이 있으며 혈통기록상의 오류로 그릇된 혈연관계의 크기를 유전체 정보를 통하여 보완할 수 있다는 장점이 있다. 이러한 장점을 활용하면 유전체정보를 이용한 유전능력 평가의 정확성을 크게 향상시킬 수 있을 것으로 사료되었다.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2003년도 학술발표대회 발표논문초록집
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• pp.55-55
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• 2003

The random insertion of useful gene in genome has been a common method to produce transgenic animals. This method is inefficient for induction of high levels gene expression in transgenic animals. To improve this limit, we tried to develop the system which target the gene at the specific genomic region. Thus, in our experiment, the vector system to target the human thrombopoietin (TPO) gene was developed. Targeting vector including TPO, neo and DT genes was transfrcted into bovine embryonic fibroblasts (bEF) or bovine ear skin fibroblasts (bESF). First of all, we determined concentration of the geneticin (G418) for selection of transfected cell lines. Our results showed that 1200 and 900 $\mu\textrm{g}$/ml of G418 were the most proper for selection of transfscted bEF and bESF cells. In this study, lipofectamine was used as a transfection reagent. Thus, the proper ratio of DNA:lipofectamine for transfection was also required to elevate targeting efficiency in primary mammalian cells. Our result indicates that the most proper ratios of DNA:lipofectamine were 4:2 and 1:2 in bEF and bESF cells. According to the optimized these conditions, single colonies were picked following transfection and were analyzed by PCR. More than 90% of the single colonies have TPO gene. However, there were no colonies with targeted TPO at the specific genomic region. Therefore, further experiments to select the specifically targeted colonies and to find more efficient methods such as reducing selection time and shortening a size of TPO gene are required.

• Animal Bioscience
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• 제37권8호
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• pp.1355-1366
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• 2024

Objective: The analysis of runs of homozygosity (ROH) has been applied to assess the level of inbreeding and identify selection signatures in various livestock species. The objectives of this study were to characterize the ROH pattern, estimate the rate of inbreeding, and identify signatures of selection in the red-brown Korean native chickens. Methods: The Illumina 60K single nucleotide polymorphism chip data of 651 chickens was used in the analysis. Runs of homozygosity were analysed using the PLINK v1.9 software. Inbreeding coefficients were estimated using the GCTA software and their correlations were examined. Genomic regions with high levels of ROH were explored to identify selection signatures. Results: A total of 32,176 ROH segments were detected in this study. The majority of the ROH segments were shorter than 4 Mb. The average ROH inbreeding coefficients (F_ROH) varied with the length of ROH segments. The means of inbreeding coefficients calculated from different methods were also variable. The correlations between different inbreeding coefficients were positive and highly variable (r = 0.18-1). Five ROH islands harbouring important quantitative trait loci were identified. Conclusion: This study assessed the level of inbreeding and patterns of homozygosity in Red-brown native Korean chickens. The results of this study suggest that the level of recent inbreeding is low which indicates substantial progress in the conservation of red-brown Korean native chickens. Additionally, Candidate genomic regions associated with important production traits were detected in homozygous regions.

• BMB Reports
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• 제51권1호
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• pp.1-2
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• 2018

Positive selection on a new beneficial mutation generates a characteristic pattern of DNA sequence polymorphism when it reaches an intermediate allele frequency. On genome sequences of African Drosophila melanogaster, we detected such signatures of selection at 37 candidate loci and identified "sweeping haplotypes (SHs)" that are increasing or have increased rapidly in frequency due to hitchhiking. Based on geographic distribution of SH frequencies, we could infer whether selective sweeps occurred starting from de novo beneficial mutants under simple constant selective pressure. Single SHs were identified at more than half of loci. However, at many other loci, we observed multiple independent SHs, implying soft selective sweeps due to a high beneficial mutation rate or parallel evolution across space. Interestingly, SH frequencies were intermediate across multiple populations at about a quarter of the loci despite relatively low migration rates inferred between African populations. This invokes a certain form of frequency-dependent selection such as heterozygote advantage. At one locus, we observed a complex pattern of multiple independent that was compatible with recurrent frequency-dependent positive selection on new variants. In conclusion, genomic patterns of positive selection are very diverse, with equal contributions of hard and soft sweeps and a surprisingly large proportion of frequency-dependent selection in D. melanogaster populations.

• 식물조직배양학회지
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• 제25권1호
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• pp.45-50
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• 1998

꽃양배추의 하배축 조직을 proteinase inhibitor II 유전자가 도입된 Agrobacterium tumefaciens LBA 4404와 2일간 pH 5.5로 조절된 MS 액체배지에서 공동배양후 carbenicillin 500mg/L kanamycin 20mg/L와 BA 1mg/L가 함유된 MS 재분화배지에 옮겼다. 이들 조직을 매 2주마다 계대배양하였으며 약 4주후에 kanamycin 저항성 개체를 얻었다. 형질전환된 것으로 추정되는 식물체는 kanamycin 30mg/L가 함유된 선발배지에서 생존하였다. PCR 분석결과, PI-II 유전자가 형질전환체의 게놈상에 삽입되어 있음을 확인하였다. 형질전환체의 Southern blot 분석을 통하여 ECL-labelling된 PI-II 유전자와 동일한 것으로 판단되는 약 500bp 위치에서 밴드를 확인할 수 있었다.

• Animal Bioscience
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• 제37권5호
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• pp.807-816
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• 2024

Objective: This study aims to identify the significant regions and candidate genes of growth-related traits (adjusted backfat thickness [ABF], average daily gain [ADG], and days to 90 kg [DAYS90]) in Korean commercial GGP pig (Duroc, Landrace, and Yorkshire) populations. Methods: A genome-wide association study (GWAS) was performed using single-nucleotide polymorphism (SNP) markers for imputation to Illumina PorcineSNP60. The BayesB method was applied to calculate thresholds for the significance of SNP markers. The identified windows were considered significant if they explained ≥1% genetic variance. Results: A total of 28 window regions were related to genetic growth effects. Bayesian GWAS revealed 28 significant genetic regions including 52 informative SNPs associated with growth traits (ABF, ADG, DAYS90) in Duroc, Landrace, and Yorkshire pigs, with genetic variance ranging from 1.00% to 5.46%. Additionally, 14 candidate genes with previous functional validation were identified for these traits. Conclusion: The identified SNPs within these regions hold potential value for future marker-assisted or genomic selection in pig breeding programs. Consequently, they contribute to an improved understanding of genetic architecture and our ability to genetically enhance pigs. SNPs within the identified regions could prove valuable for future marker-assisted or genomic selection in pig breeding programs.

• 생명과학회지
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• 제32권4호
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• pp.279-284
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• 2022

본 연구는 일반농가에서 적용 가능한 유전평가시스템을 구축을 위해 경기 지역에서 사육중인 암소 619두를 BLUP (Best Linear Unbiased Prediction)과 GBLUP (Genomic Best Linear Unbiased Prediction)을 사용하여 각 형질(도체중, 등심단면적, 등지방두께, 근내지방도) 별 추정 육종가의 정확도를 비교분석 하였다. GBLUP의 경우 참조집단의 크기를 다르게 그룹을 나누어 분석하였다. 분석결과 GBLUP 참조집단의 크기가 커질수록 각 형질의 육종가의 정확도도 상승하는 것을 확인 하였다. BLUP과 GBLUP 방법을 사용하여 추정한 육종가의 정확도를 비교하면, GBLUP 방법을 사용하여 육종가를 추정하였을 때 도체중, 등심단면적, 등지방두께 근내지방도순으로 각각 0.10, 0.09, 0.09, 0.11 이상 상승한 것을 확인할 수 있었다. 따라서, GBLUP 방법을 암소 평가 및 선발에 적용한다면, 정밀하고 정확한 개체 선발이 가능하고 참조집단의 크기를 더욱 키운다면 보다 정확한 개체 선발을 할 수 있기 때문에 선발의 효율성이 증가할 것으로 사료된다.

• 응용통계연구
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• 제29권6호
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• pp.1117-1128
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• 2016

고차원 유전체 자료를 사용하는 유전체 연관 분석에서는 벌점 우도함수 기반의 회귀계수 규제화 방법이 질병 및 표현형질에 영향을 주는 유전자를 발견하는데 많이 이용된다. 특히, 네트워크 기반의 규제화 방법은 유전체 연관성 연구에서의 유전체 경로나 신호 전달 경로와 같은 생물학적 네트워크 정보를 사용할 수 있으므로, Lasso나 Elastic-net과 같은 다른 규제화 방법들과 비교했을 경우 네트워크 기반의 규제화 방법이 보다 더 정확하게 관련 유전자들을 찾아낼 수 있다는 장점을 가지고 있다. 그러나 네트워크 기반의 규제화 방법은 그룹 구조를 갖고 있는 고차원 유전체 자료에는 적용시킬 수 없다는 문제점을 가지고 있다. 실제 SNP 데이터와 DNA 메틸화 데이터처럼 대다수의 고차원 유전체 자료는 그룹 구조를 가지고 있으므로 본 논문에서는 이러한 그룹 구조를 가지고 있는 고차원 유전체 자료를 분석하고자 네트워크 기반의 규제화 방법에 주성분 분석(principal component analysis; PCA)과 부분 최소 자승법(partial least square; PLS)과 같은 차원 축소 방법을 결합시키는 새로운 분석 방법을 제안하고자 한다. 새롭게 제안한 분석 방법은 몇 가지의 모의실험을 통해 변수 선택의 우수성을 입증하였으며, 또한 152명의 정상인들과 123명의 난소암 환자들로 구성된 고차원 DNA 메틸화 자료 분석에도 사용하였다. DNA 메틸화 자료는 대략 20,000여개의 CpG sites가 12,770개의 유전자에 포함되어 있는 그룹 구조를 가지고 있으며 Illumina Innium uman Methylation27 BeadChip으로부터 생성되었다. 분석 결과 우리는 실제로 암에 연관된 몇 가지의 유전자를 발견할 수 있었다.

• IMMUNE NETWORK
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• 제2권4호
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• pp.233-241
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• 2002

Background: Monoclonal antibodies (mAb) of rodent origin are produced with ease by hybridoma fusion technique, and have been successfully used as therapeutic reagents for humans after humanization by genetic engineering. However, utilization of these antibodies for therapeutic purpose has been limited by the fact that they act as immunogens in human body causing undesired side effects. So far, there have been several attempts to produce human mAbs for effective in vivo diagnostic or therapeutic reagents including the use of humanized xenomouse that is generated by mating knockout mice which lost Ig heavy and light chain genes by homologous recombination and transgenic mice having both human Ig heavy and light gene loci in their genome. Methods: Genomic DNA fragments of mouse Ig heavy and light chain were obtained from a mouse brain ${\lambda}$ genomic library by PCR screening and cloned into a targeting vector with ultimate goal of generating Ig knockout mouse. Results: Through PCR screening of the genomic library, three heavy chain and three light chain Ig gene fragments were identified, and restriction map of one of the heavy chain gene fragments was determined. Then heavy chain Ig gene fragments were subcloned into a targeting vector. The resulting construct was introduced into embryonic stem cells. Antibiotic selection of transfected cells is under the progress. Conclusion: Generation of xenomouse is particularly important in medical biotechnology. However, this goal is not easily achieved due to the technical difficulties as well as huge financial expenses. Although we are in the early stage of a long-term project, our results, at least, partially contribute the successful generation of humanized xenomouse in Korea.

• Communications for Statistical Applications and Methods
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• 제27권5호
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• pp.535-546
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• 2020

In genetic association studies, pleiotropy is a phenomenon where a variant or a genetic region affects multiple traits or diseases. There have been many studies identifying cross-phenotype genetic associations. But, most of statistical approaches for detection of pleiotropy are based on individual tests where a single variant association with multiple traits is tested one at a time. These approaches fail to account for relations among correlated variants. Recently, multivariate regularization methods have been proposed to detect pleiotropy in analysis of high-dimensional genomic data. However, they suffer a problem of tuning parameter selection, which often results in either too many false positives or too small true positives. In this article, we applied selection probability to multivariate regularization methods in order to identify pleiotropic variants associated with multiple phenotypes. Selection probability was applied to individual elastic-net, unified elastic-net and multi-response elastic-net regularization methods. In simulation studies, selection performance of three multivariate regularization methods was evaluated when the total number of phenotypes, the number of phenotypes associated with a variant, and correlations among phenotypes are different. We also applied the regularization methods to a wild bean dataset consisting of 169,028 variants and 17 phenotypes.