• 농업과학연구
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• 제49권3호
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• pp.431-440
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• 2022

Hanwoo cattle are a unique and historical breed in Korea that have been genetically improved and maintained by the national evaluation and selection system. The aim of this study was to provide information that can help improve the accuracy of the estimated breeding values in Hanwoo cattle by showing the difference between the imputation reference chip platforms of genomic data and the scaling factor of the genetic relationship matrix (GRM). In this study, nine sets of data were compared that consisted of 3 reference platforms each with 3 different scaling factors (-0.5, 0 and 0.5). The evaluation was performed using MTG2.0 with nine different GRMs for the same number of genotyped animals, pedigree, and phenotype data. A five multi-trait model was used for the evaluation in this study which is the same model used in the national evaluation system. Our results show that the Hanwoo custom v1 platform is the best option for all traits, providing a mean accuracy improvement by 0.1 - 0.3%. In the case of the scaling factor, regardless of the imputation chip platform, a setting of -1 resulted in a better accuracy increased by 0.5 to 1.6% compared to the other scaling factors. In conclusion, this study revealed that Hanwoo custom v1 used as the imputation reference chip platform and a scaling factor of -0.5 can improve the accuracy of the estimated breeding value in the Hanwoo population. This information could help to improve the current evaluation system.

• Journal of Animal Science and Technology
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• 제55권1호
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• pp.13-18
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• 2013

본 연구는 농협 한우개량사업소 후대검정우 552두의 도체중, 배최장근단면적, 등지방두께 및 근내지방도를 측정한 후 고밀도 SNP 패널(777K)을 사용하여 유전체 혈연 행렬(Genetic Relationship Matrix, GRM)을 추정하고 GBLUP (Genomic Best Linear Unbiased Prediction) 방법으로 GEBV (Genomic Estimated Breeding Value)를 구하여 교차 검증(Cross-validation) 방법으로 그 정확도를 추정함으로써 유전체 선발 기법을 한우 유전평가 체계에 적용하기 위한 기초자료로 이용하고자 수행하였다. 교차 검증 방법으로 각 형질별로 추정된 유전체 육종가의 정확도는 0.915~0.957로 상당히 높게 추정되었다. 대립유전자의 빈도로 계산된 유전체 혈연 행렬을 이용하여 GBLUP 방법으로 추정된 육종가 정확도의 최대 차이는 후대검정우 534두에 대하여 도체중, 배최장근단면적, 등지방 두께 및 근내지방도 순으로 각각 9.56%, 5.78%, 5.78% 및 4.18% 정도의 수준으로 상승했고, 혈통 기록상의 모든 개체 3,674두에 대해서는 형질 별로 최대 13.54%, 6.50%, 6.50% 및 4.31% 정도의 수준으로 증가한 결과가 추정되었다. 이는 한우 보증씨수소의 선발 시스템에서 아직 표현형 자료를 생산할 수 없는 당대검정 후보축 대한 집단을 조성할 때 유전체 정보를 이용한 사전 선발을 활용하면 기존의 상대적으로 낮았던 육종가의 정확도의 상승 효과와 세대 간격의 단축으로 인하여 유전적 개량량을 증대시킬 수 있을 것으로 기대된다. 본 연구에서 genomic breeding value 추정을 위하여 조성된 집단의 경우는 후대 검정우 집단으로서 개체들 간의 혈연관계가 높으며, 이미 전통적인 BLUP 방법으로도 상당히 높은 정확도를 가진 집단을 이용하였다. 그러나, 현재 한우 집단에 대한 유전체 자료 구축 시 이용할 수 있는 정확한 자료는 후대검정우 집단 외에는 참조 집단을 조성할 수 있는 대안이 없으므로, 지속적인 유전체 검정을 위해서는 다양한 유전적 조성이 구축된 참조 집단을 구축해야 할 것으로 사료된다. 또한 유전체 검정을 통한 정확도 상승효과를 기대하기 위해서 지속적으로 참조 집단의 크기를 늘릴 필요성이 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제24권2호
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• pp.162-172
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• 2011

In this paper, simulation was used to determine accuracies of genomic breeding values for polygenic traits associated with many thousands of markers obtained from high density genome scans. The statistical approach was based upon stochastically simulating a pedigree with a specified base population and a specified set of population parameters including the effective and noneffective marker distances and generation time. For this population, marker and quantitative trait locus (QTL) genotypes were generated using either a single linkage group or multiple linkage group model. Single nucleotide polymorphism (SNP) was simulated for an entire bovine genome (except for the sex chromosome, n = 29) including linkage and recombination. Individuals drawn from the simulated population with specified marker and QTL genotypes were randomly mated to establish appropriate levels of linkage disequilibrium for ten generations. Phenotype and genomic SNP data sets were obtained from individuals starting after two generations. Genetic prediction was accomplished by statistically modeling the genomic relationship matrix and standard BLUP methods. The effect of the number of linkage groups was also investigated to determine its influence on the accuracy of breeding values for genomic selection. When using high density scan data (0.08 cM marker distance), accuracies of breeding values on juveniles were obtained of 0.60 and 0.82, for a low heritable trait (0.10) and high heritable trait (0.50), respectively, in the single linkage group model. Estimates of 0.38 and 0.60 were obtained for the same cases in the multiple linkage group models. Unexpectedly, use of BLUP regression methods across many chromosomes was found to give rise to reduced accuracy in breeding value determination. The reasons for this remain a target for further research, but the role of Mendelian sampling may play a fundamental role in producing this effect.

• Asian-Australasian Journal of Animal Sciences
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• 제28권11호
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• pp.1551-1557
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• 2015

The missing heritability has been a major problem in the analysis of best linear unbiased prediction (BLUP). We introduced the traditional genome-wide association study (GWAS) into the BLUP to improve the heritability estimation. We analyzed eight pork quality traits of the Berkshire breeds using GWAS and BLUP. GWAS detects the putative quantitative trait loci regions given traits. The single nucleotide polymorphisms (SNPs) were obtained using GWAS results with p value <0.01. BLUP analyzed with significant SNPs was much more accurate than that with total genotyped SNPs in terms of narrow-sense heritability. It implies that genomic estimated breeding values (GEBVs) of pork quality traits can be calculated by BLUP via GWAS. The GWAS model was the linear regression using PLINK and BLUP model was the G-BLUP and SNP-GBLUP. The SNP-GBLUP uses SNP-SNP relationship matrix. The BLUP analysis using preprocessing of GWAS can be one of the possible alternatives of solving the missing heritability problem and it can provide alternative BLUP method which can find more accurate GEBVs.

• 치위생과학회지
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• 제22권2호
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• pp.99-107
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• 2022

Background: Obesity weakens acquired immunity and causes infection. This study aimed to investigate the relationship between the inflammatory markers in the gingival crevicular fluid and serum and periodontal bacteria in saliva through obesity control for 4 weeks. Methods: Forty-six subjects with a body mass index (BMI) of ≥23 kg/m² stayed in the camp for 4 weeks, followed by exercise and a low salt-low fat diet. Body size measurements, oral examinations, blood, saliva, and gingival crevicular fluid were collected before and after the program. C-reactive protein (CRP) in serum, matrix metalloproteinase (MMP)-8, MMP-9, and interleukin (IL)-1β in the gingival sulcus fluid were measured. After extracting bacterial genomic DNA from saliva, the presence of periodontal bacteria were detected using Taq probe. The relationship of each index before and after the program was analyzed through paired t-test and partial correlation analysis. Results: Campylobacter rectus (Cr) increased after the program, and there was no significant change in other bacteria. Serum CRP and Fusobacterium nucleatum (Fn), Aggregatibacter actinomycetemcomitans, Cr, ratio of Fn, and ratio of Cr had a positive relationship at baseline; however, the relationship was not significant after the program. Ratio of Prevotella intermedia had a positive relationship with MMP-9, MMP-8, IL-1β at baseline. Moreover, the ratio of Treponema denticola and the ratio of Tannerella forsythia showed a positive relationship with MMP-8, MMP-9, and IL-1β. The relationship between the ratio of Porphyromonas gingivalis and IL-1β showed a constant positive relationship at baseline and after the program. Conclusion: Obesity control program in subjects with a BMI of ≥23 kg/m² accompanied by diet and exercise did not affect the changes in periodontal bacteria itself, but changes in the relationship between periodontal bacteria and serum CRP, the relationship between the inflammatory index in the gingival crevicular fluid and periodontal bacteria was observed.

• 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.

• Journal of Microbiology and Biotechnology
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• 제27권11호
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• pp.1942-1951
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• 2017

Campylobacter jejuni and Campylobacter coli are important foodborne pathogenic bacteria, particularly in poultry meat. In this study, the presence of extracellular DNase activity was investigated for biofilm-deficient Campylobacter strains versus biofilm-forming Campylobacter strains isolated from chickens, to understand the relationship between extracellular DNase activity and biofilm formation. A biofilm-forming reference strain, C. jejuni NCTC11168, was co-incubated with biofilm non-forming strains isolated from raw chickens or their supernatants. The biofilm non-forming strains or supernatants significantly prohibited the biofilm formation of C. jejuni NCTC11168. In addition, the strains degraded pre-formed biofilms of C. jejuni NCTC11168. Degradation of C. jejuni NCTC11168 biofilm was confirmed after treatment with the supernatant of the biofilm non-forming strain 2-1 by confocal laser scanning microscopy. Quantitative analysis of the biofilm matrix revealed reduction of extracellular DNA (16%) and proteins (8.7%) after treatment. Whereas the biofilm-forming strains C. jejuni Y23-5 and C. coli 34-3 isolated from raw chickens and the C. jejuni NCTC11168 reference strain showed no extracellular DNase activity against their own genomic DNA, most biofilm non-forming strains tested, including C. jejuni 2-1, C. coli 34-1, and C. jejuni 63-1, exhibited obvious extracellular DNase activities against their own or 11168 genomic DNA, except for one biofilm non-former, C. jejuni 22-1. Our results suggest that extracellular DNase activity is a common feature suppressing biofilm formation among biofilm non-forming C. jejuni or C. coli strains of chicken origin.

• 한국축산식품학회지
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• 제31권6호
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• pp.827-833
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• 2011

The objective of this study was to develop a fluorogenic real-time PCR-based assay for detecting and quantifying amounts of cow milk in cow/goat milk mixtures or goat milk products. In order to quantify the exact amount of cow milk in cow/goat raw milk mixtures and commercial goat milk products, it was necessary to achieve quantitative extraction of total genomic DNA from the raw milk matrix. Both mammalian-specific PCR and cow-specific PCR were performed. A cow-specific 252 bp band obtained from the raw cow milk and raw goat milk mixtures, commercial goat milk, and two goat milk powders was identified, along with the relationship between the cow milk amount and band intensity of the electrophoresis image. The detection threshold was found to be 0.1%. The expression of cow's 12S rRNA in the cow/goat milk mixtures, commercial goat milk, and two goat milk powders was identified. The expression quantity of the milk 12S rRNA increased with increasing ratios of the cow/goat milk mixtures. Using these calibrated relative expression levels as a standard curve in the cow/goat raw milk mixtures, the contents of cow milk were 1.8% in the commercial goat milk, 9.6% in goat milk powder A, and 11.6% in goat milk powder C. However, cow milk was not detected in goat milk powder B.

• 생명과학회지
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• 제18권10호
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• pp.1442-1446
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• 2008

본 연구는 10개의 Microsatellite를 이용하여 국내 한우집 단 586두(경기: 100, 전남: 100, 전북: 100, 경남: 100, 경북:86, 강원: 100)와 보증종모우 집단(39두)간의 유전적 거리추정 및 계통지도의 작성을 통해 보증종모우 집단과 지역별 한우집단의 유전적 특성과 유연관계 분석을 실시하였다. 10개의 MS marker의 분석 결과 기대이형접합도의 경우 경남지역에서 가장 높은 0.780을 나타내었으며 종모우 집단에서 가장 낮은 0.760을 나타내었다. 관측된 이형접합도의 경우 종모우 집단에서 가장 높은 0.818을 나타내었으며 경북지역에서 가장 낮은 0.721을 나타내었다. 검출된 대립유전자의 수에서는 것으로 확인 되었다. 종모우 집단은 가장 높은 관측이형접합도를 나타냈음에도 불구하고 가장 낮은 대립유전자의 수를나타내고 음을 확인하였다. 7개의 집단 간의 유전적 유연관계 분석한 결과 강원도 집단의 한우와 경기, 경북의 유전적 거리가 각 0.021로 가장 가까운 것으로 확인 되었으며 경기와 경북 간의 유전적 거리는 0.032인 것으로 가장 먼 것으로 확인 되었다. 또한 경북은 전남과도 0.032의 먼 유전적 거리를 나타내고 있음을 확인하였다. 종모우 집단의 경우 각 지역별 집단 간의 유전적 거리에 비해 상당히 큰 차이의 유전적 거리를 나타내고 있는데 이는 각 지역별 암소집단에 소수의 종모우를 이용해 계획 교배를 실시하고 있어 나타난 것으로 사료된다. 각 개체들 간의 유전적 거리에 대한 추정값을 계산하여 개체별 분지도를 작성한 결과 같은 지역 내의몇몇 개체들이 그룹을 이루어 존재하기는 하지만 일반적으로 넓게 분포되어 있어 각 지역별로 그룹을 이루어 존재하고 있다고 보기엔 어려움이 있음을 확인 하였다. 반면 종모우 집단의 경우 크게 두개의 그룹을 이루어 분지도 내에 분포하고 있음을 확인 할 수 있었다. 따라서 종모우의 유전적 배경이 상당히 좁게 나타나고 있음을 확인 할 수 있었으며 이러한 결과로 인해 국내의 유전자원의 다양성이 작아질 수도 있을 것으로 추정된다. 따라서 국내 유전자원의 다양성 보존을 위해 종모우의 선발 및 사업 추진에 있어 대책을 마련하기 위한 고찰이 진행되어질 필요가 있는 것으로 사료된다.

• 원예과학기술지
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• 제17권4호
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• pp.489-493
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• 1999

한국에 자생하고 있는 Sedum속 12종 15계통에 대하여 형태적 특성을 조사하여 화훼자원으로의 이용가능성을 탐색하고, 수집종들 간의 유연관계를 RAPD방법으로 조사한 결과는 다음과 같다. 기린초와 섬기린초는 황색의 꽃이 화총(花叢)을 이루면서 화려하게 피므로 화단용(花壇用)으로, 큰꿩의비름은 분홍색의 화색이 둥글게 모여 피며 화총이 아름다우면서 잎 모양이 독특하여 분화(盆花) 또는 화단용(花壇用)으로, 돌나물, 바위채송화 및 땅채송화 등은 포복형이면서 초장이 낮아 지피식물(地被植物) 및 화단용(花壇用)으로 이용 가능성이 있을 것으로 생각된다. 18개의 임의 primer를 이용하여 15계통을 RAPD분석한 결과 총 125개 밴드 중 95개의 다형성 밴드를 얻을 수 있었으며, 증폭된 DNA단편들의 크기는 224~3,675bp 사이였다. RAPD 결과 유연계수 0.418에서는 수집한 Sedum속 식물이 3개 군으로 분류되었으며, 유연계수 0.328에서는 총 12개의 종으로 분류되었다. 제I군에는 기린초, 가는기린초 및 섬기린초, 제II군은 꿩의비름, 큰꿩의비름, 새끼꿩의비름 및 둥근잎꿩의비름, 제III군은 돌나물, 바위채송화, 땅채송화로 분류되었다. 본 연구 결과 RAPD 분석에 의한 종간 유연관계가 형태적 특성에 의한 것과 대체로 유사하게 나타났다.