• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.407-420
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• 2022

Chicken dominates meat consumption because it is low in fat and high in protein and has less or no religious and cultural barriers. Recently, meat quality traits have become the focus of the poultry industry more than ever. Currently, poultry farming is focusing on meat quality to satisfy meat consumer preferences, which are mostly based on high-quality proteins and a low proportion of saturated fatty acids. Meat quality traits are polygenic traits controlled by many genes. Thus, it is difficult to improve these traits using the conventional selection method because of their low to moderate heritability. These traits include pH, colour, drop loss, tenderness, intramuscular fat (IMF), water-holding capacity, flavour, and many others. Genome-wide association studies (GWAS) are an efficient genomic tool that identifies the genomic regions and potential candidate genes related to meat quality traits. Due to their impact on the economy, meat quality traits are used as selection criteria in breeding programs. Various genes and markers related to meat quality traits in chickens have been identified. In chickens, GWAS have been successfully done for intramuscular fat (IMF) content, ultimate pH (pHu) and meat and skin colour. Moreover, GWAS have identified 7, 4, 4 and 6 potential candidate genes for IMF, pHu, meat colour and skin colour, respectively. Therefore, the current review summarizes the significant genes identified by genome-wide association studies for meat quality traits in chickens.

• Journal of Animal Science and Technology
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• v.65 no.6
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• pp.1194-1204
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• 2023

Meat quality comprises a set of key traits such as pH, meat color, water-holding capacity, tenderness and marbling. These traits are complex because they are affected by multiple genetic and environmental factors. The aim of this study was to investigate the molecular genetic basis underlying nine meat quality-related traits in a Yorkshire pig population using a genome-wide association study (GWAS) and subsequent biological pathway analysis. In total, 45,926 single nucleotide polymorphism (SNP) markers from 543 pigs were selected for the GWAS after quality control. Data were analyzed using a genome-wide efficient mixed model association (GEMMA) method. This linear mixed model-based approach identified two quantitative trait loci (QTLs) for meat color (b^*) on chromosome 2 (SSC2) and one QTL for shear force on chromosome 8 (SSC8). These QTLs acted additively on the two phenotypes and explained 3.92%-4.57% of the phenotypic variance of the traits of interest. The genes encoding HAUS8 on SSC2 and an lncRNA on SSC8 were identified as positional candidate genes for these QTLs. The results of the biological pathway analysis revealed that positional candidate genes for meat color (b^*) were enriched in pathways related to muscle development, muscle growth, intramuscular adipocyte differentiation, and lipid accumulation in muscle, whereas positional candidate genes for shear force were overrepresented in pathways related to cell growth, cell differentiation, and fatty acids synthesis. Further verification of these identified SNPs and genes in other independent populations could provide valuable information for understanding the variations in pork quality-related traits.

• Genomics & Informatics
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• v.10 no.1
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• pp.65-67
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• 2012

We have discovered copy number variations (CNVs) in 3,578 Korean individuals with the Affymetrix Genome-Wide SNP array 5.0, and 4,003 copy number variation regions (CNVRs) were defined in a previous study. To explore the details of the variants easily in related studies, we built a database, cataloging the CNVs and related information. This system helps researchers browsing these variants with gene and structure variant annotations. Users can easily find specific regions with search options and verify them from system-integrated genome browsers with annotations.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.7
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• pp.938-943
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• 2016

Development of body hair is an important physiological and cellular process that leads to better adaption in tropical environments for dairy cattle. Various studies suggested a major gene and, more recently, associated genes for hairy locus in dairy cattle. Main aim of this study was to i) employ a variant of the discordant sib pair model, in which half sibs from the same sires are randomly sampled using their affection statues, ii) use various single marker regression approaches, and iii) use whole genome regression approaches to dissect genetic architecture of the hairy gene in the cattle. Whole and single genome regression approaches detected strong genomic signals from Chromosome 23. Although there is a major gene effect on hairy phenotype sourced from chromosome 23: whole genome regression approach also suggested polygenic component related with other parts of the genome. Such a result could not be obtained by any of the single marker approaches.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2006.02a
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• pp.125-126
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• 2006

NimbleGen has developed strategies to use its high-density oligonucleotide microarray platform (385,000 probes per array) to map both promoter binding sites and copy number variation at very high-resolution in the human genome. Here we describe a genome-wide map of active promoters determined by experimentally locating the sites of transcription imitation complex binding throughout the human genome using microarrays combined with chromatin immunoprecipitation. This map defines 10,567 active promoters corresponding to 6,763 known genes and at least 1,196 un-annotated transcriptional units. Microarray-based comparative genomic hybridisation (CGH) is animportant research tool for investigating chromosomal aberrations frequently associated with complex diseases such as cancer, neuropsychiatric disorders, and congenital developmental disorders. NimbleGen array CGH is an ultra-high resolution (0.5-50 Kb) oligo array platform that can be used to detect amplifications and deletions and map the associated breakpoints on the whole-genome level or with custom fine-tiling arrays. For whole-genome array CGH, probes are tiled through genic and intergenic regions with a median probe spacing of 6 Kb, which provides a comprehensive, unbiased analysis of the genome.

• Journal of Embryo Transfer
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• v.31 no.4
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• pp.313-318
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• 2016

The aim of this study was to identify quantitative trait loci (QTLs) influencing teat number traits in an $F_2$ intercross between Landrace and Korean native pigs (KNP). Three teat number traits (left;right;and total) were measured in 1105 $F_2$ progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We detect that seven chromosomes harbored QTLs for teat number traits: genome regions on SSC1;3;7;8;10;11;and 13. Six of fourteen identified QTL reached genome-wide significance. In SSC7;we identified a major QTL affecting total teat number that accounted for 5.6 % of the phenotypic variance;which was the highest test statistic (F-ratio = 61.1 under the additive model;nominal $P=1.3{\times}10^{-14}$) observed in this study. In this region;QTL for left and right teat number were also detected with genome-wide significance. With exception of the QTL in SSC10;the allele from KNP in all 6 identified QTLs was associated with decreased phenotypic values. In conclusion;our study identified both previously reported and novel QTL affecting teat number traits. These results can play an important role in determining the genetic structure underlying the variation of teat number in pigs.

• Journal of Life Science
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• v.31 no.6
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• pp.568-573
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• 2021

This study identified genomic factors associated with endoplasmic reticulum protein (ERp)29 gene expression in a genome-wide association study (GWAS) of genetic variants, including single-nucleotide polymorphisms (SNPs). In total, 373 European genes from the 1000 Genomes Project were analyzed. SNPs with an allelic frequency of less than or more than 5% were removed, resulting in 5,913,563 SNPs including in the analysis. The following expression quantitative trait loci (eQTL) from the long noncoding RNA LOC105372577 were strongly associated with ERp29 expression: rs6138266 (p<4.172e10), rs62193420 (p<1.173e10), and rs6138267 (p<2.041e10). These were strongly expressed in the testis and in the brain. The three eQTL were identified through a transcriptome-wide association study (TWAS) and showed a significant association with ERp29 and osteosarcoma amplified 9 (OS9) expression. Upstream sequences of rs6138266 were recognized by ChIP-seq data, while HaploReg was used to demonstrate how its regulatory DNA binds upstream of transcription factor 1 (USF1). There were no changes in the expression of OS9 or USF1 following ER stress.

• BMB Reports
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• v.45 no.1
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• pp.47-50
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• 2012

The International HapMap Project and the Human Genome Diversity Project (HGDP) provide plentiful resources on human genome information to the public. However, this kind of information is limited because of the small sample size in both databases. A Genome-Wide Association Study has been conducted with 8,842 Korean subjects as a part of the Korea Association Resource (KARE) project. In an effort to build a publicly available browsing system for genome data resulted from large scale KARE GWAS, we developed the KARE browser. This browser provides users with a large amount of single nucleotide polymorphisms (SNPs) information comprising 1.5 million SNPs from population-based cohorts of 8,842 samples. KAREBrowser was based on the generic genome browser (GBrowse), a web-based application tool developed for users to navigate and visualize the genomic features and annotations in an interactive manner. All SNP information and related functions are available at the web site http://ksnp.cdc. go.kr/karebrowser/.

• Genomics & Informatics
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• v.14 no.4
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• pp.149-159
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• 2016

With the success of the genome-wide association studies (GWASs), many candidate loci for complex human diseases have been reported in the GWAS catalog. Recently, many disease prediction models based on penalized regression or statistical learning methods were proposed using candidate causal variants from significant single-nucleotide polymorphisms of GWASs. However, there have been only a few systematic studies comparing existing methods. In this study, we first constructed risk prediction models, such as stepwise linear regression (SLR), least absolute shrinkage and selection operator (LASSO), and Elastic-Net (EN), using a GWAS chip and GWAS catalog. We then compared the prediction accuracy by calculating the mean square error (MSE) value on data from the Korea Association Resource (KARE) with body mass index. Our results show that SLR provides a smaller MSE value than the other methods, while the numbers of selected variables in each model were similar.

• Preventive Nutrition and Food Science
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• v.20 no.1
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• pp.1-7
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• 2015

Obesity has become one of the major public health problems all over the world. Recent novel eras of research are opening for the effective management of obesity though gene and nutrient intake interactions because the causes of obesity are complex and multifactorial. Through GWASs (genome-wide association studies) and genetic variations (SNPs, single nucleotide polymorphisms), as the genetic factors are likely to determine individuals' obesity predisposition. The understanding of genetic approaches in nutritional sciences is referred as "nutrigenomics". Nutrigenomics explores the interaction between genetic factors and dietary nutrient intake on various disease phenotypes such as obesity. Therefore, this novel approach might suggest a solution for the effective prevention and treatment of obesity through individual genetic profiles and help improve health conditions.