• Korean Journal of Poultry Science
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• v.36 no.2
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• pp.111-115
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• 2009

Chicken has been being used as the protein sources for humans for long times. Since the release of chicken genome sequencing, large efforts have been carried out for identifying valuable genomic information in chicken including the genes affecting quantitative traits, development and immune responses. In this review, the recent progress of genomic researches has been discussed including the available world wide genetic materials in chicken.

• Korean Journal of Poultry Science
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• v.37 no.3
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• pp.275-282
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• 2010

Chicken is an important livestock as a valuable biomedical model as well as food for human, and there is a strong rationale for improving our understanding on metabolism and physiology of this organism. The first draft of chicken genome assembly was released in 2004, which enables elaboration on the linkage between genetic and metabolic traits of chicken. The objectives of this study were thus to reconstruct metabolic pathway of the chicken genome and to construct a chicken specific pathway genome database (PGDB). We developed a comprehensive genome database for chicken by integrating all the known annotations for chicken genes and proteins using a pipeline written in Perl. Based on the comprehensive genome annotations, metabolic pathways of the chicken genome were reconstructed using the PathoLogic algorithm in Pathway Tools software. We identified a total of 212 metabolic pathways, 2,709 enzymes, 71 transporters, 1,698 enzymatic reactions, 8 transport reactions, and 1,360 compounds in the current chicken genome build, Gallus_gallus-2.1. Comparative metabolic analysis with the human, mouse and cattle genomes revealed that core metabolic pathways are highly conserved in the chicken genome. It was indicated the quality of assembly and annotations of the chicken genome need to be improved and more researches are required for improving our understanding on function of genes and metabolic pathways of avian species. We conclude that the chicken PGDB is useful for studies on avian and chicken metabolism and provides a platform for comparative genomic and metabolic analysis of animal biology and biomedicine.

• KOREAN POULTRY JOURNAL
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• v.55 no.6
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• pp.154-156
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• 2023

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.99-108
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• 2022

Avian leukosis virus (ALV) is a highly contagious retrovirus that causes tumors and has resulted in great economic loss worldwide owing to its high transmission rate. Various ALV viral subgroups exist, with infections occurring via specific host receptors. The susceptibility or resistance of avian species to the ALV-A and K subgroups is determined by the host receptor, the tumor virus locus A (tva) gene, while that to ALV-B depends on another host receptor, the tumor virus locus B (tvb) gene. The resistance alleles of tva and tvb have primarily been identified in China, but none have beendetected in Korea. We analyzed the frequencies of tva and tvb genotypes in White Leghorn (WL), Korean Ogye (KO), and Korean native chicken (KNC) breeds, and assessed the resistance to ALV subgroups. In WL, both tva and tvb had various genotypes, including susceptibility and resistance alleles, whereas in KO, tva and tvb resistance alleles were dominant. In KNC, tva susceptibility and resistance alleles were mixed, whereas tvb resistance alleles were dominant. In addition, we showed that there were differences in the splicing pattern of tva transcripts and the expression level of tvb transcripts within breeds. Finally, we confirmed that ALV resistance depended on KO and KNC genotypes by in vitro infection of chicken embryonic fibroblasts with ALV. These results highlight that some KO and KNC individuals are naturally resistant to ALV subgroups A, B, and K, and will facilitate the preservation of economically superior traits through selective breeding.

• Korean Journal of Poultry Science
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• v.32 no.1
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• pp.29-34
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• 2005

This study was conducted to estimate the effects of genotype for chicken major histocompatibility complex (MHC) B-LB genes on economic traits. To detect polymorphism, 400 bp fragments of MHC B-LB genes were obtained and sequenced. After digestions using restriction enzyme Hea III, two restriction enzyme sites were observed. There were two mutations at position 427 and 651 those were decided as Type I and Type II, respectively. Using RFLP analyses, type I were genotyped to TT, TC and CC, and type II to MM, Mm and mm. The relatively higher TC genotype frequencies (0.8) of Type I and Mm genotype frequencies (0.88) of Type II were observed in Korean native chickens. The effects of the genotype on 150 days body weight trait were investigated by the associations of CC and Mm genotypes (P<0.05) in Korean native chickens. This result suggests that a significant association exists between the SNP and 150 days body weight.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2005.11a
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• pp.53-59
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• 2005

Sequences of candidate chicken testis-specific genes were analyzed in order to develop a resource for functional genomic studies of the testis and male germ cells. Tentative consensus sequences (TCs) containing ESTs expressed in testis libraries only were selected from the TIGR Gallus gallus Gene Index, resulting in a total of 292 TCs. The transcriptional expression of these genes were evaluated in a variety of chicken tissues, including testis and ovary, Of the panel of 292 TCs, 110 were expressed in a testis-specific manner. The correlation between the number of ESTs assembled into each TC and the number of testis-specific TCs was not significant. Annotation of the TCs using the Gene Ontology database terms showed that the proportion of testis-specific TCs that were classified as having catalytic activity (within the Molecular Function branch) was larger than the proportion of total chicken TCs classified in the same way. Our results might facilitate the investigation of testis-specific genes and their functional analysis in the chicken as well as in other avian species.

• Korean Journal of Poultry Science
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• v.37 no.1
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• pp.81-87
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• 2010

To estimate the genetic characteristics and cumulative power of discrimination (CPD) Korean Native Chicken. We used a total of 195 genomic DNAs from four breeds population (Korean Native Red chicken: R, Korean Native Yellow chicken: Y, Korean Native Black chicken: L, Ogal chicken: S). Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. The lowest distance (0.05) was observed between the R and L strains and the highest distance (0.158) between the L and S strains. Korean native chicken strains (R, Y, K) have each other comparatively near genetic distance. Cumulative power of discriminate (CPD) was 99.999% by including the 10 microsatellites loci individual identification system. And then matching probability in that two different individuals incidentally have same genotype was estimated to $0.36{\times}10^{-7}$. The system employing the 10 markers therefore provided to be applicable to individual identification in Korea native chicken.

• Korean Journal of Poultry Science
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• v.37 no.4
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• pp.355-360
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• 2010

To estimate the genetic characteristics within two brands of Korean native commercial chicken, we used a total of 302 genomic DNAs from two groups (Woorichicken: 152, Hanhyup3chicken: 150). Sizes of 10 microsatellite markers were decided using GeneMapper Software (v.4.0) after analyzing ABI 3130. Genetic diversity indices including expected heterozygosity (Ex H), observed heterozygosity (Ob H) and polymorphism information content (PIC). Frequencies of microsatellites markers were used to estimate heterozygosities and genetic distances. LEI0073 showed the highest value in all genetic diversity (Ex H, Ob H and PIC). On the other hand, MCW322 showed the lowest value in all genetic diversity. The calculated genetic distance of the two brand groups is 0.199 (standard genetic distance) and 0.132 (DA distance). Genetic distances of the two groups were relatively close to each other. Each individual is ramified to two brand groups in phylogenetic dendrogram.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.67-68
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• 2003

한국 재래 닭의 유전적 특성 규명 및 기능 유전체 연구의 기초재료를 확보하고자 대량 EST 염기서열 결정 및 생물정보학 분석을 실시하였다. 대량 EST 염기서열 분석을 위한 첫 번째 단계로 재래 닭의 뇌, 비장, 정소, 배아 생식기를 이용하여 cDNA library를 구축하였다. 각각의 library로부터 총 15,121개의 클론을 선정하여 염기서열을 결정하였다. 생물정보학 분석결과 15,121개의 염기서열은 총 10,353개의 contig로 정리되었다. 이들 염기서열을 기존 데이터베이스를 대상으로 tBlastX(http://www.ncbi.nlm.nih.gov/BLAST) 분석을 실시한 결과, 염기서열 중 56 ％가 기존 데이터베이스에 존재하는 유전자와의 상동성을 보였다. 상동성을 보이는 유전자들은 유전자의 구조 및 기능 분석에 이용될 것이고, 상동성을 보이지 않는 유전자들은 microarray와 같은 대량 유전자 발현분석 시스템을 이용하여 선별한 후 기능분석이 실시될 것이다.

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.305-311
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• 2014

Copy number variation (CNV) is a form of structural variation that shows various numbers of copies in segments of the DNA. It has been shown to account for phenotypic variations in human diseases and agricultural production traits. Currently, most of chicken breeds in the poultry industry are based on European-origin breeds that have been mostly provided from several international breeding companies. Therefore, National Institute of Animal Science, RDA has been trying to restore and improve Korean native chicken breeds (12 lines of 5 breeds) for about 20 years. Thanks to the recent advance of sequencing technologies, genome-wide CNV can be accessed in the higher resolution throughout the genome of species of interest. However, there is no systematic study available to dissect the CNV in the native chicken breed in Korea. Here, we report genome-wide copy number variations identified from a genome of Korean native chicken (Line L) by comparing between the chicken reference sequence assembly (Gallus gallus) and a de novo sequencing assembly of the Korean native chicken (Line L). Throughout all twenty eight chicken autosomes, we identified a total of 501 CNVs; defined as gain and loss of duplication and deletion respectively. Furthermore, we performed gene ontology (GO) analysis for the putative CNVs using DAVID, leading to 68 GO terms clustered independently. Of the clustered GO terms, genes related to transcription and gene regulation were mainly detected. This study provides useful genomic resource to investigate potential biological implications of CNVs with traits of interest in the Korean native chicken.