• Toxicological Research
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• 제8권2호
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• pp.331-342
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• 1992

The chicken major histocompatibility complex (MHC), the B complex, is beginning to be analyzed at the DNA level. Inbred lines of chickens have been reported to possess 3~5 MHC class II genes. To further analyzed the molecular structure of the chicken MHC class II genes, cDNA clones coding for chicken MHC class II (B-L) ${\beta}$ chain molecules were isolated from chicken spleen and liver. Tissue-specific transcription of B-L ${\beta}$genes was studied by Northern blot analysis. A high level of expression was detected for spleen poly(A)$^+$ RNA whereas a faint signal was detected for liver poly(A)$^+$ RNA. Twenty-nine cDNA clones were isolated from the spleen and eight cDNA clones were isolated from the liver. Based on restriction maps, most clones could be clustered into one family of genes. Four cDNA clones were sequenced (S7, S10 and S19 from the spleen and L1, which was identical to S19, from the liver). Complete amino acid sequences of B-L ${\beta}$ chain molecules were predicated from the nucleotide sequences of the cDNA clones. Although both the nature and the location of the conserved residues were similar in chicken and mammalian sequences, some species-specific differences were found, suggesting that the structures of the B-L molecules are similar, but not identical to their mammalian counterparts.

• Animal Bioscience
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• 제37권5호
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• pp.826-831
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• 2024

Objective: The major histocompatibility complex in chicken demonstrates a great range of variations within varities, breeds, populations and that can eventually influence their immuneresponses. The preset study was conducted to understand the major histocompatibility complex-B (MHC-B) variability in five major populations of Bangladesh native chicken: Aseel, Hilly, Junglefowl, Non-descript Deshi, and Naked Neck. Methods: These five major populations of Bangladesh native chicken were analyzed with a subset of 89 single nucleotide polymorphisms (SNPs) in the high-density MHC-B SNP panel and Kompetitive Allele-Specific polymerase chain reaction genotyping was applied. To explore haplotype diversity within these populations, the results were analyzed both manually and computationally using PHASE 2.1 program. The phylogenetic investigations were also performed using MrBayes program. Results: A total of 136 unique haplotypes were identified within these five Bangladesh chicken populations, and only one was shared (between Hilly and Naked Neck). Phylogenetic analysis showed no distinct haplotype clustering among the five populations, although they were shared in distinct clades; notably, the first clade lacked Naked Neck haplotypes. Conclusion: The present study discovered a set of unique MHC-B haplotypes in Bangladesh chickens that could possibly cause varied immune reponses. However, further investigations are required to evaluate their relationships with global chicken populations.

• Animal Bioscience
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• 제37권6호
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• pp.993-1000
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• 2024

Objective: This study was conducted to investigate the differential expression of the major histocompatibility complex (MHC) gene region in Eimeria-infected broiler. Methods: We profiled gene expression of Eimeria-infected and uninfected ceca of broilers sampled at 4, 7, and 21 days post-infection (dpi) using RNA sequencing. Differentially expressed genes (DEGs) between two sample groups were identified at each time point. DEGs located on chicken chromosome 16 were used for further analysis. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis was conducted for the functional annotation of DEGs. Results: Fourteen significant (false discovery rate <0.1) DEGs were identified at 4 and 7 dpi and categorized into three groups: MHC-Y class I genes, MHC-B region genes, and non-MHC genes. In Eimeria-infected broilers, MHC-Y class I genes were upregulated at 4 dpi but downregulated at 7 dpi. This result implies that MHC-Y class I genes initially activated an immune response, which was then suppressed by Eimeria. Of the MHC-B region genes, the DMB1 gene was upregulated, and TAP-related genes significantly implemented antigen processing for MHC class I at 4 dpi, which was supported by KEGG pathway analysis. Conclusion: This study is the first to investigate MHC gene responses to coccidia infection in chickens using RNA sequencing. MHC-B and MHC-Y genes showed their immune responses in reaction to Eimeria infection. These findings are valuable for understanding chicken MHC gene function.

• Asian-Australasian Journal of Animal Sciences
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• 제31권10호
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• pp.1558-1564
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• 2018

Objective: We report monitoring conservation effect for a Chinese indigenous chicken (Langshan) breed using major histocompatibility complex (MHC) and DNA barcords. Methods: The full length of MHC B-G gene and mitochondrial cytochrome oxidase I (COI) gene in generations 0, 5, 10, 15, 16, and 17 was measured using re-sequencing and sequencing procedures, respectively. Results: There were 292 single nucleotide polymorphisms of MHC B-G gene identified in six generations. Heterozygosity (He) and polymorphic information content (PIC) of MHC B-G gene in generations 10, 15, 16, and 17 remained stable. He and PIC of MHC B-G gene were different in six generations, with G10, G15, G16, G17 >G5>G0 (p<0.05). For the COI gene, there were five haplotypes in generations 0, 5, 10, 15, 16, and 17. Where Hap2 and Hap4 were the shared haplotypes, 164 individuals shared Hap2 haplotypes, while Hap1 and Hap3 were the shared haplotypes in generations 0 and 5 and Hap5 was a shared haplotype in generations 10, 15, 16, and 17. The sequence of COI gene in 6 generations was tested by Tajima's and D value, and the results were not significant, which were consistent with neutral mutation. There were no differences in generations 10, 15, 16, and 17for measured phenotypic traits. In other generations, for annual egg production, with G5, G10, G15, G16, G17>G0 (p<0.05). For age at the first egg and age at sexual maturity, with G10, G15, G16, G17>G5>G0 (p<0.05). Conclusion: Combined with the results of COI gene DNA barcodes, MHC B-G gene, and phenotypic traits we can see that genetic diversity remained stable from generations 10 to 17 and the equimultiple random matching pedigrees conservation population conservation effect of Langshan chicken was effective as measured by these criteria.

• 한국가금학회지
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• 제36권4호
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• pp.317-322
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• 2009

닭의 MHC 유전자 내에 있는 microsatellite marker LEI0258은 혈청의 구분 및 질병 저항성 유전자로 많은 연구가 되어 있다. 본 연구는 유전변이가 있는 microsatellite marker LEI 0258을 한국 재래계 흑색종, 한국 재래계 갈색종, 코니쉬종, 로드아일랜드 레드종에 적용하여 품종 특이 유전자형 및 allele을 탐색하고, 품종 구분 활용에 가능하지 여부를 실험하기 위하여 실시하였다. 한국 재래계만이 가지고 있는 특이 대립 유전자는 찾을 수는 없었지만 품종간 유전자형의 빈도 차이를 보이는 대립 유전자들을 확인할 수 있어 마커의 조합을 통하여 품종을 구분할 수 있는 가능성을 제시하였으며, 질병 저항성 연구의 기초 자료로 그 이용성이 높을 것으로 사료된다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권1호
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• pp.29-35
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• 2016

The aim of the present study was to investigate the effect of single nucleotide polymorphisms in the major histocompatibility complex (MHC) class II gene on resistance to Newcastle disease virus and body weight of the Thai indigenous chicken, Leung Hang Khao (Gallus gallus domesticus). Blood samples were collected for single nucleotide polymorphism analysis from 485 chickens. Polymerase chain reaction sequencing was used to classify single nucleotide polymorphisms of class II MHC. Body weights were measured at the ages of 3, 4, 5, and 7 months. Titres of Newcastle disease virus at 2 weeks to 7 months were determined and the correlation between body weight and titre was analysed. The association between single nucleotide polymorphisms and body weight and titre were analysed by a generalized linear model. Seven single nucleotide polymorphisms were identified: C125T, A126T, C209G, C242T, A243T, C244T, and A254T. Significant correlations between log titre and body weight were found at 2 and 4 weeks. Associations between single nucleotide polymorphisms and titre were found for C209G and A254T, and between all single nucleotide polymorphisms (except A243T) and body weight. The results showed that class II MHC is associated with both titre of Newcastle disease virus and body weight in Leung Hang Khao chickens. This is of concern because improved growth traits are the main goal of breeding selection. Moreover, the results suggested that MHC has a pleiotropic effect on the titre and growth performance. This mechanism should be investigated in a future study.

• Asian-Australasian Journal of Animal Sciences
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• 제32권5호
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• pp.614-628
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• 2019

Objective: The inhibitory leukocyte immunoglobulin-like receptors (LILRBs) play an important role in innate immunity. The present study represents the first description of the cloning and structural and functional analysis of LILRB1 and LILRB3 isolated from two genetically disparate chicken lines. Methods: Chicken LILRB1-3 genes were identified by bioinformatics approach. Expression studies were performed by transfection, quantitative polymerase chain reaction. Signal transduction was analyzed by western blots, immunoprecipitation and flow cytometric. Cytokine levels were determined by enzyme-linked immunosorbent assay. Results: Amino acid homology and phylogenetic analyses showed that the homologies of LILRB1 and LILRB3 in the chicken line 6.3 to those proteins in the chicken line 7.2 ranged between 97%-99%, while homologies between chicken and mammal proteins ranged between 13%-19%, and 13%-69%, respectively. Our findings indicate that LILRB1 and LILRB3 subdivided into two groups based on the immunoreceptor tyrosine-based inhibitory motifs (ITIM) present in the transmembrane domain. Chicken line 6.3 has two ITIM motifs of the sequence LxYxxL and SxYxxV while line 7.2 has two ITIM motifs of the sequences LxYxxL and LxYxxV. These motifs bind to SHP-2 (protein tyrosine phosphatase, non-receptor type 11) that plays a regulatory role in immune functions. Moreover, our data indicate that LILRB1 and LILRB3 associated with and activated major histocompatibility complex (MHC) class I and ${\beta}2-microglobulin$ and induced the expression of transporters associated with antigen processing, which are essential for MHC class I antigen presentation. This suggests that LILRB1 and LILRB3 are transcriptional regulators, modulating the expression of components in the MHC class I pathway and thereby regulating immune responses. Furthermore, LILRB1 and LILRB3 activated Janus kinase2/tyrosine kinase 2 (JAK2/TYK2); signal transducer and activator of transcription1/3 (STAT1/3), and suppressor of cytokine signaling 1 genes expressed in Macrophage (HD11) cells, which induced Th1, Th2, and Th17 cytokines. Conclusion: These data indicate that LILRB1 and LILRB3 are innate immune receptors associated with SHP-2, MHC class I, ${\beta}2-microglobulin$, and they activate the Janus kinase/signal transducer and activator of transcription signaling pathway. Thus, our study provides novel insights into the regulation of immunity and immunopathology.

• 한국가금학회지
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• 제32권1호
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• pp.29-34
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• 2005

본 연구는 한국 재래 닭의 유전적 특성을 분자표지를 이용하여 그 차이를 규명하고 초기성장에 미치는 영향을 분석하여 이를 이용한 재래닭의 개량을 목적으로 실시하였다. MHC class II B-LB 유전자 내의 염기변이체가 경제형질에 미치는 영향에 대하여 연구하였다. MHC class II B-LB유전자 내 400 bp 크기의 유전자를 증폭하여 염기서열 분석과 제한효소 처리를 이용한 다형성 분석을 실시하였다. 연구결과 두 개의 제한효소 절단지역이 발견되었으며 427 지역을 Type I 으로 651 지역은 Type II로 정하여 RFLP 분석을 실시하였다. Type I지역의 유전자형은 TT, TC, CC로 나타났으며, TypeII 지역의 유전자형은 MM, Mm, mm으로 나타났다. TC와 Mm 유전자형이 다른 유전자형과 비교하였을 때 한국재래 닭에서 높은 출현빈도를 보였다(0.8, 0.88). 유전자형이 한국 재래 닭의 150일령 체중에 미치는 영향을 분석한 결과 CC와 Mm 유전자형에서 통계적 유의성이 도출되었다 (P<0.05). 따라서 본 연구의 결과를 이용하여 한국 재래 닭의 유전적 특성을 규명할 수 있으며 초기 성장이 높은 성적을 나타내는 CC, Mm 유전자형을 개량에 이용하게 된다면 큰 효과를 얻을 수 있을 것으로 사료되어진다. 본 연구의 결과는 차후 한국 재래 닭의 과학적이고 지속적인 유전자원의 보존과 육종 전략에 있어 매우 유용하게 활용될 것으로 기대된다.

• 한국가금학회지
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• 제43권2호
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• pp.63-76
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• 2016

The genetic diversity of Korean native chicken is important for conservation of native chicken breeds and developing economically valuable traits in Korea. In this review, various types of genetic markers using Korean native chickens were investigated, which are mtDNA variations, microsatellite markers, markers in Major Histocompatibility Complex (MHC), and single nucleotide polymorphisms (SNPs). These genetic markers are suitable for breed discrimination and diversity studies because of their high polymorphism status. Thus, the purpose of this study was to summarize the genetic markers developed in the Korean native chickens and diversity studies using these breeds. Ultimately, these markers can be used for the future studies for understanding of genetic characteristics.

• Asian-Australasian Journal of Animal Sciences
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• 제24권12호
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• pp.1637-1643
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• 2011

Korean native chickens are a very valuable chicken population in Korea and their prices are higher than that of commercial broilers. In order to discriminate two commercial Korean native chicken populations (CCP1 and CCP2), single nucleotide polymorphisms (SNPs) from mitochondrial (mt) DNA D-loop sequences and LEI0258 marker polymorphisms in the major histocompatibility complex (MHC) region were investigated. A total of 718 birds from nine populations were sampled and 432 mtDNA sequences were obtained. Of these, two commercial Korean native chicken populations (363 birds) were used for investigation of their genetic relationship and breed differentiation. The sequence data classified the chickens into 20 clades, with the largest number of birds represented in clade 1. Analysis of the clade distribution indicated the genetic diversity and relation among the populations. Based on the mtDNA sequence analysis, three selected SNPs from mtDNA polymorphisms were used for the breed identification. The combination of identification probability (Pi) between CCP1 and CCP2 using SNPs from mtDNA and LEI0258 marker polymorphisms was 86.9% and 86.1%, respectively, indicating the utility of these markers for breed identification. The results will be applicable in designing breeding and conservation strategies for the Korean native chicken populations and also used for the development of breed identification markers.