• Toxicological Research
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• v.8 no.2
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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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• v.37 no.5
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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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• v.37 no.6
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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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• v.31 no.10
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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.

• Korean Journal of Poultry Science
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• v.36 no.4
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• pp.317-322
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• 2009

The chicken major histocompatibility complex (MHC) is known to be associated with disease resistance and susceptibility to several pathogens. The microsatellite marker LEI0258 is physically located between the BG and BF of MHC region and variations near this marker have been well documented. In this report, the LEI0258 marker was used to find specific alleles for the Korean native chicken. The MHC haplotype was analyzed by PCR screening and sequencing of LEI0258 region in four different breeds including black Korean native chicken, brown Korean native chicken, Cornish and Rhode island red. The serologically same MHC haplotypes showed the differences in repeat numbers, a few indels or single nucleotide polymorphisms by sequencing analysis. Even though we could not identify specific alleles for Korean native chickens, the genotypes analyzed in these breeds can give valuable information for the relationships with disease resistance and establishment of breeding strategies for the Korean native chicken.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.1
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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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• v.32 no.5
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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.

• 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.

• Korean Journal of Poultry Science
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• v.43 no.2
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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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• v.24 no.12
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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.