• Asian-Australasian Journal of Animal Sciences
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• v.2 no.2
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• pp.103-114
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• 1989

Reciprocal crosses were conducted between three strains of Taiwan Country chickens, developed in the National Chung-Hsing University, and two strains of Single Comb White Leghorns, developed in the Taiwan Livestock Research Institute. Traits studied were growing performances, laying performances, egg quality traits and traits concerning disease resistance, including resistance to Marek's disease virus and immune responses to Newcastle disease virus vaccine and to sheep red blood cell. Results indicated that laying performances of Taiwan country chickens were much inferior to White Leghorns, but they matured earlier, their eggs had better shell strength and larger proportion of yolk, and their general disease resistance was much better than White Leghorns. Heterosis were found in laying performances and egg quality traits. The heterosis in laying traits was so large that the hybrid laid as many eggs and as large eggs as did pure strains of White Leghorns. Strategies on the improvement of native chickens and the utilization of genetic merits of native chickens were also discussed.

• Korean Journal of Veterinary Pathology
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• v.6 no.2
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• pp.101-104
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• 2002

닭의 전신장기에 림프종 발생이 특정인 마렉병(Marek's disease; MD)은 림프구성 백혈병(Lymphoid leukosis; LL)과 병리학적 소견이 매우 유사하여 감별이 요구된다. 마렉병 바이러스(Marek's disease virus; MDV)는 질병초기에서 후기에 이르기까지 모낭상피세포에 세포용해성 감염을 지속적으로 일으킨다. 세포용해성 감염이 있는 모낭상피세포는 변성내지 괴사되어 있고 핵내봉입체가 관찰된다. 또한 세포용해성 감염이 있는 모낭상피세포 바로 밑의 진피와 깃털 수질(feather pulp)내의 혈관주위에 림프구 침윤이 관찰된다. 이러한 피부병변은 MD의 특징적인 병변들로서 LL과 감별할 수 있는 결정적인 단서이다. 본 고에서는 MD에 관한 전반적인 것과 특히 MD 진단을 위한 피부병변의 유용성에 대해서 자세히 논하고자 한다. 양계산업에 문제를 야기하고 있는 림프구 증식성 종양은 크게 마렉병(Marek’s disease; MD)과 백혈병(Lymphoid leukosis; LL)이 있다. 이들 질환의 원인체들이 분리되기 전까지는 이들 질병들은 발병부위에 따라 질병명을 붙였다. 즉, 내부장기냐 근육에 발생한 것은 visceral lymphomatosis, 피부에 발생한 것은 skin leukosis, 말초신경의 병변은 poly­n neuritis, neuritis, neurolymphomatosis gallinarum, range paralyis로 불리었다. 또한 눈에 발생한 것은 blindness, gray eye, iritis, uveitis, ocular lymphomatosis라고 불리었다. 1961년에 Biggs는 이러한 림프구 증식성 질병을 마렉병과 백혈병 으로 분류하자는 제안을 하였고, 드디어 1960년대 중반에 림프구 증식성 병변 중의 일부에서 herpesvirus가 분리되어서 Biggs가 제안한 병명인 마렉병을 본격적으로 사용하게 되었다. MD는 마렉병 바이러스(Marek’s disease virus; MDV)가 원 인제로서 닭에 전염성이 강한 염증성에서 종양성의 병변을 내부장기, 피부, 근육, 안구, 중추신경계, 말초신경계 등에 일 으킨다. MDV는 림프종을 유발하기 때문에 처음에는 사람에서 림프종을 유발하는 Epstein-Bar 바이러스와 관련이 있을 것으로 생각되어 gamma-herpesvirus로 분류되었지만, MDV의 게놈 구조와 세포배양에서 빠르게 성장한다는 점 때문에 지금은 alpha-herpesvirus로 재분류 되었다. MDV는 바이러스 중화시험과 한천 겔 침강법에 의해서 3개의 혈청형으로 분류 된다. 혈청형 1은 종양원성 바이러스와 종양원성 바이러스의 계대배양에 의한 약독주가 있다. 혈청형 2는 자연적으로 발 생하는 비종양원성 닭의 MDV이고, 혈정형 3은 바종양원성 칠면조 herpesvirus (HVT)이다. 림프종을 유발하는 MDV 감염은 4개의 과정, 즉 초기 세포용해성 감염, 잠복감염, 후기 세포용해성 감염, 마지막으로 종양화로 나눌 수 있다. 감염의 경로를 보면, 흡입된 MDV는 폐의 대식세포에 감염한 후 전선 장기로 MDV를 전파 시킨다. 특히, 흉선, F냥, 비장 등의 림프구에 초기 세포용해성 감염을 일으키는데, B 림프구가 주로 감염된다. 세포용해성 감염음 방어하기 위해 몰려든 T 림프구가 활성화가 되면, T 세포도 감염되게 된다. 잠복감염은 여러 가지 사이토카인 등 을 포함한 면역반응에 의해서 일어나며, 이 때 잠복감염된 세포는 특히 혈중의 T 세포라고 한다. 혈중 MDV 감염세포 는 피부 모낭상피세포, 선장 등 상피세포 유래의 조직에 MDV를 전파 시켜서 이들 조직에서 후기 세포용해성 감염이 일어나게 한다. 후기 세포용해성 감염을 유발하는 것은 이러한 MDV가 감염된 혈중 림프구라는 증거는 혈중의 세포 외에는 감염성 바이러스가 없기 때문이다. 후기 세포용해성 감염이 있는 후 육안적 혹은 현미경적으로 검출이 가능한 림프종이 여러 장기에서 관찰된다. MDV가 감염되면 병변 발생부위에 따라서 다양한 임상증상이 발생한다. 즉 내부장기에 병변이 있을 경우는 침울, 체중감소, 산란율 저하 등이 발생하며, 신경계는 발생부위별 신경증상이 일어난다. 이러한 장기나 조직에서는 육안적으로 백색에서 회백색의 종양성 병변이 관찰된다. 말초신경에 병변이 발생한 경우에는 특히 좌골신경 및 신경총에서 호발하는데, 이들 조직은 편측성 혹은 양측성으로 종창되어 있다. 안구는 간혹 육안적으로 식별이 가능한 홍채 퇴색 및 증식 병변이 관찰된다. 피부형 MD는 특히 육용계에서 문제가 되고 있으며, 산란계의 내장형 MD가 발생한 경우에도 피부를 자세히 설펴보면 피부형 MD를 간혹 관찰할 수 있다. 피부형 MD는 모낭주위에 원형의 결절형태로 발생하는데, 이들 병변이 커지면 바로 옆의 병변과 융합 되어 큰 결절을 형성하기도 한다. (중략)

• Korean Journal of Poultry Science
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• v.44 no.3
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• pp.199-209
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• 2017

Mitogen-activated protein kinase (MAPK) signaling pathways play a key role in innate immunity, inflammation, cell proliferation, cell differentiation, and cell death. The main objective of this study was to investigate the expression level of candidate MAPK pathway genes in the intestinal mucosal layer of two genetically disparate chicken lines (Marek's disease-resistant line 6.3 and Marek's disease-susceptible line 7.2) induced with necrotic enteritis (NE). Using high-throughput RNA sequencing, we investigated 178 MAPK signaling pathway related genes that were significantly and differentially expressed between the intestinal mucosal layers of the NE-afflicted and control chickens. In total, 15 MAPK pathway genes were further measured by quantitative real-time PCR(qRT-PCR) and the results were consistent with the RNA-sequencing data. All 178 identified genes were annotated through Gene Ontology and mapped onto the KEGG chicken MAPK signaling pathway. Several key genes of the MAPK pathway, ERK1/2, JNK1-3, p38 MAPK, MAP2K1-4, $NF-{\kappa}B1/2$, c-Fos, AP-1, Jun-D, and Jun, were differentially expressed in the two chicken lines. Therefore, we believe that RNA sequencing and qRT-PCR analysis provide resourceful information for future studies on MAPK signaling of genetically disparate chicken lines in response to pathogens.

• Korean Journal of Poultry Science
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• v.44 no.3
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• pp.211-223
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• 2017

Transforming growth factor beta ($TGF-{\beta}$) signaling pathways are involved in the regulation of proliferation, differentiation, immunity, survival, and apoptosis of many cells. The aim of this study was to investigate the differential expression of $TGF-{\beta}$-related genes, and their interactions and regulators in the spleen of two genetically disparate chicken lines (Marek's disease resistant line 6.3 and Marek's disease-susceptible line 7.2) induced with necrotic enteritis (NE) by Eimeria maxima and Clostridium perfringens infection. By using high-throughput RNA-sequencing, we investigated 76 $TGF-{\beta}$-related genes that were significantly and differentially expressed in the spleens of the chickens. Approximately 20 $TGF-{\beta}$ pathway genes were further verified by qRT-PCR, and the results were consistent with our RNA sequencing data. All 76 identified genes were analyzed through Gene Ontology and mapped onto the KEGG chicken $TGF-{\beta}$ pathway. Our results demonstrated that several key genes, including $TGF-{\beta}$1-3, bone morphogenetic proteins (BMP)1-7, inhibitor of differentiation (ID) proteins ID1-3, SMAD1-9, and Jun, showed a markedly differential expression between the two chicken lines, relative to their respective controls. We then further predicted 24 known miRNAs that targeted BMP7 mRNA from 139 known miRNAs in the two chicken lines. Among these, six miRNAs were measured by qRT-PCR. In conclusion, this study is the first to analyze most of the genes, interactions, and regulators of the $TGF-{\beta}$ pathway in the innate immune responses of NE afflicted chickens.

• Korean Journal of Veterinary Service
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• v.33 no.1
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• pp.7-12
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• 2010

There are several immunosuppressive viral diseases in chickens such as avian adenovirus (AAV), chicken anemia virus (CAV), infectious bursal disease (IBD) and Marek's disease (MD). In this study, we have investigated two broiler chicken farms suffered from high mortality in Jeonbuk in July to August 2009. Clinically high fever and growth retardation were observed in the diseased chicken. In necropsy, the hemorrhages in thigh leg and thymus, hemorrhages and enlargement of liver, kidney and proventriculus, and yellowish fluid in heart were seen. Histologically, necrotic foci and basophilic intranuclear inclusion bodies of hepatocytes, hemorrhages and infiltrated lymphocytes in kidney and proventriculus were observed. By using polymerase chain reaction (PCR), the genes of avian adenovirus, CAV and ND virus were detected in specimens. We suggested that these coinfection cases with high mortality were due to primarily infection of immunosuppressive diseases such as avian adenovirus, CAV, followed by secondary infection of Newcastle disease (ND) virus.

• Korean Journal of Poultry Science
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• v.19 no.3
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• pp.137-150
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• 1992

Poultry production in korea is a very complex situation. Large modernized farms and old styles of small farming coexist with one another. This gives rise to a tangled epidemiological situation in terms of infectious diseases. The main poultry diseases of economic importance are colibacillosis, pullorum diseases, Mycoplasma gallisepticum infection, infectious coryza, infectious synovitis, Newcasyle disease, fowl pox, Marek's disease, avian encephalomyelitis, infectious bursal disease, infectious laryngotracheitis, infectious bronchitis and coccidiosis. Avian influenza, fowl cholera and fowl typhoid have not been reported for a few decades, and these are rated as exotic diseases.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.401-408
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• 1987

Nine monoclonal antibodies directed against infectious bovine rhinotracheitis virus (IBRV) were prepared by using cell hybridization technique, and the biological properties of the antibodies were investigated by means of immunofluorescence, serum neutralization, and electrophoretic analysis. Eight of 9 monoclonal antibodies reacted specifically with the antigenic constituents of IBRV, infectious laryngotracheitis virus, Marek's disease virus, turkey herpesvirus, hog cholera virus, porcine parvovirus and transmissible gastroenteritis virus. However, the remaining one, 26-2 clone, was found to be cross-reactive with pseudorabies virus. Two monoclonal antibodies, 7-C-2 and 12-A-2, which had neutralizing activity, were reactive with the molecular weights of 72 kilo daltons (72K) and 125K of IBRV proteins electrophoretically separated, respectively. The monoclonal antibody, 3-H-3, which is corresponding to 94K of IBRV proteins, revealed no neutralizing activity. The cross-reactive monoclonal antibody, 26-2, was proved by electrophoretical analysis to be reactive with 100K of IBRV proteins and 40K of pseudorabies virus.

• Korean Journal of Veterinary Service
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• v.20 no.2
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• pp.183-189
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• 1997

This article reports a spontaneous thoracic teratoma in a laying hen (Deklb brown warren). In this case, a 40 days old hen was submitted for necropsy as part of an investigation into a flock problem suspected Marek's disease to Chonbuk Veterinary Service Laboratory in 1983. On the gross finding, mass was In the cranial subpulmonary cavity and attached to the vertebral column. It contained fully developed contour feathers. Histologically, feathers were arised from feather follicles complete with arrector plumi muscle, nerve, vessel and mucous gland composed with simple tall columnar epithelium. The outer surface of mass was lined by keratinized or nonkeratinized stratified squamous epithelium. It converted to pseudostratified ciliated columnar epithelium in some area. There were lymphocyte infiltration around gland tissue and eosinophilic intranuclear inclusion bodies in nonkeratinized epithelium. This thoracic teratoma was composed of ectodermal origin, squamous epithelium and nerve, and endodermal origin, mucous gland. This case in laying hen has never been reported in the literature in the world.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.10
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• pp.1496-1511
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• 2015

The study aimed to compare the necrotic enteritis (NE)-induced transcriptome differences between the spleens of Marek's disease resistant chicken line 6.3 and susceptible line 7.2 co-infected with Eimeria maxima/Clostridium perfringens using RNA-Seq. Total RNA from the spleens of two chicken lines were used to make libraries, generating 42,736,296 and 42,617,720 usable reads, which were assembled into groups of 29,897 and 29,833 mRNA genes, respectively. The transcriptome changes were investigated using the differentially expressed genes (DEGs) package, which indicated 3,255, 2,468 and 2,234 DEGs of line 6.3, line 7.2, and comparison between two lines, respectively (fold change ${\geq}2$, p<0.01). The transcription levels of 14 genes identified were further examined using qRT-PCR. The results of qRT-PCR were consistent with the RNA-seq data. All of the DEGs were analysed using gene ontology terms, the Kyoto Encyclopedia of Genes and Genomes (KEGG) database and the DEGs in each term were found to be more highly expressed in line 6.3 than in line 7.2. RNA-seq analysis indicated 139 immune related genes, 44 CD molecular genes and 150 cytokines genes which were differentially expressed among chicken lines 6.3 and 7.2 (fold change ${\geq}2$, p<0.01). Novel mRNA analysis indicated 15,518 novel genes, for which the expression was shown to be higher in line 6.3 than in line 7.2 including some immune-related targets. These findings will help to understand host-pathogen interaction in the spleen and elucidate the mechanism of host genetic control of NE, and provide basis for future studies that can lead to the development of marker-based selection of highly disease-resistant chickens.

• Korean Journal of Veterinary Service
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• v.47 no.2
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• pp.107-113
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• 2024

A broiler farm in Jeonbuk province experienced high mortality due to decreased feed intake and poor growth, and pathological evaluation of 11- and 17-day-old broilers was performed, which led to the diagnosis of runting-stunting syndrome. From the start of the rearing period to shipment, 18.4% of the chickens in the three barns experiencing continuous culling and mortality were affected, compared to 7.7% in the other five barns. Gross findings on the 11-day-old broiler chicken revealed proventricular dilatation and hemorrhage, intestinal hemorrhage, urate deposition in the pericardium and renal tubule, nephropathy, and mild hepatic capsulitis. Similar proventricular dilatation and hemorrhage were observed in the 17-day-old broiler chickens. In addition, hepatitis and pericarditis were observed with the progression of secondary bacterial infection, and pathogenic Escherichia coli was isolated from these lesions. As a result of PCR, Newcastle disease virus, fowl adenovirus, chicken anemia virus and Marek's disease virus were not detected in the all tissue samples. In contrast, infectious bronchitis virus was detected in the proventriculus, kidney and cecal tonsil. chicken astrovirus was detected in the intestine, cecal tonsil and bursa of Fabricius, and chicken parvovirus was detected in proventriculus, intestine, cecal tonsil and bursa of Fabricius. By sharing the diagnostic process of a case of malabsorption syndrome through this case report, we hope that it can be widely utilized in the diagnostic process of livestock disease pathognomonic institutions.