• 한국동물위생학회지
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• 제30권3호
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• pp.393-406
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• 2007

Bovine tuberculosis is an important zoonosis worldwide. Mycobacterium bovis, the causative agent of this disease in cattle, is also a pathogen for humans and several economically important animals. The cases of tuberculosis are reported in two cow found at slaughter house located in Gwangju city. Histopathologically, in the lymph nodes, granulomas consisted of large areas of necrosis surrounded by variable thick bands of cellular infiltrate containing macrophages, Langhans-type multinucleated giant cells and lymphocytes. Lesions in the lung followed the same developmental pattern as did lesions in the lymph nodes with some exceptions. With the acid-fast staining, numerous mycobacteria were revealed in the lung and lymph nodes. M bovis was confirmed as a causative agent in these cattle using bacterial isolation and PCR and restriction fragment length polymorphism method based on a unique 12.7 kb fragment insertion sequence from the Mycobacterium tuberculosis genome and the pncA polymorphism, The insertion element IS6110 and IS1081 were present M bovis isolated from lungs and lymph nodes of cattle using PCR assay. These cases are interesting and important in public health aspect that M bovis-infected cattle were found during a routine post-mortem inspection at slaughter house.

• 미생물학회지
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• 제38권2호
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• pp.86-95
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• 2002

최근 인간을 비롯한 다양한 생명체의 genome project연구결과 밝혀진 유전자들의 염기서열을 토대로, 생명체 구성성분의 실질적 인 역할을 하는 단배질의 기능을 밝히는 proteomics에 관한 연구의 필요성 이 대두되고 있다. 따라서, 이 연구는 post-genomics시대에 다양한 종류의 단백질 기능과 상호작용의 기초연구에 필수적 인 새로운 포유동물세포 유전자 발현벡터를 RNA 바이러스인 소설사성 바이러스(Bovine Viral Diarrhea Virus)의 infectious CDNA molecular clone을 이용하여 개발하였다. 먼저 BVDV의 infectious CDNA molecular clone (pNADLclns-)을 이용하여 puromycin 항생제에 저항성을 나타내는 puromycin acetyltransferase (pac) 유전자를 삽입하여 recombinant full-length infectious CDNA clone을 합성하였다. 합성된 recombinant CDNA clone을 주형으로 T7 RNA polymerase를 사용하여 in vitro transcribed full-length viral RNA를 합성하였다. 합성된 viral RNA의 자가복제 여부는 MDBK세포에 transfection시킨 후, $^{32}P$ 로 metabolically label함으로써 확인하였다. 또한, transfection된 세포에서의 바이러스 단백질 발현여부는 바이러스에 특이적으로 반응하는 anti-NS3 단클론항체를 사용하여 분석하였다. 또한, infectious CDNA clone을 응용하여 새로운 포유동물세포유전자 발현벡터의 개발을 위해서, 먼저 바이러스의 구조단백질이 바이러스의 자가복제에 필수적인 지를 평가하였다. 실험결과, 각각의 구조단백질 유전자를 deletion한 recombinant cDNA clone으로부터 합성된 viral RMA의 자가복제여부는pac유전자의 발현여부로 recombinant cDNA clone으로부터 합성된 recombinant viral RMA를 MDBK 세포에 transfection시킨 후, puromycin으로 selection함으로써 할 수 있었다. Deletion실험결과, 각각의 구조단백질 capsid및 E0, El, E2는 바이러스의 자가복제에 영향을 기치지 않음을 알 수 있었다. 이와 더불어, 바이러스의 모든 구조단백질을 함께deletion하였을 경우에도 자가복제에는 영향을 기치지 않는 것을 합성된 viral replicon을 이용한 실험에서 알 수 있었다. 이렇게 합성된 BVDV의 replicon을 사용하여 포유동물의 발현벡터로써 사용할수 있는 지의 여부를 분석하기 위해서 pac유전자 이외에 luciferase유전자를 사용하여 MDBK및 HeLa, BHK세포에서의 단백질 발현정도를 시간 별로 분석한 결과, BVDV의 replicon을 다양한 종류의 유전자 발현벡터로사용할 수 있음을 알 수 있었다. 그러므로, RNA바이러스의 하나인 BVDV의 viral replicon을 이용하여 다양한 종류의 포유동물 세포에 유전자 발현벡터로써 사용할 수 있음으로 post-genomics시대에 다양한 종류의 단백질 기능연구에 맡은 도움이 되리라 기대한다.

• Journal of Animal Science and Technology
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• 제53권3호
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• pp.195-202
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• 2011

Maintenance of adequate telomere length in developing cells is the most important concern to preserve the integrity of the genome. The length of telomere is strictly regulated by numerous telomere-binding proteins and/or interacting factors. Even though the expression of telomerase in the male reproductive tract has been characterized, developmental expressional profiling of telomerase and other telomere-associated proteins has not been determined in detail. The present study was attempted to examine expression patterns of catalytic subunit (Tert) and RNA component (Terc) of telomerase and two telomerase associated factors, telomerase associated protein 1 (Tep1) and TERF1 (TRF1) interacting nuclear factor 2 (Tinf2) in the testis and seminal vesicle of male rat during postnatal development. The real-time PCR analysis was utilized to quantify mRNA expression of molecules. The abundance of Tep1 mRNA in the testis and seminal vesicle was the highest at 5 months of age. Expressional fluctuation of Tinf2 during postnatal development was found in the testis, while expression of Tinf2 in the seminal vesicle was gradually increased until 5 months of age and then significantly decreased later. mRNA level of Tert gene in the testis was significantly increased at the adult and the elder, while the highest expression of Tert gene in the seminal vesicle was found at 5 months of age. Expression of Terc transcript in the testis and seminal vesicle was the highest at 5 months of age, followed by significant reduction at 1 and 2 years of ages. Such differential gene expression of telomere-associated factors and telomerase components in different male reproductive tissues during postnatal development indicates that maintenance of telomere length would be regulated in tissue- and/or age-specific manners.

• Journal of Animal Science and Technology
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• 제57권12호
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• pp.47.1-47.10
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• 2015

Background: Knowledge of linkage disequilibrium (LD) levels among different populations can be used to detect genetic diversity and to investigate the historical changes in population sizes. Availability of large numbers of SNP through new sequencing technologies has provided opportunities for extensive researches in quantifying LD patterns in cattle breeds. The aim of this study was to compare the extent of linkage disequilibrium among Iranian cattle breeds using high density SNP genotyping data. Results: A total of 70 samples, representing seven Iranian indigenous cattle breeds, were genotyped for 777962 SNPs. The average values of LD based on the $r^2$ criterion were computed by grouping all syntenic SNP pairwises for intermarker distances from 0 Kb up to 1 Mb using three distance sets. Average $r^2$ above 0.3 was observed at distances less than 30 Kb for Sistani and Kermani, 20 Kb for Najdi, Taleshi, Kurdi and Sarabi, and 10 Kb for Mazandarani. The LD levels were considerably different among the Iranian cattle breeds and the difference in LD extent was more detectable between the studied breeds at longer distances. Lower level of LD was observed for Mazandarani breed as compared to other breeds indicating larger ancestral population size in this breed. Kermani breed continued to have more slowly LD decay than all of the other breeds after 3 Kb distances. More slowly LD decay was observed in Kurdi and Sarabi breeds at larger distances (>100 Kb) showing that population decline has been more intense in more recent generations for these populations. Conclusions: A wide genetic diversity and different historical background were well reflected in the LD levels among Iranian cattle breeds. More LD fluctuation was observed in the shorter distances (less than 10 Kb) in different cattle populations. Despite of the sample size effects, High LD levels found in this study were in accordance with the presence of inbreeding and population decline in Iranian cattle breeds.

• 한국가축번식학회지
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• 제27권4호
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• pp.309-315
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• 2003

DNA methylation at CpG sites, which is a epigenetic modification, is associated with gene expression without change of DNA sequences. During early mouse embryogenesis, dynamic changes of DNA methylation occur. In this study, DNA methylation patterns of porcine embryos produced in vivo and in vitro were examined at various developmental stages by the immunocytochemical staining method. Interestingly, active demethylation was not observed on the paternal pronucleus of porcine zygotes. However, differences were detected in the passive demethylation process between in vivo and in vitro embryos. There was no change in the DNA methylation state until the blastocyst stage of in vivo embryos, whereas partial demethylation was observed in several blastomeres from a 4 cell stage to a morula stage of in vitro embryos. The whole genome of inner cell mass (ICM) and trophectoderm (TE) cells in porcine blastocysts were evenly methylated without de novo methylation. Our findings demonstrate that genome-wide demethylation does not occur in pig embryos during preimplantation development unlike murine and bovine embryos. It indicates that the machinery regulating epigenetic reprogramming may be different between species.

• Asian-Australasian Journal of Animal Sciences
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• 제27권10호
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• pp.1381-1386
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• 2014

In spite of variation in coat color, size, and production traits among indigenous Bangladeshi cattle populations, genetic differences among most of the populations have not been investigated or exploited. In this study, we used a high-density bovine single nucleotide polymorphism (SNP) 80K Bead Chip derived from Bos indicus breeds to assess genetic diversity and population structure of 2 Bangladeshi zebu cattle populations (red Chittagong, n = 28 and non-descript deshi, n = 28) and a semi-domesticated population (gayal, n = 17). Overall, 95% and 58% of the total SNPs (69,804) showed polymorphisms in the zebu and gayal populations, respectively. Similarly, the average minor allele frequency value was as high 0.29 in zebu and as low as 0.09 in gayal. The mean expected heterozygosity varied from $0.42{\pm}0.14$ in zebu to $0.148{\pm}0.14$ in gayal with significant heterozygosity deficiency of 0.06 ($F_{IS}$) in the latter. Coancestry estimations revealed that the two zebu populations are weakly differentiated, with over 99% of the total genetic variation retained within populations and less than 1% accounted for between populations. Conversely, strong genetic differentiation ($F_{ST}=0.33$) was observed between zebu and gayal populations. Results of population structure and principal component analyses suggest that gayal is distinct from Bos indicus and that the two zebu populations were weakly structured. This study provides basic information about the genetic diversity and structure of Bangladeshi cattle and the semi-domesticated gayal population that can be used for future appraisal of breed utilization and management strategies.

• Asian-Australasian Journal of Animal Sciences
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• 제26권5호
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• pp.603-608
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• 2013

Hanwoo have been subjected over the last seventy years to intensive artificial selection with the aim of improving meat production traits such as marbling and carcass weight. In this study, we performed a signature of selection analysis to identify recent positive selected regions driven by a long-term artificial selection process called a breeding program using whole genome SNP data. In order to investigate homozygous regions across the genome, we estimated iES (integrated Extended Haplotype Homozygosity SNP) for the each SNPs. As a result, we identified two highly homozygous regions that seem to be strong and/or recent positive selection. Five genes (DPH5, OLFM3, S1PR1, LRRN1 and CRBN) were included in this region. To go further in the interpretation of the observed signatures of selection, we subsequently concentrated on the annotation of differentiated genes defined according to the iES value of SNPs localized close or within them. We also described the detection of the adaptive evolution at the molecular level for the genes of interest. As a result, this analysis also led to the identification of OLFM3 as having a strong signal of selection in bovine lineage. The results of this study indicate that artificial selection which might have targeted most of these genes was mainly oriented towards improvement of meat production.

• Journal of Animal Science and Technology
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• 제62권2호
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• pp.141-158
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• 2020

Skin is a major thermoregulatory organ in the body controlling homeothermy, a critical function for climate adaptation. We compared genes expressed between tropical- and temperate-adapted cattle to better understand genes involved in climate adaptation and hence thermoregulation. We profiled the skin of representative tropical and temperate cattle using RNA-seq. A total of 214,754,759 reads were generated and assembled into 72,993,478 reads and were mapped to unique regions in the bovine genome. Gene coverage of unique regions of the reference genome showed that of 24,616 genes, only 13,130 genes (53.34%) displayed more than one count per million reads for at least two libraries and were considered suitable for downstream analyses. Our results revealed that of 255 genes expressed differentially, 98 genes were upregulated in tropically-adapted White Fulani (WF; Bos indicus) and 157 genes were down regulated in WF compared to Angus, AG (Bos taurus). Fifteen pathways were identified from the differential gene sets through gene ontology and pathway analyses. These include the significantly enriched melanin metabolic process, proteinaceous extracellular matrix, inflammatory response, defense response, calcium ion binding and response to wounding. Quantitative PCR was used to validate six representative genes which are associated with skin thermoregulation and epithelia dysfunction (mean correlation 0.92; p < 0.001). Our results contribute to identifying genes and understanding molecular mechanisms of skin thermoregulation that may influence strategic genomic selection in cattle to withstand climate adaptation, microbial invasion and mechanical damage.

• Genomics & Informatics
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• 제13권4호
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• pp.146-151
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• 2015

Previous studies in Holstein have shown 35% to 51.8% heritability in milk production traits, such as milk yield, fat, and protein, using pedigree data. Other studies in complex human traits could be captured by common single-nucleotide polymorphisms (SNPs), and their genetic variations, attributed to chromosomes, are in proportion to their length. Using genome-wide estimation and partitioning approaches, we analyzed three quantitative Holstein traits relevant to milk production in Korean Holstein data harvested from 462 individuals genotyped for 54,609 SNPs. For all three traits (milk yield, fat, and protein), we estimated a nominally significant (p = 0.1) proportion of variance explained by all SNPs on the Illumina BovineSNP50 Beadchip ($h^2_G$). These common SNPs explained approximately most of the narrow-sense heritability. Longer genomic regions tended to provide more phenotypic variation information, with a correlation of 0.46~0.53 between the estimate of variance explained by individual chromosomes and their physical length. These results suggested that polygenicity was ubiquitous for Holstein milk production traits. These results will expand our knowledge on recent animal breeding, such as genomic selection in Holstein.

• Asian-Australasian Journal of Animal Sciences
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• 제30권7호
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• pp.907-911
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• 2017

Objective: Intramuscular fat is one of the meat quality traits that is considered in the selection strategies for Hanwoo (Korean cattle). Different methods are used to estimate the breeding value of selection candidates. In the present work we focused on accuracy of different genotype relationship matrices as described by forni and pedigree based relationship matrix. Methods: The data set included a total of 778 animals that were genotyped for BovineSNP50 BeadChip. Among these 778 animals, 72 animals were sires for 706 reference animals and were used as a validation dataset. Single trait animal model (best linear unbiased prediction and genomic best linear unbiased prediction) was used to estimate the breeding values from genomic and pedigree information. Results: The diagonal elements for the pedigree based coefficients were slightly higher for the genomic relationship matrices (GRM) based coefficients while off diagonal elements were considerably low for GRM based coefficients. The accuracy of breeding value for the pedigree based relationship matrix (A) was 13% while for GRM (GOF, G05, and Yang) it was 0.37, 0.45, and 0.38, respectively. Conclusion: Accuracy of GRM was 1.5 times higher than A in this study. Therefore, genomic information will be more beneficial than pedigree information in the Hanwoo breeding program.