• Food Science of Animal Resources
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• v.38 no.4
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• pp.806-815
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• 2018

This study was performed to isolate some strains of Bifidobacterium breve from fecal materials of neonates and to screen them for the biotransformation activity of converting linoleic acid into conjugated linoleic acid (CLA). Fecal samples were collected from twenty healthy neonates between 14 and 100 days old, and four hundred colonies were randomly selected from a Bifidobacterium selective transoligosaccharide medium. A duplex polymerase chain reaction technique was developed for the rapid and accurate molecular characterization of the B. breve strains that have been reported to show the species-specific characteristic of CLA production. They are identified by 16S ribosomal DNA, fructose-6-phosphate phosphoketolase encoding genes (xfp), and rapid pulsed field gel electrophoresis. Thirty-six isolates were identified as B. breve, and just two of the 12 neonates were harboring B. breve strains. Each isolate showed different CLA-producing ability in the spectrophotometric assay. All of the positive strains from the primary spectrophotometric assay were confirmed for their CLA-producing activities using gas-chromatographic analysis, and their conversion rates were different, depending on the strain isolated in this study. Some strains of B. breve were successfully isolated and characterized based on the CLA-producing activity, and further studies are necessary to characterize the enzyme and the gene responsible for the enzyme activity.

• The Plant Pathology Journal
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• v.33 no.2
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• pp.140-147
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• 2017

Fusarium wilts of strawberry, caused by Fusarium oxysporum f. sp. fragariae, is a serious soil-borne disease. Fusarium wilt causes dramatic yield losses in commercial strawberry production and it is a very stubborn disease to control. Reliable chemical control of strawberry Fusarium wilt disease is not yet available. Moreover, other well-known F. oxysporum have different genetic information from F. oxysporum f. sp. fragariae. This analysis investigates the genetic diversity of strawberry Fusairum wilt pathogen. In total, 110 pathogens were isolated from three major strawberry production regions, namely Sukok, Hadong, Sancheong in Gyeongnam province in South Korea. The isolates were confirmed using F. oxysporum f. sp. fragariae species-specific primer sets. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses were executed using the internal transcribed spacer, intergenic spacer, translation elongation factor1-${\alpha}$, and ${\beta}$-tubulin genes of the pathogens and four restriction enzymes: AluI, HhaI, HinP1I and HpyCH4V. Regarding results, there were diverse patterns in the three gene regions except for the ${\beta}$-tubulin gene region. Correlation analysis of strawberry cultivation region, cultivation method, variety, and phenotype of isolated pathogen, confirmed that genetic diversity depended on the classification of the cultivated region.

• Korean Journal of Veterinary Service
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• v.33 no.4
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• pp.345-351
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• 2010

Toxoplasma gondii is a species of parasitic protozoa in the genus Toxoplasma. The definitive host of T. gondii is the cat, but the parasite can be carried by the vast majority of warm-blooded animals, including humans. It is often found in the tissues of food animals including pigs and sheep. To determine the regional prevalence of infection with T. gondii, bloods (n=300) from domestic pigs and tissues (n=200) from slaughter pigs in Gyeongnam province were tested using an enzyme-linked immunosorbent assay (ELISA) and a polymerase chain reaction (PCR) for detection of antibody and antigen. A total of 115 sero-positive pigs were identified for a prevalence rate of 38.3%. Of the 50 herds from domestic pigs tested, 34 had at least one sero-positive pig for a herd prevalence rate of 68.0%. Sero-positive rates of pigs in fattening farm were higher than that of pigs in breeding company. Sero-positive rates of sows were higher than that of growing pigs. Seasonally, sero-positive rates of pigs were highest in winter (80.0%) and lowest in spring (23.8%). According to farm size, sero-positive rates of pigs were higher in small size farms (${\leq}$2,000) than that of big size farms (>2,000). However, none of the bloods (n=300) from domestic pigs and tissues (n=200) from slaughter pigs were positive for T. gondii specific DNA by PCR.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.6
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• pp.850-855
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• 2007

Leptin is the adipocyte-specific product of the obese gene and plays a major role in food intake and energy metabolism. Leptin research was mainly focused on mammalian species, but understanding of leptin and its function in poultry is very poor. In this study, the duck leptin gene was amplified using the reverse transcription-polymerase chain reaction (RT-PCR) from duck liver RNA. The cDNA fragment was inserted into the pET-28a expression vector, and the resulting plasmid was expressed in Escherichia coli BL21 (DE3). Experimental mice were given an intraperitoneal injection of 10 mg/kg leptin dissolved in phosphate buffered saline (PBS), while the control mice were injected with PBS. The effect of leptin on food intake, body weight and fatty deposition in mice was detected. Sequence analysis revealed that duck leptin had a length of 438 nucleotides which encoded a peptide with 146 amino acid residues. The sequence shares highly homology to other animals. The coding sequence of duck leptin was 84 and 86% identical to human and pig leptin nucleotides sequence. Highest identity was with the rat coding sequence (95%). The identity of the amino acid sequence was 84, 82 and 96% respectively compared to that of the human, pig and rat. Results of SDS-PAGE analysis indicated that a fusion protein was specifically expressed in E. coli BL21 (DE3). The purified product was found to be biologically active during tests. Continuous administration of recombinant duck leptin inhibited food intake. Despite the decrease of food intake, leptin significantly induced body weight and fatty deposition. These changes were accompanied by a significant down-secretion of plasma glucose, cholesterol, triglyceride and insulin levels in mice. The observations provide evidence for an inhibitory effect of leptin in the regulation of food intake and for a potential role of duck leptin in the regulation of lipogenesis.

• Food Science and Biotechnology
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• v.15 no.6
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• pp.967-974
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• 2006

Cyclomaltodextrinases (CDases), maitogenic amylases, and neopullulanases share highly conserved primary structures and similar characteristics, and are thus classified into the same family. BLAST search has showed that a variety of bacterial strains harbor putative CDase family genes with several well-conserved motif amino acid sequences. In this study, four degenerate polymerase chain reaction (PCR) primer sets were designed for the detection of CDase genes, on the basis of their highly conserved amino acid blocks (WYQIFP, DGWRLD, LGSHDT, and KCMVW). The PCR detection conditions were optimized and the detection specificity of each for the primer sets was tested against the genomic DNAs isolated from 23 different Bacillus-associated species. Consequently, all tested primer sets evidenced successful amplification of specific PCR products in length, which share 55-98% amino acid sequence identity with known and putative CDases. The primers developed herein, therefore, can be applied for the easy and efficient detection and isolation of CDase family genes for the modification of functional food carbohydrates.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.1
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• pp.33-38
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• 2004

This study was aimed at testing the gene expression of antioxidant enzymes and apoptosis genes for in vitro culture in porcine embryos produced by in vitro maturation/in vitro fertilization (IVM/IVF). Pocine preimplantation embryos obtainted from IVM/IVF can be successfully culture in vitro, but they are delayed or stop to develop at specific developmental stage. Many factors such as reactive oxygen species and apoptosis in an IVM/IVF system followed by in vitro culture influence the rate of production of viable blastocysts. Porcine embryos derived from IVM/IVF were cultured in the atmosphere of 5% $CO_2$ and 20% $O_2$ at $38.5^{\circ}C$ in NCSU23 medium. The patterns of gene expression for antioxidant enzymes and apoptosis genes during in vitro culture in pocine IVM/IVF embryos were examined by the modified semi-quantitative single cell reverse transcriptase-polymerase chain reaction (RT-PCR). Porcine embryos produced by in vitro procedures were expressed mRNAs for CuZn-SOD, GAPDH and GPX, whereas transcripts for Mn-SOD and catalase were not detected at any developmental stages. Expression of caspase-3 mRNA was detected at 2 cell, 8 cell 16 cell and blastocyst, but p53 mRNA was not detected at any stages. The fas transcripts was only detected in blastocyst stage. These results suggest that various antioxidant enzymes and apoptosis genes play crucial roles in vitro culture of porcine IVM/IVF embryos.

• The Plant Pathology Journal
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• v.18 no.3
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• pp.130-137
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• 2002

Potato virus Y (PVY) is one of the most important viruses in many field crops in Korea. In this study, 31 PVY isolates were isolated from infected potato (Solanum tuberosum), tobacco (Nicotiana tabacum), pea (Pisum sativum), and weeds (Veronica persica, Lamium amplexicause and Capsella bursa-pastoris) showing different mosaic symptoms in Jeonbuk, Chungnam, Gangwon, and Gyeongbuk areas in Korea. The 640 nucleotide region containing the C-terminal portion of coat protein (CP) gene and 3'non-translated region (NTR) was amplified by reverse transcription-polymerase chain reaction (RT-PCR) using PVY-specific oligonucleotide primers. Sequence analyses of the amplified DNA fragments showed that the C-terminal portion of CP gene was not significantly different from that of previously reported PVY strains from potato (PVY-OK and -T) and tobacco (PVY-VN) in Korea. Homologies of the deduced CP amino acid sequences were 93.3-99.0% to corresponding regions of the other PVY strains including PV $Y^{N}$, PV $Y^{o}$ , PV $Y^{OK}$ , PV $Y^{T}$ , and PV $Y^{VN}$ . In contrast the sequences located at the 3'-NTR showed more diverse sequence homologies (76.4-99.7%). These results indicate that the C-terminal portion of the CP gene was relatively conserved while sequences at the 3'NTR were more diverse and variable over the host species and the regions where they were isolated.e isolated.

• The Plant Pathology Journal
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• v.36 no.1
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• pp.87-97
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• 2020

The development of reverse transcription-polymerase chain reaction using degenerate primers against conserved regions of most potyviral genomes enabled sampling of the potyvirome. However, these assays usually involve sampling potential host plants, but identifying infected plants when they are asymptomatic is challenging, and many plants, especially wild ones, contain inhibitors to DNA amplification. We used an alternative approach which utilized aphid vectors and indicator plants to identify potyviruses capable of infecting common bean (Phaseolus vulgaris). Aphids were collected from a range of asymptomatic leguminous weeds and trees in Iran, and transferred to bean seedlings under controlled conditions. Bean plants were tested serologically for potyvirus infections four-weeks postinoculation. The serological assay and symptomatology together indicated the presence of one potyvirus, and symptomology alone implied the presence of an unidentified virus. The partial genome of the potyvirus, encompassing the complete coat protein gene, was amplified using generic potyvirus primers. Sequence analysis of the amplicon confirmed the presence of an isolate of Wisteria vein mosaic virus (WVMV), a virus species not previously identified from Western Asia. Phylogenetic analyses of available WVMV sequences categorized them into five groups: East Asian-1 to 3, North American and World. The Iranian isolate clustered with those in the World group. Multiple sequence alignment indicated the presence of some genogroup-specific amino acid substitutions among the isolates studied. Chinese isolates were sister groups of other isolates and showed higher nucleotide distances as compared with the others, suggesting a possible Eastern-Asian origin of WVMV, the main region where Wisteria might have originated.

• Korean Journal of Veterinary Research
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• v.40 no.1
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• pp.86-93
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• 2000

Paratuberculosis (Johne's disease), a chronic enteritis produced by Mycobacterium paratuberculosis, affects a large proportion of ruminants in all continents and causes important economic losses. The identification of well-characterized and species-specific components of M paratuberculosis would provide the means to improve the specificity and sensitivity of immunodiagnostic assays for Johne's disease. The aims of this study were to express the recombinant C-terminal of 34kDa protein (rC34P) of M paratuberculosis in E coli and to investigate the effectiveness of this protein in detecting antibodies to the native protein in sera from paratuberculosis infected cattle. The C-terminal of the gene encoding the 34kDa protein was amplified by polymerase chain reaction from the chromosomal DNA of M paratuberculosis (ATCC 19698) and cloned into vector pGEX-4T-2. Then, cloned plasmid was transformed into E coli DH5${\alpha}$ and the rC34P was overexpressed. The rC34P was purified by affinity chromatography and gel filtration. The rC34P was examined antigenicity by Western blot. The rC34P was reactive with culture positive bovine serum and hyperimmune rabbit anti-M paratuberculosis serum but was not reactive with culture negative bovine serum and tuberculin positive bovine serum in Western blot. In conclusion, the rC34P produced in this study is expected as a useful candidate for antigen in serological diagnosis of Johne's disease.

• The Korea Journal of Herbology
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• v.26 no.3
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• pp.15-21
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• 2011

Objectives : The application of polymerase chain reaction (PCR) for the discrimination of the herbal medicine Leonuri Herba (Leonurus japonicus) was evaluated by the comparison of the DNA sequence with Lamiaceae herbal medicine. Method : Genetic analysis showed that phylogenetic tree and comparing sequences through the DNA analysis of rbcL (ribulose-1, 5-bisphosphatecarboxylase) region and trnL-F (tRNA-Leu, trnL-trnF intergeni cspacer, and tRNA-Phe) region of chloroplast DNA from six Lamiaceae sold in market. And we developed IMCF and IMCR primers in order to distinction Leonuri Herba in six Lamiaceae using rbcL and trnL-F sequences. Results : Genetic analysis showed that six Lamiaceae showed individual group on phylogenetic tree. PCR amplification product of Leonuri Herba and another five Lamiaceae were developed for amplification of a 281 bp sequence and the specific PCR amplification of a 460 bp sequence that was exclusive to Leonuri Herba was designed using IMCF and IMCR primers. Conclusion : PCR analysis based on the chloroplast DNA sequences allows the discrimination of Leonuri Herba-based medicine.