• Molecules and Cells
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• v.44 no.7
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• pp.517-528
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• 2021

A recent genetic study with Brucella abortus revealed the secretion activator gene A (SagA) as an autolysin component creating pores in the peptidoglycan (PGN) layer for the type IV secretion system (T4SS) and peptidoglycan hydrolase inhibitor A (PhiA) as an inhibitor of SagA. In this study, we determined the crystal structures of both SagA and PhiA. Notably, the SagA structure contained a PGN fragment in a space between the N- and C-terminal domains, showing the substrate-dependent hinge motion of the domains. The purified SagA fully hydrolyzed the meso-diaminopimelic acid (DAP)-type PGN, showing a higher activity than hen egg-white lysozyme. The PhiA protein exhibiting tetrameric assembly failed to inhibit SagA activity in our experiments. Our findings provide implications for the molecular basis of the SagA-PhiA system of B. abortus. The development of inhibitors of SagA would further contribute to controlling brucellosis by attenuating the function of T4SS, the major virulence factor of Brucella.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.197-217
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• 2022

As the number of households that raise dogs and cats is increasing, there is growing interest in animal health. The gut plays an important role in animal health. In particular, the microbiome in the gut is known to affect both the absorption and metabolism of nutrients and the protective functions of the host. Using probiotics on pets has beneficial effects, such as modulating the immune system, helping to reduce stress, protecting against pathogenic bacteria and developing growth performance. The goals of this review are to summarize the relationship between probiotics/the gut microbiome and animal health, to feature technology used for identifying the diversity of microbiota composition of canine and feline microbiota, and to discuss recent reports on probiotics in canines and felines and the safety issues associated with probiotics and the gut microbiome in companion animals.

• Food Science of Animal Resources
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• v.42 no.2
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• pp.341-349
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• 2022

The objective of this study was to examine the effect of temperature abuse prior to cold storage on changes in quality and metabolites of frozen/thawed beef loin. The aerobic packaged samples were assigned to three groups: refrigeration (4℃) (CR); freezing (-18℃ for 6 d) and thawing (20±1℃ for 1 d), followed by refrigeration (4℃) (FT); temperature abuse (20℃ for 6 h) prior to freezing (-18℃ for 6 d) and thawing (20±1℃ for 1 d), followed by refrigeration (4℃) (AFT). FT and AFT resulted in higher volatile basic nitrogen (VBN) values than CR (p<0.05), and these values rapidly increased in the final 15 d. Cooking loss decreased significantly with an increase in the storage period (p<0.05). In addition, cooking loss was lower in the FT and AFT groups than in the CR owing to water loss after storage (p<0.05). A scanning electron microscope (SEM) revealed that frozen/thawed beef samples were influenced by temperature abuse in the structure of the fiber at 15 d. Metabolomic analysis showed differences among CR, FT, and AFT from partial least square discriminant analysis (PLS-DA) based on proton nuclear magnetic resonance (¹H NMR) profiling. The treatments differed slightly, with higher FT than AFT values in several metabolites (phenylalanine, isoleucine, valine, betaine, and tyrosine). Overall, temperature abuse prior to freezing and during thawing of beef loin resulted in accelerated quality changes.

• IMMUNE NETWORK
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• v.23 no.6
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• pp.47.1-47.16
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• 2023

Scrub typhus, a mite-borne infectious disease, is caused by Orientia tsutsugamushi. Despite many attempts to develop a protective strategy, an effective preventive vaccine has not been developed. The identification of appropriate Ags that cover diverse antigenic strains and provide long-lasting immunity is a fundamental challenge in the development of a scrub typhus vaccine. We investigated whether this limitation could be overcome by harnessing the nanoparticle-forming polysorbitol transporter (PST) for an O. tsutsugamushi vaccine strategy. Two target proteins, 56-kDa type-specific Ag (TSA56) and surface cell Ag A (ScaA) were used as vaccine candidates. PST formed stable nano-size complexes with TSA56 (TSA56-PST) and ScaA (ScaA-PST); neither exhibited cytotoxicity. The formation of Ag-specific IgG2a, IgG2b, and IgA in mice was enhanced by intranasal vaccination with TSA56-PST or ScaA-PST. The vaccines containing PST induced Ag-specific proliferation of CD8⁺ and CD4⁺ T cells. Furthermore, the vaccines containing PST improved the mouse survival against O. tsutsugamushi infection. Collectively, the present study indicated that PST could enhance both Ag-specific humoral immunity and T cell response, which are essential to effectively confer protective immunity against O. tsutsugamushi infection. These findings suggest that PST has potential for use in an intranasal vaccination strategy.

• Journal of Life Science
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• v.12 no.2
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• pp.75-79
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• 2002

Tea catechins, the most important compounds in tea polyphenols, can efficiently scavenge superoxide anion free-radical ($O_2$.), hydroxyl radical. (.OH) The mechanism of scavenging active oxygen free radicals was investigated by ESR spin trapping technique and Chemiluminescence. Results showed that various tea catechins constitute an antioxidant cycle in accordance with the decreasing order of the first reductive potential, and produce the effect of cooperative strength each other. Esterificated catechins could scavenge active oxygen free radicals more effectively than the non-esterificated ones. When.OH and $O_2$.- were scavenged by (-)-epigallocatechin gallate [(-)- EGCG], the stoichiometric factors were 6, and the rate constants of scavenging reaction reached $7.71{\times}10^6$ and $3.52{\times}10^{11}$ L $mmol^{-1}s^{-1}$, respectively. In the mean time, tea catechins could scavenge superoxide anion fiee radical ($O_2$-.) and hydroxyl radical (.OH) in a dose dependent manner. But at higher concentration or pH value, tea catechins can induce the prooxidant.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.99-104
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• 2013

To detect five plant viruses (Beet black scorch virus, Beet necrotic yellow vein virus, Eggplant mottled dwarf virus, Pelargonium zonate spot virus, and Rice yellow mottle virus) for quarantine purposes, we designed 15 RT-PCR primer sets. Primer design was based on the nucleotide sequence of the coat protein gene, which is highly conserved within species. All but one primer set successfully amplified the targets, and gradient PCRs indicated that the optimal temperature for the 14 useful primer sets was $51.9^{\circ}C$. Some primer sets worked well regardless of annealing temperature while others required a very specific annealing temperature. A primer specificity test using plant total RNAs and cDNAs of other plant virus-infected samples demonstrated that the designed primer sets were highly specific and generated reproducible results. The newly developed RT-PCR primer sets would be useful for quarantine inspections aimed at preventing the entry of exotic plant viruses into Korea.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.223-233
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• 2013

Rice stripe virus (RSV) is one of the most destructive viruses of rice, and greatly reduces rice production in China, Japan, and Korea, where mostly japonica cultivars of rice are grown. RSV is transmitted by the small brown plant-hopper (SBPH) in a persistent and circulative-propagative manner. Several methods have been developed for detection of RSV, which is composed of four single-stranded RNAs that encode seven proteins. Genome sequence data and comparative phylogenetic analysis have been used to identify the origin and diversity of RSV isolates. Several rice varieties resistant to RSV have been selected and QTL analysis and fine mapping have been intensively performed to map RSV resistance loci or genes. RSV genes have been used to generate several genetically modified transgenic rice plants with RSV resistance. Recently, genome-wide transcriptome analyses and deep sequencing have been used to identify mRNAs and small RNAs involved in RSV infection; several rice host factors that interact with RSV proteins have also been identified. In this article, we review the current statues of RSV research and propose integrated approaches for the study of interactions among RSV, rice, and the SBPH.

• Journal of Microbiology and Biotechnology
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• v.18 no.12
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• pp.1915-1918
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• 2008

An entomopathogenic fungus was isolated from an infected aphid. The isolate conformed most closely to Lecanicillium attenuatum CBS 402.78 (AJ292434) based on the internal transcribed spacer (ITS) region of its 18S rDNA, and thus was designated L. attenuatum CNU-23. Laboratory and field evaluations of CNU-23 blastospores were carried out for the control of green peach aphids. The laboratory evaluations of CNU-23 revealed an aphid mortality of about 80% with an estimated $LT_{50}$ of 3.72 days after the application of CNU-23 at $1{\times}10^6$ blastospores/ml. Meanwhile, the field evaluations of CNU-23 performed on greenhouse pepper plants during the rainy season showed an aphid mortality ranging from 72% to 97%. Significant sporulation was observed in the aphids treated with CNU-23. Therefore, the results suggest that L. attenuatum CNU-23 can be used as a biocontrol agent for green peach aphids on greenhouse pepper plants.

• Molecules and Cells
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• v.28 no.1
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• pp.19-24
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• 2009

The goal of this study was to create a novel baculovirus expression system that does not require recombinant virus purification steps. Transfection of insect cells with transfer vectors containing barnase under control of the Cotesia plutellae bracovirus (CpBV) promoters ORF3004 or ORF3005 reduced cell growth. Co-transfection with bApGOZA DNA yielded no recombinant viruses and nonrecombinant backgrounds. To further investigate the detrimental effects of barnase on insect cells, two recombinant bacmids harboring the barnase gene under control of the CpBV promoters, namely bAcFast-3004ProBarnase and bAcFast-3005ProBarnase, were constructed. While no viral replication was observed when only the recombinant bacmids were transfected, recombinant viruses were generated when the bacmids were co-transfected with the transfer vector, pAcUWPolh, through substitution of the barnase gene with the native polyhedrin gene by homologous recombination. Moreover, no non-recombinant backgrounds were detected from unpurified recombinant stocks using PCR analysis. These results indicate that CpBV promoters can be used to improve baculovirus expression vectors by means of lethal gene expression under the control of these promoters.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.271-276
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• 2013

The Asian honeybee, Apis cerana, is a native honeybee species in Korea which is important in agriculture for pollination and honey production. For better understanding of the physiology of A. cerana, high-throughput Illumina transcriptome sequencing was performed to analyze the gene expression profiles of queen, worker, and larva. A total of 219,799,682 clean reads corresponding to 22.2 Gb of nucleotide sequences was obtained from the whole body total RNA samples. The Apis mellifera reference mRNA sequence database was used to measure the gene expression level with Bowtie2 and eXpress software, and the Illumina short reads were then mapped to 11,459 out of 11,736 A. mellifera reference genes. Total of 9,221 genes with FPKM value greater than 5 of each sample group were subjected to eggNOG with BLASTX for gene ontology analysis. The differential gene expression between queen and worker, and worker and larva were analyzed to screen the overexpressed genes in each sample group. In the queen and worker sample group, total of 1,766 genes were differentially expressed with 887 and 879 genes overexpressed over two folds in queen and worker, respectively. In the worker and larva sample group, total of 1,410 genes were differentially expressed with 1,009 and 401 genes overexpressed over two folds in worker and larva, respectively.