• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.420-422
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• 2005

TMC (Tautomycetin) is a liner polyketide immunosuppressive antifungal compound produced by Streptomyces spp. Inhibition of T cell proliferation with TMC was observed highly efficient at 100-fold lower than those needed to achieve maximal inhibition with cyclosporin A. To elucidate the biosynthetic pathway of TMC, a genomic DNA library was constructed using a E. coil-Streptomyces shuttle cosmid vector, pOJ446. The DNA libraries were screened by colony blot hybridization using several polyketide ${\beta}-ketosynthase$ (KS) probes amplified from TMC-producing Streptomyces genomic DNA using polymerase chain reaction (PCR), of which the degenerate primers were designed based on the highly conserved sequences present in KS domains of various type I polyketide synthase genes in Streptomyces species. This library construction and screening approach led to the isolation of several positive cosmid clones representing type I polyketide biosynthetic gene clusters. In addition, a Streptomyces regulatory gene called afsR2 (a global regulatory gene stimulating antibiotic production in both S. coelicolor and S. lividans) was successfully integrated into the TMC-producing Streptomyces chromosome via E. coil-Streptomyces heterologous conjugation mehtod. The more detailed results of production improvement and genetic characterization of TMC-producing Streptomyces spp. will be discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.743-749
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• 2004

The gene encoding human serum albumin (HSA) was cloned from human liver cDNA library by PCR. The HSA cDNA in size of 2,176 bp, including 1,830 bp of open reading frame, was cloned into the plasmid carried with the 5'flanking sequence of goat $\beta$-casein gene (-4,044 to +2,025 bp) to get a tissue specific expression vector in mammary gland named pGB562/HSA (12.5 kb). A 9.6 kb DNA fragment in which the sequence is in order of goat $\beta$-casein gene regulatory sequence, HSA cDNA and SV40 polyadenylation signals was isolated from the pGB562/HSA by SacI and DraIII cutting, and used to microinject into the pronuclei of mouse fertilized eggs to produce transgenic mice. Three transgenic mice (2 female and 1 male) were identified by PCR and dot Southern blot analysis. The copy numbers of integrated transgene were more than 10 copies in line #21 and #26 as well as over 50 copies in line #31 of transgenic mice. HSA protein collected from the milk of lactating transgenic mice was confirmed by immuno-detection of Western and slot blot. The concentrations of HSA in the milk were from 0.05 to 0.4 mg/ml. An obvious antigen and antibody conjugate could be observed in immunohistochemical stain of mammary gland tissue from lactating day 11 of HSA transgenic mice. The transmission of transgene and its expression was recognized according to the results of RT-PCR and sequences analyses of their progeny.

• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.53-58
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• 2001

To develop herbicide-resistant cucumber plants (Cucumis sativus L. cv Green Angle) embryogenic suspension cultures were co-cultured with Agrobacterium tumefaciens strain LBA4404 carrying a disarmed binary vector pGA-bar. The T-DNA region of this binary vector contains the nopalin synthase/neomycin phosphotransferase Ⅱ (npt Ⅱ) chimeric gene for kanamycin resistance and the cauliflower 35S/phosphinothricin acetyltransferase (bar) chimeric gene for phosphinothricin (PPT) resistance, After co-cultivation for 48 h, embryogenic calli were placed on maturation media containing 20 mg/L PPT. Approximately 200 putatively transgenic plantlets were obtained in hormone free media containing 40 mg/L PPT. Northern blot hybridization analysis confirmed the expression of the bar gene that was integrated into the genome of five transgenic plants. Transgenic cucumber plants were grown to maturity. Mature plants in soil showed tolerance to the commercial herbicide (Basta) of PPT at the manufacturer's suggested level (3 mL/L).

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.149-155
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• 1995

The coat protein (CP) gene was cloned from RNA genome of the Cucumber Mosaic Virus strain ABI (CMV-ABI) isolated in Korea. The comparisons of the nucleotide sequence of the cloned CP gene and its deduced amino acid sequences with other CP genes revealed that the CMV-ABI belongs to subgroup I (type I), CMV-ABI developed the typical mosaic symptom in infected plants. Tobacco plants (Samsun and NC82) were transformed by leaf-disc transformation via Agrobacterium, temefaciens LB4404 harboring pVCP, witch CMV-ABI CP gene was inserted into the pBI121, and a number of mature transgenic tobacco plants were developed. Southern and PCR analysis of genomic DNA from the transgenic plants showed that the CP gene was integrated into the genomes of the most of the transgenic plant. Result of the segregation patterns of resistance in T1 seedlings of the plants to kanamycin showed that the transgenic plants containing l,2 and 3 copies of CP gene were50%, 39% and 11% of the total transgenic plants, respectively.

• Journal of Integrative Natural Science
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• v.4 no.2
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• pp.113-120
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• 2011

Brassinosteroids (BRs) are plant steroid hormones that play essential roles in growth and development. Mutations in BR-signaling pathways cause defective in growth and development like dwarfism, male sterility, abnormal vascular development and photomorphogenesis. Transition from vegetative to reproductive growth is a critical phase change in the development of a flowering plant. In a screen of activation-tagged Arabidopsis, we identified a mutant named abz126 that displayed longer hypocotyls when grown in the dark on MS media containing brassinazole (Brz), an inhibitor of BRs biosynthesis. We have cloned the mutant locus using adapter ligation PCR walking and identified that a single T-DNA had been integrated into the ninth exon of the GIGANTEA (GI) gene, involved in controling flowering time. This insertion resulted in loss-of-function of the GI gene and caused the following phenotypes: long petioles, tall plant height, many rosette leaves and late flowering. RT-PCR assays on abz126 mutant showed that the T-DNA insertion in GIGANTEA led to the loss of mRNA expression of the GI gene. In the hormone dose response assay, abz126 mutant showed: 1) an insensitivity to paclobutrazole (PAC), 2) an altered response with 6-benzylaminopurine (BAP) and 3) insensitive to Brassinolide (BL). Based on these results, we propose that the late flowering and tall phenotypes displayed by the abz126 mutant are caused by a loss-of-function of the GI gene associated with brassinosteroid hormone signaling.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.155-160
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• 2008

Several studies have reported quantitative trait loci (QTL) for meat quality on porcine chromosome 2 (http://www.animalgenome.org/QTLdb/pig.html). For application of the molecular genetic information to the pig industry through marker-assisted selection, single nucleotide polymorphism (SNP) markers were analyzed by comparative re-sequencing of polymerase chain reaction (PCR) products of 13 candidate genes with DNA from commercial pig breeds such as Berkshire, Yorkshire, Landrace, Duroc and Korean Native pig. A total of 34 SNPs were identified in 15 PCR products producing an average of one SNP in every 253 bp. PCR restriction fragment length polymorphism (RFLP) assays were developed for 11 SNPs and used to investigate allele frequencies in five commercial pig breeds in Korea. Eight of the SNPs appear to be fixed in at least one of the five pig breeds, which indicates that different selection among pig breeds might be applied to these SNPs. Polymorphisms detected in the PTH, CSF2 and FOLR genes were chosen to genotype a Berkshire-Yorkshire pig breed reference family for linkage and association analyses. Using linkage analysis, PTH and CSF2 loci were mapped to pig chromosome 2, while FOLR was mapped to pig chromosome 9. Association analyses between SNPs in the PTH, CSF2 and FOLR suggested that the CSF2 MboII polymorphism was significantly associated with several pork quality traits in the Berkshire and Yorkshire crossed F2 pigs. Our current findings provide useful SNP marker information to fine map QTL regions on pig chromosome 2 and to clarify the relevance of SNP and quantitative traits in commercial pig populations.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.8
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• pp.3825-3827
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• 2012

FISH is one of the most sensitive molecular methods to detect genetic abnormalities with DNA probes. When cytogenetic studies are normal or insufficient, FISH may detect cryptic rearrangements, rare or slowly proliferative abnormal populations in non-mitotic cells. We cytogenetically evaluated 70 childhood ALL - 67.1% were found to have an abnormal karyotype. The 23 patients (32.9%) with a normal karyotype were analyzed by FISH applying two probes; TEL/AML1 and MYB which detect cryptic rearrangements of t(12;21)(p13;q22) and deletion of (6q) respectively, associated with a good prognosis. Out of 23 patients, one was positive for t(12;21)(p13;q22) (4.3%). None of our patients were positive for MYB del(6q). Two patients showed an extra signal for MYB on chromosomes other than 6 (8.6 %) indicating amplification or duplication. Findings were compared with the available literature. Our study clearly indicated the integrated FISH screening method to increase the abnormality detection rate in a narrow range. FISH is less useful for diagnostic study of patients with suspected del(6q) but it helps in detecting known cryptic rearrangements as well as identification of new abnormalities(translocation , duplication and amplification) at the gene level.

• Journal of Plant Biotechnology
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• v.35 no.4
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• pp.275-280
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• 2008

One of the limitation for Agrobacterium-mediated transformation via organogenesis from cotyledon explants routinely in cucumber is the production of chimeric plants. To overcome the limitation, Agrobacterium-mediated transformation system via somatic embryogenesis from hypocotyl explants of cucumber (c.v., Eunsung) on the selection medium with paromomycin as antibiotics was developed. The hypocotyl explants were inoculated with Agrobacterium tumefaciens strain EHA101 carrying binary vector pPTN290; then were subsequently cultured on the following media: co-cultivation medium for 2 days, selection medium for $5{\times}14$ days, and regeneration medium. The T-DNA of the vector (pPTN290) carried two cassettes, Ubi promoter-gus gene as reporter and 35S promoter-nptll gene conferring resistance to paromomycin as selectable agent. The confirmation of stable transformation and the efficiency of transformation was based on the resistance to paromomycin indicated by the growth of putative transgenic calli on selection medium amended with 100mg/L paromomycin, and GUS gene expression. Forty eight clones (5.2%) with GUS gene expressed of 56 callus clones with resistance to paromomycin were independently obtained from 928 explants inoculated. Of 48 clones, transgenic plants were only regenerated from 5 clones (0.5%) at low frequency. The histochemical GUS assay in the transgenic seeds ($T_1$) also revealed that the gus gene was successfully integrated and segregated into each genome of transgenic cucumber.

• IMMUNE NETWORK
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• v.14 no.3
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• pp.138-148
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• 2014

MicroRNAs (miRNAs) are endogenous small RNA molecules best known for their function in post-transcriptional gene regulation. Immunologically, miRNA regulates the differentiation and function of immune cells and its malfunction contributes to the development of various autoimmune diseases including systemic lupus erythematosus (SLE). Over the last decade, accumulating researches provide evidence for the connection between dysregulated miRNA network and autoimmunity. Interruption of miRNA biogenesis machinery contributes to the abnormal T and B cell development and particularly a reduced suppressive function of regulatory T cells, leading to systemic autoimmune diseases. Additionally, multiple factors under autoimmune conditions interfere with miRNA generation via key miRNA processing enzymes, thus further skewing the miRNA expression profile. Indeed, several independent miRNA profiling studies reported significant differences between SLE patients and healthy controls. Despite the lack of a consistent expression pattern on individual dysregulated miRNAs in SLE among these studies, the aberrant expression of distinct groups of miRNAs causes overlapping functional outcomes including perturbed type I interferon signalling cascade, DNA hypomethylation and hyperactivation of T and B cells. The impact of specific miRNA-mediated regulation on function of major immune cells in lupus is also discussed. Although research on the clinical application of miRNAs is still immature, through an integrated approach with advances in next generation sequencing, novel tools in bioinformatics database analysis and new in vitro and in vivo models for functional evaluation, the diagnostic and therapeutic potentials of miRNAs may bring to fruition in the future.

• Korean Journal of Microbiology
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• v.44 no.1
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• pp.10-13
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• 2008

Endocrine disrupting chemicals (EDCs) are hard to be degraded in nature, and are also accumulated in diverse organisms. They finally give negative effects to human through the food web. White rot fungi which have lignin-degrading enzymes have high potentials for degradation of recalcitrant compounds, and a white rot fungus, Phlebia tremellosa, isolated in Korea show good degrading activity against the endocrine disrupting phthalates. We have isolated a laccase cDNA which was involved in the degradation of EDCs, and constructed a laccase expression vector to use in the genetic transformation of P. tremellosa. The expression vector was stably integrated into the chromosomal DNAs and showed increased laccase activity in transformants. One of transformants showed not only increased degradation of several EDCs but also faster estrogenic decreasing activities generated by the EDCs.