• Journal of Microbiology and Biotechnology
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• v.14 no.3
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• pp.498-502
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• 2004

The current study was conducted to monitor the possibility of the gene transfer among soil bacteria, including the effect of drift due to rain and surface water, in relation to the release of genetically modified organisms into the environment. Four types of bacteria, each with a distinct antibiotic marker, kanamycin-resistant P. fluorescens, rifampicin-resistant P. putida, chloramphenicol-resistant B. subtilis, and spectinomycin-resistant B. subtilis, were plated using a small-scale soil-core device designed to track drifting microorganisms. After three weeks of culture in the device, no Pseudomonas colonies resistant to both kanamycin and rifampicin were found. Likewise, no Bacillus colonies resistant to both chloramphenicol and spectinomycin were found. The gene transfer from glyphosate-tolerant soybeans to soil bacteria, including Rhizobium spp. as a symbiotic bacteria, was examined by hybridization using the DNA extracted from soil taken from pots, in which glyphosate-tolerant soybeans had been growing for 6 months. The results showed that 35S, T-nos, and EPSPS were observed in the positive control, but not in the DNA extracted from the soilborne microorganisms. In addition, no transgenes, such as the 35S promoter, T-nos, and EPSPS introduced into the GMO soybeans were detected in soilborne bacteria, Rhizobium leguminosarum, thereby strongly rejecting the possibility of gene transfer from the GMO soybeans to the bacterium.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.5
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• pp.768-774
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• 2007

To study the effect of dietary docosahexaenoic acid (DHA) enrichment on the expression of hepatic genes in pigs, weaned, crossbred pigs (30 d old) were fed diets supplemented with either 2% tallow or DHA oil for 18 d. Hepatic mRNA was extracted. Suppression subtractive hybridization was used to explore the hepatic genes that were specifically regulated by dietary DHA enrichment. After subtraction, we observed 288 cDNA fragments differentially expressed in livers from pigs fed either 2% DHA oil or 2% tallow for 18 d. After differential screening, 7 genes were found to be differentially expressed. Serum amyloid A protein 2 (SAA2) was further investigated because of its role in lipid metabolism. Northern analysis indicated that hepatic SAA2 was upregulated by dietary DHA enrichment (p<0.05). In a second experiment, feeding 10% DHA oil for 2d significantly increased the expression of SAA2 (compared to the 10% tallow group; p<0.05). The porcine SAA2 full length cDNA sequence was cloned and the sequence was compared to the human and mouse sequences. The homology of the SAA2 amino acid sequence between pig and human was 73% and between pig and mouse was 62%. There was a considerable difference in SAA2 sequences among these species. Of particular note was a deletion of 8 amino acids, in the pig compared to the human. This fragment is a specific characteristic for the SAA subtype that involved in acute inflammation reaction. Similar to human and mouse, porcine SAA2 was highly expressed in the liver of pigs. It was not detectable in the skeletal muscle, heart muscle, spleen, kidney, lung, and adipose tissue. These data suggest that SAA2 may be involved in mediation of the function of dietary DHA in the liver of the pig, however, the mechanism is not yet clear.

• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.113-120
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• 2009

Twenty-seven fenitrothion-degrading bacteria were isolated from different soils, and their genetic and phenotypic characteristics were investigated. Analysis of the 16S rDNA sequence showed that the isolates were related to members of the genera Burkholderia, Pseudomonas, Sphingomonas, Cupriavidus, Corynebacterium, and Arthrobacter. Among the 27 isolates, 12 different chromosomal DNA fingerprinting patterns were obtained by polymerase chain reaction(PCR) amplification of repetitive extra genic palindromic(REP) sequences. The isolates were able to utilize fenitrothion as a sole source of carbon and energy, producing 3-methyl-4-nitrophenol as the intermediate metabolite during the complete degradation of fenitrothion. Twenty-two of 27 isolates were able to degrade parathion, methyl-parathion, and p-nitrophenol but only strain BS2 could degrade EPN(O-ethyl-O-p-nitrophenyl phenylphosphorothioate) as a sole source of carbon and energy for growth. Eighteen of the 27 isolates had plasmids. When analyzed with PCR amplification and dot-blotting hybridization using various specific primers targeted to the organophosphorus pesticide hydrolase genes of the previously reported isolates, none of the isolates showed positive signals, suggesting that the corresponding genes of our isolates had no significant sequence homology with those of the previously isolated organophosphate pesticide-degrading bacteria.

• Journal of Microbiology and Biotechnology
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• v.17 no.11
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• pp.1875-1879
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• 2007

Strain $CH7^T$, a pale yellow-pigmented bacterium and new isolate from deep subsurface water of the South Coast of Korea, was subjected to a polyphasic taxonomic study. $CH7^T$ grew between 5 and $37^{\circ}C$, pH 5.3-10.5, and tolerated up to 13% NaCl. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain $CH7^T$ was associated with the genus Arthrobacter and phylogenetically closely related to the type strains Arthrobacter tumbae (99.4%) and Arthrobacter parietis (99.1%). However, DNA-DNA hybridization experiments revealed 2.1% and 12% between strain $CH7^T$ and Arthrobacter tumbae and Arthrobacter parietis, respectively. Thus, the phenotypic and phylogenetic differences suggested that $CH7^T$ should be placed in the genus Arthrobacter as a novel species, for which the name Arthrobacter subterraneus sp. novo is proposed. In addition, the type strain for the new species is $CH7^T$ ($=KCTC\;9997^T=DSM\;17585^T$).

• 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.26 no.1
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• pp.21-26
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• 1999

These experiments were attempted to introduce rolC gene in the Petunia hybrida cv. Titan white by Agrobacterium mediated. The maximum frequency of shoot regeneration was obtained by 60% on MS medium containing 1.0 mg/L BA, 0.1 mg/L NAA, 200 mg/L kanamycin, 500 mg/L carbenicillin, 30 g/L sucrose, and 8 g/L agar. Kanamycin-resistant calli were selected from petunia leaf discs by cocultivation with Agrobacterium suspension cultures on MS medium. The addition of AgNO$_3$ and KMnO$_4$ in the medium increased the shoot regeneration by 31.3% from leaf disc as compared with non-treated leaf disc. Among clones exhibiting kanamycin resistance, only 3 clones were confirmed by southern hybridization analysis.

• Molecules and Cells
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• v.25 no.2
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• pp.163-171
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• 2008

The genus Cynodon comprises ten species. The objective of this study was to evaluate the genetic diversity of Korean bermudagrasses at the morphological, cytological and molecular levels. Morphological parameters, the nuclear DNA content and ploidy levels were observed in 43 bermudagrass ecotypes. AFLP markers were evaluated to define the genetic diversity, and chromosome counts were made to confirm the inferred cytotypes. Nuclear DNA contents were in the ranges 1.42-1.56, 1.94-2.19, 2.54, and 2.77-2.85 pg/2C for the triploid, tetraploid, pentaploid, and hexaploid accessions, respectively. The inferred cytotypes were triploid (2n = 3x = 27), tetraploid (2n = 4x = 36), pentaploid (2n = 5x = 45), and hexaploid (2n = 6x = 54), but the majority of the collections were tetraploid (81%). Mitotic chromosome counts verified the corresponding ploidy levels. The fast growing fine-textured ecotypes had lower ploidy levels, while the pentaploids and hexaploids were coarse types. The genetic similarity ranged from 0.42 to 0.94 with an average of 0.64. UPGMA cluster analysis and principle coordinate analysis separated the ecotypes into 6 distinct groups. The genetic similarity suggests natural hybridization between the different cytotypes, which could be useful resources for future breeding and genetic studies.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.262-269
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• 2005

An antiviral producing bacterial strain was isolated from a ginseng rhizosphere in Kangwon province of Republic of Korea. In order to identify the bacterial strain, microbiological, physiological and biochemical tests were performed, along with RAPD, 16S rRNA, 16S-23S rRNA ITS (intergenic spacer region) and DNA-DNA hybridization analyses. The bacterium was found to be a strain of Pseudomonas fluorescens, which was designated as Gpf01. The strain was grown in Muller-Hinton (MH) broth, and the culture supernatant obtained was filtered through a $0.45{\mu}l$ filter. It was further boiled at $100^{\circ}C$ and tested in two experiments for its ability to control a yellow strain of Cucumber mosaic virus (CMV-Y). In the first experiment, boiled culture filtrate (RCF) was treated on one half of the leaves of Chenopodium amaranticolor followed by CMV- Y inoculation on both halves. In the second experiment, BCF was treated on the lower leaves of Nicotiana tobacum var. Xanthi-nc, with the CMV-Y mechanically inoculated onto the upper untreated leaves. In the first experiment, BCF treatment was able to considerably reduce the number of viral lesion, and in the second experiment, plants treated with BCF showed no visible viral symptoms compared to the Muller-Hinton (MH) media treated controls 15 days post inoculation (dpi), and remained symptomless throughout the study period. Thus, Gpf01, identified as P. fluorescence, was able to produce an antiviral component in the culture filtrate, which was found to be heat stable, non-phytotoxic and effective in local as well as systemic hosts of CMV.

• BMB Reports
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• v.38 no.4
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• pp.420-431
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• 2005

The differentially virulent race T1 of common bunt (Tilletia tritici) was used to inoculate the wheat lines Neepawa (compatible) and its sib BW553 (incompatible) that are nearly isogenic for the Bt-10 resistance gene. Inoculated crown tissues were used to construct a suppression subtractive hybridization (SSH) cDNA library. Of the 1920 clones arrayed from the SSH cDNA library, approximately 10% were differentially regulated. A total of 168 differentially up-regulated and 25 down-regulated genes were identified and sequenced; 71% sequences had significant homology to genes of known function, of which 59% appeared to have roles in cellular metabolism and development, 24% in abiotic/biotic stress responses, 3% involved in transcription and signal transduction responses. Two putative resistance genes and a transcription factor were identified among the up regulated sequences. The expression of several candidate genes including a lipase, two non-specific lipid transfer proteins (ns-LTPs), and several wheat pathogenesis-related (PR)-proteins, was evaluated following 4 to 32 days post-inoculation in compatible and incompatible interactions. Results confirmed the higher overall expression of these genes in resistant BW553 compared to susceptible Neepawa, and the differential up-regulation of wheat lipase, chitinase and PR-1 proteins in the expression of the incompatible interaction.

• BMB Reports
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• v.37 no.5
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• pp.522-526
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• 2004

Prader-Willi (PWS) and Angelman (AS) are syndromes of developmental impairment that result from the loss of expression of imprinted genes in the paternal (PWS) or maternal (AS) 15q11-q13 chromosome. Diagnosis on a clinical basis is difficult in newborns and young infants; thus, a suitable molecular test capable of revealing chromosomal abnormalities is required. We used a variety of cytogenetic and molecular approaches, such as, chromosome G banding, fluorescent in situ hybridization, a DNA methylation test, and a set of chromosome 15 DNA polymorphisms to characterize a cohort of 27 PWS patients and 24 suspected AS patients. Molecular analysis enabled the reliable diagnosis of 14 PWS and 7 AS patients, and their classification into four groups: (A) 6 of these 14 PWS subjects (44%) had deletions of paternal 15q11-q13; (B) 4 of the 7 AS patients had deletions of maternal 15q11-q13; (C) one PWS patient (8%) had a maternal uniparental disomy (UPD) of chromosome 15; (D) the remaining reliably diagnoses of 7 PWS and 3 AS cases showed abnormal methylation patterns of 15q11-q13 chromosome, but none of the alterations shown by the above groups, although they may have harbored deletions undetected by the markers used. This study highlights the importance of using a combination of cytogenetic and molecular tests for a reliable diagnosis of PWS or AS, and for the identification of genetic alterations.