• International Journal of Industrial Entomology and Biomaterials
• /
• v.6 no.1
• /
• pp.45-48
• /
• 2003

We have previously cloned and characterized the complete fibroin L-chain gene from one of the silkworm races Baekok-Jam (Bombyx mori) and found two variable regions (I, intron 2 ~ exon 3; II, intron 6) with the primer sets designed to cover these variable regions. We tested the utility of these regions as genetic markers among silkworm races. For the purpose of study, Japanese race (Jam 123), Chinese race (Jam 124) and their F$_1$hybrid Baekok-Jam were used. The PCR product size of region I was 787 bp in Jam 123, 770 bp in Jam 124 and 768 bp in Baekok-Jam. The size of region II was 470 bp in Jam 123, 428 bp in Jam 124 and 429 Up in Baekok-Jam. In the extended experiment, Jam 125 (Japanese race), Jam 126 (Chinese race) and their F$_1$hybrid Daeseong-Jam were also analyzed. The sizes of region I and II in Jam 125, Jam 126 and Daeseong-Jam were similar to those of Jam 123, Jam 124 and Baekok-Jam. DNA sequence divergence between the two geographic races of Jam 123 or Jam 125 and Jam 124 or Jam 126 was substantial. The result suggests that the fibroin L-chain gene of F$_1$hybrids were inherited from Chinese races. These results are concordant with cocoon shapes of tested animals, and suggested that Baekok-Jam or Daeseong-jam is more closely related to Jam 124 or Jam 126 than to Jam 123 or Jam 125. Taken these data together, the primer sets designed from two variable regions of fibroin L-chain gene would be highly useful, as the genetic markers for silkworm races, at least in Japanese and Chinese races, although an extended study including more geographic races is required.

• International Journal of Oral Biology
• /
• v.46 no.3
• /
• pp.140-145
• /
• 2021

This study aimed to develop Lautropia mirabilis-specific quantitative real-time polymerase chain reaction (qPCR) primers based on the sequence of DNA-directed RNA polymerase subunit beta gene. The PrimerSelect program was used in designing of the qPCR primers, RTLam-F4 and RTLam-R3. The specificity of the qPCR primers were performed by conventional PCR with 37 strains of 37 oral bacterial species, including L. mirabilis. The sensitivity of the primers was determined by qPCR with the serial dilution of purified genomic DNA of L. mirabilis KCOM 3484, ranged from 4 ng to 4 fg. The data showed that the qPCR primers could detect only L. mirabilis strains and as little as 40 fg of genome DNA of L. mirabilis KCOM 3484. These results indicate that this qPCR primer pair (RTLam-F4/RTLam-R3) may be useful for species-specific detection of L. mirabilis in epidemiological studies of oral bacterial infectious diseases such as periodontal disease.

• Food Science and Biotechnology
• /
• v.14 no.3
• /
• pp.387-391
• /
• 2005

Competitive polymerase chain reaction (cPCR) was used to develop a direct enumeration method of Listeria monocytogenes in pork meat. Pork meat was artificially inoculated with L. monocytogenes and DNA was extracted using guanidine thiocyanate-phenol-chloroform and subjected to PCR amplification. Sixteen primer sets for L. monocytogenes hlyA gene were tested for sensitive detection and the DG69/DG74 primer set was selected. The detection limit achieved with this primer set was as low as 860 colony-forming units (cfu) per 0.1 g of pork meat. When the samples were cultured at $30^{\circ}C$ for 16 hr in Brain Heart Infusion (BHI) medium, even a single bacterium could be detected with this primer set by PCR. For cPCR, the hlyA gene, which features a 148 bp-deletion, was cloned in the pGEM-4Z vector. A known amount of competitor DNA which has the same primer binding sites was co-amplified with L. monocytogenes total DNA from the artificially inoculated pork meat. The cell-number determined by cPCR was approximately equal to cfu from the Most Probable Number (MPN) method. The whole procedure took only 5 hr.

• Korean Journal of Food Science and Technology
• /
• v.31 no.6
• /
• pp.1628-1634
• /
• 1999

The polymerase chain reaction (PCR) for the sensitive and specific detection of Listeria monocytogenes was employed by using LM 1 and LM 2 primers which were based on the listeriolysin O gene. The direct use of cell suspension as DNA template, without DNA extraction or lysis step, was suitable and specific enough to detect L. monocytogenes at the level of $10^2$ CFU or less per PCR for the pure culture and milk sample, however, the detection sensitivity became blunt for other food samples such as kimchi and chicken. The nested PCR, in which L-1 and L-2 (both designed from listeriolysin O gene) were employed as inner primers, was specific for detecting L. monocytogenes and enhanced the detection limit by 10 times. The PCR using LM 1 and LM 2 primers was very effective to detect L. monocytogenes from foods in terms of the specificity and time consumed, i. e. within $4{\sim}8\;hrs$ (nested PCR).

• Journal of Microbiology and Biotechnology
• /
• v.10 no.6
• /
• pp.881-884
• /
• 2000

A polymerase chain reaction (PCR) was performed to rapidly identify Lactobacillus plantarum from type strains and kimchi samples. The PCR experiments were carried out using specific oligonucleotide primer sets based on the 16S rRNA gene sequences of L. plantarum. The expected DNA amplificate of 419 bp was obtained when either purified DNA or whole cells of L. plantarum strains reacted with LP primers, yet not with any of the other strains. The PCR product was confirmed by DNA sequencing. Accordingly, since the PCR method used is simple, specific, and rapid, it will be useful for monitoring and evaluation L. plantarum in the mixed microbial population found in kimchi.

• Korean Journal of Microbiology
• /
• v.28 no.2
• /
• pp.91-97
• /
• 1990

Complementary DNA (cDNA) coding for human cytoplasmic superoxide dismutase (SOD1) (superoxide: superoxide oxidoreductase E.C.1.15.1.1) was isolated from human liver cDNA library of $\lambda$gt11 by in situ plaque hybridization. The insery cDNA gas the 5' untranslational region (UTR) and 3'UTR of SOD1 gene. Polymerase Chain Reaction (PCR) method was used fro subcloning of SOD1 structural gene. Using synthetic sense strand primer (24mer) containing a start codon and antisense strand primer (24mer), SOD1 structural gene was selectively amplified. Amplified DNA was directly cloned into the HincII site of pUC19 plasmid. Insery cDNA was subcloned into M13 mp19 and sequenced by dideowy chain termination method with Sequenase. The nucleotide sequence of insert cDNA had an open reading frame (ORF) coding for 153 amino acid residues. The structural gene of cytoplasmic SOD was placed under the control of bacteriophage $\lambda P_{L}$ regulatory sequences, generating a highly efficient expression plasmid. The production of human SOD1 in E. coli cells was about 7% of total cellular proteins and recombinant human SOD1 possessed its own enzymatic acitivity.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.3
• /
• pp.169-173
• /
• 2000

A 1,183bp cDNA, AmA1, encoding the seed storage protein of Amaranthus hypochondriacus was isolated by reverse transcriptase-polymerase chain reaction (RT-PCR) and characterized. AmA1 gene was subcloned into plant binary vector under Cauliflower Mosaic Virus (CaMV) 35S promoter and nopaline synthase terminator (3'NOS). The recombinant binary vector was used to transform Nicotiana tabacum using Agrobacterium tumefacien -mediated transformation procedure. Shoots were induced on MS medium with 0.1 mg/L NAA, 1.0 mg/L BA, 100 mg/L kanamycin and 250 mg/L cefotaxime. Transgenic plants were selected on rooting medium based on MS medium containing 200 mg/L kanamycin and 250 mg/L cefotaxime without phytoregulators. The presence of AmA1 gene in the transgenic plants was confirmed by PCR followed by DNA hybridization. The expression of AmA1 gene in the transgenic plant was observed by RT-PCR method.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.47 no.5
• /
• pp.556-561
• /
• 2014

We applied a combination of most probable number-polymerase chain reaction (MPN-PCR) methods using a PCR procedure targeting the H-NS (VP1133) gene to detect Vibrio parahaemolyticus presence and density in seawater as well as within short-necked clam Ruditapes philippinarum tissues collected from Gomso Bay, Korea. In 30 seawater samples, V. parahaemolyticus levels ranged from less than 1.8 to $1.1{\times}10^3MPN/100mL$, and samples from August showed higher than those from other months. Furthermore, the levels of V. parahaemolyticus in six short-necked clam samples ranged from $7.8{\times}10^2$ to $2.1{\times}10^3MPN/100g$, approximately 2.5 times higher than in seawater samples from the corresponding month. Our results provide data on V. parahaemolyticus contamination in seawater and short-necked clam tissues, and help to improve quantitative methods of assessing V. parahaemolytcius levels.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.3
• /
• pp.515-519
• /
• 2004

Listeria spp. were isolated from a total of 402 naturally contaminated domestic ready-to-eat (RTE) vegetable samples by the conventional Food and Drug Administration protocol and confinned by API-Listeria kit. Also, the susceptibility to 12 antibiotics, polymerase chain reaction (PCR) assay for virulence gene of pathogenic Listeria monocytogenes isolates, and in vitro virulence assay using myeloma and hybridoma cells from murine and human sources were tested. Among the samples, 17 samples (4.2％) were found to be contaminated with Listeria species. Among the 17 strains of Listeria spp. isolates, only 2 strains (11.8％) of L. monocytogenes and 15 strains (88.2％) of L. innocua were identified. Antibiotic susceptibility test showed that the Listeria spp. isolates were very susceptible to the antibiotics tested, except for nalidixic acid. Among 17 strains of Listeria spp., PCR analysis showed that 2 strains of L. monocytogenes isolates proved to have a virulence hly gene, but none of L. innocua had the hly gene. Also, hybridoma Ped-2E9 cells assay showed that only L. monocytogenes isolates killed approximately 95-99％ hybridoma cells after 6 h, but L. innocua isolates had about 0-5％ lethal effect. These results indicate that PCR assay with hly primer or hybridoma Ped-2E9 cells assay could be used as a good monitoring tool or in vitro virulence test for L. monocytogenes.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.11 no.2
• /
• pp.154-159
• /
• 2006

Interleukin-18 (IL-18), otherwise known as interferon-gamma-inducing factor (IGIF), is one of several well characterized and important cytokines that contribute to host defenses. The complementary DNA (cDNA) of mature human interleukin-18 gene (hIL-18) was fused with the signal peptide of the rice amylase 1A gene (Ramy1A) and introduced into the plant expression vector under the control of a duplicated CaMV 35S promoter. The recombinant plasmid was transformed into tobacco (Nicotiana tabacum L. cv Havana) using the Agrobacterium-mediated transformation method. The integration of the hlL-18 gene into the genome of transgenic tobacco plants was confirmed by polymerase chain reaction (PCR) amplification and its expression was observed in the suspension cells that were derived from the transgenic plant callus by using Northern blot analysis. The hlL-18 protein was detected in the extracts of the transgenic callus and in the medium of the transgenic tobacco suspension culture by using immunoblot analysis. Based upon enzyme-linked immunosorbant assay (ELISA) results, the expression level of the hlL-18 protein approximated $166{\mu}g/L$ in the suspension culture medium. Bioassay results from the induction of $interferon-{\gamma}$ from a KG-1 cell line indicated that the hlL-18 secreted into the suspension culture medium was bioactive.