• Korean Journal of Microbiology
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• v.30 no.5
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• pp.391-396
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• 1992

Anabaena variabilis A TCC 29413. a photoautotrophic and nitrogen fixing cyanobacteria. was investigated on the environmental factors regulating the growth and nitrogen lixation activity. A good growth of cyanobacteria] cells was observed due to nitrogen t1xation by the heterocyst differentiation in nitrogen free Allen and Arnon (]/8) medium. The nitrogenase activity was appeared to be in proportion to the cell growth lor 6 days then drastically decreased in the later growth period when the nitraTe was accumulated to high level in the culture to cause the inhibition. The optima] conditions lilr the cell growth and nitrogenase activity of A. varillbili.l were anaerobic. IO.OO0 lux. $30^{\circ}C$ and pH 8 with the nitrogen Cree minimal medium. The activity was significantly inhihited by the low concentrations of ammonium and nitrate. but was stimulated b) the ]ow Ieve] of phosphate and carbonate sources. The treatments of several toxic heavy metals showed strong inhibition of the cell growth and nitrogenase activity by O.3~10 ppm in the order of $Hg^{2+}$ > $Cd^{2+}$ > $Co^{2+}$ > $Zn^{2+}$ > $Ph^{2+}$, and the concentrations for 50% inhibition of the maximum activity were 0.41. 0.47. 0.5 L 0.66 and 8.1 ppm. respectively. The addition of carbohydrates (0.5~ 1.0%) in the dark condition stimulated the growth and activity in the order of sucrose > fructose > glucose.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.306-311
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• 2009

A new PCR method was developed to detect Pectobacterium carotovorum which is the causative agent of soft rot in Brassica pekinensis. A specific detection primer set based on Lytic murein transglycolase gene was designed and evaluated. Using ERB3_F (5'-TGC GAC ACC TCC TCA TCA CG-3') and ERB3_R (5'-CTT ATC ACG CTG TAA CCA GC-3') primers, 437 nucleotides long fragment was specifically amplified. The amplified products were observed in 52 out of 55 strains of P. carotovorum or Pectobacterium carotovorum subsp. carotovorum. On the other hand, no amplification was observed in 8 organisms including Chinese cabbage and potato. The optimal PCR condition for the ERB3_F/ERB3_R primer set was $58^{\circ}C$ for annealing and 15 mM for $MgCl_2$. With serially diluted templates, the specific PCR sensitivitie limit was $2\times10^3$ copies. Also, this method can be applied not only to DNA but also to field samples. This PCR method may be expected to be useful for specific detection of P. carotovorum.

• Journal of fish pathology
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• v.6 no.2
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• pp.93-101
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• 1993

The RNAI mutation of Saccharomyces cerevisia is a recessive and temperature sensitive lethal mutation which interferes with the production of mRNA, rRNA, and tRNA. However, the precise role of RNAI gene have not been revealed until yet. We have cloned rna1-1 mutant gene from rna1-1 mutant yeast strain(R49 ; trpl, ura3-52, rna1-1). The 3.4kb BglII fragment of wild type RNAI clone(81-2-6) contains whole RNAI gene. The genomic southern blotting with BglII digested R49 genomic DNA as a probe shows the unique and identical band with wild type 3.4kb BglII fragment. Therefore, We prepared partial BglII genomic library(3~4kb BglII fragments) into BamH I site of pUC19. The rna 1-1 mutant clone was screened with Digoxigenin(DIG)-lableled probe by high density colony hybridization. The 5'-flanking region of rna1-1 gene was sequenced by dideoxy chain termination method. The 5'-flanking sequence of RNAI gene contains three TATA-like sequence ; TAATA, TATA and TTTTAA at position of -67, -45, and -36 from first ATG codon respectively. The 5'-flanking region of wild type RNA I gene from ATG codon to -103nt was deleted with Bal31 exonuclease digestion, generating $pUC{\Delta}$/RNA I. After constructing $pYEP{\Delta}RNA$ I (consists of -103nt deleting RNA I gene, URA3 gene, $2{\mu}m$ rep. origin), pYEPrna1-1(consists of Xba I fragment of pUCrna1-1. URA3 gene, $2{\mu}m$ rep. origin), and pYEPRNAI. each plasmid was transformed into host strain(trpl, ura3-52, rna1-1) by electroporation, respectively. Yeast transformant carrying $pYEP{\Delta}RNA$ I did not complement the thermal sensitivity of rna1-1 gene. It means that TATA-like sequences in 5'-flanking region is not TATA sequence for transcribing RNAI gene and there may be other essential sequence in upstream region for the transcription of RNAI gene.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.151-156
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• 2007

The Function of the calcium sensing receptor (CaSR) is to control calcium levels by altering PTH (parathyroid hormone) secretion and renal calcium resorption. The influence of calcium on the basal and stimulated release of several hormones from chicken pituitary glands has been determined in vitro. The objective of this study was to identify SNP in chicken CaSR gene and to investigate the effect of the SNP on economic traits. The sequencing analysis method was used to identify nucleotide polymorphisms within chicken CaSR gene. This study identified SNP at position 1949 bp(Genebank accession No : XM_416491) in the exon 1. The SNP changed the amino acid to alanine(GCC) from serine(TCC). This SNP showed three genotypes, AA, AS and SS by digestion with the restriction enzyme NcoⅠ using the PCR-RFLP method. The A963S showed significant effect only on the first lay day (P<0.05) in Leghorn population. Leghorn with the genotype AA had significantly faster the first lay day(137.6) than the genotype AS(143.0, P<0.05). Also, the A963S showed significant effect only on the first lay day(P<0.05) and mean of egg weight(P<0.05) in KNC population. KNC with the genotypes AA ans AS had significantly faster the first lay day (151.0 and 152.6, respectively) than the genotype SS(159.4, P<0.05). And the genotypes SS had significantly heavier the mean of egg weight(50.4 kg, P<0.05) than the genotype AA ans AS (47.5 and 47.8 kg, respectively). According to result of this study, an a allele of the A963S was found to have a significant effect on the first lay day. It will be possible to use this SNP marker on selecting chicken to improve the first lay day.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.729-741
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• 1997

Background : We have recently reported that airway epithelial cells can produce RANTES and IL-8 in response to the stimulation of tubercle bacilli suggesting a certain role of airway epithelial cells in the pathogenesis of pulmonary tuberculosis. The pathogenesis of tuberculosis is determined by several factors including phagocytosis, immunological response of host, and virulence of tubercle bacilli. Interestingly, there have been reports suggesting that difference in immunological response of host according to the virulence of tubercle bacilli may be related with the pathogenesis of tuberculosis. We, therefore, studied the expressions and productions of RANTES and IL-8 in airway epithelial cells in response to tubercle bacilli(H37Rv, virulent strain and H37Ra, avirulent strain), in order to elucidate the possible pathophysiology of pulmonary tuberculosis. Methods : Peripheral blood monocytes were isolated from normal volunteers. Peripheral blood monocytes (PBM) were stimulated with LPS($10{\mu}g/ml$), H37Rv, or H37Ra($5{\times}10^5$ bacilli/well) along with normal control for 24 hours. A549 cells were stimulated with supernatants of cultured PBM for 24 hours. ELISA kit was used for the measurement of $TNF{\alpha}$ and IL-$1{\beta}$ production in supernatants of cultured PBM and for the measurement of RANTES and IL-8 in supernatants of cultured A549 cells. Northern blot analysis was used for the measurement of RANTES and IL-8 mRNA expression in cultured A549 cells. Results : $TNF{\alpha}$ and IL-$1{\beta}$ productions were increased in cultured PBM stimulated with LPS or tubercle bacilli(H37Rv or H37Ra) compared with the control. There was, however, no difference in $TNF{\alpha}$ and IL-$1{\beta}$ production between cultured PBM stimulated with H37Rv and H37Ra. RANTES and IL-8 expressions and productions were also increased in cultured A549 cells stimulated with LPS or tubercle bacilli compared with the control. RANTES and IL-8 mRNA expressions were significantly increased in cultured A549 cells stimulated with H37Ra-conditioned media(CM) compared with A549 cells stimulated with H37Rv-CM (p<0.05). However, there was no difference in RANTES and IL-8 productions between A549 cells stimulated with H37Rv-CM and H37Ra-CM. Conclusion : Airway epithelial cells can produce the potent chemokines such as RANTES and IL-8, in response to the stimulation of tubercle bacilli. These results suggest that airway epithelial cells may play a certain role in the pathogenesis of pulmonary tuberculosis. However, the role of airway epithelial cells in the pathogenesis of tuberculosis according to the virulence of tubercle bacilli was not clear in this study.