• Korean Journal of Microbiology
• /
• v.44 no.3
• /
• pp.251-257
• /
• 2008

Four potential microcystin-producing cyanobacteria were isolated from large reservoirs which act as sources of drinking water supply in Korea. Strain DC-2, YD-l, and YD-6 were closely related to Microcystis aeruginosa based on the analysis of l6S rRNA gene and mcyA gene sequences. mcyA gene sequence of YDS2-3, isolated from Yongdam Reservoir, was closed to that of M. aeruginosa, whereas l6S rRNA gene sequence was not related to the known sequences of microcystin-producing cyanobacteria indicating this strain can be a novel cyanobacterium belonging to the genus Microcystis. When mcyA gene sequences of isolated cyanobacteria were compared with the mcyA gene sequence library of two reservoirs, the sequence of DC-2 matched with the dominant ones.

• Radiation Oncology Journal
• /
• v.19 no.4
• /
• pp.381-388
• /
• 2001

Purpose : This study was conducted to assess the effects of x-irradiation on the expression of the novel glutathione S-transferase K1 gene. Materials and methods : Human glutathione S-transferase K1 (hGSTK1) DNA was purified and ligated to a pcDNA3.1/Myc-His(+) vector for the overexpression of hGSTK1 gene. MCF-7 cells were transfected with or without the recombinant hGSTK1 gene, and irradiated with 6 MV x-ray. After incubation of 14 days, cell survival was measured and compared. The expression of hGSTK1 and the effect of x-irradiation on hGSTK1 expression were also estimated in MCF-7 cells transfected with or without the hGSTK1 gene by RT-PCR. Results : Following 2 to 12 Gy of x-irradiation, the cell survivals were higher in the MCF-7 cells transfected with the hGSTK1 gene than in those without transfection. Despite the higher cell survival in the hGSTK1-transfected cells, RT-PCR for hGSTK1 mRNA revealed no significant differences according to radiation dose, fractionation, and time after irradiation. Conclusion : The MCF-7 cells transfected with the hGSTK1 gene showed higher cell survival than those without transfection of the gene. The hGSTK1 gene might be associated with the radiosensitivity of MCF-7 cell line and further analysis should be needed.

• Molecules and Cells
• /
• v.20 no.1
• /
• pp.43-50
• /
• 2005

Glutaredoxin (Grx) is a small, heat-stable redox protein acting as a multi-functional glutathione (GSH)-dependent disulfide oxidoreductase. We have cloned the monothiol Grx5 gene from the genomic DNA of the fission yeast Schizosaccharomyces pombe. It has 1,904 bp, with one intron, and encodes a putative protein of 146 amino acids with a molecular mass of 16.5 kDa. Recombinant Grx5 produced functional Grx in S. pombe cells. NO-generating sodium nitroprusside (SNP, 1.0 and 2.0 mM) and potassium chloride (KCl, 0.2 and 0.5 M) increased the synthesis of ${\beta}$-galactosidase from a Grx5-lacZ fusion gene, and transcription of Grx5 was also enhanced by SNP and KCl. Synthesis of ${\beta}$-galactosidase from the Grx5-lacZ fusion was lower in Pap1-negative TP108-3C cells than in wild type KP1 cells, and when Pap1 was overproduced in KP1 cells, the level of ${\beta}$-galactosidase increased. We also found that Pap1 is involved in the induction of Grx5 by SNP and KCl. S. pombe Grx5 may play a crucial role in responses to nitrosative and osmotic stresses.

• Asian-Australasian Journal of Animal Sciences
• /
• v.18 no.4
• /
• pp.453-457
• /
• 2005

The genetic variations in three major river populations viz. the Halda, the Jamuna and the Padma of the Indian major carp, Catla catla were analyzed by Random Amplified Polymorphic DNA (RAPD) markers. Four decamer primers were used for amplifying DNA of 10 individuals from each population. The proportion of polymorphic loci and the gene diversity estimates were 59.4 and 0.20 for the Halda, 37.5 and 0.14 for the Jamuna and 46.9 and 0.16 for the Padma populations respectively indicating the existence of a relatively high level of genetic variation in the Halda river population. The inter-population similarity indices, gene flow and genetic distance values indicated that the Jamuna-Padma population pair of catla was genetically closer than the Halda-Jamuna and the Halda-Padma population pairs in compliance with the geographical distances among them. The coefficient of gene differentiation ($G_{ST}$=0.13) reflects some degree of genetic differentiation among three populations of catla studied. The data suggest that the RAPD technique could be used to discriminate different river populations of catla.

• Korean Journal of Medicinal Crop Science
• /
• v.16 no.3
• /
• pp.195-198
• /
• 2008

Karyotypic analysis and FISH (fluorescence in situ hybridization) with 45S and 5S rRNA genes were carried out in Persicaria tinctoria H Gross. The somatic metaphase chromosomes were ranged from 2.25 ${\mu}m$ to 1.50 ${\mu}m$ in length. Chromosome number was 2n = 4x = 40 with the basic number of x = 10. The chromosome complement of the species consisted of 16 pairs of metacentrics (chromososomes 1,2,3,4,6,7,8,9, 10, 11, 12, 13, 15, 18, 19 and 20) and 4 pairs of submetacentrics (chromosome 5, 14, 16 and 17). The karyotype formula was K(2n) = 4x = 32 m + 8 sm. In FISH analysis, three pairs of 45S rRNA gene loci on the terminal region of submetacentrics (chromosomes 5, 16 and 17) and two pairs of 5S rRNA gene loci on the centromeric region of metacentrics (chromosomes 9 and 11) were detected, respectively.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.11
• /
• pp.1644-1650
• /
• 2013

Ribosomal protein (rp) S6 is the substrate of ribosomal protein S6K (S6 kinase) and is involved in protein synthesis by mTOR/S6K/S6 signaling pathway. Some S6 cDNA have been cloned in mammals in recent years but has not been identified in the goat. To facilitate such studies, we cloned the cDNA encoding Cashmere goat (Capra hircus) S6 (GenBank accession GU131122) and then detected mRNA expression in seven tissues by real time PCR and protein expression in testis tissue by immunohistochemisty. Sequence analysis indicated that the obtained goat S6 was a 808 bp product, including a 3' untranslated region of 58 bp and an open reading frame of 750 bp which predicted a protein of 249 amino acids. The predicted amino acid sequence was highly homologous to cattle, human, mouse and rat S6. Expression analysis indicated S6 mRNA was expressed extensively in detected tissues and S6 protein was expressed in testis tissue.

• Parasites, Hosts and Diseases
• /
• v.42 no.3
• /
• pp.129-135
• /
• 2004

We compared the DNA sequences of the genus Metagonimus: M. yokogawai, M. takahashii, and M. miyatai. We obtained 288 D1 ribosomal DNA (rDNA) and mitochondrial cytochrome c oxidase subunit I (mtCOI) fragments from the adult worms by PCR, that were cloned and sequenced. Phylogenetic relationships inferred from the nucleotide sequences of the 28S D1 rDNA and mtCOI gene. M. takahashii and M. yokogawai are placed in the same clade supported by DNA sequence and phylogenie tree analysis in 28S D1 rDNA and mtCOI gene region. The above findings tell us that M. takahashii is closer to M. yokogawai than to M. miyatai genetically. This phylogenetic data also support the nomination of M. miyatai as a separate species.

• The Korean Journal of Physiology and Pharmacology
• /
• v.2 no.1
• /
• pp.101-108
• /
• 1998

We investigated the effect of ${\alpha}-subunit$ of the stimulatory GTP-binding protein ($G{\alpha}_s$) gene mutation on the expression of the thyrotropin-releasing hormone (TRH) receptor (TRH-R) gene in GH3 cells and in growth hormone (GH)-secreting adenomas of acromegalic patients. In the presence of cyclohexicmide, forskolin and isobutylmethylxanthine, cholera toxin, and GH-releasing hormone (GHRH) decreased rat TRH-R (rTRH-R) gene expression by about 39%, 43.7%, and 46.7%, respectively. Transient expression of a vector expressing mutant-type $G{\alpha}_s$ decreased the rTRH-R gene expression by about 50% at 24 h of transfection, whereas a wild-type $G{\alpha}_s$ expression vector did not. The transcript of human TRH-R (hTRH-R) gene was detected in 6 of 8 (75%) tumors. Three of them (50%) showed the paradoxical GH response to TRH and the other three patients did not show the response. The relative expression of hTRH-R mRNA in the tumors from patients with the paradoxical response of GH to TRH did not differ from that in the tumors from patients without the paradoxical response. Direct PCR sequencing of $G{\alpha}_s$ gene disclosed a mutant allele and a normal allele only at codon 201 in 4 of 8 tumors. The paradoxical response to TRH was observed in 2 of 4 patients without the mutation, and 2 of 4 patients with the mutation. The hTRH-R gene expression of pituitaty adenomsa did not differ between the tumors without the mutation and those with mutation. The present study suggests that the expression of TRH-R gene is not likely to be a main determinant for the paradoxical response of GH to TRH, and that $G{\alpha}_s$ mutation may suppress the gene expression of TRH-R in GH-secreting adenoma. However, a certain predisposing factor(s) may play an important role in determining the expression of TRH-R.

• Microbiology and Biotechnology Letters
• /
• v.23 no.3
• /
• pp.288-296
• /
• 1995

To investigate high-level expression of Serratia marcescens metalloprotease (SMP) in Escherichia coli and S. marcescens, we constructed various recombinant plasmids: pSP2, containing SMP gene and lac promoter; pKSP2, containing SMP gene and tac promoter; pTSP2, containing SMP gene, trc99a promoter, and lacI$^{q}$. The recombinant E. coli (pKSP2) strain expressed SMP to a high-level, about 36% of total cellular proteins but accumulated inactive SMP precursors intracellularly, which indicated that E. coli does not have activation and secretion system for SMP. To overproduce active SMP, we transformed S. marcescens with the recombinant plasmids by a modified CaCl$_{2}$ method. The recombinant S. marcescens ATCC27117 (pSP2) containing lac promoter for SMP transcription produced 530 U/ml of active SMP on LB broth, which is about 5.1 times of the SMP yield, 105 U/ml of a control strain, S. marcescens ATCC27117 (pUC19). However, S. marcescens ATCC27117 (pKSP2) containing tac promoter for SMP transcription did not grow healthy and hardly produced SMP. To overcome a harmful effect of the strong tac promoter, we constructed a regulatory plasmid pTSP2 containing a strong trc99a promoter and its repressor gene lacI$^{q}$. When S. marcescens ATCC27117 (pTSP2) was induced with 1.0 mM IPTG after 9 hr cultivation, 2,200 U/ml of SMP was obtained in LB broth, which is about 21 times of that of a control strain.

• Korean Journal of Microbiology
• /
• v.36 no.1
• /
• pp.46-51
• /
• 2000

Salmonella typhi is one of important causes of human enteric infections. S. typhi KNIH100 was isolated from a patient of typhoid fever in Korea. We cloned a 5.0 kb SalⅠ fragment containing the aroA gene encoding a 5-enolpyruvylshikimate-3-phosphate synthetase from chromosomal DNA of this strain. This recombinant plasmid was named pSAL80. E. coli CGSC2829, an aroA- mutant, was not grown on the M9 minimal medium but E. coli CGSC2829 (pSAL80) was grown on the M9 minimal medium. The aroA gene was composed of 1,284 base pairs with ATG initiation codon and TAA termination codon. Sequence comparison of the aroA gene exhibited 99%, 98%, and 77% identity with those of S. typhi Ty2, S. typhimurium, and E. coli respectively. As in the cases of Shigella sonnei and E. coli, the serC and aroA genes lie in a single operonic structure.