• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.240-241
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• 2004

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2000.10a
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• pp.30.1-30
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• 2000

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.260.1-260
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• 2000

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.47.2-47
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• 1999

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.1-7
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• 2000

The genes involved in riboflavin synthesis (ribI, II, III, and IV) were found immediately downstream of luxG in the lux operon from Photobacterium species. The single stranded DNA containing the intergenic region of lux genes and rib genes from Photobacterium phosphoreum was fully protected by P. phosphoreum mRNA from the S1 nuclease mapping assay suggesting that a transcriptional terminator was not present in the region. In addition, the levels of riboflavin synthase activity in P. phosphoreum was increased during the development of bacterial bioluminescence in the same fashion as the luciferase and fatty acid reductase activities. Insertion of the Photobacterium leiognathi DNA extending from luxB to ribII, between a strong lux promoter and a reporter gene (chloramphenicol acetyltransferase, CAT) and transferred by conjugation into P. leiognathi, did not affect expression of reporter gene. Moreover the CAT gene was not expressed in an analogous construct missing the lux promoter indicating that a promoter was not present in this region. Based on the data here, it can be concluded that the lux genes and rib genes in Photobacterium species are under common regulation.

• Mycobiology
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• v.44 no.4
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• pp.314-318
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• 2016

Breeding the button mushroom requires genetic information about its strains. This study was undertaken to genetically characterize four domestically bred button mushroom strains (Saea, Saejung, Saedo, Saeyeon cultivars) and to assess the possibility of using the intergenic spacer 1 (IGS1) region of rDNA as a genetically variable region in the genetic characterization. For the experiment, 34 strains of Agaricus bisporus, two strains of A. bitorquis, and one strain of A. silvaticus, from 17 countries were used. Nucleotide sequence analysis of IGS1 rDNA in these 37 Agaricus strains confirmed that genetic variations exist, not only among the four domestic strains, but also between the four domestic strains and foreign strains. Crossing two different haploid strains of A. bisporus seems to generate genetic variation in the IGS1 region in their off-spring haploid strains. Phylogenetic analysis based on the IGS1 sequence revealed all A. bisporus strains could be differentiated from A. silvaticus and A. bitorquis strains. Five genetic groups were resolved among A. bisporus strains. Saejung and Saeyeon cultivars formed a separate genetic group. Our results suggest that IGS1 could be complementarily applied in the polymorphism analysis of button mushroom.

• Journal of Microbiology
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• v.42 no.3
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• pp.194-199
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• 2004

Investigation of the expression of the riboflavin (rib) genes, which are found immediately downstream of luxG in the lux operon in Photobacterium phosphoreum, provides more information relevant to the evolution of bioluminescence, as well as to the regulation of supply of flavin substrate for bacterial bioluminescence reactions. In order to answer the question of whether or not the transcriptions of lux and rib genes are integrated, a transcriptional termination assay was performed with P. phoxphoreum DNA, containing the possible stem-loop structures, located in the intergenic region of luxF and luxE ($\Omega$$\_$A/), of luxG and ribE ($\Omega$$\_$B/), and downstream of ribA ($\Omega$$\_$c/). The expression of the CAT (Chloram-phenicol Acetyl Transferase) reporter gene was remarkably decreased upon the insertion of the stem-loop structure ($\Omega$$\_$c/) into the strong lux promoter and the reporter gene. However, the insertion of the structure ($\Omega$$\_$B/) into the intergenic region of the lux and the rib genes caused no significant change in expression from the CAT gene. In addition, the single stranded DNA in the same region was protected by the P. phosphoreum mRNA from the Sl nuclease protection assay. These results suggest that lux genes and rib genes are part of the same operon in P. phosphoreum.

• The Plant Pathology Journal
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• v.16 no.2
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• pp.98-104
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• 2000

For the taxonomic evaluaition, 15 strains of the genus Pectobacterium and Erwinia were analyzed for 16S-23S rDNA intergenic spacer regions (ISRs). These species contained two types of ISRs, large and small ISRs. Large ISRs were on the range of 474-569 bp size, and coding transfer $\textrm{RNA}^{11e}$($\textrm{tRNA}^{11e}$) and $\textrm{tRNA}^{Ala}$. Small ISRs were 354-459 bp in length and coding $\textrm{tRNA}^{Glu}$. The sequence variations of two ISRs among species and strains were very high as compared with 16S rRNA gene sequences. By phylogenetic trees on the basis of two ISRs, Pectobacterium ere differentiated into P. carotovorum-P. cactiaidum group and P. chrysanthemi group. However, the taxonomic position of E. cypripedii and E. rhapontici, which were not clear on taxonomic delineation between Pectobacterium and Erwinia, were not clearly resolved on the basis of ISRs.

• Genomics & Informatics
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• v.3 no.3
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• pp.74-79
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• 2005

The H19 gene, located at human chromosome 11p15.5, is imprinted in most normal human tissues. However, imprinting is often lost in tumors suggesting H19 is a putative tumor suppressor. We analyzed the single nucleotide polymorphisms (SNPs) of a 16 kb region that includes the H19 gene and its imprinting control region (ICR) in the Korean population. To identify SNPs, we directly sequenced this region in 18 Korean subjects. We identified 64 SNPs, of which 7 were in the exons of H19, 2 were in the introns, 14 were in the 3' intergenic region and 41 were in the 5' intergenic region. Of the 64 SNPs, 21 had not previously been reported and thus appear to be unique to the Korean population. The identified SNPs of H19 in the Korean population may eventually be useful as genetic markers associated with various diseases. In this study, 7 of the 64 identified SNPs were at CTCF binding sites in the ICR and may affect regulation of H19 gene imprinting. Thus, several genetic variations of the H19 gene may be important markers in human diseases that involve genomic imprinting, including cancer.

• Parasites, Hosts and Diseases
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• v.44 no.4 s.140
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• pp.343-353
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• 2006

Giardia intestinalis infections arise primarily from contaminated food or water Zoonotic transmission is possible, and at least 7 major assemblages including 2 assemblages recovered from humans have been identified. The determination of the genotype of G. intestinalis is useful not only for assessing the correlation of clinical symptoms and genotypes, but also for finding the infection route and its causative agent in epidemiological studies. In this study, methods to identify the genotypes more specifically than the known 2 genotypes recovered from humans have been developed using the intergenic spacer (IGS) region of rDNA. The IGS region contains varying sequences and is thus suitable for comparing isolates once they are classified as the same strain. Genomic DNA was extracted from cysts isolated from the feces of 5 Chinese, 2 Laotians and 2 Koreans infected with G. intestinalis and the trophozoites of WB, K1, and GS strains cultured in the laboratory, respectively. The rDNA containing the IGS region was amplified by PCR and cloned. The nucleotide sequence of the 3' end of IGS region was determined and examined by multiple alignment and phylogenetic analysis. Based on the nucleotide sequence of the IGS region, 13 G. intestinalis isolates were classified to assemblages A and B, and assemblage A was subdivided into A1 and A2. Then, the primers specific to each assemblage were designed, and PCR was peformed using those primers. It detected as little as 10 pg of DNA, and the PCR amplified products with the specific length to each assemblage (A1, 176bp; A2, 261 bp; B, 319 bp) were found. The PCR specific to 3 assemblages of G. intestinalis did not react with other bacteria or protozoans, and it did not react with G. intestinalis isolates obtained from dogs and rats. It was thus confirmed that by applying this PCR method amplifying the IGS region, the detection of G. intestinalis and its genotyping can be determined simultaneously.