• Molecules and Cells
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• v.26 no.5
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• pp.474-480
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• 2008

OsMADS1 is a rice MADS box gene necessary for floral development. To identify the key cis-regulatory regions for its expression, we utilized transgenic rice plants expressing GUS fusion constructs. Histochemical analysis revealed that the 5.7-kb OsMADS1 intragenic sequences, encompassing exon 1, intron 1, and a part of exon 2, together with the 1.9-kb 5' upstream promoter region, are required for the GUS expression pattern that coincides with flower-preferential expression of OsMADS1. In contrast, the 5' upstream promoter sequence lacking this intragenic region caused ectopic expression of the reporter gene in both vegetative and reproductive tissues. Notably, incorporation of the intragenic region into the CaMV35S promoter directed the GUS expression pattern similar to that of the endogenous spatial expression of OsMADS1 in flowers. In addition, our transient gene expression assay revealed that the large first intron following the CaMV35S minimal promoter enhances flower-preferential expression of GUS. These results suggest that the OsMADS1 intragenic sequence, largely intron 1, contains a key regulatory region(s) essential for expression.

• Korean Journal of Microbiology
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• v.29 no.5
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• pp.270-277
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• 1991

A mutational alteration in the signal sequence of ribose-binding protein (RBP) of Escherichia coli, rbsB103, completely blocks the export of the protein to the periplasm. Intragenic suppressors for this mutation have been selected on minimal medium with ribose as a sole carbon source. Six suppressor mutations were characterized in detail and were found to have single amino acid wubstitution in the mature portion of RBP, which resulted in the mobility shift of the proteins on SDS polyacrylamide gel. Amino acid changes of these suppressors were localized in several peptides which are packed to form the N terminal domain of typical bilobate conformation of RBP. The involvement of SecB, a molecular chaperone, was investigated in the suppression of signal sequence mutation. Translocation efficency was found to be increased by the presence of SecB for all suppressors. It is likely that the folding characteristics of RBP altered by the suppressor mutations affect the affinity of interaction between SecB and RBP.

• Korean Journal of Breeding Science
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• v.40 no.4
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• pp.387-393
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• 2008

Over 7 individual rice (Oryza sativa L.) plants per a line were sowed and sampled by pooled sampling method for genomic DNA extraction. The 5,400 flanking sequence tags (FSTs) were analysed by adaptor PCR and direct sequencing. FST analysis showed that the intragenic FSTs, the intergenic FSTs, and the original insertional sequences including hot spot covered 48.1% (2,597), 25.6% (1,383), and 25% (1,350), respectively. The 2,597 intragenic FSTs were used for genotyping to determine whether they are heterozygous or homozygous, and 1,393 core lines were selected. Among them, 422 knockout genes were distributed on chromosome 3, while 56 - 157 intragenic FSTs scattered on other chromosomes. Among 1,393 FSTs, known genes such as transcription factor covered 59.4% (827), while unknown genes such as expressed protein covered 40.6% (566). RT-PCR indicated that some core lines had no expression or decreased expression level in their knockout genes. It means that core lines are very useful knockout lines for functional genomic studies.

• Food Science and Biotechnology
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• v.27 no.6
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• pp.1755-1760
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• 2018

The objective of this study was to perform genetic diversity analysis of 13 strains isolated from South Korean foods by multilocus sequence typing (MLST). For typing, seven housekeeping loci (atpA, dnaA, dnaK, gyrB, pheS, pyrG, and rpoA) were selected, amplified and analyzed. Fifty-one polymorphic sites varying from 1 to 22 in each species were identified. Thirteen sequence types were generated with allele numbers ranged from 2 to 10. The overall relationship between strains was assessed by unweighted pair group method with arithmetic mean dendrogram and minimum spanning tree. In addition, combined spits tree analysis revealed intragenic recombination. No clear relationship was observed between the isolation sources and strains. The developed MLST scheme enhanced our knowledge of the population diversity of Leu. citreum strains and will be used further for the selection of industrially important strain.

• BMB Reports
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• v.28 no.5
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• pp.458-463
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• 1995

Two apparent rho-independent transcription terminator structures within the coding sequence of aceK have been destroyed to access their roles in the differential expression between aceA and aceK in the glyoxylate bypass operon of E. coli. The effect of mutations on the expression of aceK was evaluated in two different ways: one by maxicell labeling and the other by lacZ fusion gene construction. The maxicell labeling experiment with the mutant operon clones has failed, like that of the wild type operon clone, to visibly show isocitrate dehrogenase (IDH) kinase/phosphatase, the product of aceK, on the autoradiogram of a protein gel. When the same mutations were introduced into an aceK::lacZ fusion gene to quantitatively evaluate the mutational effect, the activity of ${\beta}-galactosidase$ in neither of the mutant versions of the fusion gene was elevated significantly enough to explain the degree of polarity observed in this region. Thus, we conclude that neither of these intragenic, apparent rho-independent transcription terminator structures, which have long been suspected as a major determinant in the down regulation of aceK, really act as a premature transcriptional terminator.

• Genomics & Informatics
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• v.4 no.1
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• pp.1-10
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• 2006

Epigenetic alterations are common features of human solid tumors, though global DNA methylation has been difficult to assess. Restriction Landmark Genomic Scanning (RLGS) is one of technology to examine epigenetic alterations at several thousand Notl sites of promoter regions in tumor genome. To assess sequence information for Notl sequences in RLGS gel, we cloned 1,161 unique Notl-linked clones, compromising about 60% of the spots in the soluble region of RLGS profile, and performed BLAT searches on the UCSC genome server, May 2004 Freeze. 1,023 (88%) unique sequences were matched to the CpG islands of human genome showing a large bias of RLGS toward identifying potential genes or CpG islands. The cloned Notl-loci had a high frequency (71%) of occurrence within CpG islands near the 5' ends of known genes rather than within CpG islands near the 3' ends or intragenic regions, making RLGS a potent tool for the identification of gene-associated methylation events. By mixing RLGS gels with all Notl-linked clones, we addressed 151 Notl sequences onto a standard RLGS gel and compared them with previous reports from several types of tumors. We hope our sequence information will be useful to identify novel epigenetic targets in any types of tumor genome.

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.879-886
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• 2000

Background : Thyroid Transcription Factor-1(TTF-1) acts as a tissue specific transcription factor in the regulation of lung specific gene expression and as morphogenic protein during lung organogenesis. Currently, there is very little information on the cis-acting sequences and transcription factors that direct the TTF-1 gene expression. DNAse 1 hypersensitive (DH) sites represent a marker for active or potentially active chromatin and are likely to be especially important in gene regulation, being associated with many DNA sequences that regulate gene expression. It is clear that DH regions correlate with genetic regulatory loci and binding for sequence-specific DNA-binding proteins. Methods : We have used DH site assays to identify putative distal regulatory elements in H441 lung adenocarcinoma cells, which express the TTF-1 gene and HeLa cells. Results : There are four DH sites 5' of the TTF-1 gene. These sites are located at base pair approximately +150, -450, -800, and -1500 from the start of transcription. Conclusion : These data suggest that there may be at least one intragenic site and regulatory region 5' prime to the promotor region.