• Journal of Korean Society of Forest Science
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• v.78 no.1
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• pp.42-54
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• 1989

These studies were carried out to examine the anatomical, karyological characteristics, the variation of isozymes in needle and the frost damage of tissue for the purpose of investigating the relationships among the three natural Torreya nucifera populations of Cheju-do, Namhae, and Mt. Naejang in Korea. The results obtained can be summed up as follows : 1. The numbers of endodermal cells and inner layer cells of mucilage canal of needle conductive tissue were different in each population. The number of those of Cheju-do population was the largest. 2. In somatic chromosome, Namhae population showed one more secondary constriction. The values of $b^{arm}/a^{arm}$ were the same in all the three populations, but Cheju-do population particularly showed a different minimum value. And the karyotype formulas of each population showed difference. 3. During the meiosis, each population showed no significant difference in the irregular phenomena of chromosome. 4. In isoperoxidase and esterase variations of needle, each population showed its particular number and variation of bands. Cheju-do population showed the largest number and greatest variation of bands. 5. Under the same freeging conditions, the frost damage of Mt. Naejang population was comparatively slight, and Cheju-do population suffered from a greater frost damage than the others.

• Korean Journal of Plant Tissue Culture
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• v.27 no.4
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• pp.317-323
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• 2000

Molecular genetic techniques can now be applied to the development of advanced plant genotypes, either through genetic transformation or genomic approaches which allow researchers to transfer specific traits using molecular markers. In this paper, we discuss the use of these techniques towards understanding the genetics of blackleg resistance in Brassica. In a comparative mapping study between Arabidopsis thaliana and Brassica napus, 6 R-ESTs, 7 B. napus RFLP markers and a B. napus EST were located in a collinear region of N7 (B. napus) and chromosome 1 (A. thaliana). One of the A. thaliana R-ESTs and 4 of the B. napus RFLPs co-segregated and mapped to the LmRl locus for blackleg resistance. Introgression of blackleg resistance from wild relatives is also investigated with the possibility of accelerating the introgression process via marker assisted selection.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.529.2-529
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• 1986

pSp-Si (1.6kbp) was originally found in pediococcus halophilus to be a cryptic multicopy-plasmid. Hoping that the plasmid can also replicate in Bacillus subtilis, protoplast transformation of strain 207-25 (recE) was performed using pSP-Sl onto which was added the marker of tmrB8 (on 4.9 kbp EcoRI fragment ) or tmrB+ (on 0.9 kbp xbaI fragment) gene. Though the tmrB8 gene can expres tunicamycin-resistance at the single copy state, and the tmrB+ gene exerts the resistance only at the multicopy state, we could not confirm the replication of pSP-Sl (tmrB8) or pSP-Sl(tmrB+) in B. subtilis. During the experiment, however, we unexpectedly found that the circularized 0.9 kbp xgaI fragment (tmrB+) itself, which had no replication origin, could transform strain 207-25 to tunicamycin-resistant by protoplast transformation. Southern hybridization analyses with tmrB+ and other probes revealed the integration of the fragment at a single copy state into a position other than the homologous tmrB gene. This recE independent integration of another tmrB+ gene into the chromosome may contribute to the tunicamycinresistance in the transformants.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.751-756
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• 2012

Fluorescence in situ hybridization (FISH) is a powerful tool for the detection of DNA sequences in the specific region of the chromosomes. As well as for the integrated physical mapping, FISH karyotype analysis has to be preceded. Karyotype of Raphanus sativus 'Wonkyo 10039' was analyzed by a dual-color FISH technique; using various repetitive DNA probes, including 5S rDNA, 45S rDNA, and centromere retrotransposon. The length of the somatic metaphase chromosome ranged from 1.35 to $2.06{\mu}m$ with a total length of $15.29{\mu}m$. The chromosome complements comprised of eight pairs of metacentrics and one pair of submetacentric. Bleached DAPI Band analysis revealed a heterochromatin region, covering 28.6% to 50.4% each chromosomes. 5S and 45S rDNA sequences were located on two and three pairs of chromosomes, respectively. The centromere retrotransposon of Brassica (CRB) is a major component in Brassica related species that has been maintained as a common centromere component. CRB signals were detected on the centromere and pericentromeric region of R. sativus 'Wonkyo 10039' and three basic Brassica species (B. rapa, B. nigra, and B. oleracea). These results will provide a valuable background for physical mapping and elucidation of the evolutionary relationship among the Brassica related species.

• Journal of Animal Science and Technology
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• v.45 no.1
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• pp.1-12
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• 2003

The present study was carried out to establish the standard karyotype of the Korean Native Chicken and to find their chromosomal band markers using high-resolution banding technique. Chromosome analysis was performed on early chick embryos following in vitro culture of fertilized eggs of the yellow-brown and the red-brown lines of the Korean Native Chicken which had been established at National Livestock Research Institute. The high-resolution banding of the chromosome was achieved by treating the embryos with ethidium bromide and colchicine during culture. On GTG-banding, the Korean Native Chicken exhibited a typical chick banding pattern in all the macrochromosomes. Overall chromosomal morphology and positions of typical landmarks of the Korean Native Chicken were virtually identical to those of White Leghorn and International System for Standardized Avian Karyotypes(ISSAK). However, the lengths and G-band numbers of the Korean Native Chicken macrochromosomes were greater than those of White Leghorn and ISSAK. Especially in chromosomes 1 and Z, the Korean Native Chicken exhibited more separated bands in compared with ISSAK. In C-banding patterns, although a lot of observed cells had C-band polymorphic patterns, almost the Korean Native Chicken macrochromosomes had heterochromatic C-band on centromeres and/or near terminal part. However, the heterochromatic C-band was constantly observed at the end of q-arm of Z chromosomes and on the whole W chromosome. In addition, the Korean Native Chicken exhibited distinctive heteromorphic patterns of C-bands on the centromere of chromosome 3 and at the end of q-arm of Z chromosome between homologous chromosomes.

• Journal of Life Science
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• v.28 no.11
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• pp.1277-1284
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• 2018

In this study, a repeated yeast integrative plasmid (R-YIp) harboring Cre/loxP system was constructed to integrate various gene expression cassettes into the yeast chromosome. The R-YIp system contains a reusable selective marker (CgTRP1), loxP sequence, and target sequence for integration. Therefore, many gene expression cassettes can be integrated into the same position of the same yeast chromosome. In the present study, several model enzymes involving xylan/xylose metabolism were examined, including endoxylanase (XYLP), ${\beta}$-xylosidase (XYLB), xylose reductase (GRE3) and xylitol dehydrogenase (XYL2). Efficient expression of these genes was obtained using two promoters (GAL10p and ADH1p) and various plasmids (pGMF-GENE and pAMF-GENE plasmids) were constructed. The XYLP, XYLB, GRE3, and XYL2 genes were efficiently expressed under the control of the GAL10 promoter. Subsequently, R-YIps containing the GAL10p-GENE-GAL7t cassette were constructed, resulting in pRS-XylP, pRS-XylB, pRS-Gre3, and pRS-Xyl2 plasmids. These plasmids were sequentially integrated into chromosome VII of a Saccharomyces cerevisiae strain by repeated gene integration and selective marker rescue. These genes were integrated by the R-YIp system and were stably expressed in the yeast transformants to produce active recombinant enzymes. Therefore, we expect that the R-YIp system will be able to overcome current limitations of the host cells and allow selective marker selection for the integration of various genes into the yeast chromosome.

• The Korean Journal of Malacology
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• v.1 no.1
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• pp.24-50
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• 1985

Five different populations of Parafossarulus manchouricus (Chongpyung, Chinju and Kunsan, Korea; and Japan and Taiwan), a population of Bitbynia (Gabbia) misella (Gongju, Korea) and two different populations of Bithynta tentaculata (Michigan, U.S.A. and Bodensee, Germany) were compared in regard to eff-laying characteristics, morphology, chromosome cytology, natural infections of parasites and ecology of habitats. A satisfactory culture method was devised for laboratory rearing of the snails. Tropical fish food (Terra SML) and powdered green leaves (Ceralife) were used as the main food sources for the snails. Benthic diatoms such as Navicula and Gomphonema from the periphyton were also essential for satisfactory growth, especially for the baby snails. The aquaria were stabilized with small stones from a local stream. Young P. manchouricus snails grew to adult size in about 54 days after hatching. They laid eggs 150-156 days after hatching. The whole cycle (birth to egg-laying) took approximately 5 months. The three species of bithyniid snails are iteroparous and lay eggs once a year. There were no major morphological differences in the shells of genera or subgenera studied here. They did exhibit the following rather minor differences. The shell of Parafossarulus has spirally raised ridges, and its apex is usually eroded; the other two genera lack these characteristics. The shell of B. (Gabbia) misella is small, nor exceeding 7.5 mm in length, while the shells of the other two species are larger, being more than 10 mm in length. Scanning electron microscopy (SEM) of the protoconch of P. manchouricus reveals nearly smooth sculpture with small, low, spiral wrinkles. This sculpture is quite different from that of the Hydrobiidae, a family to which the bithyniids are frequently assigned. Scanning electron microscopy of the radulae of the three bithyniid species showed that their radular morphologies are very similar, but there are some small differences, which may be species-specific. There were some statistical differences in shell heights between the Korean and the other populations of P. manchouricus, and between this species and the other two bithyniids as well. The shell differences between the several populations of Korean P. manchouricus may be related to environment. Edtails of the chromosome cycle of these bithyniid snails are similar to those reported for other snails. No specific differences were observed in the chromosome cycle between the various species and populations of snails employed in this study. Reporred for the first time in molluscs are two darkly stained "nucleolar organizers" during pachyterne stages of meiosis. Two different chromosome numbers were observed in the three bithyniid species: n=17 in B. tentaculata and P. manchouricus, and n=18 in B. (G.) misella. no sex chromosomes or supernumerary chromosomes were seen. There were no morphological differences in karyotypes of three Korean strains of P. manchouricus. The infection rates of cercariae of Clonorchis sinensis in Chinju and Kunsan strains of P. manchouricus were 0.14% and 1.25%, respectively. However, Clonorchis cercariae were found in Chongpyung strain of P. manchouriceu and Gongju strain of B. (G.) misella. The habitats of P. manchouricus around Jinyang Lake were relatively clean without any heavy pollution of aquatic microorganisms and organic materials during the period of this study. The levels of dissolved oxygen (D.O.) and biochemical oxygen demand (B.O.D.) of the water specimens sampled from the study areas ranged from 6.0 to 9.6 ppm and from 0.4 to 1.6 ppm, respectively. Eight metalic constituents from the water samples were also assayed, and all metalic ions detercted were remarkably low below the legal criteria. However, calcium ion in the water samples from the habitats of P. manchouricus was considerably higher than others.

• Toxicological Research
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• v.17 no.1
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• pp.1-6
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• 2001

To determine whether ozone is genotoxic at environmentally relevant exposure level, B6C3F1 mice were exposed to 0.5 ppm ozone for 12 weeks, 6 hr/day. Chromosomal aberration, supravital micronucleus and hprt mutation assays were performed. The percentage of abnormal cells was significantly increased at 0.5 ppm ozone when compared to unexposed control in chromosome aberration assay. Significant increase in the frequencies of micro nucleated reticulocytes and 6-thioguanine-resistant ($TG^r$) lymphocytes was also observed in supravital micronucleus assay using peripheral blood and lymphocyte hprt mutation assay, respectively. The results indicate, that under our experimental conditions, 0.5 ppm ozone are genotoxic in exposed B6C3F1 mice.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.599-606
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• 1994

Bacillus stearothermomophilus, a strong xylan degrader, was confirmed to express multiple esterase activities in addition to the major xylanolytic enzymes. One of the genes encoding the esterases was isolated from the genomic library of B. stearothermophilus constructed with EcoRl restriction endonuclease and pBR322 plasmid. Three recombinant plasmids showing the tributyrin degrading activity were selected from approximately 7, 000 E. coli HB101 transformants, and were found to have the same insert of a 3.2 kb DNA fragment. Restriction mapping and hybridization studies revealed that the gene(estII) on the hybrid plasmid (pKMG7) had originated from the B. stearothermophilus chromosome, and was distinct from the estl, another esterase gene of B. stearothermophilus isolated in the previous work. The E. coli cells harboring pKMG7 produced an acetylxylan esterase that exibited similar substrate specificity to the esterase encoded by the estI gene.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2489-2493
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• 2015

Background: Loss of heterozygosity (LOH) on chromosomal regions is crucial in tumor progression and this study aimed to identify genome-wide LOH in pancreatic cancer. Materials and Methods: Single-nucleotide polymorphism (SNP) profiling data GSE32682 of human pancreatic samples snap-frozen during surgery were downloaded from Gene Expression Omnibus database. Genotype console software was used to perform data processing. Candidate genes with LOH were screened based on the genotype calls, SNP loci of LOH and dbSNP database. Gene annotation was performed to identify the functions of candidate genes using NCBI (the National Center for Biotechnology Information) database, followed by Gene Ontology, INTERPRO, PFAM and SMART annotation and UCSC Genome Browser track to the unannotated genes using DAVID (the Database for Annotation, Visualization and Integration Discovery). Results: The candidate genes with LOH identified in this study were MCU, MICU1 and OIT3 on chromosome 10. MCU was found to encode a calcium transporter and MICU1 could encode an essential regulator of mitochondrial $Ca^{2+}$ uptake. OIT3 possibly correlated with calcium binding revealed by the annotation analyses and was regulated by a large number of transcription factors including STAT, SOX9, CREB, NF-kB, PPARG and p53. Conclusions: Global genomic analysis of SNPs identified MICU1, MCU and OIT3 with LOH on chromosome 10, implying involvement of these genes in progression of pancreatic cancer.