• Journal of Life Science
• /
• v.19 no.4
• /
• pp.449-456
• /
• 2009

Murine Neuro-2a (N2a) cells have been widely used for the investigation of neuronal differentiation, trophic interaction and neurotoxic effects of various compounds and their associated mechanisms. N2a cells have many genomic variations such as gains or losses in DNA copy number, similar to other neuroblastoma cells, and no systematic or high-resolution studies of their genome-wide chromosomal aberrations have been reported. Presently, we conducted a systematic genome-wide determination of chromosomal aberrations in N2a cells using a high-throughput, oligonucleotide array-based comparative genomic hybridization (oaCGH) technique. A hidden Markov Model was employed to assign each genomic oligonucleotide to a DNA copy number state: double loss, single loss, normal, gain, double gain and amplification. Unlike most neuroblastoma cells, Mycn amplification was not observed in N2a cells. In addition, these cells showed gain only in the neuron-derived neurotrophic factor (NF), while other neurotrophic factors such as glial line-derived NF and brain-derived NF presented normal copy numbers. Chromosomes 4, 8, 10, 11 and 15 displayed more than 1000 aberrational oligonucleotides, while chromosomes 3, 17, 18 and 19 displayed less than 20. The largest region of gain was located on chromosome 8 and its size was no less than 26.7 Mb (Chr8:8427841-35162415), while chromosome 4 had the longest region of single deletion, with a size of 15.1 Mb (Chr4:73265785-88374165).

• Microbiology and Biotechnology Letters
• /
• v.37 no.2
• /
• pp.140-146
• /
• 2009

Cyclosporin, an immunosuppressant, is a representative group of biologically active secondary metabolites produced by the fungus Tolypocladium inflatum. The amount and ratio of cyclosporin derivatives in the culture broth are an important factors for the production of cyclosporin A and the purification in the industrial process. Therefore, we studied the effect of amino acids and complex organic nitrogen sources using Tolypocladium inflatum mutants on the productivity of cyclosporin A and the ratio of cyclosporin derivatives. Overproducing mutant YHC-004 having seven times higher productivity than mother strain's could be obtained through the artificial mutation by UV irradiation. The concentration and kind of organic nitrogens and amino acids shows the profound effect on the productivity of cyclosporin A and ratio of cyclosporin derivatives. As a result, it was possible to raise the productivity and the ratio of cyclosporin A up to 3,430 mg/L and 93% respectively, but on the other hand the other cyclosporin derivatives decreased less than 2% in the culture broth.

• Journal of Korean Society of Forest Science
• /
• v.104 no.4
• /
• pp.543-548
• /
• 2015

We studied the genetic impact of natural regeneration practices, such as Single seed tree, Group seed tree, Patch clear cutting and Alternate strip clear cutting systems, by comparing the nuclear microsatellite(nSSR) variation of post-practice natural regeneration one-year old seedlings of Pinus densiflora to that of pre-practice mature trees. The levels of genetic diversity of seedlings (A=13.6, $A_e$=4.3, $H_o$=0.571, $H_e$=0.597) were similar to those of mature trees (A=13.4, $A_e$=4.3, $H_o$=0.596, $H_e$=0.598) and the differences in the level of genetic diversity between seedlings and mature trees for each of the practices were not statistically significant. The degree of genetic differentiation between seedlings and mature trees was very low ($F_{ST}$=0.002) and the pairwise $F_{ST}$ values between seedlings and mature trees for all practices were less than 0.01. Overall, the natural regeneration practices appeared to have only minor impacts on the genetic diversity and the genetic composition in the studied P. densiflora stands. For a better understanding of the genetic effects of natural regeneration practices, subsequent studies such as temporal genetic variation of seedlings formed by crossing among post-practice mature trees should be considered.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.4
• /
• pp.440-448
• /
• 1989

The present experiment was conducted to investigate the effects of seeding date on agronomic characters including seed weight of soybean (Glycine max (L.) Merr.) at Sunchon, the southern coastal area of Korea. One hundred eighteen native and improved varieties were used in this study. As the seeding date was delayed, the number of days to flowering for the cultivars was reduced. This trend was more obvious in late maturing cultivars(LMC) than in early and medium maturing cultivars (EMC and MMC). Late seeding also resulted in decrease in the number of leaves, stem length, and number of nodes. The heaviest seed weight was obtained with EMC and MMC planted on May, and seed weight decreased with delayed seeding date. Seed weight was positively correlated with number of days to flowering, number of total leaves at flowering, stem length and number of nodes on main stem at maturity. Based on seed weight the cultivars was classified into five types: Type I; Seed weight of the cultivars decreases with delayed seeding date. Type II; Seed weight of the cultivars does not vary with seeding date. Tyep III; Seed weight of the cultivars increases with delayed seeding date. Type IV; Seed weight of the cultivars increases when the seeding date approached the appropriate seeding date, but decreases thereafter. Type V; The reversed type IV. Type I, II, III, IV and V occupied 37, 16, 17, 10 and 20％ of the tested cultivars, respectively.

• Clinical and Experimental Pediatrics
• /
• v.48 no.8
• /
• pp.877-880
• /
• 2005

Purpose : Glycogen storage disease type Ia(GSD Ia) is an autosomal recessive disorder caused by the deficiency of glucose-6-phosphatase(G6Pase). The aim of the study was to investigate the spectrum of G6Pase gene mutations and relationship between genotype and clinical findings in Korean patients with GSD Ia. Methods : Genomic DNA was extracted from peripheral leukocytes of 20 patients with GSD Ia. The five exons of G6Pase gene were amplified and PCR products were directly sequenced. The frequency of short stature, hypoglycemia, hypercholesterolemia, hyperuricemia, hypercalciuria, nephrocalcinosis and hepatic adenoma was compared between 727G>T homozygotes and 727G>T compound heterozygotes. Results : A total of 5 different mutations were identified. The most common mutation was the 727G>T with an allele frequency of 80%. All patients were either homozygous(12/20) or heterozygous(8/20) for the 727G>T mutation. G122D was found in 3 patients, P178A in 1, G222R in 2, and S339R in 2. There was no difference in the frequency of short stature, hypoglycemia, hypercholesterolemia, hyperuricemia, nephrocalcinosis, and hepatic adenoma between 727G>T homozygotes and heterozygotes. Conclusion : Diagnosis of GSD Ia can be based on clinical and biochemical abnormalities combined with mutation analysis instead of enzymatic diagnosis that requires liver biopsy. Homozygosity for the 727G>T does not seem to alter the disease phenotype as compared with the heterozygous state.

• Korean Journal of Plant Taxonomy
• /
• v.42 no.4
• /
• pp.253-259
• /
• 2012

The genetic variation in populations of Eranthis byunsanensis, an endemic and rare species of Korea, was studied using starch gel electrophoresis. All five known populations were sampled for allozyme electrophoresis of nine enzymes coded by 10 loci. The overall genetic variation of E. byunsanensis population was shown to be considerably high within the populations (A = 2.4, P = 90.0, $H_E$ = 0.311). A positive $F_{IS}$ value of E. byunsanensis indicated an overall deficiency of heterozygotes, and a low $F_{ST}$ value (0.131) showed little differentiation among populations. The high genetic variation, less genetic differentiation among populations, and a significant amount of heterozygote deficiency propose the hypothesis that they have an experience of recent isolation and fragmentation of their habitat. Thus, the rate of gene flow has been drastically reduced, and the rate of inbreeding in E. byunsanensis populations has increased. Current habitats in Mai-san and Naro-do are vulnerable due to their small population size and the levels of anthropogenic activity in the region constantly threatening survival of this species. Because of the high genetic variation and low levels of differentiation among populations in E. byunsanensis, it is not issue which populations have a priority for protection, but we may concern the plan to maintain population continuously and diminish the rate of inbreeding.

• Korean Journal of Plant Resources
• /
• v.18 no.3
• /
• pp.359-366
• /
• 2005

Effects of neutron beam irradiation on seed germination, growth and RAPD pattern of tobacco (Nicotiana tabacum L. cv.; N. plumbaginifolia) and rice (Orya sativa L. cv.) plants were estimated. Seed germination rate was not significantly changed by the neutron beam treatment in both tobacco and rice seeds. And there was no significant differance in growth of the plants by the neutron beam treatment. Interestingly, however, some of morphological changes, including leaf shape (about $36\%$), stem color and leaf color were observed in neutron beam treated tobacco plants. In addition, abnormal flower in petal was observed in the neutron beam treated plant. This results indicate that neutron beam is able to use as an effective mutagen in plant mutations. Scorable products from 20 primers were obtained by RAPD analysis in the leaves of the beam irradiated tobacco plants and most of the plants showed the similar band patterns.

• Korean Journal of Environment and Ecology
• /
• v.25 no.3
• /
• pp.295-301
• /
• 2011

In order to investigate the geographical variation of Glycine max distributed in southern area of Korean peninsula, 19 local strains(Goseng, Pyeongchang, Ganghwa, Pocheon, Geumsan, Seocheon, Jincheon, Danyang, Tongyeong, Sancheong, Gumneung, Wolseong, Woolneung, Wando, Naju, Gochang, Jangsu, Jeju, Bukjeju), which located from $33^{\circ}15'N$ to $38^{\circ}11'N$, were selected according to their latitudes and geographical distances. The seeds of these strains were collected and their contents of mannose and galactose were investigated. Mannose contents in the seeds were variable in the range between the highest 12.207mg/g(Gochang) and the lowest 6.648mg/g(Geumsan). The contents of galactose were represented remarkable differences from 9.967mg/g(Danyang) to 16.949mg/g(Bukjeju) also. The local strains were classified into 4 variation types such as the inland type I(Wolseong, Jangsu, Danyang), the coastal type I(Gochang, Naju, Jeju, Goseng, Woolneung, Bukjeju, Ganghwa, Seocheon, Tongyeong), the inland type II(Geumsan, Pocheon, Pyeongchang) and the coastal type II(Wando, Jincheon) and 2 strange strains(Gumneung, Sancheong) according to the geographical climatic type and the ratio of mannose/galactose, which indicate the hardness of seeds in Leguminosae, ranged from 0.63 to 0.78. The variation types are very significant genecologically as an evidence for microevolution related to speciation in cultivated plants.

• Journal of Life Science
• /
• v.17 no.6 s.86
• /
• pp.783-790
• /
• 2007

G protein coupled receptors (GPCRs) transmit various extracellular signals into the cells. Upon binding of the ligands, conformational changes in the extracellular and/or transmembrane (TM) domains of CPCRs were propagated into the cytoplasmic (CP) domain of the molecule leading to the activation of their cognate heterotrimeric C proteins and kinases. Constitutively active GPCR mutants causing the activation of C Protein signaling even in the absence of ligand binding are of interest for the study of activation mechanism of GPCRs. Two classes of constitutively active mutations, categorized by their effects on the salt bridge between Ell3 and K296, were found in the TM domain of rhodopsin. Opsin mutants containing combinations of the mutations were constructed to study the conformational changes required for the activation of rhodopsin. Rhodopsin chromophore regenerated with 11-cis-retinal showed a thermal stability inversely correlated with its constitutive activity. In contrast, rhodopsin mutants exhibited a binding affinity to an agonist, all-trans-retinal, in a constitutive activity-dependent manner. In order to test whether the conformational changes responsible for the activation of trans-ducin (Gt) are the same as the conformation required for the recognition of rhodopsin kinase, analysis of the mutants were carried out with phosphorylation by rhodopsin kinase. Rhodopsin mutants containing combinations of different classes of the mutations showed a strong synergistic effect on the phosphorylation of the mutants in the dark as similar to that of Gt activation. The results suggest that at least two or three kinds of segmental and independent conformational changes are required for the activation of rhodopsin and the conformational changes responsible for activating rhodopsin kinase and Gt are similar to each other.

• Journal of Chest Surgery
• /
• v.31 no.11
• /
• pp.1106-1109
• /
• 1998

Primary malignant melanoma of the esophagus(PMME) is an uncommon neoplasm. And the world literature reports only about 200 cases. A case of primary malignant melanoma of the esophagus is presented, and followed by review of the literature. In our patient, the walnut-sized melanoma was located at the midportion of esophagus and there were two small satellite lesions at the esophagogastric junction. The main mass was diagnosed as primary malignant melanoma histologically and immunohistologically. The tumor was curatively resected by the transthoracic subtotal esophagectomy and the 2 fields node dissection. Post- operative immunotherapy was performed but the tumor recurred 7 months later at the stomach.