• Animal Systematics, Evolution and Diversity
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• v.32 no.2
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• pp.105-111
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• 2016

The genetic structure of marine animals that inhabit the seashore is affected by numerous factors. Of these, gene flow and natural selection during recruitment have strong influences on the genetic structure of seashore-dwelling species that have larval periods. Relative contributions of these two factors to the genetic structure of marine species would be determined mainly by the duration of larval stage. The relationship between larval period and genetic structure of population has been rarely studied in Korea. In this study, genetic variations of cytochrome oxidase subunit I (COI) were analyzed in two dominant species on rocky shore habitats in the Korean peninsula: periwinkle Littorina brevicula and acorn barnacle Fistulobalanus albicostatus. Both species are not strongly structured and may have experienced recent population expansion. Unlike periwinkle, however, barnacle populations have considerable genetic variation, and show a bimodal pattern of mismatch distribution. These results suggest that barnacle populations are more affected by local adaptation rather than gene flow via larval migration. The bimodal patterns of barnacle populations observed in mismatch distribution plots imply that they may have experienced secondary contact. Further studies on seashore-dwelling species are expected to be useful in understanding the evolution of the coastal ecosystem around Korean waters.

• Journal of Plant Biology
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• v.38 no.1
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• pp.39-45
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• 1995

Glycine soja Sieb. et Zucc., a predominantly selfing annual, has been served as a reservoir of germplasm for soybean, G. max (L.) Merr., cultivar improvement. This study describes the levels and distribution of genetic variation within and among 22 Korean populations of G. soja using starch gel electrophoresis. The species maintains very similar levels of genetic variability within populations observed in most other annuals. At the population level, the mean percent of polymorphic loci (P) was 32.6%, mean number of allele per locus (A) was 1.32, and mean expected heterozygosity (He) was 0.112. In addition, total genetic diversity (HT) calculated only for polymorphic loci was 0.347. However, significant differences in allele frequencies among populations were found for all loci (P<0.001 in each case) and, on average, about 70% of the total variation in the species is common to all populations. Indirects estimate of the number of migrants per generation (Nm=0.58, calculated from mean GST) indicates that gene flow is low among Korean populations of the species. In addition, analysis of fixation indices revealed a substantial heterozygote deficiency in most populations and at all loci. This indicates that most populations sampled may have been substructed largely due to inbreeding (predominantly selfing) and restricted gene flow, coupled with founder effect and genetic drift. Considering a high genetic divergence among populations, it is recommended that several Korean populations of the species should be preserved, especially such as populations in the eastern and southeastern Korean peninsula with high variation.

• Journal of Species Research
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• v.1 no.2
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• pp.224-231
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• 2012

To assess the genetic diversity of Aconitum coreanum (Ranunculaceae) populations in Korea, we have amplified and sequenced eight organellar marker regions, and developed and analyzed microsatellite markers. No sequence variation was detected from the eight organellar markers. Ten microsatellites were developed using Next Generation Sequencing and two microsatellite markers, AK_CA03 and AK_CT07, were identified polymorphic and applied for 143 individuals of twelve A. coreanum populations. Four and five alleles were detected for the two microsatellite loci, respectively, and number of migrants ($N_m$) was estimated as 1.12586. Two microsatellite marker loci showed $F_{ST}$ of 0.205 and 0.275, respectively. The heterozygosity deficit, low level of among-population differentiation, small size of gene flow, and lack of sequence variation of the organellar markers suggest that A. coreanum is reproductively isolated from other Aconitum species and there has been continuous gene flow among the populations of A. coreanum or it has dispersed relatively recently after speciation. Though population pairwise $F_{ST}$'s presented significant geographic structure, further sampling and study will be necessary to confirm this.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.531-538
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• 2009

We used enzyme electrophoresis to evaluate genetic diversity in five populations of endemic ash, Fraxinus chiisanensis in Korea. Of 15 putative allozyme loci examined 26.7% were polymorphic and expected heterozygosity for the species was low (0.082). Within the range, population were highly differentiated ($F_{ST}$=0.356) and little genetic variation was explained by geography. The pattern of distribution of variation showed low genetic variation within populations and pronounced divergence among populations, which was consistent with the prediction for the effects of limited gene flow and local genetic erosion. Although the frequencies of male plants were dominant ranging from 79.3% to 89.4%, most mating events seems to be inevitable mating between relatives in small populations based on heterozygote deficiency of this species. Small effective population size and the limited dispersal contributed to the low rates of gene flow within as well as between populations.

• Animal cells and systems
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• v.4 no.1
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• pp.39-44
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• 2000

To assess the genetic diversity and population structure of Korean K. borealis, allozyme analysis was performed. The average genetic variability of Korean K. borealis populations was %P=13.2, Ho=0.048, and He=0.045. This value was the lowest in comparison with other Korean amphibian species studied. Also, the value was much lower than that of a reference population from Chinese K. borealis (%P=50, Ho=0.125, He=0.172). Wright's F-statistics showed that Korean K. borealis has distinctly low level of gene flow among regional populations (F$_{ST}$=0.339, Nm=0.487) in comparison with other Korean amphibian species studied. However, the average level of genetic divergence among Korean K. borealis populations was moderate (Nei's D=0.020). Therefore, it appeared that low levels of genetic diversity (He=0.045) and gene flow (Nm=0.487) among regional populations ave probably due to the results of decreasing population size and patchy distribution of this species in Korea.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.12
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• pp.6517-6521
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• 2012

To analyze the growth, proliferation, apoptosis, invasiveness and chemotherapy sensitivity of EC9706 cells after K-Ras gene silencing, an expression carrier pSilencer-siK-Ras was constructed, and the EC9706 cell line was transfected using a liposome technique. Six groups were established: Control, siRNA NC (transfected with empty vector pSilencer2.1); Ras siRNA (transfected with pSilencer-siK-Ras2); Paclitaxel; Paclitaxel + siRNA NC; and Ras siRNA + Paclitaxel. After the treatment, RT-PCR, Western blotting, MTT assay, flow cytometry and the Transwell technique were used to assess expression of K-Ras mRNA and protein in EC9706 cells, as well as cell growth, proliferation, apoptosis and invasiveness. The effect of Paclitaxel chemotherapy was also tested. pSilencer-siK-Ras2 effectively down-regulated expression of K-Ras mRNA and protein in EC9706 cells, growth being significantly inhibited. Flow cytometry indicated obvious apoptosis of cells in the experimental group, with arrest in the G1 phase; cell migration ability was also reduced. After pSilencer-siK-Ras2 transfection or the addition of Paclitaxel, EC9706 cells were suppressed to different extents; the suppressive effect was strengthened by combined treatment. The results suggested that RNAi-induced K-Ras gene silencing could enhance chemotherapy sensitivity of esophageal cancer.

• The Journal of Korean Obstetrics and Gynecology
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• v.18 no.1
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• pp.181-191
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• 2005

Purpose : ${\beta}$-sitosterol is kind of phytosterols or plant which are structurally similar to cholesterol. This study was aimed to investigate the inhibitory effect of the ${\beta}$-sitosterol on the proliferation of human uterine leiomyoma cells and the expression of gene related the mechanism of cell apoptosis. Methods : We counted the number of death cells treated with indicated time of the ${\beta}$-sitosterol and investigated cell death rate by cell count assay. Furthermore, flow cytometry analysis and DNA fragmentation assay were used to dissect between necrosis and apoptosis. and then we observed the differential gene expression by western blot analysis. Results : 1) The inhibitory effect on the growth of uterine leiomyoma cell treated with the ${\beta}$-sitosterol $16{\mu}M$ was increased in a time dependent. 2) The result of flow cytometry analysis, subG1 phase arrest related cell apoptosis was investigated 16.97% in uterine leiomyoma cell treated with the ${\beta}$-sitosterol $16{\mu}M$ and showed the fashion of proportional time dependent. 3) The gene expression of p27, p21 related cell cycle was increased according to increasing time interval but cyclin E-CDK2 complex was decreased expression. 4) The character of apoptosis, DNA fragmentation was significantly observed on the time dependent. 5) The expression of pro-caspase 3 and PARP were decreased dependent on treatment with time dependent. Conclusion : This study showed that the ${\beta}$-sitosterol have the inhibitory effect on the proliferation of human uterine leiomyoma cell and the effect was related with apoptosis.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.214-214
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• 2022

Soluble starch synthases (SSs) elongate α-glucans from ADP-Glc to the glucan nonreducing ends and play a critical role in synthesizing resistant starch in the rice. A total of 10 SSs isoforms were reported in rice, including granules-bound starch synthase I (GBSSI), GBSSII, starch synthase I (SSI), SSIIa (SSII-3), SSIIb (SSII-2), SSIIc (SSII-1), SSIIIa (SSIII-2), SSIIIb (SSIII-1), SSIVa (SSIV-1), and SSIVb (SSIV-2). SSIII proteins are involved in forming the B chain and elongating cluster filling chains in amylopectin metabolism. The functions of SSIIIb (SSIII-1) are less clear as compared to SSs. Here, we sought to shed light on the genetic diversity profiling of the SSIII-1 gene in 374 rice accessions composed of 54 wild-type accessions and 320 bred cultivars (temperate japonica, indica, tropical japonica, aus, aromatic, and admixture). In total, 17 haplotypes were identified in the SSIII-1 coding region of 320 bred cultivars, while 44 haplotypes were detected from 54 wild-type accessions. The genetic diversity indices revealed the most negative Tajima's D value in the temperate-japonica, followed by the wild type, while Tajima's D values in other ecotypes were positive, indicating balancing selection. Nucleotide diversity in the SSIII-1 region was highest in the wild group (0.0047) while lowest in temperate-japonica. Lower nucleotide diversity in the temperate-japonica is evidenced by the negative Tajima's D and suggested purifying selection. The fixation index (F_ST) revealed a very high level of gene flow (low F_ST) between the tropical-japonica and admixture groups (F_ST=-0.21) followed by admixture and wild groups (-0.04), indica and admixture groups (0.02), while low gene flow with higher F_ST estimates between the temperate-japonica and aus groups (0.72), tropical-japonica and aromatic groups (0.71), and temperate-japonica and admixture groups (0.52). Taken together, our study offers insights into haplotype diversity and evolutionary fingerprints of SSIII-1. It provides genomic information to increase the resistant starch content of cooked rice.

• Journal of KIISE:Computing Practices and Letters
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• v.15 no.4
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• pp.284-288
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• 2009

With explosively growing PPI databases, the computational approach for a prediction and configuration of PPI network has been a big stream in the bioinformatics area. Recent researches gradually consider physicochemical properties of proteins and support high resolution results with integration of experimental results. With regard to current research trend, it is very close future to complete a PPI network configuration of each organism. However, direct applying the PPI network to real field is complicated problem because PPI network is only a set of co-expressive proteins or gene products, and its network link means simple physical binding rather than in-depth knowledge of biological process. In this paper, we suggest a protein functional flow model which is a directed network based on a protein functions' relation of signaling transduction pathway. The vertex of the suggested model is a molecular function annotated by gene ontology, and the relations among the vertex are considered as edges. Thus, it is easy to trace a specific function's transition, and it can be a constraint to extract a meaningful sub-path from whole PPI network. To evaluate the model, 11 functional flow models of Homo sapiens were built from KEGG, and Cronbach's alpha values were measured (alpha=0.67). Among 1023 functional flows, 765 functional flows showed 0.6 or higher alpha values.

• Reproductive and Developmental Biology
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• v.32 no.1
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• pp.9-14
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• 2008

Efficient gene transfer into hematopoietic stem cells is a great tool for gene therapy of hematopoietic disease. Retrovirus have been extensively used for gene delivery and gene therapy. However, current in vitro gene transfer has some obstacles suck as induction of differentiation loss of self-renewal capacity, and down-regulation of homing efficiency for in vitro hematopoietic stem cells transplantation. To overcome these problems, we developed efficient in vitro retroviral transfer technique by direct intra-bone marrow injection (IBM). We identified effective retrovirus gene transfer in bone marrow hematopoietic cells in vitro. Two weeks after retrovirus transfer via IBM injection, we observed stable EGFP gene expression in bone marrow, lymph node, spleen, and liver cells. In addition, $6.4{\pm}2.7%$ of hematopoietic stem/progenitor cells were expressed EGFP transgene from flow cytometry analysis. Our results demonstrate that in vitro retrovirus gene transfer via IBM injection can provide a viable alternative to current or moo gene transfer approach.