Epigenetic regulations including DNA methylation, long noncoding RNAs and histone modification are considered to be involved in many biological processes. Such regulations in general begin with change of covalent bonds on the substrates. Moieties involving the covalent bond include methyl- and acetyl-group, glucose, SUMO and etc. Among them, methyl group-mediated modulation is commonly observed in all three substrates. Mouse primordial germ cells (PGCs) first appear at embryonic day (E)7.25 on the base of the allantois, and then migrate through the hindgut to the genital ridge. Once PGCs reach genital ridge, they become dimorphic, in that female PGCs undergo meiosis whereas male PGCs are mitotically arrested. Meiosis is a germ-cell-specific cell division process through which haploid gametes are produced for sexual reproduction. Before the initiation of meiosis, mouse primordial germ cells undergo a series of epigenetic reprogramming steps including the global erasure of DNA methylation at the 5-position of cytosine (5mC) in CpG-rich DNA. I will discuss role of Ten-to-Eleven translocation (Tet) in DNA demethylation in the process of PGC reprogramming.

Next Generation Small Satellite-1 (NEXTSat-1) is scheduled to launch in 2017 and Instruments for the Study of Space Storm (ISSS) is planned to be onboard the NEXTSat-1. High Energy Particle Detector (HEPD) is one of the equipment comprising ISSS and the main objective of HEPD is to measure the high energy particles streaming into the Earth radiation belt during the event of a space storm, especially, electrons and protons, to obtain the flux information of those particles. For the design of HEPD, the Geometrical Factor was calculated to be 0.05 to be consistent with the targets of measurement and the structure of telescope with field of view of 33.4° was designed using this factor. In order to decide the thickness of the detector sensor and the classification of the detection channels, a simulation was performed using GEANT4. Based on the simulation results, two silicon detectors with 1 mm thickness were selected and the aluminum foil of 0.05 mm is placed right in front of the silicon detectors to shield low energy particles. The detection channels are divided into an electron channel and two proton channels based on the measured LET of the particle. If the measured LET is less than 0.8 MeV, the particle belongs to the electron channel, otherwise it belongs to proton channels. HEPD is installed in the direction of 0°,45°,90° against the along-track of a satellite to enable the efficient measurement of high energy particles. HEPD detects electrons with the energy of 0.1 MeV to several MeV and protons with the energy of more than a few MeV. Thus, the study on the dynamic mechanism of these particles in the Earth radiation belt will be performed.

The Amon-Ra instrument is the main optical payload of the proposed EARTHSHINE satellite. It consists of a visible wavelength instrument and an IR energy channel instrument to measure a global Earth albedo. We report a new sensitivity technique for efficient alignment of the visible channel instrument. Whilst the sensitivity table method has been widely used in the alignment process, the straightforward application of the method tends to produce slow process convergence because of shop floor alignment practice uncertainties. We investigated the error sources commonly associated with alignment practices and used them when estimating the Zernike polynomial coefficients. Aided with single center field wavefront error (WFE) measurements and their corresponding Zernike polynomial coefficients, the method involves the construction and use of an experimental, instead of simulated, sensitivity table to be used for alignment state estimations. A trial alignment experiment for the Amon Ra optical system was performed and the results show that 71.28 nm in rms WFE was achieved only after two alignment iterations. This tends to demonstrate its superior performance to the conventional method.

The communications link in a space program is a crucial point for upgrading its performance by handling data between spacecraft bus and payloads, because spacecraft’s missions are related to the data handling mechanism using communications ports such as a controlled area network bus (CAN Bus) and a universal asynchronous receiver and transmitter (UART). The NEXTSat-1 has a lot of communications ports for performing science and technology missions. However, the top level system requirements for the NEXTSat-1 are mass and volume limitations. Normally, the communications for units shall be conducted by using point to point link which require more mass and volume to interconnect. Thus, our approach for the novel communications link in the NEXTSat-1 program is to use CAN and serializer and deserializer low voltage differential signal (SerDesLVDS) to meet the system requirements of mass and volume. The CAN Bus and SerDesLVDS were confirmed by using already defined communications link for our missions in the NEXTSat-1 program and the analysis results were reported in this study in view of data flow and size analysis.

The first Korean satellite laser ranging (SLR) system, Daedeok SLR station (DAEK station) was developed by Korea Astronomy and Space Science Institute (KASI) in 2012, whose main objectives are space geodesy researches. In consequence, Korea became the 25th country that operates SLR system supplementing the international laser tracking network. The DAEK station is designed to be capable of 2 kHz laser ranging with precision of a few mm both in daytime and nighttime observation of satellites with laser retro-reflector array (LRA) up to the altitude of 25,000 km. In this study, characteristics and specifications of DAEK station are investigated and its data quality is evaluated and compared with International Laser Ranging Service (ILRS) stations in terms of single-shot ranging precision. The analysis results demonstrated that the DAEK station shows good ranging performance to a few mm precision. Currently, the DAEK station is under normal operations at KASI headquarters, however, it will be moved to Sejong city in 2014 to function as a fundamental station for space geodesy researches in combination with other space geodesy systems (GNSS, VLBI, DORIS, etc.).

Legume and rhizobia symbiosis plays an important role in conversion of atmospheric dinitrogen to ammonia. On a global scale, this interaction represents a key entry point for reduced nitrogen into the biosphere, and as a consequence this symbiosis is important in both natural and agricultural systems. Symbiotic development of nodule organ is triggered by chito-oligosaccharide signals (Nod factors) from the bacterium which are perceived by the legume root. Understanding the molecular and cellular processes that underlie Nod factor perception is one focus of legume biology. Although forward genetics has proved to be an important tool to identify key players in Nod factor perception, we still know relatively little regarding the functional networks of genes and proteins that connect the earliest steps of Nod factor perception to immediate downstream outcomes. To elucidate genes and proteins that link Nod factor perception to cellular and physiological responses we are taking a discovery-based strategy based on whole transcriptome profiling using RNA-seq analysis in the roots of Medicago truncatula in response to Sinorhizobium meliloti. Functional characterization of a number of candidate genes is currently in progress to further examine their role in nodulation such as generating transgenic plants

Chrysanthemums (Asteraceae) are important ornamental crops in worldwide that are well known as commercial valuable cultivars for cut flowers, potted plants, and garden flowering plants. Genus chrysanthemum consisted of 41 species that are mostly distributed in East Asia. Chrysanthemum has diverse ploidy levels with the basic chromosome number of x=9 from 2n=2x=18 (diploid) to 2n=10x=90 (decaploid). Fluorescence in situ hybridization (FISH) is a useful tool for studying the distribution of ribosomal DNAs. In this study, we have confirmed ploidy level by chromosome counting method. The somatic metaphase chromosome numbers were observed 2n=2x=18 in Chrysanthemum boreale, and 2n=6x=54 in C. indicum and C. zawadskii. More detailed Karyotype was constructed based on FISH method using 5S and 45S rDNA probes. Two (2) loci of 5S rDNA signals were detected in interstitial region of long arm chromosome in C. boreale and six (6) loci were in C. indicum and C. zawadskii. All of 45S rDNAs were located in terminal region of short arm chromosome which were visualize in six (6) loci in C. boreale and C. indicum and twelve(12) loci in C. zawadskii. In this study, it was the main topic to perform physical mapping of the location of 5S and 45S rDNA. Three of wild chrysanthemum showed variations in number of ribosomal DNAs. In the present investigation will help to further study of genome sequencing project in chrysanthemum.

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. The detailed karyotypes of two onion cultivars, which are resources for onion genome sequencing project (‘Eumginara’ and ‘Sinsunhwang’), were constructed based on triple color fluorescence in situ hybridization (FISH) using 5S rDNA, 45S rDNA, and tandem repeat sequence. All used our materials showed 2n=2x=16 with x=8 as basic chromosome number. 5S rDNAs were located on 4 loci in one pair of interstitial region of short arm chromosome in both onion cultivars. Two pairs of 45S rDNAs were positioned in distal region of short arm chromosome in ‘Eumginara’. Otherwise 5 loci of 45S rDNAs were located in distal region of two pairs of short arm chromosome in ‘Sinsunhwang’. Among them, two signals of 45S rDNAs were co-localized in distal part of short arm and long arm chromosome, respectively. In case of tandem repeat sequence was detected on telomeric region of 8 pairs of chromosomes except on 45S ribosomal DNA sites. These results will provide a valuable background for physical mapping and help to further more understand the genome sequencing project in Allium cepa.

The newly developed varieties, Jayoung (violet flesh color) and Hongyoung (red flesh color) that harboring various anthocyanins and flavonoids in flesh colored potato are highly increase their interesting not only for food but also functional characteristics such as anti-inflammatory effects. Up to date, most of the molecular markers developed in potato are linked to disease resistance including late blight and PVY, nematode. A few markers linked to economically important functional materials such as anthocyanin biosynthesis are published. With the low cost and high throughput of NGS (Next Generation Sequencing) technology, numerous molecular markers are highly increased in may crops. Among the molecular markers, SNPs (Single nucleotide Polymorphisms) are most useful markers owing to their large numbers in inter and intra varieties in potato. Here we reported SNPs discovery from transcriptome sequencing data acquired from colored flesh potato cultivars, Jayoung and Hongyoung with white flesh color Atlantic. Total RNA was isolated from shoot in tuber after breaking dormancy about 2cm length. Short read sequence data were obtained form Illumina Hiseq2000 and the raw dat set were trimmed with Q socore over 20. Sequencing data were align to reference genome (Solanum tuberosum v4.03, http://potatogeomics.plantbiolgy.msu.edu). About 70% of sequence read were mapped int to reference genome. 139,050, 140,976 and 146,429 total SNPs were discovered in Hongyoung, Jayoung and Atlantic, respectively. All SNPs are mapped into the psedomolecules in reference genome by chromosome. SNPs are also analyzed with homozygous and heterozygous SNPs and genic and intergenic region. SNPs are compared with Potato Infinium 8K Chip data. SNPs found in candidate genes of anthocyanin biosynthesis were discovered. These SNPs information of flesh colored potato will be further analyzed for the allele mining for anthocyanin syhthesis and control region

Steroidal glycoalkaloids which serve the plant defense, are toxic secondary metabolites present in the plants of solanaceae family. The upper safe limit of glycoalkaloids for human consumption is 20mg/KG FW, excess of which may cause severe health disorders. Several factors like drought, high temperature, light exposure, and wounding increase tuber glycoalkaloid content. Among these, drought is an important factor which causes a rapid increase in potato glycoalkaloid content. Glycoalkaloid biosynthetic genes and their expression pattern need to be characterized to regulate the glycoalkaloid accumulation. Three key genes SGT1, SGT2 and SGT3 are demonstrated to be directly participated in the biosynthetic pathway for glycoalkaloid formation. Present study was focused on the study of expression pattern of key genes in GA pathway under drought stress in two different potato cultivars Atlantic and Haryoung which are low and high glycoalkaloid accumulating respectively. Drought stress was imposed by withholding water to the plants grown in pots and control plants kept irrigated. Expression analysis of SGT1, SGT2 and SGT3 was done from the leaf and tuber sample of three time intervals i.e 5, 10 and 20 days after imposing stress. Variation in the expression level of genes was observed in leaf and tuber where the fold increase in expression over control was higher in tuber sample compared to leaf. Expression levels also varied in leaf and tuber among two cultivars. However, expression of SGT1, SGT2 and SGT3 is significant indicating the involvement of these genes in glycoalkaloid accumulation under drought stress.

Sorghum (Sorghum bicolor (L.) Moench) has been cultivated for cereal grain which has been traditionally used for steaming with rice in Korea. Various Korean sorghum varieties have been developed and distributed for farmers and consumers to meet their needs. Korean sorghum grains have been mostly sold at higher price in the market than sorghum grains imported from abroad. However, no varietal identification method was established to support fair trade in the cereal market. The objective of this study is to develop the identification method of Korean sorghum varieties using a multiplexed fingerprinting platform of SSR markers. One marker for the waxy allele and nine SSR markers were carefully selected based on their product sizes for the multiplexing. A robust multiplexed combination was revealed from serially designed experiments for the optimization of multiplex PCR. Five varieties and two elite breeding lines could be separated with their unique fingerprinting pattern from other sorghum individuals collected over the world. The platform separated most of individuals tested in this study, remaining three genotypes contained two or three identical individuals. The technique may be applied to detect closely-related individuals including full sibling progeny

The correct development of male gametophytes (pollen grains) in flowering plants is essential for proliferate in gamete production. Here we have taken a map-based cloning approach using Arabidopsis male gametophytic mutant, named gemini pollen3 (gem3) to identify and characterize key gene that is expressed gametophytically for the completion of microgametogenesis focusing on genes which control cell division and cell fate determination. Previously reported gem1 and gem2 mutants with similar characteristics to gem3 that are disturbed at asymmetric division and cytokinesis at pollen mitosis I (PMI) in Arabidopsis. However, gem3 was mapped to a different genetic locus, and pollen developmental analysis revealed that gem3 exert an effect at meiosis and mitosis causing complete sterility. We also discovered that gem3 homozygous lines produce aberrant pollen grains, arising from incomplete cytokinesis during male meiosis with sporophytic phenotypes of twisted-shape leaves, large flowers. This mutation shows reduced genetic transmission of gem3 allele through male gametophyte. In previous results, the gem3 locus was confirmed by mapping to the region located on chromosome 5. To further confirm strong candidate gene, we performed sequencing and genetic complementation analysis. Currently, we are performing functional studies of the gem3 gene for the better understanding of molecular mechanisms that control asymmetric division at meiosis and mitosis during pollen development.

Plastochron and phyllotaxy are important traits to determine plant architecture. A plastochron 1-6 mutant was derived from japonica rice cultivar Koshihikari treated with ethylmethane sulfonate (EMS). The plastochron 1-6 mutant showed reduced plant height, shorter internode length, smaller and more leaves than Koshihikari, its wild type. In addition, the mutant has abnormal panicle, abnormal seed and upper node tillers. The F1 plants between mutant and Koshihikari were normal. In F2 population, segregation ratio between the wild type and mutant was fitted to 3:1. This genetic analysis indicated that plastochron 1-6 is controlled by a single recessive gene. Bulked segregant analysis revealed that the gene was located on chromosome 10. Through sequencing analysis, we found that plastochron 1-6 mutant had a single nucleotide transition occurred in the first exon of LOC_Os10g26340 (encoding P450 CYP78A11). This work was supported by a grant from the Next-Generation BioGreen 21 Program (Plant Molecular Breeding Center No. PJ008125), Rural Development Administration, Republic of Korea.

The aim of the study was to assess the safety of methionine sulfoxide reductase B2(CaMsrB2) protein as toxicity, allergenecity and identity of inserted gene product that transformed rice. Through bioinfomatical research of CaMsrB2, amino acid sequence of CaMsrB2 did not share overall homology with any known or suspected to be allergen or toxin protein. For the biochemical research, CaMsrB2 protein was expressed and purified. Using purified protein, we made a specific antibody. Purified protein was sequenced by Edman degradation methods and confirmed sequence identify.. The amino acid sequences of purified protein were the same as deduced amino acid sequences exclude N-terminal Histidine. And for the internal sequences of CaMsrB2, we performed MALDI-TOF Mass. The results of MALDI-TOF MS was compared Mascot Database and confirmed the sequence coverage was 56%. These results mean bacterially produced CaMsrB2 was the same with inserted gene product. With these purified and identified CaMsrB2 protein, we performed acute toxicity test. Following the OECD guideline 423, 2,000mg/Kg body weight protein were injected as oral administration. After 2 weeks, there did not shown any death and special symptoms.

Genetically modified (GM) crops have never been cultivated commercially in Korea, it is necessary for a thorough assessment of the risks associated with their environmental release. We quantified the amount determined the frequency of pollen mediated gene flow from disease resistant GM rice to weedy rice (R55). A total of 164,604 seeds were collected from weedy rice, which were planted around GM rice. Resistance of the hybrids was determined by repeated spraying of herbicide and DNA analysis using specific primer to confirm hybrids. Though weedy rice has similar flowering time, the hybrids were found only in non-GM rice and out-crossing ranged from 0.018% at 0.3 m to 0.013% at 0.6 m. All of hybrids were located within 0.6 m distance from the GM rice plot in southerly direction. The meteorological factors including temperature and relative humidity during flowering time were found to be the most important factors for determining rice out-crossing. It should be considered many factors like the local weather condition and flowering time to set up the safety management policy to prevent pollen mediated gene flow between GM and conventional crop.

Rice (Oryza sativa) is the most important staple food of over half the world’s population. This study was conducted to evaluate the possible impact of transgenic rice cultivation on the soil microbial community. Microorganisms were isolated from the rhizosphere of GM and non-GM rice cultivation soils. Microbial community was identified based on the culture-dependent and molecular biology methods. The total numbers of bacteria, fungi, and actinomycete in the rhizosphere soils cultivated with GM and non-GM rice were similar to each other, and there was no significant difference between GM and non-GM rice. Dominant bacterial phyla in the rhizosphere soils cultivated with GM and non-GM rice were Actinobacteria, Firmicutes, and Proteobacteria. The microbial communities in GM and non-GM rice cultivated soils were characterized using the denaturing gradient gel electrophoresis (DGGE). The DGGE profiles showed similar patterns, but didn’t show significant difference to each other. DNAs were isolated from soils cultivating GM and non-GM rice and analyzed for persistence of inserted gene in the soil by using PCR. The PCR analysis revealed that there were no amplified protox gene in soil DNA. These data suggest that transgenic rice does not have a significant impact on soil microbial communities, although continued research may be necessary.

Korea is a origin of three basic species, P. ussuriensis, P. pyrifolia and P. fauriei. Genetic relationship among Korean pear cultivars compared with their parents were also identified that they are closely related P. pyrifolia, P. ussuriensis and/or hybrid between two species. SSRs or Microsatellites are co-dominant and typically neutral inheritance showing high degree of polymorphism, large number of alleles per locus, abundance in genomes, and suitability for automation. SSR markers were developed in apple and pear where they were used for construction of genetic linkage maps, evaluation of the genetic diversity, cultivar identification, genotype identification, and in the determination of genetic relatedness. Many apple (Malus × domestica Borkh.) SSRs would be useful for genetic mapping in European and Asian pears in previous experiments and cross-species amplification was observed between apple and pear. The objectives of this study were to develop polymorphic SSR markers in ‘Whangkeumbae’ and ‘Minibae’, which were chosen as the representative cultivars of P. pyrifolia and P. ussuriensis in each among Korean pears, from ‘Golden Delicious’ genomic sequences generated by next generation sequencing technology and to evaluate the utility of the SSR markers based on ‘Golden Delicious’ sequences. Of 51 SSR markers, 18 were polymorphic in ‘Whangkeumbae’ and ‘Minibae’. The cross-species transportability of primers designed in ‘Golden Delicious’ sequences makes SSR markers more useful, given the current high level of investment in mapping the genomes of related Rosaceae.

Currently, the type of short insertions and deletions (InDels) polymorphisms are increasingly focused in genomic research. InDels have been known as a source of genetic markers that are widely spread across the genome. Genetic relationship among Korean pear cultivars compared with their parents was also identified that they are closely related P. pyrifolia, P. ussuriensis and/or hybrids between two species. Lack of genetic resources including molecular markers has made it difficult to study pears severely. Recently developed next generation sequencing (NGS) platforms offer opportunities for high-throughput and inexpensive genome sequencing and rapid marker development. The main goal of this study was to develop polymorphic InDel markers in ‘Whangkeumbae’ and ‘Minibae’, which were chosen as the representative cultivars of P. pyrifolia and P. ussuriensis × pyrifolia in each among Korean pears using genomic sequences generated by NGS technology. In this study, more than 18.6 Gbp and 15.8 Gbp sequences were obtained from NGS of ‘Whangkeumbae’ and ‘Minibae’, respectively. ‘Whangkeumbae’ contained 197,210 InDels and 197,272 InDels in ‘Minibae’. In InDels validations between ‘Whangkeumbae’ and ‘Minibae’, the number of polymorphic InDels were 149,338 and non-polymorphic InDels were 122,572. For InDel primer set designing, 11,308 of primers were designed from polymorphic InDels and 10,919 of InDel primers were recommended. The study shows that the utility of NGS technology to design amount of efficient InDels and the developed InDel primers will be used for genetic mapping, breeding by marker assisted selection (MAS) and QTL mapping of Korea native pear as well as further genetic studies.

Single nucleotide polymorphisms (SNPs) are the most frequent type among variations found in genomic regions and are valuable markers for genetic mapping, genetic diversity studies and association mapping in plants. There are three basic species known as Korean native which are Pyrus ussuriensis, P. pyrifolia, and P. fauriei. Genetic relationship among Korean pear cultivars compared with their parents was identified that they are closely related P. pyrifolia, P. ussuriensis and/or hybrids between two species. Lack of genetic resources, including molecular markers to study pears are very severe. Recently developed next generation sequencing (NGS) platforms offer opportunities for high-throughput and inexpensive genome sequencing and rapid marker development. The objective of this study was to develop polymorphic SNP markers in ‘Whangkeumbae’ and ‘Minibae’, which were chosen as the representative cultivars of P. pyrifolia and P. ussuriensis × pyrifolia in each among Korean pears, using genomic sequences generated by NGS technology. In this study, more than 18.6 Gbp and 15.8 Gbp sequences were obtained from NGS of ‘Whangkeumbae’ and ‘Minibae’, respectively. ‘Whangkeumbae’ and ‘Minibae’ contained 2,712,288 and 2,747,224 SNPs, respectively. In SNPs validations between ‘Whangkeumbae’ and ‘Minibae’, the number of polymorphic SNPs were 2,516,438 and non-polymorphic SNPs were 1,179,391. For HRM primer design, 2,125,479 HRM candidate primers were obtained from polymorphic SNPs and 343,731 SNP primers were developed. This study shows that the utility of NGS technology to discover efficiently a large number of SNPs and SNP primers can provide valuable information in the genome study of Pyrus spp.

Genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by various agricultural biotechnology companies. Commercialization of GM crops will be required the assessment of risk associated with the release of GM crops. The purpose of this research is a molecular characterization of introduced T-DNA in transgenic rice T4 ∼ T6 generation lines harboring a pepper MsrB2 gene under the control of stress inducible Rab21 promoter, as a part of biosafety evaluation for drought-tolerant transgenic rice (Agb0103). We identified the structure and sequence of transformation vector of T-DNA and analyzed insertion sites, flanking sequences, and generational stability of inserted T-DNA in transgenic rice lines. The transformation vector was consisted of right border, a drought-tolerant CaMsrB2 gene unit (Rab21 promoter::CaMsrB2::PinII terminator), a selectable marker herbicide resistance unit (CaMV 35S promoter::bar::Nos terminator), and left border in sequential order. Based on the adaptor-ligation PCR and whole genome sequence database, we confirmed that T-DNA was introduced 2 copies (head to head type) at the position of 2,471,957 ∼ 2,472,049 bp of chromosome No. 8. From the generational stability study, T-DNAs were stably inherited through the T4 to T6 generations, and also stable expression of bar gene from T-DNA was confirmed. It was also confirmed that the backbone DNA of transformation vector containing antibacterial gene (aadA) was not present in Agb0103 rice genome. These results will be filed to biosafety assessment document of Agb0103