• Journal of Plant Biotechnology
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• v.30 no.2
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• pp.115-121
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• 2003

In this study, plant regeneration and Agrobacterium tumefaciens-mediated transformation Kentucky bluegrass(Poa pratensis L.) were evaluated. Three different types of calli were produced depending on the combinations of growth regulators. They were non-friable brown or gray-colored callus (type I), compact, friable and yellow or white-colored callus (typeII), and soft, watery translucent callus with differentiated structure (typeIII). The highest regenerable organogenic callus (typeII) was obtained on the medium containing 1mg/L, 2,4-D and 0.1mg/L BA. Additionally, the production of typeII calli increased significantly when AgNO$_3$ was added to the callus induction and growth medium. The highest frequency of multiple shout formation from typeII callus was obtained on MS medium containing 1mg/L BA and 1mg/L Thidiazuron(TDZ). The organogenic calli(typeII) were inoculated with Agrobacterium tumefaciens strain EHA101 harboring the binary vector pIG121Hm with $\beta$-glucuronidase gene, and various factors were found to influence the transfer-DNA delivery efficiency. The highest transient GUS activity was observed on typeIIcallus. In the present work, we reported the first transient GUS activity of Kentucky bluegrass mediated by Agrobacterium tumefaciens. Our system may contribute to genetic improvement for breed-recalcirtrant grass species, Kentucky bluegrass.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.179-183
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• 2009

To facilitate the genetic manipulation of Cladosporium phlei, a causal agent of leaf spot disease in timothy (Phleum pretense), protoplast-mediated transformation of C. phlei has been developed and the resulting transformants were characterized in this study. Hygromycin B resistance was applied as a dominant selection marker due to the sensitivity of C. phlei to this antibiotic. The transformation efficiency ranged from approximately 20-100 transformants per experiment. Southern blot analysis of stable transformants revealed that transformation occurred by way of stable integration of the vector DNA into the fungal chromosome. PCR analysis and plasmid rescuing of randomly selected transformants suggested that integration of tandem repeat copies of vector DNA was common. In addition, multiple integrations of the transforming vector at different chromosomal sites were also observed. The establishment of a transformation method for C. phlei facilitates strain improvement of this fungus and can be applied as an initial step in the molecular analysis of pigment production in this fungus.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.2
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• pp.159-163
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• 2004

Data pertaining to first lactation records of 316 Murrah buffaloes, progeny of 47 sires, maintained at NDRI Farm for a period of 18 years were analysed to construct selection indices and to examine their robustness by changing the relative economic values of different economic traits. A total of 120 selection indices were constructed for three sets of relative economic values ( 40 for each set) considering different combinations of seven first lactation traits viz. age at first calving (AFC), first lactation 305 day or less milk yield (FLMY), first lactation length (FLL), first calving interval (FCI), milk yield per day of first lactation length (MY/FLL), milk yield per day of first calving interval (MY/FCI) and milk yield per day age at second calving (MY/ASC). The three sets of relative economic values were based on economic values of different traits, 1% standard deviation of different traits and regression of different traits on FLMY. The 'optimum' indices for the first two sets had five traits each namely AFC, FLMY, FLL, FCI and MY/ASC giving improvement in aggregate genotype of Rupees 269.11 and Rs. 174.88, respectively. The accuracy of selection from both indices was 70.79 and 69.39%, respectively. The 'best' selection index from the third set of data again had five traits (AFC, FLMY, FLL, FCI and MY/FLL) giving genetic gain of Rs. 124.16 and accuracy of selection of 71.81%. The critcal levels or break-even points for FLMY for varying levels of AFC and FCI estimated from the "optimum index" suggested the need of enhancement of present production level of the herd or reduction of AFC or FCI. It was concluded that economic values of various first lactation traits were the most appropriate to construct selection indices as compared to other criteria of assigning relative economic weights in Murrah buffaloes.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.123-123
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• 2017

In spite of the potential medicinal significance and a wide range of pharmacologic properties of Platycodon grandiflorum, the molecular mechanism of its roots is still unknown. The present study was conducted to profile proteins from 3, 4 and 5 months aged diploid and tetraploid roots of Platycodon grandiflorum using high throughput proteome approach. Two-dimensional gels stained with CBB, a total of 68 differential expressed proteins were identified from the diploid root out of 767 protein spots using image analysis by Progenesis SameSpot software. Out of total differential expressed spots, 29 differential expressed protein spots (${\geq}2-fold$) were analyzed using LTQ-FTICR MS whereas a total of 24 protein spots were up-regulated and 5 protein spots were down-regulated. On the contrary, in the case of tetraploid root, a total of 86 differential expressed proteins were identified from tetraploid root out of 1033 protein spots of which a total of 39 differential expressed protein spots (${\geq}2-fold$) were analyzed using LTQ-FTICR MS whereas a total of 21 protein spots were up-regulated and a total of 18 protein spots were down-regulated. It was revealed that the identified proteins from the explants were mainly associated with the nucleotide binding, oxidoreductase activity, transferase activity. Taken together, the identified proteins may be helpful to identify key candidate proteins for genetic improvement of plants.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.550-558
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• 2015

To analyze the linkage relationships among molecular markers recently reported to be linked to onion (Allium cepa L.) Ms, a restorer-of-fertility locus, in onion (Allium cepa L.), three single nucleotide polymorphism markers were converted into cleaved amplified polymorphic sequence (CAPS) markers based on onion transcriptome sequences and the rice genome database. Analysis of the recombinants selected from 4,273 segregating plants using CAPS and other linked markers demonstrated the jnurf13 and jnurf610 markers to perfectly co-segregate with the Ms locus. In contrast to jnurf13, the jnurf610 marker was not in perfect linkage disequilibrium with the Ms locus in diverse breeding lines. Thus, the jnurf13 marker and the marker for identification of cytoplasm types were utilized to enhance the efficiency of onion breeding through four applications. First, 89 maintainer lines containing the normal cytoplasm and homozygous recessive Ms genotypes were successfully identified from 100 breeding lines. Second, these two molecular markers were used to analyze the main sources of male-fertile contaminants frequently found in the male-sterile parental lines during F1 hybrid seed production. The majority of the contaminants contained heterozygous Ms genotypes, indicating that pollen grains harboring the dominant Ms genotype may have been introduced during propagation of the maintainer lines. Therefore, the genetic purity of the two maintainer lines was analyzed in the third application, and the results showed that both maintainer lines contained 13-21% off-types. Finally, the two markers were used to increase the seed yield potentials of two open-pollinated varieties containing sterile cytoplasms by removing the plants harboring homozygous recessive and heterozygous Ms genotypes.

• School Mathematics
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• v.8 no.2
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• pp.123-138
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• 2006

The fraction concept consists of various meanings and is one of the more abstract and difficult in elementary school mathematics. This study intends to analyze the fraction concept from historical and psychological viewpoints, to examine the current elementary mathematics textbooks by these viewpoints and to seek the direction for improvement of it. Basic ideas about fraction are the partitioning - the dividing of a quantity into subparts of equal size - and about the part-whole relation. So these ideas are heavily emphasized in current textbooks. However, from the learner's point of view, situations related to different meanings of fraction concept draw qualitatively different response from students. So all the other meanings of fraction concept should be systematically represented in elementary mathematics textbooks. Especially based on historico-genetic principle, the current textbooks need the emphasis on the fraction as a measure and on constructing fraction concept by unit fraction as a unit.

• Korean Journal of Poultry Science
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• v.45 no.2
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• pp.109-118
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• 2018

A great progress in genetic selection, nutrition and management practices has contributed to the improved growth rate of broilers and egg production in laying hens. For the increased productivity of modern poultry, a healthy chicken liver needs to cope with the increased metabolic demands. The liver is the major site of de novo fatty acid synthesis; therefore, hepatic lipogenesis is crucial for producing better quality meat and eggs. When de novo lipogenesis exceeds the capacity of lipid metabolism and secretion, large amounts of lipids accumulate in the liver of broilers, leading to a fatty liver. Upon onset of egg-laying in hens, lipids including free fatty acids, triglycerides, and phospholipids are dramatically increased in blood plasma for the synthesis of yolk precursors in oocytes. Productive hens with fatty liver often have hemorrhagic syndrome and sudden death due to the heavy demands of yolk synthesis, which burdens the liver. Understanding the lipid metabolism and hepatic lipid disorders is a key point in the improvement of the growth and production of chickens. This review focuses on the recent studies on lipid metabolism, the hepatic lipid disorders, and the prevention or reduction of fatty liver in poultry.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.631-639
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• 2009

Ectodermal dysplasia is a genetic disease which shows various congenital dysplasias in tissues differentiated from the ectoderm. As the most common type of the ectodermal dysplasia, hypohidrotic ectodermal dysplasia(HED) shows dysplasia mainly in the hair, fingernails, teeth and the skin. Symptoms are more severe in males than in females and heterozygous females are usually normal showing no symptom. The treatment for these patients differ according to individuals, but since patients can easily become depressed socially and emotionally due to a decrease in mastication and speech function caused by multiple loss of teeth as well as some aesthetic problems, an early treatment is required. In a case, with a 10 years-old boy diagnosed with HED which shows partial edentia of the maxilla, and the edentia of the mandible in the pediatric dentistry department of the Chosun University Dental Hospital, a fabrication of denture resulted in the recovery of mastication and speech function and aesthetic improvement due to an increase of the face height.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.5
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• pp.743-748
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• 2017

Objective: Based on rapid advancement of genetic modification techniques, genomic editing is expected to become the most efficient tool for improvement of economic traits in livestock as well as poultry. In this study, we examined and verified the nickase of mutated CRISPR-associated protein 9 (Cas9) to modulate the specific target gene in chicken DF1 cells. Methods: Chicken myostatin which inhibits muscle cell growth and differentiation during myogenesis was targeted to be deleted and mutated by the Cas9-D10A nickase. After co-transfection of the nickase expression vector with green fluorescent gene (GFP) gene and targeted multiplex guide RNAs (gRNAs), the GFP-positive cells were sorted out by fluorescence-activated cell sorting procedure. Results: Through the genotyping analysis of the knockout cells, the mutant induction efficiency was 100% in the targeted site. Number of the deleted nucleotides ranged from 2 to 39 nucleotide deletion. There was no phenotypic difference between regular cells and knockout cells. However, myostatin protein was not apparently detected in the knockout cells by Western blotting. Additionally, six off-target sites were predicted and analyzed but any non-specific mutation in the off-target sites was not observed. Conclusion: The knockout technical platform with the nickase and multiplex gRNAs can be efficiently and stablely applied to functional genomics study in poultry and finally adapted to generate the knockout poultry for agribio industry.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.6
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• pp.793-798
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• 2006

The quality characteristics of semen are important indicators of the fertility of a boar. Development of genetic markers for the semen quality in boars will be beneficial to the improvement of porcine fertility. We investigated the relationship between the polymorphisms of epidermal growth factor (EGF), prostaglandin-endoperoxide synthase 2 (PTGS2) and prolactin receptor (PRLR) genes, and semen quality traits in boars. The genomic DNA of 233 boars (157 Duroc and 86 Landrace) from a central testing station was subjected to genotyping for surveying gene frequency. The EGF, PTGS2 and PRLR genotypes were determined using the restriction fragment length polymorphism method. Thirty-seven normal, mature Duroc boars from an AI center were also genotyped and their semen quality traits were collected. The effect of genotype on semen quality traits was analyzed by the least-squares means method using data corrected for season. The frequencies of the AA genotype of EGF, PTGS2 and PRLR in Duroc boars were 0.14, 0.01 and 0.66, respectively. In Landrace, the frequencies of the AA genotype were 0.03, 0.09 and 0.62, respectively. Boars with the BB genotype in EGF, with the AB genotype in PTGS2 and with the AA genotype in PRLR had significantly better semen quality with a higher percentage of normal sperm and a lower percentage of immature sperm than those with other genotypes. These findings imply that polymorphisms of EGF, PTGS2 and PRLR genes might be used as markers for improving the semen quality of boars.