• The Plant Pathology Journal
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• v.17 no.2
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• pp.67-70
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• 2001

Medicago truncatula is a diploid legume plant related to the forage crop alfalfa. Recently, it has been chosen as a model species for genomic studies due to its small genome, self-fertility, short generation time, and high transformation efficiency. M. truncatula engages in symbiosis with nitrogen-fixing soil bacterium Rhizobium meliloti. M. truncatula mutants that are defective in nodulation and developmental processes have been generated. Some of these mutants exhibited altered phenotypes in symbiotic responses such as root hair deformation, expression of nodulin genes, and calcium spiking. Thus, the genes controlling these traits are likely to encode functions that are required for Nod-factor signal transduction pathways. To facilitate genome analysis and map-based cloning of symbiotic genes, a bacterial artificial chromosome library was constructed. An efficient polymerase chain reaction-based screening of the library was devised to fasten physical mapping of specific genomic regions. As a genomics approach, comparative mapping revealed high levels of macro- and microsynteny between M. truncatula and other legume genomes. Expressed sequence tags and microarray profiles reflecting the genetic and biochemical events associated with the development and environmental interactions of M. truncatula are assembled in the databases. Together, these genomics programs will help enrich our understanding of the legume biology.

• Journal of Korean Society of Forest Science
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• v.51 no.1
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• pp.1-21
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• 1981

Populus glandulosa and Populus tomentiglandulosa, which were known to be natural hybrids, were examined for morphological, physiological and karyological traits to illucidate its hybridity and taxonomical importance. The results abtained were as follows; 1. Survival rate in rooting of cuttings and grafting was different between the hybrids and their rooting abilities showed incomplete dominance. 2. Their leaf openings showed incomplete dominance. The leaf longevities of P. alba ${\times}$ glandulosa and P. tomentiglandulosa were stronger than the other hybrids. 3. There were differences in resistance to toxicity of $KClO_3$ between the hybrids. 4. Many external leaf characters of the hybrids also showed incomplete dominance. P. tomentiglandulosa was similar in those characters to P. alba ${\times}$ glandulosa while P. glandulosa was similar to hybrids crossed, reciprocally crossed or back-crossed between P. davidiana and P. alba. 5. Their numbers of male flower showed incomplete dominance or hybrid vigor. The numbers of P. tomentiglandulosa were similar to thosa of P. alba ${\times}$ glandulosa while those of P. glandulosa to those of P. alba ${\times}$ davidiana or P. davidiana ${\times}$ alba. 6. Morphology and band color of male catkin bract showed incomplete dominance. Those of P. glandulosa were similar to those of P. alba ${\times}$ davidiana while those of P. tomentiglandulosa to those of. P. alba ${\times}$ glandulosa. 7. There were differences in vascular bundle number and arrangement of petiole between the hybrids. 8. Differences in the anatomical traits of stem did not exist between the hybrids but those in wood fiber size existed. 9. The chromosomes of artificial hybrids, P. glandulosa and P. tomentiglandulosa showed irregular behavior in metaphase I and II. 10. All hybrids including P. glandulosa and P. tomentiglandulosa showed small number of P.M.C. with 19 II but many univalent chromosomes were exhibited in metaphase I. 11. All hybrids including P. glandulosa and P. tomentiglandulosa showed a little abnormal nuclear plates as laggard chromosome and chromosome bridge in anaphase I and II. 12. The frequency of pollen tetrad and fertile pollen was low in most of the hybrids including P. glandulosa and P. tomentiglandulosa.

• Journal of Life Science
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• v.26 no.1
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• pp.1-7
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• 2016

Fatness is one of the most important economic traits in pigs. The leptin receptor (LEPR) gene may be a potential candidate for the fatness quantitative trait locus (QTL) on porcine chromosome 6, due to its position and physiological role. Thus, this study was carried out to evaluate the associations between structural variants in the LEPR gene and economic traits in pigs. We obtained an approximately 114-kb sequence containing the complete genomic DNA of the porcine LEPR gene, using shotgun sequencing of a bacterial artificial chromosome clone. We report the complete genomic structure of the porcine LEPR gene. Dozens of transcription factor-binding sites were found in the 1.2 kb upstream region from the transcription start point. An association study was performed with 550 Duroc pigs for 24 single-nucleotide polymorphisms (SNPs), including 6 SNPs within exons and 18 SNPs within the putative 5‘ regulatory region of the porcine LEPR gene. Among them, one SNP (−790C/G) was significantly associated with backfat thickness and lean meat percentage, whereas the others, including two SNPs with missense polymorphisms, had no effect on any phenotype. These results suggest that SNP −790C/G may be a useful marker for genetic improvements of fatness and leanness in Duroc pigs.

• Journal of Life Science
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• v.20 no.11
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• pp.1634-1639
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• 2010

This study was conducted to increase the efficiency of farming practice in rainbow trout, Oncorhynchus mykiss, by sex reversal and chromosome-set manipulation techniques. To obtain phenotypic males, hormonal sex reversal was carried out using an exogenous hormone treatment method. 5 mg of 17 alpha-methyltestosterone per kg diet was supplied for 82 days after first feeding at $10^{\circ}C$ and $13^{\circ}C$. More than 93% of the male population was produced by this method and growth of hormone-treated fish at $13^{\circ}C$ was faster than that of untreated bi-sexual groups. Induced diploid gynogenesis was carried out using artificial insemination of UV-irradiated sperm into haploid eggs. Based on the appearance of the rate of haploid syndrome and survival of embryo, a UV ray dose of at least $3,600\;erg/cm^2$ was required to inactivate rainbow trout sperm genetically. Haploid embryos were restored to diploid by blocking the extrusion of the second polar body using heat shock treatment at $28^{\circ}C$ for 20 min, 10 min post insemination. Gynogenetic diploid sex ratios were confirmed after maturation of the fish erythrocyte measurements and chromosome counts.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.128-134
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• 2003

Transformation-associated recombination (TAR) cloning is based on co-penetration into yeast spheroplasts of genomic DNA along with TAR vector DNA that contains 5'- and 3'-sequences (hooks) specific for a gene of interest, followed by recombination between the vector and the human genomic DNA to establish a circular YAC. Typically, the frequency of recombinant insert capture is 0.01-1% for single-copy genes by TAR cloning. To further refine the TAR cloning technology, we determined the effect of GC content on target hooks required for gene isolation utilizing the $Tg\cdot\AC$ mouse transgene as the targeted region. For this purpose, a set of vectors containing a B1 repeated hook and Tg AC-specific hooks of variable GC content (from 18 to 45%) was constructed and checked for efficiency of transgene isolation by radial TAR cloning. Efficiency of cloning decreased approximately 2-fold when the TAR vector contained a hook with a GC content ～${\leq}23$% versus ～40%. Thus, the optimal GC content of hook sequences required for gene isolation by TAR is approximately 40%. We also analyzed how the distribution of high GC content (65%) within the hook affects gene capture, but no dramatic differences for gene capturing were observed.

• Research in Plant Disease
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• v.17 no.2
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• pp.111-120
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• 2011

A bacterial artificial chromosome library of Pectobacterium carotovorum 35 was constructed to characterize the genome and to sequence its hrp region. The hrp cluster of P. carotovorum 35 consisted of 26 open reading frames in five operons. A promoter-based green fluorescent protein technology was used to identify the genes regulated by the alternative sigma factor, HrpL, in P. carotovorum 35. The majority of the selected clones contained the hrpJ operon promoter sequence, which harbors a hrp box, but no putative hrp boxes were detected within the promoter sequences of two other hrpL-regulated genes encoding for pectate lyase and large repetitive protein. Although the promoters of five other hrp operons also contained hrp boxes, their expression was not HrpL-dependent in the promoter-based selection in E. coli. However, transcriptional analysis showed that expression from all operons harboring hrp boxes, except for the hrpN operon, was reduced significantly in the hrpL mutant. The severity of soft-rot symptoms when the hrpL mutant was applied to the surface of tobacco leaves, mimicking natural infection, was greatly attenuated. These results indicate that the hrpL gene of P. carotovorum 35 may be involved in the development of soft-rot symptoms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.458-468
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• 2007

To tolerate environmentally adverse conditions such as cold, drought, and salinity, plants often synthesize and accumulate proline in cells as compatible osmolytes. ${\Delta}^1$-Pyrroline-5-carboxylate synthetase(P5CS) catalyzes the rate-limiting step of proline biosynthesis from glutamate. Two complete genes, MtP5CS1 and MtP5CS2, were isolated from the model legume Medicago truncatula by cDNA cloning and bacterial artificial chromosome library screening. Nucleotide sequence analysis showed that both genes consisted of 20 exons and 19 introns. Alignment of the predicted amino acid sequences revealed high similarities with P5CS proteins from other plant species. The two MtP5CS genes were expressed in response to high salt and low temperature treatments. Semi-quantitative reverse transcription-polymerase chain reaction showed that MtP5CS1 was expressed earlier than MtP5CS2, indicating differential regulation of the two genes. To evaluate the reverse genetic effects of nucleotide changes on MtP5CS function, a Targeting Induced Local Lesions in Genomes approach was taken. Three mutants each were isolated for MtP5CS1 and MtP5CS2, of which a P5CS2 nonsense mutant carrying a codon change from arginine to stop was expected to bring translation to premature termination. These provide a valuable genetic resource with which to determine the function of the P5CS genes in environmental stress responses of legume crops.

• Korean Parent-Child Health Journal
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• v.2
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• pp.53-63
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• 1999

The purpose of this study is to describe how what influence sexuality has on women's health. Sex is determined by the sex chromosome: but sociocultural norms have much influence on the sex role of a woman or man. Women's sexuality has had a negative impact on them in a male-dominated society, which destroyed women's health, put women in a powerless position and forced them to live as dependent persons. Sociocultural perception of the sex role has not been very open, and very strict rules have controlled those perceptions; but currently these perceptions have been changing dramatically. Especially, women's sex role has changed, bringing about many problems: the number of women engaging in premarital sex, the number of unwed mothers, the number of pregnancies without marriage, the divorce rate, and the number of dysfunctional families have all increased. Those kinds of problems have negative effects on women, children and members of the whole family. Sexually transmitted disease because of free sex is a serious health issue for women: the number of women with AIDS has increased rapidly. Another big issue is sexual abuse, which is insulting to women, decreases women's self-esteem, increases depression, puts women in a powerless position and eventually causes women to get sick. Male-preference (among newborns) ideology raises health issues for women, such as artificial abortion. In the area of sex differentiation, therefore, we have to change people's thinking from male-preference ideology to equal sex preference. Finally, we have to use a holistic approach for women's health and increase awareness of the fact that the sex role and women's health are very important for the family, society and nation. Women's health is the nation's power.

• Journal of the korean society of oceanography
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• v.32 no.4
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• pp.163-170
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• 1997

Some CMP gathers acquired from shallow marine seismic reflection survey in offshore Korea do not show the hyperbolic trend of moveout. It originated from so-called swell effect of source and streamer, which are towed under rough sea surface during the data acquisition. The observed time deviations of NMO-corrected traces can be entirely ascribed to the swell effect. To correct these time deviations, a residual statics is introduced using Genetic Algorithms (GA) into the swell correction. A new class of global optimization methods known as GA has recently been developed in the field of Artificial Intelligence and has a resemblance with the genetic evolution of biological systems. The basic idea in using GA as an optimization method is to represent a population of possible solutions or models in a chromosome-type encoding and manipulate these encoded models through simulated reproduction, crossover and mutation. GA parameters used in this paper are as follows: population size Q=40, probability of multiple-point crossover P$_c$=0.6, linear relationship of mutation probability P$_m$ from 0.002 to 0.004, and gray code representation are adopted. The number of the model participating in tournament selection (nt) is 3, and the number of expected copies desired for the best population member in the scaling of fitness is 1.5. With above parameters, an optimization run was iterated for 101 generations. The combination of above parameters are found to be optimal for the convergence of the algorithm. The resulting reflection events in every NMO-corrected CMP gather show good alignment and enhanced quality stack section.

• The Plant Pathology Journal
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• v.38 no.6
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• pp.572-582
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• 2022

Sheath blight disease caused by the necrotrophic, soilborne pathogen Rhizoctonia solani Kuhn, is the global threat to rice production. Lack of reliable stable resistance sources in rice germplasm pool for sheath blight has made resistance breeding a very difficult task. In the current study, 101 rice landraces were screened against R. solani under artificial epiphytotics and identified six moderately resistant landraces, Jigguvaratiga, Honasu, Jeer Sali, Jeeraga-2, BiliKagga, and Medini Sannabatta with relative lesion height (RLH) range of 21-30%. Landrace Jigguvaratiga with consistent and better level of resistance (21% RLH) than resistant check Tetep (RLH 28%) was used to develop mapping population. DNA markers associated with ShB resistance were identified in F₂ mapping population developed from Jigguvaratiga × BPT5204 (susceptible variety) using bulk segregant analysis. Among 56 parental polymorphic markers, RM5556, RM6208, and RM7 were polymorphic between the bulks. Single marker analysis indicated the significant association of ShB with RM5556 and RM6208 with phenotypic variance (R²) of 28.29 and 20.06%, respectively. Co-segregation analysis confirmed the strong association of RM5556 and RM6208 located on chromosome 8 for ShB trait. This is the first report on association of RM6208 marker for ShB resistance. In silico analysis revealed that RM6208 loci resides the stearoyl ACP desaturases protein, which is involved in defense mechanism against plant pathogens. RM5556 loci resides a protein, with unknown function. The putative candidate genes or quantitative trait locus harbouring at the marker interval of RM5556 and RM6208 can be further used to develop ShB resistant varieties using molecular breeding approaches.