• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.286-286
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• 2022

The properties of starch play an important role in determining the palatability of rice. In addition, the gelatinization temperature (GT) of rice starch is an important factor in determining the quality of rice because it is related to the cooking time and texture of rice. For the development of high-quality rice, it is important to understand the genetic basis of palatability-related traits, and QTL analysis is an effective method to explain the genetic basis of variation in complex traits. QTL mapping related to alkali digestion value (ADV) of brown and milled rice was performed using the 120 Cheongcheong/Nagdong double haploid (CNDH) line. As a result, 12 QTLs related to ADV were detected, and 20 candidate genes were selected from the RM588-RM1163 region of chromosome 6 through screening by gene function analysis. The comparison of the relative expression level of candidate genes showed that OsSS1q6 is highly expressed in CNDH lines with high ADV in both brown rice and milled rice. In addition, OsSS1q6 has high homology with starch synthase 1 protein, and interact with various starch biosynthesis-related proteins, such as GBSSII, SBE, and APL. Therefore, we suggest that OsSS1q6 identified through QTL mapping could be one of the various genes involved in the GT of rice by regulating starch biosynthesis. This study can be used as basic data for breeding high-quality rice and provides a new genetic resource that can increase the palatability of rice.

• Genomics & Informatics
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• 제6권1호
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• pp.18-28
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• 2008

Single nucleotide polymorphisms (SNPs) are the most abundant forms of human genetic variations and resources for mapping complex genetic traits and disease association studies. We have constructed a linkage disequilibrium (LD) map of chromosome 22 in Korean samples and compared it with those of other populations, including Yorubans in Ibadan, Nigeria (YRI), Centre d'Etude du Polymorphisme Humain (CEPH) reference families (CEU), Japanese in Tokyo (JPT) and Han Chinese in Beijing (CHB) in the HapMap database. We genotyped 4681 of 111,448 publicly available SNPs in 90 unrelated Koreans. Among genotyped SNPs, 4167 were polymorphic. Three hundred and five LD blocks were constructed to make up 18.6% (6.4 of 34.5 Mb) of chromosome 22 with 757 tagSNPs and 815 haplotypes (frequency $\geq$ 5.0%). Of 3430 common SNPs genotyped in all five populations, 514 were monomorphic in Koreans. The CHB + JPT samples have more than a 72% overlap with the monomorphic SNPs in Koreans, while the CEU + YRI samples have less than a 38% overlap. The patterns of hot spots and LD blocks were dispersed throughout chromosome 22, with some common blocks among populations, highly concordant between the three Asian samples. Analysis of the distribution of chimpanzee-derived allele frequency (DAF), a measure of genetic differentiation, Fst levels, and allele frequency difference (AFD) among Koreans and the HapMap samples showed a strong correlation between the Asians, while the CEU and YRI samples showed a very weak correlation with Korean samples. Relative distance as a quantitative measurement based upon DAF, Fst, and AFD indicated that all three Asian samples are very proximate, while CEU and YRI are significantly remote from the Asian samples. Comparative genome-wide LD studies provide useful information on the association studies of complex diseases.

• Clinical and Experimental Reproductive Medicine
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• 제23권3호
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• pp.367-377
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• 1996

Genes on the long arm of Y chromosome, particularly interval 6, are believed to playa critical role in human spermatogenesis. The objective of this study was to validate a sequenced-tagged site(STS)-mapping strategy for the detection of Yq microdeletion and to use this method to determine the proportion of men with Yq microdeletions in idiopathic, obstructive, nonobstructive azoospermia, severe OATS and in normal males. We analyzed three STS markers mapped to interval 6 within long arm of the Y chromosome from 106 nonobstructive, 30 obstructive azoospermia, 15 severe OATS patients, and normal 42 males in Korean men. By PCR, we tested leukocyte DNA, for the presences of STS markers(DAZ, sY129 and sY134) and SRY gene as internal control. And PCR results were confirmed by Southern hybridization, and were investigated by SSCP analysis for DAZ gene mutation. None of 42 normal males and 30 obstructive azoospermia had microdeletions, Of the 15 severe OATS typed with DAZ, sY129 and sY134, 3(20.0%) patients failed to amplify 1 or more STS markers, and of the 106 nonobstructive azoospermia typed with DAZ, sY129 and sY134, 12(11.3%) patients failed to amplify 1 or more STS markers. From these results, high prevalence(12.4%) of Yq deletion(DAZ, sY129, sY134) in men with nonobstructive idopathic azoospermia and severe OATS were observed in Korean infertility patients. To avoid the infertile offspring by assisted reproductive technique using ICSI or ROSI, genetic diagnosis will be needed in IVF-ET program.

• Journal of Crop Science and Biotechnology
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• 제11권1호
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• pp.7-12
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• 2008

Quantitative trait loci, a genetic concept for explaining the inheritance of non-Mendelian traits in 1940s, have been realized as particular fragments of chromosome even unique genes in most crops in 21st century. However, only very a small portion of QTL has been screened out by geneticists comparing to a great number of genes underneath the quantitative traits. These identified QTL even have been seldom used into breeding program because crop breeders may not find the QTL in their breeding populations in their field station. Several key points will be proposed to meet the challenges of QTL analysis today: a fine mapping population and the related reference genetic map, QTL evaluation in multiple environments, recognizing real QTL with small genetic effect, map integration.

• 한국미생물·생명공학회지
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• 제25권4호
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• pp.379-385
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• 1997

Several protease-deficient mutants of Aspergillus niger have been isolated by halo-screening on skim milk plate after UV irradiation of conidiospores. The extracellular proteolytic activities of the mutant strains grown in an optimized medium varied from 3% to 85% of that of the parental strain. Especially, two mutant strains named as ANPD-129 and ANPD-153, which had 3% and 49% of acid protease activity of the parental strain, respectively, were further characterized both physiologically and genetically. The growth rates of the mutants, ANPD-129 and ANPD-153, were similar to that of the parental strain, unlike other protease-deficient mutants. The diploid formed between the two mutants restored protease activity to a similar level of that of the parental strain. This result revealed that ANPD-129 and ANPD-153 had mutations at different loci. Using master strains with marked chromosomes these loci were assigned to linkage groups. The mutation locus (prt129) in ANPD-129 was assigned to linkage group VI and the locus (prt153) in ANPD-153 to linkage group III.

• Animal cells and systems
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• 제11권2호
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• pp.93-98
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• 2007

Gonadotropin-releasing hormone (GnRH), synthesized in the hypothalamus, plays a pivotal role in the regulation of vertebrate reproduction. Since molecular isoforms of GnRH and their receptors (GnRHR) have been isolated in a broad range of vertebrate species, GnRH and GnRHR provide an excellent model for understanding the molecular co-evolution of a peptide ligand-receptor pair. Vertebrate species possess multiple forms of GnRH, which have been created through evolutionary mechanisms such as gene/chromosome duplication, gene deletion and modification. Similar to GnRHs, GnRH receptors (GnRHR) have also been diversified evolutionarily. Comparative ligand-receptor interaction studies for non-mammalian and mammalian GnRHRs combined with mutational mapping studies of GnRHRs have aided the identification of domains or motifs responsible for ligand binding and receptor activation. Here we discuss the molecular basis of GnRH-GnRHR co-evolution, particularly the structure-function relationship regarding ligand selectivity and signal transduction of mammalian and non-mammalian GnRHRs.

• 한국미생물·생명공학회지
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• 제22권6호
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• pp.599-606
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• 1994

Bacillus stearothermomophilus, a strong xylan degrader, was confirmed to express multiple esterase activities in addition to the major xylanolytic enzymes. One of the genes encoding the esterases was isolated from the genomic library of B. stearothermophilus constructed with EcoRl restriction endonuclease and pBR322 plasmid. Three recombinant plasmids showing the tributyrin degrading activity were selected from approximately 7, 000 E. coli HB101 transformants, and were found to have the same insert of a 3.2 kb DNA fragment. Restriction mapping and hybridization studies revealed that the gene(estII) on the hybrid plasmid (pKMG7) had originated from the B. stearothermophilus chromosome, and was distinct from the estl, another esterase gene of B. stearothermophilus isolated in the previous work. The E. coli cells harboring pKMG7 produced an acetylxylan esterase that exibited similar substrate specificity to the esterase encoded by the estI gene.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 추계학술대회 논문집
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• pp.548-554
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• 1996

A new method to locate modular fixtures using an optimization technique is proposed. The optimal fixture arrangement is derived to minimize the elastic deformation of a workpiece. That is, a fixture arrangement is regarded better if it minimized the elastic deformation of the workpiece while fixing a workpart of course. In this approach, the workpiece is projected into two dimensional domain to simplify the 3-dimensional fixture arrangement problem into 2-dimensional one. Thus the problem is reduced to find the optimal positions of one horizontal clamp and three locators which minimize the total deformation of the workpiece and the design variables are the location of the contact points between the boundary of the workpiece and the 4-fixels. The Genetic Algorithm is used for the optimization by mapping each design variables to a gene of a chromosome. The fitness value is the total strain energy of the workpiece calculated by the fin element analysis.

• Molecules and Cells
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• 제24권3호
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• pp.394-408
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• 2007

Several genes/QTLs governing resistance/tolerance to abiotic and biotic stresses have been reported and mapped in rice. A QTL for submergence tolerance was found to be co-located with a major QTL for broad-spectrum bacterial leaf blight (bs-blb) resistance on the long arm of chromosome 5 in indica cultivars FR13A and IET8585. Using the Nipponbare (japonica) and 93-11 (indica) genome sequences, we identified, in silico, candidate genes in the chromosomal region [Kottapalli et al. (2006)]. Transcriptional profiling of FR13A and IET8585 using a rice 22K oligo array validated the above findings. Based on in silico analysis and arraying we observed that both cultivars respond to the above stresses through a common signaling system involving protein kinases, adenosine mono phosphate kinase, leucine rich repeat, PDZ/DHR/GLGF, and response regulator receiver protein. The combined approaches suggest that transcription factor EREBP on long arm of chromosome 5 regulates both submergence tolerance and blb resistance. Pyruvate decarboxylase and alcohol dehydrogenase, co-located in the same region, are candidate downstream genes for submergence tolerance at the seedling stage, and t-snare for bs-blb resistance. We also detected up-regulation of novel defense/stress-related genes including those encoding fumaryl aceto acetate (FAA) hydrolase, scramblase, and galactose oxidase, in response to the imposed stresses.

• Reproductive and Developmental Biology
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• 제32권4호
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• pp.223-227
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• 2008

Human embryonic stem (ES) cells retain the capacity for self-renewal, are pluripotent and differentiate into the three embryonic germ layer cells. The regulatory transcription factors Oct4, Nanog and Sox2 play an important role in maintaining the pluripotency of human ES cells. The aim of this research was to identify unknown genes upregulated in human ES cells along with Oct4, Nanog, and Sox2. This study characterizes an unknown gene, named chromosome 1 open reading frame 31 (C1orf31) mapping to chromosome 1q42.2. The product of C1orf31 is the hypothetical protein LOC388753 having a cytochrome c oxidase subunit VIb (COX6b) motif. In order to compare expression levels of C1orf31 in human ES cells, human embryoid body cells, vascular angiogenic progenitor cells (VAPCs), cord-blood endothelial progenitor cells (CB-EPCs) and somatic cell lines, we performed RT-PCR analysis. Interestingly, C1orf31 was highly expressed in human ES cells, cancer cell lines and SV40-immortalized cells. It has a similar expression pattern to the Oct4 gene in human ES cells and cancer cells. Also, the expression level of C1orf31 was shown to be upregulated in the S phase and early G2 phase of synchronized HeLa cells, leading us to purpose that it may be involved in the S/G2 transition process. For these reasons, we assume that C1orf31 may play a role in on differentiation of human ES cells and carcinogenesis.