• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.208-214
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• 1987

A genetic study on the panicle characters in Oryza sativa was carried out by means of a 5 x 5 diallel cross. The five parental varieties were Raekyung, Yeongnamjosaeng, Nongbaek, Yushin and Honenwase. All characters were correlated positively each other, except number of kernels per primary branch. The number of secondary branches per primary branch.was the most effective factor in determining the number of kernels per panicle, the next being the number of primary branches per panicle. Regression analyses of the data of Vr/Wr indicated the presence of non-allelic gene interactions for all characters. Overdominant characters were the number of kernels per panicle, the number of primary branches per panicle, the number of secondary branches per primary branch, the number of kernels per primary branch and sum of kernels on all the tertiary branches per panicle, suggesting that the characters were more influenced by dominant effect than additive effect. However, the number of kernels per secondary branch was partially dominant where the genetic variation was due more to additive effect than to dominance effect. But after omitting the parent which had non-allelic interaction gene, the characters; the number of kernels per panicle, the number of secondary branches per primary branch, and the number of kernels per secondary branch, were partially dominant. Narrow sense heritabilities(h$^2$ N) in number of kernels per panicle and number of secondary branches were high and moderate, respectively, but those of the rest were lower. Mean squares of GCA and SCA of all characters, except SCA of the number of kernels per secondary branch, were highly significant. Effects of GCA were larger than SCA effects in all characters. Raekyung, Yushin and Nongbaek had highly positive GCA, and the best positive SCA was observed in crosses of Nongbaek x Tongillines (Raekyung, Yushin, and Yeongnamjosaeng) in all characters.

• Animal cells and systems
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• v.14 no.4
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• pp.305-313
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• 2010

Pacific abalone Haliotis discus discus is an important fisheries resource in Jeju, Korea. For basic information about its current genetic status in relation to stock enhancement, the level and distribution of genetic variation between wild and released stocks of Pacific abalone in Jeju were examined at nine cross-species microsatellite markers including the use of two novel primers. High levels of polymorphism were observed between the two populations. A total of 146 different alleles were found at all loci, with some alleles being unique. The allelic variability ranged from five to 27 in the wild population and from four to 16 in the released sample. The average observed and expected heterozygosities were estimated to be 0.74 and 0.84 in the wild sample and 0.70 and 0.78 in the released sample, respectively. Although a considerable loss of rare alleles was observed in the released sample, no statistically significant reductions were found in heterozygosity or allelic diversity in the released sample compared to the wild population. Low but significant genetic differentiation was found between the wild and released populations. These results suggest that the intensive breeding practices for stock enhancement may have resulted in a further decrease in genetic diversity, and that the cross-species microsatellite markers used in this study represent a potentially efficient means for further genetic studies, providing beneficial information for the protection and management of H. discus discus.

• The Journal of the Korean Society for Microbiology
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• v.34 no.6
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• pp.519-532
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• 1999

Helicobacter pylori is a causative agent of type B gastritis and plays a central role in the pathogenesis of gastroduodenal ulcer and gastric cancer. To elucidate the host-parasite relationship of the H. pylori infection on the basis of molecular biology, we tried to evaluate the genomic diversity of H. pylori. An ordered overlapping bacterial artificial chromosome (BAC) library of a Korean isolate, H. pylori 51 was constructed to set up a genomic map. A circular physical map was constructed by aligning ApaI, NotI and SfiI-digested chromosomal DNA. When the physical map of H. pylori 51 was compared to that of unrelated strain, H. pylori 26695, completely different restriction patterns were shown. Fifteen known genes were mapped on the chromosome of H. pylori 51 and the genetic map was compared with those of strain 26695 and J99, of which the entire genomic sequences were reported. There were some variability in the gene location as well as gene order among three strains. For further analysis on the genomic diversity of H. pylori, when comparing the genomic structure of 150 H. pylori Korean isolates with one another, genomic macrodiversity of H. pylori was characterized by several features: whether or not susceptible to restriction digestion of the chromsome, variation in chromosomal restriction fingerprint and/or high frequency of gene rearrangement. We also examined the extent of allelic variation in nucleotide or deduced amino acid sequences at the individual gene level. fucT, cagA and vacA were confirmed to carry regions of high variation in nucleotide sequence among strains. The plasticity zone and strain-specific genes of H. pylori 51 were analyzed and compared with the former two genomic sequences. It should be noted that the H. pylori 51-specific sequences were dispersed on the chromosome, not congregated in the plasticity zone unlike J99- or 26695-specific genes, suggesting the high frequency of gene rearrangement in H. pylori genome. The genome of H. pylori 51 shows differences in the overall genomic organization, gene order, and even in the nucleotide sequences among the H. pylori strains, which are far greater than the differences reported on the genomic diversity of H. pylori.

• Korean Journal of Plant Resources
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• v.25 no.6
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• pp.745-752
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• 2012

Compared to wide ranges of genetic variation of natural populations, very limited Miscanthus cultivar has been released. This study was the first report on the development of Miscanthus cultivar by means of radiation breeding. Seeds of M. sinensis were initially exposed to gamma rays of 250 Gy for 24 h, generated from a $^{60}Co$ gamma-irradiator. The irradiated seeds were sown and then the highly tiller-producing mutants were selected for this study. Biomass-related parameters including tiller number, plant height, stem diameter, and leaf number were measured. Ploidy level and internal transcribed spacer (ITS) were investigated to characterize the mutants compared to wild type (WT) Miscanthus. Plant height and tiller number were negatively related, where multi-tillering mutants were relatively short after 4 month growth. However stem diameter and leaf number were greater in mutants. All the materials used in this study were diploid, implying that the mutants with greater tiller numbers and stem diameter were not likely related to polyploidization. Based on the sequence of ITS regions, the mutants demonstrated base changes from the gamma irradiation where G+C content (%) was decreased in the ITS1, but increased in ITS2 when compared to WT sequence. ITS2 region was more variable than in ITS1 in the mutants, which collectively allows identification of the mutants from WT. Those mutants having enhanced tillers and allelic variations might be used as breeding materials for enhanced biomass-producing Miscanthus cultivars.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.911-915
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• 2013

The aim of this study was to investigate allele frequencies at the CSN1S2 locus in two Chinese dairy goat breeds and the effects of its variation on dairy goat economic traits. Seven hundred and eight goats from Xinong Saanen (XS, n = 268) and Guanzhong (GZ, N = 440) breeds were selected. The milk samples of 268 XS goats were collected during the middle of lactation, body size parameters (708 goats) and daily milk yield (202 goats) were registered. The RFLP (restriction fragment length polymorphism) and SSCP (single strand conformation polymorphism) were used to detect the polymorphisms in CSN1S2. The Hardy-Weinberg (HW) equilibrium and the associations between body size, milk yield and composition and the genotypes were calculated. The results revealed that only A and F CSN1S2 alleles were found in the two Chinese dairy goat breeds. Allelic frequencies of A and F were 0.795, 0.205 and 0.739, 0.261 in Xinong Saanen and Guanzhong population respectively. Xinong Saanen breed was in Hardy-Weinberg equilibrium, while Guanzhong breed deviated from Hardy-Weinberg equilibrium (p<0.05). The association of polymorphism with economic traits indicated that the goats with FF genotype have higher milk fat and total solid concentration than those with AA and AF genotypes (p<0.05).

• Toxicological Research
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• v.17
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• pp.145-155
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• 2001

Cytochrome P4502C19 (CYP2C19) is one of human polymorphic xenobiotic-metabolizing enzymes. The enzyme has been reported to catalyze more than 70 substrates, involving more than 100 reactions. These include several classes of therapeutic agents (e.g. anti-microbial. cardiovascular, psycho-active, etc.), sex hormones and insecticides. Associations of the CYP2C19 genotype/phenotype with individual differences in drug efficacy (e.g. diazepam, omeprazole, proguanil) and toxicity (e.g. mephenytoin, barbiturates) have been documented by many investigators. At least 11 allelic variants of CYP2C19 gene were reported to date. Most of the mutant alleles found in the poor metabolizer (PM) led to the production of truncated and/or inactive proteins. Except for the exon 6, single-nucleotide mutations were reported in all nine exons of the gene. Genetic polymorphism of CYP2C19 shows marked interethnic variation with the population frequencies of PM phenotype ranging from 1∼2% up to more than 50%. The prevalence of CYP2C19 PM tends to be higher in Asian and certain Pacific Islanders than other race or ethnic specificity. Genotyping results of CYP2C19 also revealed that there are different proportions of individual mutant alleles among ethnic populations. This may, in part, explains the interethnic difference in the metabolism of certain drugs (i.e. diazepam), though they were from the same CYP2C19 phenotype. Recently, our research group has studied the genotype and phenotype of CYP2C19 and found that the PM frequency (7∼8%) in Thais is lower than other Asian populations. Molecular and clinical impacts of this finding warrant to further investigation.

• Molecules and Cells
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• v.25 no.2
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• pp.301-304
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• 2008

Microsatellites, short tandem repeats, are useful markers for genetic analysis because of their high frequency of occurrence over the genome, high information content due to variable repeat lengths, and ease of typing. To establish a panel of microsatellite markers useful for genetic studies of the Korean population, the allele frequencies and heterozygosities of 207 microsatellite markers in 119 unrelated Korean, Indian and Pakistani individuals were compared. The average heterozygosity of the Korean population was 0.71, similar to that of the Indian and Pakistani populations. More than 80% of the markers showed heterozygosity of over 0.6 and were valuable as genetic markers for genome-wide screening for disease susceptibility loci in these populations. To identify the allelic distributions of the multilocus genetic data from these microsatellite markers, the population structures were assessed by clustering. These markers supported, with the most probability, three clustering groups corresponding to the three geographical populations. When we assumed only two hypothetical clusters (K), the Korean population was separate from the others, suggesting a relatively deep divergence of the Korean population. The present 207 microsatellite markers appear to reflect the historical and geographical origins of the different populations as well as displaying a similar degree of variation to that seen in previously published genetic data. Thus, these markers will be useful as a reference for human genetic studies on Asians.

• Journal of Life Science
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• v.22 no.1
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• pp.25-30
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• 2012

Thymic stromal lymphopoietin(TSLP) is a novel IL-7-like hematopoietic cytokine. Human TSLP is produced by epithelial cells, stromal cells, and mast cells. The TSLP gene is highly expressed in synovial fluid specimens derived from rheumatoid arthritis (RA) patients. We previously identified four single nucleotide polymorphisms (SNPs) and one variation site in human TSLP gene. In this study, we analyzed the genotypic and allelic frequencies of the TSLP SNPs between RA patients and healthy controls. We also investigated the relationships between SNP genotypes and the RF levels and anti-synthetic cyclic citrullinated peptide (CCP) levels in RA patients. We then calculated the haplotype frequencies defined by these SNPs for both groups. The genotype and allele frequencies of the TSLP SNPs did not differ significantly between the RA patients and the healthy controls. We also found that TSLP SNPs in the RA patients had no significant association with the levels of RF or anti-CCP. Our results suggest that TSLP SNPs are not associated with susceptibility to RA.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.258-258
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• 2017

We received 73 wheat resources from CIMMYT for analysis of agricultural characteristics and qualities of them. We sowed 73 lines and 4 Korean varieties in fall and spring to compare differences of wheat traits between fall and spring seeding. The heading and maturity date of fall seeding lines has coming faster average 18 days than spring seeding lines. Fall seeding lines have more number of spike per $m^2$ and grain number of spike. Spike and awn length of spring seeding lines were shorter than fall seeding lines and stem length was variable to varieties in both condition. Protein contents of five of 73 lines, Jokyoung and Jopoom varieties decreased but the others increased. The sedimentation values of 34 lines include Jokyoung and falling number (F/N) of 44 lines include two varieties, Keumkang and Jokyoung, decreased but the others increased, respectively. Particle size was presented that most spring seeding lines were bigger. However, when it sowed in fall, the lightness (L) of wheat flour was lighter. Consequently, we confirmed when it was sowed in spring, agricultural traits and qualities of wheat got weak.

• Molecules and Cells
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• v.26 no.3
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• pp.250-257
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• 2008

Microsatellites or simple sequence repeats (SSR) are widely distributed in eukaryotic genomes and are informative genetic markers. Despite many advantages of SSR markers such as a high degree of allelic polymorphisms, co-dominant inheritance, multi-allelism, and genome-wide coverage in various plant species, they also have shortcomings such as low polymorphic rates between genetically close lines, especially in Capsicum annuum. We developed an alternative technique to SSR by normalizing and alternating anchored primers in random amplified microsatellite polymorphisms (RAMP). This technique, designated reverse random amplified microsatellite polymorphism (rRAMP), allows the detection of nucleotide variation in the 3' region flanking an SSR using normalized anchored and random primer combinations. The reproducibility and frequency of polymorphic loci in rRAMP was vigorously enhanced by translocation of the 5' anchor of repeat sequences to the 3' end position and selective use of moderate arbitrary primers. In our study, the PCR banding pattern of rRAMP was highly dependent on the frequency of repeat motifs and primer combinations with random primers. Linkage analysis showed that rRAMP markers were well scattered on an intra-specific pepper map. Based on these results, we suggest that this technique is useful for studying genetic diversity, molecular fingerprinting, and rapidly constructing molecular maps for diverse plant species.