• Journal of Korean Society of Forest Science
• /
• v.94 no.1 s.158
• /
• pp.16-20
• /
• 2005

Tricholoma matsutake ectomycorrhizas are unique in their morphology: not bifurcated broom shaped roots with not easily wettable brilliant and profuse white hyphae. To understand these characteristics the ectomycorrhizas were investigated with electron microscopy. T. matsutake ectomycorrhiza have thin mantle and typical Hartig net development in the epidermis and cortex, but no fungal mantle on the root apex. There were no penetrating hyphae inside of the cells of either epidermis, cortex or stele. Inside of the walls of epidermis and cortex cells are lined with ca. $2{\mu}m$ hemispherical amyloplasts. The brilliant hyphal surface was covered with various fine amorphous granules. The hyphal cell wall was thin membrane less than $0.3{\mu}m$ thick. There is no clamp connection on the hyphae. This thin membraneous cell wall with high elasticity can be related to survival strategy of the species without plasmolysis under frequent soil water stress environment. And the coarse hyphal surface with some water repellency can control sudden inrush of water of the hyphae with an extremely low osmotic potential. It is concluded that no mantle on the tip can induce mycorrhizas not bifurcated and that finely coarse surface of T. matsutake hyphae can make the hyphae brilliantly white but less wetted.

• Journal of Life Science
• /
• v.29 no.12
• /
• pp.1314-1320
• /
• 2019

This study aimed to identify single nucleotide polymorphisms in exon 8 region of the calmin (CLMN) gene and to evaluate their associations with meat yield and quality traits in Hanwoo (Korean cattle). We compared gene expression pattern of CLMN between high and low marbling score groups with extremely different intramuscular fat content of the longissimus lumborum muscles in Hanwoo. The CLMN gene was highly expressed in the high marbling score group. Total of nine SNPs were identified in the exon 8 region of CLMN gene, genotyping of the SNPs was carried out using direct-sequencing analysis in Hanwoo population (n=300) to evaluate their association with meat yield and quality traits. As a result, g.23249G>C in exon 8 was significantly associated with marbling score. Animals with the CC and GC genotypes had higher marbling score than those with the GG genotype. We constructed haplotypes of CLMN gene by linkage disequilibrium analysis and analyzed association between haplotypes and meat yield and quality traits. Haplotype of CLMN gene was associated with marbling score. As a result, animals with the CC-CC haplotype (g.23249G>C and g.23465T>C SNPs) had higher marbling score than those with CT and GT haplotypes. These findings suggest that the SNPs of bovine CLMN gene may be a useful molecular marker for selection of meat quality traits in Hanwoo.

• Journal of Life Science
• /
• v.20 no.1
• /
• pp.22-26
• /
• 2010

Seven rice germplasms with red pigmentation within the pericarp were isolated from a large mutant collection. These red pericarp phenotypes resulted from the functions of the Rc, Rd and RdRc genes. Among them, two brown pericarp of the Rc type, four red pericarp of the RdRc type, and one white pericarp of the Rd type were identified. Morphological and agronomic characteristics of those rice germplasms were studied. The Rc type germplasms have the faint red or brown color pericarp and the Rd types produce the white pericarp, whereas the RdRc type germplasms have the dark red pericarp. Most of the important agronomic characteristics including plant stature, tillering ability, spikelet fertility, and total grain yield were lower in the colored rice than those of the wild-type control. All of the studied colored rice germplasms had a tendency of easy seed-shattering in comparison to the control. These characteristics of newly identified germplasms will be useful for identifying the genes responsible for pericarp color phenotype determination.

• Journal of Life Science
• /
• v.26 no.9
• /
• pp.999-1006
• /
• 2016

This paper studies an infection of norovirus and astrovirus in outbreaks in Korea. In March 2016, gastroenteritis outbreaks occurred in Busan. 522 students of three departments at university D had meeting at a restaurant near the university. Some of them had symptom such as diarrhea, vomiting. Epidemiological, laboratory and environmental investigations were performed to identify the agents of the outbreaks. Fecal specimens were collected from 35 students and 7 food handlers to identify causative viral agents. Norovirus genogroup GI and GII were detected from diarrhea patients. Astrovirus was also detected from some of them. In particular, these outbreaks were the first occurrence associated with astrovirus in Busan. Total of 42 samples were collected, and 24 samples resulted in positive to norovirus (16 cases) and astrovirus (8 cases). To identify the molecular genetic information of norovirus, we carried out sequences analysis of the detected strains. Norovirus genotypes were classified into GI.3, GI.4, GII.4, GII.13, GII.17 and GII.21. Astrovirus genotypes were seven astrovirus type 5 and one astrovirus type 2. We performed environmental investigation about water at the kitchen, but norovirus and astrovirus were not detected. The statistical analysis was conducted to evaluate the association between illness and risk factors. The results of this study may contribute to accumulate more the epidemiological data and develop the public health and hygiene.

• Korean Journal of Plant Taxonomy
• /
• v.41 no.4
• /
• pp.299-314
• /
• 2011

The choice of molecular markers is the first step when selecting experimental plans in the field of population genetics. The popular molecular markers in population genetic studies are mainly allozyme, RAPD, RFLP, AFLP, microsatellite, SNP and ISSR. Among these, microsatellites are frequently found in nuclear, chloroplast and mitochondrial genome, showing a high level of polymorphism and nuclear microsatellites are codominant. Thus, it is a favorable molecular marker for population structure analyses and genetic diversity studies. Microsatellites are composed of tandem repeated 1~6 base pair nucleotide motifs and can be easily amplified by PCR reactions using locus specific primers. Because microsatellites have low cross-species transferability, however, they are only applicable between phylogenetically close species. In wild plants, the lack of genomic information and the high development cost of the microsatellite obstruct the wider use of microsatellites in plant population genetics research. In this review, we introduce the basis for microsatellite markers, the development process, and analytical methods as well as evolutionary models and their applications. In addition, possible genotyping errors which lead to erroneous conclusions are discussed.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.209-212
• /
• 2008

DBS method of underground works can reduce the term of works for manufacturing the underground members in factory and producing members in modularization, apart from that, the horizontal member could be used as permanent members, which are the advantages of this method. As the component element of DBS method, in order th transfer the vertical load on horizontal member to the column during the construction or in service, developed ${\sharp}$ shaped double beam-column connection is dominated by shear failure in the complicated state of multi-axial stresses. In this study, in order to check the shear-failure mechanism of ${\sharp}$ shaped connection of double beam-column and an increase of shear internal force with the thickness of the steel plate. 7 specimens were made and one-way static tests. All of the specimens were subjected to brittle failure. Constraint of slab will increase its shear strength by 1.06${\sim}$1.48 times. Shear strength of slabs with different constraints steel plate in two-way increase more than which are same. So the slab with different constraints steel plate will be more effective.

• Journal of Periodontal and Implant Science
• /
• v.34 no.3
• /
• pp.623-637
• /
• 2004

중증 만성 치주염과 1L-1B+3954 및 1L-1A+4845 유전자의 대립유전자 2 보유 유전자 다변성이 관련된다고 보고되었다. 그러나 이러한 1L-1 복합유전자 다변성과 만성 치주염 및 급진성 치주염과의 관련성에 대해서는 상반되게 보고되고 있는데 이는 인종적 배경과 질환특성의 차이에 기인한 것으로 보인다. 이 연구는 한국인에서 경도, 중등도와 중증의 만성 치주염 그리고 급진성 치주염 환자를 대상으로 하여 1L-1A+4845, 1L-1B+3954, 1L1B-511, 1L-1 RN intron 2 (VNTR) 유전자 다변성의 분포를 평가하고, 치주질환의 심도와 유형에 관련되는지 알아보고자 시행되었다. 전남대학교 병원 치주과에서 검진과 치료를 받은 100명의 치주질환자를 대상으로 하였고 질환군은 치주낭 깊이, 부착 소실, 골 소실을 기준으로 하여 경도, 중등도, 중증의 만성 치주염, 급진성 치주염군으로 분류하였다. 대조군으로는 전남대학교 병원 소아치과에 내원한 전신적으로 건강한 92명의 아동을 포함하였다. 각 대상 환자에서 채취된 협점막상피에서 genomic DNA를 얻어 1L-1A+4845, 1L-1B+3954, 1L-1B-511 genotype은 중합효소 연쇄반응을 시행한 후 제한 효소분해과정을 거쳐 전기영동 후 분리한 결과를 해석하였으며 1L-1 RN(VNTR) 유전형은 중합효소연쇄반응 후 분리한 결과를 해석하여 다음의 결과를 얻었다. 대립유전자 2 보유자 비율은 치주질환자에서 1L-1A+4845, 1L-1B+3954, 1L-1B-511, 1L-1 RN이 각각 61%, 13%, 76.6%, 34%였으며 대조군에서는 76.9%, 7.7%, 62.2%, 19.1%였다. 1L-1B+3954과 1L-1A+4845 대립유전자 2 보유자인 양성유전자형 비율은 경도, 중등도, 중증의 만성치주염, 급진성 치주염환자에서 각각 10%, 7.9%, 22.2%, 12% 였으며 치주질환자의 13%, 대조군의 7.7%에서 양성 복합유전자형(positive genotype)을 보였다. IL-1B-511 유전자 다변성은 치주질환자에서 대조군에 비하여 높았으며 급진성 치주염환자에서 대립유전자 2 보유자율이 유의하게 높았다(p<0.01). IL-1 RN intron 2 유전자 다변성은 중등도 및 중증 만성 치주염환자에서 대립유전자 2 보유자율이 유의하게 증가하였다. 이러한 결과는 IL-1 gene cluster의 유전형이 한국인에서도 치주염의 유형과 질환 심도에 관련될 수 있음을 시사하였다.

• Elastomers and Composites
• /
• v.41 no.3
• /
• pp.182-193
• /
• 2006

The retardation effects of a new polymeric UV stabilizer, DGEBA-HALS, on the UV degradation of SBR and NR were investigated in this study. The UV degradation behaviors of three different rubber compounds, without any photostabilizer and with commercial Cyabsorb UV-3529 and DGEBA-HALS, were compared. Also, the physical characteristics such as Young's modulus, tensile strength, blow-off deformation and crosslink density were examined. The Young's modulus was increased by UV irradiation for all samples, and the tensile strength, after UV irradiation, of the compound with UV stabilizer was better than that of the compound without stabilizer. Especially, the tensile strength of UV irradiated NR was improved by adding DGEBA-HALS. The results of blow-off deformation were in accord with those of Young's modulus. The degree of transmission of SBR compounds obtained from UV-vis transmission spectra was improved about 4% by adding the UV stabilizer. Commercial Cyabsorb UJV-3529 and DGEBA-HALS showed similar trends of transmission. The SEM photographs of SBR surface showed that the size of cracks created by UV irradiation became smaller by adding UV stabilizer. In particular, it is observed that the stabilization effect of DGEBA-HALS was better than that of commercial Cyabsorb UV-3529.

• Journal of Life Science
• /
• v.17 no.11
• /
• pp.1505-1510
• /
• 2007

We found 8 single nucleotide polymorphisms (SNPs) in adipocyte fatty acid bonding protein (FABP4) gene as candidate gene of FAT1 locus on pig chromosome 4. With over 800 heads of major commercial pig breeds including Duroc, Landrace, Berkshire and Yorkshire, we analyzed SNPs of FABP4 gene to determine possible effects of FABP4 genotype to economically important traits. $400{\sim}800\;bp$ amplicons in FABP4 gene were used PCR-RFLP for each SNPs and we found that the frequency of some SNPs of this gene was different among the breeds. According to the statistical analyses to determine possible associations of each genotype with economic traits, it was found that subgroup with different genotypes showed significant differences in daily gain, backfat thickness, lean percentage and feed conversion ratio (P<0.05). Thus, as a Part of enhancing the selection competence related to swine growth rate and lean percentage, it is expected that FABP4 gene markers verified in this study will be useful to use for Korean commercial pig industry.

• Journal of Life Science
• /
• v.21 no.1
• /
• pp.155-158
• /
• 2011

Uncoupling protein (UCP) 3 has a number of proposed roles in the regulation of fatty acid metabolism. A number of polymorphisms in the human UCP3 gene have been identified, and the correlation with obesity related phenotypes evaluated. The objective of this study was to identify SNP in porcine UCP3 gene and to investigate the effect of the SNP on economic traits. The sequencing analysis method was used to identify nucleotide polymorphisms at position 1405 bp (Genebank accession No : AY739704) in porcine UCP3 gene. The SNP (G150R), located in the exon 3, changed the amino acid to glycine (GGG) from arginine (AGG). This G150R showed three genotypes - GG, GR and RR - by digestion with the restriction enzyme Sma Ⅰ using the PCR-RFLP method. The G150R showed significant effects only on back fat (P<0.05). Animals with the genotype GG had significantly higher back fat thickness (1.358 cm) than animals with the genotype GR (1.288 cm, P<0.05) and RR (1.286 cm, P<0.05). However, the genotypes had no significant association with ADG and days to 90kg. According to results of this study, a G allele of the G150R was found to have a significant effect on back fat thickness. It will be possible to use SNP markers on selected pigs to improve backfat thickness, an important economic trait.