• Title/Summary/Keyword: Gene Analysis

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Clinical Characteristics of Arthrogryposis, Renal Tubular Dysfunction, Cholestasis(ARC) Syndrome in Korea (ARC(Arthrogryposis, Renal Tubular Dysfunction, Cholestasis) 증후군의 발병양상에 관한 연구)

  • Lee Soon Min;Kim Ji Hong;Lee Jae Seung;Han Suk Joo
    • Childhood Kidney Diseases
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    • v.9 no.2
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    • pp.222-230
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    • 2005
  • Purpose : ARC syndrome refers to an association of arthrogryposis, renal tubular dysfunction, and cholestasis. The VPS33B gene was recently identified as the causative gene. So far, 41 cases of ARC syndrome have been reported worldwide, and it has rarely been reported in Korea. This study was conducted to report the clinical findings of seven ARC syndrome cases in Korean children, focusing especially on renal tubular dysfunction. Methods : The hospital records of 7 cases diagnosed as ARC syndrome at Severance Hospital between Mar. 1995 and Aug. 2005 were reviewed and analyzed. Results : Of the 7 cases, 4 were boys and 3 were girls. Six patients(85$\%$) were born with normal birth weight at term, and one was born at preterm. All cases presented with cholestasis and severe jaundice. According to the type of arthrogryposis described by Brown et al, type 3 and 4 were found in 2 patients and type,6, 7, and the undistributed type in one patient respectively. Other associated clinical findings were as follows : failure to thrive in 6(85$\%$), lax skin in 5(71$\%$), and gray platelet syndrome in 4(57$\%$). Urine analysis revealed 6 cases(85$\%$) with proteinuria, 3(43$\%$) with hematuria, 5(71$\%$) with glycosuria, 2(29$\%$) with phosphaturia and 2(29$\%$) with calciuria. Serum electrolytes showed 4 cases(57$\%$) with hyponatremia, 3(43$\%$) with hypokalemia, and 1(14$\%$) with creatinine elevation. Renal tubular dysfunctions were diagnosed as renal tubular acidosis in 6 cases(85$\%$), nephrogenic diabetes insipidus in 2(29$\%$), and Fanconi syndrome in 2(29$\%$). During the follow-up period, 2(29$\%$) had no treatment, 5(85$\%$) had continuous supplementation to correct the electrolyte imbalance and acidosis, and 1(14$\%$) had dialysis. Only one patient had a family history of ARE syndrome in a sibling. Four cases(57$\%$) were diagnosed at the mean age of 8.2 months, and one case was lost during follow-up. Ages of the survived 2 cases were 13 and 25 months, respectively. Conclusion : The rare disease of ARC syndrome Is associated with severe renal dysfunction. However, this study revealed that the renal manifestation of ARC syndrome in Korean children is relatively mild and survival rate is higher than that of previous studies. Contrary to previous reports, this study showed that familial cases are rare and sporadic occurence is possible in Korea. Thus, the diagnosis of this syndrome requires a careful evaluation of the venal function in cases of congenital arthrogryposis, and a mandatory genetic counseling of affected family for prevention of familial occurance. (J Korean Soc Pediatr Nephrol 2005;9:222-230)

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Cellular activities of osteoblast-like cells on alkali-treated titanium surface (알칼리 처리된 타이타늄 표면에 대한 골아 유사세포의 세포 활성도)

  • Park, Jin-Woo;Lee, Deog-Hye;Yeo, Shin-Il;Park, Kwang-Bum;Choi, Seok-Kyu;Suh, Jo-Young
    • Journal of Periodontal and Implant Science
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    • v.37 no.sup2
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    • pp.427-445
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    • 2007
  • To improve osseointegration at the boneto-implant interface, several studies have been carried out to modify titanium surface. Variations in surface texture or microtopography may affect the cellular response to an implant. Osteoblast-like cells attach more readily to a rougher titanium surface, and synthesis of extracellular matrix and subsequent mineralization were found to be enhanced on rough or porous coated titanium. However, regarding the effect of roughened surface by physical and mechanical methods, most studies carried out on the reactions of cells to micrometric topography, little work has been performed on the reaction of cells to nanotopography. The purpose of this study was to examme the response of osteoblast-like cell cultured on blasted surfaces and alkali treated surfaces, and to evaluate the influence of surface texture or submicro-scaled surface topography on the cell attachment, cell proliferation and the gene expression of osteoblastic phenotype using ROS 17/2.8 cell lines. In scanning electron micrographs, the blasted, alkali treated and machined surfaces demonstrated microscopic differences in the surface topography. The specimens of alkali treatment had a submicro-scaled porous sur-face with pore size about 200 nm. The blasted surfaces showed irregularities in morphology with small(<10 ${\mu}m$) depression and indentation among flatter-appearing areas of various sizes. Based on profilometry, the blasted surfaces was significantly rougher than the machined and the alkali treated surfaces (p$TiO_2$) were observed on alkali treated surfaces, whereas not observed on machined and blasted surfaces. The attachment morphology of cells according to time was observed by the scanning electron microscope. After 1 hour incubation, the cells were in the process of adhesion and spreading on the prepared surfaces. After 3 hours, the cells on all prepared surfaces were further spreaded and flattened, however on the blasted and alkali treated surfaces, the cells exhibited slightly irregular shapes and some gaps or spaces were seen. After 24 hours incubation, most cells of the all groups had a flattened and polygonal shape, but the cells were more spreaded on the machined surfaces than the blasted and alkali treated surfaces. The MTT assay indicated the increase on machined, alkali treated and blasted surfaces according to time, and the alkali treated and blasted surfaces showed significantly increased in optical density comparing with machined surfaces at 1 day (p<0.01). Gene expression study showed that mRNA expression level of ${\alpha}\;1(I)$ collagen, alkaline phosphatase and osteopontin of the osteoblast-like cells showed a tendency to be higher on blasted and alkali treated surfaces than on the machined surfaces, although no siginificant difference in the mRNA expression level of ${\alpha}\;1(I)$ collagen, alkaline phosphatase and osteopontin was observed among all groups. In conclusion, we suggest that submicroscaled surfaces on osteoblast-like cell response do not over-ride the one of the surface with micro-scaled topography produced by blasting method, although the microscaled and submicro-scaled surfaces can accelerate osteogenic cell attachment and function compared with the machined surfaces.

Strain Improvement of the Genus Pleurotus by Protoplast Fusion (원형질체(原形質體) 융합(融合)에 의한 느타리버섯속(屬)의 품종개발(品種開發))

  • Yoo, Young-Bok;You, Chang-Hyun;Cha, Dong-Yeul
    • The Korean Journal of Mycology
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    • v.21 no.3
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    • pp.200-211
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    • 1993
  • Somatic hybrids of Pleurotus florida ASI 2016 and Pleurotus ostreatus ASI 2018 were obtained by protoplast fusion. The 40 fusants($P1{\sim}P40$) was examined for the yield on fermented and pasteurized rice straw in a tray. The carpophore yield of them were showed as the range of $27.0{\sim}155.2$, based on parental values of 100(ASI 2018), The pilei of fusants between orange white colored P. florida and dark grey colored P. ostreatus had mixed colors in the young stage. Other breeding programmes were performed to improve new varieties with high yield and good quality. A new oyster mushroom variety, Wonhyeongneutaribeosus(P72), was developed at the Agricultural Sciences Institute, Rural Development Administration in 1990. This P.florida-ostreatus-ostreatus hybrid P72 was selected from 38 protoplast fusion products($P41{\sim}P78$) between P.florida-ostreatus recombinant P5-M 43-arg rib and P. ostreatus ASI 2-13-0 2001-19-pro orn. The yield indexes of 38 hybrids ranged $40.5{\sim}152.7$ compared with the parental values of 100(ASI 2001). Hybrid P72 was characterized by the large fruiting bundle of semispherical shape with long stipe and by the small and circular pileus, resulting in lower harvesting cost. A significant increase in carpophore production was observed in somatic hybrids of protoplasts due to heterosis. A comparision of hybrid with parents P72 was made using isozyme analysis. The esterase banding patterns could be characterized by new bands in the hybrids. Seven fusion products of four crosses between P.florida ASI 2016 and P. ostreatus ASI 2018 were analysed with respect to the distribution of progenies and segregation of gene markers by random basidiospore analysis. Segregation of alleles should yield progeny of four genotypes in a Mendelian ratio of 1 : 1 : 1 : 1 for prototrophs, auxotrophs of one parental type, auxotrophs of the other parental type, and auxotrophic recombinants, respectively. However, five fusants of them did not detect one parental, P.ostreatus, type. Basidiospores could yield progeny of 16 genotypes in the cross of one of the recombinant P5-M43-arg $rib{\times}P. ostreatus$ ASI 2-13-pro orn but the segregants of three fusants were not detected clearly. The allele ratio of loci could be expected 1 : 1 : 1 : 1 for arg, rib, pro and orn. The ratio, however, would be changed to 4 : 1 : 1 : 1 with increasing proportion of argo In almost all the fusants, prototrophic recombinants were recovered in large numbers against auxotrophic markers. Parental genotypes were recovered with the recombinant progeny amounting to $38.68{\sim}99.56%$. The analysis provides proof of heterokaryosis and strong evidence for haploidy of vegetative nuclei, a sexual cycle consisting of nuclear fusion and meiosis.

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Correlation Between Primary Tuberculous Pleurisy and NRAMP1 Genetic Polymorphism (결핵성 흉막염 환자에서 NRAMP1 유전자 다형성에 대한 연구)

  • Kim, Je-Hyeong;Kim, Byung-Gyu;Jung, Ki-Hwan;Park, Sang-Myun;Lee, Sang-Youb;Lee, Sin-Hyung;Sin, Cheol;Cho, Jae-Youn;Shim, Jae-Jeong;In, Kwang-Ho;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.48 no.2
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    • pp.155-165
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    • 2000
  • Background: The phagolysosomal function of alveolar macrophage against M. tuberculosis infection is influenced by Nramp1, which is encoded by the NRAMP1 gene. There are several genetic polymorphisms in NRAMP1, and these polymorphisms affect the innate host resistance through the defect in production and function of Nramp1. To investigate this relationship, the NRAMP1 genetic polymorphism in patients with primary tuberculous pleurisy was determined. Methods: Fifty-six primary tuberculous pleurisy patient, who were diagnosed by pleural biopsy, were designated to the pleurisy group and 45 healthy adults were designated to the healthy control group. Three genetic polymorphisms of NRAMP1, such as a single point mutation in intron 4(469+14G/C, INT4), a nonconservative single-base substitution at codon 543 that changes aspartic acid to asparagine(D543N) and a TGTG deletion in the 3' untranslated region(1729+55delI4, 3'UTR), were determined. Polymerase chain reaction(PCR) and polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP) were used. Results: The frequencies of mutant genotypes of INT4 and 3'UTR were significantly high in pleurisy group(p=0.001, p=0.023). But the frequencies of D543N were not significantly different between the two groups(p=0.079). The odds ratios, which are a comparison with wild genotype for determining mutant genotypes, were 8. 022(95% confidence interval=2.422-26.572) for INT4 and 5.733(95% confidence interval = 1.137~28.916) for 3'UTR ; these were statistically significant But the ratio for D543N was not significant In the combined analysis of the INT4 and 3'UTR polymorphisms, the odds ratios were 6.000(95% confidence interval = 1.461~24.640) for GC/++ genotype and 14.000(95% confidence interval=1.610~121.754) for GC/+del when compared with GG/++ homozygotes ; these were statistically significant. Conclusion: Among the NRAMP1 genetic polymorphisms, a single point mutation in intron 4(469+14G/C, INT4) and a TGTG deletion in the 3' untranslated region(1729+55del4, 3'UTR) were closely related to the primary tuberculous pleurisy.

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Characterization of MACS Isolated Cells from Differentiated Human ES Cells (인간 배아줄기세포로부터 분화된 세포에서 MACS 방법을 이용하여 분리한 세포의 특성에 대한 연구)

  • Cho, Jae Won;Lim, Chun Kyu;Shin, Mi Ra;Bang, Kyoung Hee;Koong, Mi Kyoung;Jun, Jin Hyun
    • Clinical and Experimental Reproductive Medicine
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    • v.33 no.3
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    • pp.171-178
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    • 2006
  • Objective: Human embryonic stem (ES) cells have a great potential in regenerative medicine and tissue engineering. The human ES cells could be differentiated into specific cell types by treatments of growth factors and alterations of gene expressions. However, the efficacy of guided differentiation and isolation of specific cells are still low. In this study, we characterized isolated cells from differentiated human ES cells by magnetic activated cell sorting (MACS) system using specific antibodies to cell surface markers. Methods: The undifferentiated hES cells (Miz-hESC4) were sub-cultured by mechanical isolation of colonies and embryoid bodies were spontaneously differentiated with DMEM containing 10% FBS for 2 weeks. The differentiated cells were isolated to positive and negative cells with MACS system using CD34, human epithelial antigen (HEA) and human fibroblast (HFB) antibodies, respectively. Observation of morphological changes and analysis of marker genes expression were performed during further culture of MACS isolated cells for 4 weeks. Results: Morphology of the CD34 positive cells was firstly round, and then it was changed to small polygonal shape after further culture. The HEA positive cells showed large polygonal, and the HFB positive spindle shape. In RT-PCR analysis of marker genes, the CD34 and HFB positive cells expressed endodermal and mesodermal genes, and HEA positive cells expressed ectodermal genes such as NESTIN and NF68KD. The marker genes expression pattern of CD34 positive cells changed during the extension of culture time. Conclusion: Our results showed the possibility of successful isolation of specific cells by MACS system from undirected differentiated human ES cells. Thus, MACS system and marker antibodies for specific cell types might be useful for guided differentiation and isolation of specific cells from human ES cells.

Activation of the NF-$\kappa$B p50/p65 Complex in Human Lung Cancer Cell Lines (인체 폐암세포주에서 NF-$\kappa$B p50/p65 Complex의 활성화)

  • Choi, Hyung-Seok;Yoo, Chul-Gyu;Lee, Choon-Taek;Kim, Young-Whan;Han, Sung-Koo;Shim, Young-Soo
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.2
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    • pp.185-194
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    • 1999
  • Background: NF-$\kappa$B is a characteristic transcriptional factor whose functional activity is determined by post-translational modification of protein and subsequent change of subcellular localization. The involvement of the NF-$\kappa$B family of the transcription factors in the control of such vital cellular functions as immune response, acute phase reaction, replication of certain viruses and development and differentiation of cells has been clearly documented in many previous studies. Several recent observations have suggested that the NF-$\kappa$B might also be involved in the carcinogenesis of some hematological and solid tumors. Investigating the possibility that members of the NF-$\kappa$B family participate in the molecular control of malignant cell transformation could provide invaluable information on both molecular pathogenesis and cancer-related gene therapy. Method: To determine the expression patterns and functional roles of NF-$\kappa$B family transcription factors in human lung cancer cell lines NCI-H792, NCI-H709, NCI-H226 and NCI-H157 were analysed by western blot, using their respective antibodies. The nuclear and the cytoplasmic fraction of protein extract of these cell lines were subsequently obtained and NF-$\kappa$B expression in each fraction was again determined by western blot analysis. The type of NF-$\kappa$B complex present in the cells was determined by immunoprecipitation. To detect the binding ability of cell-line nuclear extracts to the KB consensus oligonucleotide, electrophoretic mobility shift assay(EMSA) was performed. Results: In the cultured human lung cancer cell lines tested, transcription factors of the NF-$\kappa$B family, namely the p50 and p65 subunit were expressed and localized in the nuclear fraction of the cellular extract by western blot analysis and immunocytochemistry. Immunoprecipitation assay showed that in the cell, the p50 and p65 subunits made NF-$\kappa$B complex. Finally it was shown by Electrophoretic Mobility Shift Assay(EMSA) that nuclear extracts of lung cancer cell lines are able to bind to NF-$\kappa$B consensus DNA sequences. Conclusion: These data suggest that in human lung cancer cell lines the NF-$\kappa$B p50/p65 complex might be activated. and strengthen the hypothesis that NF-$\kappa$B family transcription factors might be involved in the carcinogenesis of human lung cancer.

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Clinical Characteristics and Genetic Analysis of Prader-Willi Syndrome (Prader-Willi 증후군의 임상 양상 및 유전학적 진단에 관한 고찰)

  • Lee, Ji Eun;Moon, Kwang Bin;Hwang, Jong Hee;Kwon, Eun Kyung;Kim, Sun Hee;Kim, Jong Won;Jin, Dong Kyu
    • Clinical and Experimental Pediatrics
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    • v.45 no.9
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    • pp.1126-1133
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    • 2002
  • Purpose : Prader-Willi syndrome(PWS) is a complex disorder affecting multisystems with characteristic clinical features. Its genetic basis is an expression defect in the paternally derived chromosome 15q11-q13. We analyzed the clinical features and genetic basis of PWS patients for early detection and treatment. Methods : We retrospectively studied 24 patients with PWS in Department of Pediatrics, Samsung Medical Center, from September 1997 to September 2001. We performed cytogenetic and molecular genetic techniques using high resolution GTG banding techniques, fluorescent in situ hybridization and methylation-specific PCR for CpG island of SNRPN gene region. Results : The average birth weight of PWS patients was $2.67{\pm}0.47kg$ and median age at diagnosis was 1.3 years. The average height and weight of PWS patients under one year at diagnostic time were located in a 3-10 percentile relatively, and a rapid weight gain was seen between two and six years. Feeding problems in infancy and neonatal hypotonia were the two most consistently positive major criteria in over 95% of the patients. In 18 of the 24 cases(75%), deletion of chromosome 15q11-q13 was demonstrated and one case among 18 had an unbalanced 14;15 translocation. In four cases without any cytogenetic abnormality, it may be considered as maternal uniparental disomy and the rest showed another findings. Conclusion : We suggest diagnostic testing for PWS in all infants/neonates with unexplained feeding problems and hypotonia. It is necessary for clinically suspicious patients to undergo an early genetic test. As the genetic basis of PWS was heterogenous and complex, further study is required.

Developmental Genetic Analysis of Avian Primordial Germ Cells and the Application to Poultry Biotechnology

  • Kagami, H.
    • Korean Journal of Poultry Science
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    • v.28 no.2
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    • pp.135-142
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    • 2001
  • A novel sterategy has been established to determine the origin of the Primordial Germ Cells (PGCs) in avian embryos directly and the developmental fate of the PGCs for the application to Poultry biotechnology. Cells were removed from 1) the centre of area pellucida, 2) the outer of area pellucida and 3) the area opaca of the stage X blastoderm (Eyal-Giladi & Kochav, 1976). When the cells were removed from the centre of area pellucida, the mean number of circulating PGCs in blood was significantly decreased in the embryo at stage 15 (Hamburger & Hamilton, 1951) as compared to intact embryos. When the cells were replenished with donor cells, no reduction in the PGCs number was observed. The removal of cells at the outer of area pellucida or at the area opaca had no effect on the number of PGCs. In case, another set of the manipulated embryos were cultured ex vivo to the hatching and reared to the sexual maturity, the absence of germ cells and degeneration of seminiferous tubules was observed in resulting chickens derived from the blastoderm in which the cells were removed from the centre of the area pellucida. It was concluded that the avian Primordial Germ cells are originated at the center of area pellucida. Developmental ability of the cells to differentiate into somatic cells and germ cells in chimeras were analyzed. Somatic chimerism was detected as black feather attributed from donor cells. Molecular identification by use of female - specific DNA was performed. It was confirmed that the donor cells could be differentiated into chimeric body and erythrocytes. Donor cells retained the ability to differentiate into germline in chimeric gonads. More than 70% of the generated chimeras transmitted donor derived gametes to their offspring indicating that the cells at the center of area pellucida had the high ability to differentiate into germ cells. A molecular technique to identify germline chimerism has been developed by use of gene scan analysis. Strain specific DNA fragments were amplified by the method. It would be greatly contributed for the detection of germline chimerism. Mixed- sex chimeras which contained both male and female cells were produced to investigate the developmental fate of male and female cells in ovary and testes. The sex combinations of donor and recipient of the resulting chimeras were following 4 pairs; (1) chimeras (ZZ/ZZ) produced by a male donor (ZZ) and a male recipient (ZZ), (2) chimeras (ZW/ZW) produced by a female donor (ZW) and a female recipient (ZW), (3) chimeras (ZZ/ZW) Produce by a male donor (ZZ) and a female recipient (ZW), (4) chimeras (ZW/ZZ) produced by a female donor (ZW) and a male recipient (ZZ). It was found that genetically male avian germ cells could differentiate into functional ova and that genetically female germ cells can differentiate into functional spermatozoa in the gonad of the mixed- sex chimeras. An ability for introduction of exogenous DNA into the PGCs from stage X blastoderms were analyzed. Two reporter genes, SV-$\beta$gal and RSV-GFP, were introduced into the PGCs. Expression of bacterial/gal was improved by complexing DNA with liposome detectedcc in 75% of embryos at 3 days embryos. At the embryos incubated for 1 day, expression of the GFP was observed all the embryos. At day 3 of incubation, GFP was detected in about 70% of the manipulated embryos. In case of GFP, expression of the transgene was detected in 30 %e of the manipulated embryos. These results suggested that the cells is one of the most promising vectors for transgenesis. The established strategy should be very powerfull for application to poultry biotechnology.

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Optimized Methods of Preimplantation Genetic Diagnosis for Trinucleotide Repeat Diseases of Huntington's Disease, Spinocerebellar Ataxia 3 and Fragile X Syndrome (삼핵산 반복서열 질환인 헌팅톤병, 척수소뇌성 운동실조증, X-염색체 취약 증후군의 착상전 유전진단 방법에 대한 연구)

  • Kim, Min-Jee;Lee, Hyoung-Song;Lim, Chun-Kyu;Cho, Jae-Won;Kim, Jin-Young;Koong, Mi-Kyoung;Son, In-Ok;Kang, Inn-Soo;Jun, Jin-Hyon
    • Clinical and Experimental Reproductive Medicine
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    • v.34 no.3
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    • pp.179-188
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    • 2007
  • Objectives: Many neurological diseases are known to be caused by expansion of trinucleotide repeats (TNRs). It is hard to diagnose the alteration of TNRs with single cell level for preimplantation genetic diagnosis (PGD). In this study, we describe methods optimized for PGD of TNRs related diseases such as Huntington's disease (HD), spinocerebellar ataxia 3 (SCA3) and fragile X syndrome (FXS). Methods: We performed the preclinical assays with heterozygous patient's lymphocytes by single cell PCR strategy. Fluorescent semi-nested PCR and fragment analysis using automatic genetic analyzer were applied for HD and SCA 3. Whole genome amplification with multiple displacement amplification (MDA) method and fluorescent PCR were carried out for FXS. Amplification and allele drop-out (ADO) rate were evaluated in each case. Results: The fluorescent semi-nested PCR of single lymphocyte showed 100.0% of amplification and 14.0% of ADO rate in HD, and 94.7% of amplification and 5.6% of ADO rate in SCA3, respectively. We could not detect the PCR product of CGG repeats in FXS using the fluorescent semi-nested PCR alone. After applying the MDA method in FXS, 84.2% of amplification and 31.3% of ADO rate were achieved. Conclusions: Fluorescent semi-nested PCR is a reliable method for PGD of HD and SCA3. The advanced MDA method overcomes the problem of amplification failure in CGG repeats of FXS case. Optimization of methods for single cell analysis could improve the sensitivity and reliability of PGD for complicated single gene disorders of TNRs.

Development of dry milling suitable rice cultivar to invigorate rice processing products

  • Jeung, Ji-Ung
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.10-10
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    • 2017
  • Rice consumption has been continuously decreasing as the eating habits of Koreans have become westernized and diversified. The per capita annual rice consumption in Korea has dropped sharply from 136.4 kg in 1970 to 61.9 kg in 2016. The Korean government, therefore, has been trying to promote rice consumption by invigorating the processed food industry using rice flour. To facilitate the market for processed rice foods, it is essential to develop proper milling technology in terms of flour particle size and damaged starch content to produce high quality rice flour at competitive cost. Dry milling and wet milling are the two major processes used to produce rice flour. Although the dry milling process is relatively simple with a lower production cost, damaged starch content increases because of the high grain hardness of rice. In wet milling, the quality of rice flour is improved by reducing flour particle size as well as damaged starch content through soaking procedures. However, the production costs are high because of the additional expenses associated with the disposal of waste water, sterilization and drying of the wet flour. Recently developed technologies such as jet milling and cryogenic milling also require expensive investment and production. Therefore, developing new rice cultivars with dry milling adaptability as well as good processing properties is an important goal of rice breeding in Korea. 'Suweon 542' is a floury endosperm mutant line derived from sodium azide treatment on a high-yield, early maturing, and non-glutinous japonica rice cultivar, 'Namil'. Compared with the wild type, after dry milling process, the grain hardness of 'Suweon 542' was significantly lower because of its round and loosely packed starch granules. Also, the flour of 'Suweon 542' had significantly smaller particles and less damaged starch than 'Namil' and other rice cultivars and its particle size distribution was similar to a commercial wheat cultivar. Recently, through collaborations with nine universities and food companies, a total of 21 kinds of processed prototypes, using the dry milling flour of 'Suweon 542', were evaluated. In the production of major rice processing products, there was no significant quality difference between the flours prepared by wet milling and dry milling. Although the amount of water added to the dough was slightly increased, it was confirmed that the recipe applying the wet flour could be used without significant change. To efficiently transfer the floury endosperm characteristics of 'Suweon 542' to other commercial rice cultivars, it is essential to develop DNA marker tightly linked to the target gene. Association analysis using 70 genome-wide SSR markers and 94 F2 plants derived from 'Suweon 542'/'Milyang 23' showed that markers on chromosome 5 explained a large portion of the variation in floury grains percentage (FGP). Further analysis with an increased number of SSR markers revealed that the floury endosperm of 'Suweon 542' was directed by a major recessive locus, flo7(t), located in the 19.33-19.86 Mbp region of chromosome 5, with RM18639 explaining 92.2% of FGP variation in the F2 population. Through further physical mapping, a co-segregate and co-dominant DNA marker with the locus, flo7(t) was successfully developed, by which, thereby, breeding efficiency of rice cultivars having proper dry milling adaptability with high yield potential or useful functional materials would be improved. 'Suweon 542' maintained the early maturity of the wild type, Namil, which can be used in rice-wheat double cropping systems in Korea not only for improved arable land but also for sharing flour production facilities. In addition to the high susceptibility against major rice diseases, nevertheless, another possible drawback of 'Suweon 542' is the high rate of viviparous under prolonged rainfall during the harvesting season. To overcome susceptibility and vivipary of 'Suweon 542', the progeny lines, derived from the crosses 'Suweon 542' and 'Jopyeong', an early maturing rice cultivar with multiple resistance against rice blast, bacterial blight, and rice strip virus, and 'Heugjinju', a anthocyanin pigment containing black rice cultivar, were intensively evaluated. As the outputs, three dry milling suitable rice elite lines, 'Jeonju614', 'Jeonju615', and 'Jeonju616' were developed.

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