• Title/Summary/Keyword: Mutation Rate

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Cryopreservation of Chrysanthemum morifolium cv. 'White ND' Shoot Tips using Encapsulation-Dehydration-Vitrification Method (캡슐화-탈수화-유리화에 의한 국화 품종 '화이트 엔디' 신초의 초저온 동결보존)

  • Jeon, Su Min;Kim, Chang Kil
    • Current Research on Agriculture and Life Sciences
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    • v.32 no.2
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    • pp.99-103
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    • 2014
  • This study investigated the effects of cryopreserving Chrysanthemum morifolium cv. 'White ND' shoot tips for eliminating viroids. As a result, smaller shoot tips (2-3 LP, 1mm) showed a better survival and regrowth than larger shoot tips (4-5 LP, 1.5mm). The most effective vitrification solution for survival and regrowth was PVS3, which induced a high survival rate after 60 minutes of incubation. For a high efficiency, the best pre-treatment condition for vitrification was incubation in 88 mM sucrose for 24 h, 0.3M sucrose for 16 h, 0.5 M sucrose for 6 h, and 0.7 M sucrose for 3 h, in a descending order. The ploidy levels were the same in the mother plants and following cryopreservation, which confirmed the absence of any gene mutation.

Isolation and Characterization of $\alpha$-Amylase Producing Bacillus sp. AIV 1940 and Properties of Starch Synthetic Wastewater Degradation ($\alpha$-Amylase 생성균주 Bacillus sp. AIV 1940의 분리, 특성 및 합성폐수분해능)

  • 박형수;김무훈;양선영;조미영;고범준;박용근
    • Korean Journal of Microbiology
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    • v.38 no.1
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    • pp.1-6
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    • 2002
  • $\alpha$-Amylase producing bacteria were isolated from activated sludge of corn processing wastewater plant and paddy field soil samples and selected by the direct iodine reaction. The isolate was identified as Bacillus sp. after morphology, API system and fatty acid analyses. To enchance $\alpha$-amylase productivity, a successive mutation of Bacillus sp. AIV 19 was performed using the treatment of nitrosoguanidine(NTG).The mutant, Bacillus sp. AIV 1940, showed about 1.8-fold level of amylase activity compared with parental strain. The isolate was Gram-positive and rod (2.8-3.0 $\mu$m long, 0.5-0.6 $\mu$m wide) type. The strain increased the bacterial mass at 3000 mg/l starch concentration. Organic substance removal rate was 40.2, 72.3% respectively after 1 and 3 day reaction using starch synthetic wastewater (intial CODcr was 4,455 mg/l).

Identification of three pathways for p-cresol catabolism and their gene expression in Pseudomonas alkylphenolica KL28 (Pseudomonas alkylphenolica KL28에 존재하는 3종류의 p-cresol 분해 경로 및 유전자 발현)

  • Sung, Jin Il;Lee, Kyoung
    • Korean Journal of Microbiology
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    • v.52 no.3
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    • pp.298-305
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    • 2016
  • Previously our laboratory showed that Pseudomonas alkylphenolica KL28 possesses two different lap and pcu gene clusters for p-cresol catabolism. In this study, additional gene cluster (pchACXF-pcaHG-orf4-pcaBC) has been identified to encode enzymes necessary for catabolism of p-cresol to ${\beta}$-carboxy-cis,cis-muconate. This gene cluster showed almost identical nucleotide sequence homologies to those in the plasmid of Pseudomonas putida NCIMB 9866 and 9869, British origins, indicating the possibility of a horizontal gene transfer. Through mutagenesis of each gene cluster and gfp-based promoter reporter assays, it has been shown that the three gene clusters are functionally operated and pch genes are induced by p-cresol. Furthermore, the pcu gene cluster of the three was shown to be dominantly expressed in utilization of p-cresol. Mutation of the pcu gene was defective in aerial structure formation under p-cresol vapor, indicating the utilization rate of carbon source is one of key elements for the multicellular development of this strain.

Induction of Somatic Embryos and RAPD Analysis in Regenerated Plantlets of Bupleurum falcatum L. (자호(紫胡)의 체세포배(體細胞胚) 형성(形成)과 재생(再生) 식물체(植物體)의 RAPD 분석(分析))

  • Park, Cheol-Ho;Yu, Chang-Yeon;Seo, Jeong-Sik;Kim, Ki-Sik;Ahn, Sang-Duek;Chang, Byoung-Ho
    • Korean Journal of Medicinal Crop Science
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    • v.3 no.1
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    • pp.50-55
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    • 1995
  • This study was conducted to determine the optimum conditions for induction and different somatic of somatic embryos as well as germination of encapsulated and stored somatic embryos. Somatic embryos was better formed in 1/2X MS medium than full - strength MS medium. 0.1 to 1.0mg/lBA and kinetin promoted shoot differentiation of somatic embryos. Higher concentration tend to inhibit differentiation. IAA affect positively both root and shoot growth. In vitro germination of somatic embryos encapsulated with 2% alginate matrix containing 1/2 MS nutrient medium and $AgNO_3$ 5mg/l was 86%. Storage of somatic embryos was effecive at $5^{\circ}C$ but the germination rate decreased with longer storage period. RAPD analyses with plants regenerated from the somatic embryos showed DNA polymorphism, indicating abolition of primer binding site by point mutation, deletion, or insertion of certain sequences.

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Genetic Variations of Congenital Hypothyroidism (선천성 갑상샘기능저하증의 유전자 변이)

  • Lee, Yong-Wha;Lee, Dong-Hwan
    • Journal of Genetic Medicine
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    • v.7 no.1
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    • pp.9-15
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    • 2010
  • Congenital hypothyroidism (CH) is detected at a rate of 1 in 3,000 to 4,000 live births, making it the most common congenital endocrine disorder worldwide. CH is most commonly caused by defects in thyroid development leading to thyroid dysgenesis or dyshormonogenesis. Congenital hypothyroidism is usually sporadic, but up to 2% of cases of thyroid dysgenesis are familial, and CH caused by organification defects is often inherited in a recessive manner. The candidate genes associated with this genetically heterogeneous disorder fall into two main groups: those causing thyroid gland dysgenesis and those causing dyshormonogenesis. Genes associated with thyroid gland dysgenesis include the TSHR gene in nonsyndromic CH, and Gsa and the thyroid transcription factor (TTF-1, TTF-2, and Pax-8) genes, which are associated with different complex syndromes that include CH. Among genes associated with dyshormonogenesis, the TPO and TG genes were initially described, and more recently PDS, NIS, and THOX2 gene defects. There is some evidence for a third group of CH conditions associated with iodothyronine transporter defects that are, in turn, associated with severe neurological sequelae.

Novel Mutations in the CPT1A Gene Identified in the Patient Presenting Jaundice as the First Manifestation of Carnitine Palmitoyltransferase 1A Deficiency

  • Choi, Jong Sub;Yoo, Hyeoh Won;Lee, Kyung Jae;Ko, Jung Min;Moon, Jin Soo;Ko, Jae Sung
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.19 no.1
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    • pp.76-81
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    • 2016
  • Carnitine palmitoyltransferase 1A (CPT1A) is an enzyme functioning in mitochondrial fatty acid oxidation (FAO) of the liver. Patients with CPT1A deficiency have impaired mitochondrial FAO and display hypoketotic hypoglycemia and hepatic encephalopathy as typical manifestations. In this report, we present a case of CPT1A deficiency presenting jaundice as the first manifestation. A 1.9 years old boy showed jaundice and elevated levels of free and total carnitine were observed. From direct sequencing analysis of CPT1A, two novel mutations, c.1163+1G>A and c.1393G>A (p.Gly465Arg), were identified. At the age of 2.2 years, hypoglycemia, tachycardia, and altered mental status developed just after cranioplasty for craniosynostosis. High glucose infusion rate was required for recovery of his vital signs and mentality. Diet rich in high carbohydrate, low fat and inclusion of medium chain triglyceride oil resulted in improvement in cholestatic hepatitis and since then the boy has shown normal growth velocity and developmental milestones to date.

In vitro and in vivo Biological Responses of Proton Irradiation from MC-50 Cyclotron

  • Jung, Uhee;Eom, Hyeon Soo;Jeong, Kwon;Park, Hae-Ran;Jo, Sung-Kee
    • Journal of Radiation Industry
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    • v.6 no.3
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    • pp.223-229
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    • 2012
  • In this study, we investigated the biological damage and stress responses induced by ion beam (proton beam) irradiation as a basis for the development of protective measures against space radiation. We examined the biological effects of proton beam produced by MC-50 cyclotron at KIRAMS on the cultured cells and mice. The proton beam energy used in this study was 34.9 MeV and the absorption dose rate for cells and mice were $0.509Gy\;sec^{-1}$ and $0.65Gy\;sec^{-1}$, respectively. The cell survival rates measured by plating efficiency showed the different sensitivity and dose-relationship between CHO cells and Balb/3T3 cells. HGPRT gene mutation frequency in Balb/3T3 was $15{\times}10^{-6}Gy^{-1}$, which was similar to the reported value of X-ray. When stress signaling proteins were examined in Balb/3T3 cells, $I{\kappa}B-{\alpha}$ decreased markedly whereas p53, phospho-p53, and Rb increased after proton beam irradiation, which implied that the stress signaling pathways were activated by proton beam irradiation. In addition, cellular senescence was induced in IMR-90 cells. In the experiments with C57BL/6 mouse, the immune cells (white blood cells, lymphocytes) in the peripheral blood were greatly reduced following proton beam irradiation whereas red blood cells and platelets showed relatively little change. These results can be utilized as basic data for studying the biological effects of proton beam using MC-50 cyclotron with respect to proton therapy research as well as space radiation research.

Improving Productivity of Pravastatin, HMG-CoA Reductase Inhibitor (HMG-CoA Reductase Inhibitor인 Pravastatin의 생산성 향상)

  • Jeon, Dong-Soo;Bai, Dong-Hoon
    • Food Engineering Progress
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    • v.13 no.4
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    • pp.243-250
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    • 2009
  • Pravastatin sodium, competitive inhibitors of HMG-CoA(3-hydroxy-3-methylglutaryl coenzyme A) reductase, is produced from the culture broth of Streptomyces carbophilus KCCM 10370, The production of Pravastatin sodium was increased about 45 fold compared to wild type by UV mutation. Production of Pravastatin was also improved by continuous feeding of Compactin sodium to 24% and bioconversion ratio was also increased to 4.3% by intermittent addition. In main culture, concentration of Compactin sodium was kept less than 0.1%(w/v) under continuous feeding of Compactin sodium then product was 0.49% and bioconversion was 70%. After finishing the fermentation, Pravastatin was purified by various chromatographies such as Diaion HP20 resin column, Partition, and ODS(Octa-Decylsilyl Silicagel) resin column with a final yield of 70~72% and over 99.7% purity. The IR, UV, and NMR study of the purified Pravastatin sodium showed the same pattern as that of EP(European Pharmacopoeia).

Genotyping of avian pathogenic Escherichia coli by DNA fragment analysis for the differences in simple sequence repeats

  • Han, Mi Na;Byeon, Hyeon Seop;Han, Seong Tae;Jang, Rae Hoon;Kim, Chang Seop;Choi, Seok Hwa
    • Korean Journal of Veterinary Service
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    • v.41 no.4
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    • pp.257-262
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    • 2018
  • Avian pathogenic E. coli (APEC) causes severe economic losses in the poultry farms, due to systemic infections leading to lethal colisepticemia. It causes a variety of diseases from air sac infection to systemic spread leading to septicemia. Secondary infection contains opportunistic infections due to immunosuppression disease. Collibacillosis causes the great problems in the poultry industry in Korea. Thus, it is necessary to identify and classify the characteristics of E. coli isolate of chicken origin to confirm the diversity of symptoms and whether they are transmitted among the farms. Fragment analysis is identify the difference in the number of Variable-Number Tandem-Repeats (VNTRs) for genotyping. VNTRs have repeating structure (Microsatellite, Short tandem repeats; STR, Simple sequence repeats; SSR) in the chromosome. This region can be used as a genetic marker because of its high mutation rate. And various lengths of the amplified DNA fragment cause the difference in the number of repetition of the DNA specific site. The number of repetition sequences indicates the separated size of fragments, so the each fragments can be distinguished by specific samples. The results of the sample show that there is no difference in six microsatellite loci (yjiD, aidB, molR_1, ftsZ, b1668, yibA). There are differences among the farms in relation of the number of repetitions of other six microsatellite loci (ycgW, yaiN, yiaB, mhpR, b0829, caiF). Four (ycgW, yiaB, b0829, caiF) of these six microsatellite loci show statistically significant differences (P<0.05). It means that the analysis using four microsatellite loci including ycgW, yiaB, b0829, and caiF can confirm among the farms. Five E. coli samples in one farm have same SSR repetition at all markers. But, there are significant differences from other farms at Four (ycgW, yiaB, b0829, caiF) microsatellite loci. These results emphasize again that the four microsatellite loci makes a difference in the amplified DNA fragments, enabling it to be used for E. coli genotyping.

A Small GTPase RHO2 Plays an Important Role in Pre-infection Development in the Rice Blast Pathogen Magnaporthe oryzae

  • Fu, Teng;Kim, Joon-Oh;Han, Joon-Hee;Gumilang, Adiyantara;Lee, Yong-Hwan;Kim, Kyoung Su
    • The Plant Pathology Journal
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    • v.34 no.6
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    • pp.470-479
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    • 2018
  • The rice blast pathogen Magnaporthe oryzae is a global threat to rice production. Here we characterized RHO2 gene (MGG_02457) that belongs to the Rho GTPase family, using a deletion mutant. This mutant ${\Delta}Morho2$ exhibited no defects in conidiation and germination but developed only 6% of appressoria in response to a hydrophobic surface when compared to the wild-type progenitor. This result indicates that MoRHO2 plays a role in appressorium development. Furthermore, exogenous cAMP treatment on the mutant led to appressoria that exhibited abnormal morphology on both hydrophobic and hydrophilic surfaces. These outcomes suggested the involvement of MoRHO2 in cAMP-mediated appressorium development. ${\Delta}Morho2$ mutation also delayed the development of appressorium-like structures (ALS) at hyphal tips on hydrophobic surface, which were also abnormally shaped. These results suggested that MoRHO2 is involved in morphological development of appressoria and ALS from conidia and hyphae, respectively. As expected, ${\Delta}Morho2$ mutant was defective in plant penetration, but was still able to cause lesions, albeit at a reduced rate on wounded plants. These results implied that MoRHO2 plays a role in M. oryzae virulence as well.