• 제목/요약/키워드: DNA polymerase

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고대 DNA의 분석과 검증 (Analysis and Verification of Ancient DNA)

  • 지상현;서민석
    • 헤리티지:역사와 과학
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    • 제40권
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    • pp.387-411
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    • 2007
  • 고대 DNA분석은 인류학, 고고학, 생물학자뿐만 아니라 대중의 관심사가 될 정도로 점차 중요성이 강조되고 있다. 고고학자와 생물학자는 인류의 기원과 집단의 이주, 민족의 형성 그리고 고대인의 질병과 매장문화를 규명하는데 있어 고대 DNA분석을 접목하고 있으며, 이미 멸종된 동물의 계통진화학적인 연구에도 이를 활용하고 있다. 고대 DNA분석의 새로운 전기가 마련된 계기는 고대 시료에서 추출되는 미량의 DNA 증폭을 가능하게 한 종합효소연쇄반응(Polymerase chain reaction, PGR)법이 개발되면서였다. 그러나 고대 DNA는 탈아미노화나 절편화 등의 분자 손상 정도가 심한데 이것은 PCR에서 중합효소의 정확한 DNA 증폭을 방해하는 요인으로 작용한다. 시토신이 탈아미노화되어 우라실을 형성하는 것은 DNA의 염기치환오류를 일으킬 수 있으며, 이런 현상은 증폭 과정에서 고유의 염기서열에 대한 고정치환($C{\rightarrow}T$, $G{\rightarrow}A$)을 유도하게 된다. 또한 대부분의 고대시료는 외부 오염물에 노출되어 있는데, 특히 외부 DNA의 오염은 고대 DNA의 염기서열을 결정함에 있어서 부정확한 결과를 도출시키는 심각한 문제를 초래하곤 한다. 이와 같이 고대 시료는 오랜 기간 동안 자연 분해과정과 다양한 오염물질에 노출되어 있어 그 훼손 정도가 심한 것이 일반적이다. 고대 DNA 연구에 있어서 많은 생화학적 손상과 외부 DNA의 오염을 극복하기 위해서는 보통의 분자생물학적인 방법과 기준보다 더욱더 엄격한 검증 절차에 의하여 연구가 진행되어야 하며, 연구 결과의 신뢰성을 확보하는 것이 무엇보다 중요하다. 따라서 본 글에서는 고대 DNA의 손상과 오염물질에 의한 부정확한 염기서열결정과 오류를 보정하고 예방할 수 있는 연구 기준과 실험적 절차를 설명하고자 한다.

Potential Biotypes in Korean Isolates of Bipolaris cactivora Associated with Stem Rot of Cactus

  • Kim, Jeong-Ho;Jeoung, Myoung-Il;Hyun, Ick-Hwa;Kim, Young-Ho
    • The Plant Pathology Journal
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    • 제20권3호
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    • pp.165-171
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    • 2004
  • A total of 62 isolates of Bipolaris cactivora causing cactus stem rots were isolated from major cactus-growing areas in Korea. Colony morphology of the isolates on potato-dextrose agar was differentiated into aerial (CA) and non-aerial mycelial types (CB). CA had profound aerial mycelium with grayish brown (CA-l), light brownish (CA-2), and brownish (CA-3) pigmentations; respectively, while CB had dark brownish pigmentations. CA had conidia of less dark pigmentation and acute terminal end. CB had darker and more round-end conidia. Twenty-eight amplified fragments were produced by polymerase chain reaction (PCR) with a set of 2 random primers. The sizes of amplified DNA fragments ranged approximately from 0.1 to 2.3 kb. The isolates were classified into 2 major genomic DNA random amplified polymorphic DNA (RAPD) groups at the genomic similarity of 97.7% and 95.1%, respectively. Cluster analysis of genetic similarity among the isolates generated a dendrogram that clearly separated all isolates into SA or SB. This result suggests that there may be two morphotypes of B. cactivora in Korea that may differ in their genetic constitutes.

유전자증폭반응 기법을 이용한 홍조류 잔금분홍잎 및 누은분홍잎의 구별 (Discrimination of Two Red Algae Acrosorium polyneurum and A. yendoi Using Polymerase Chain Reaction Technique)

  • 김용국;진형주;김영식;박중연;남기완;홍용기
    • 한국수산과학회지
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    • 제30권4호
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    • pp.585-588
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    • 1997
  • The polymerase chain reaction (PCR) technique was used to distinguish from two morphologically similar red algal species; Acrosorium polyneurum and A. yendoi. Total DNA was extracted by the LiCl method. The extracted DNA (15 ng) in a $25{\mu}\ell$ reaction volume was amplified by the PCR technique using primers covering with mitochondrial D-loop gene, nuclear rDNA internal transcribed spacer (ITS), and nuclear rDNA external transcribed spacer. A. yendoi could be distinguished from A. polyneurum on the producible basis of amplified ITS fragment of 650 bp.

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사람의 게놈에 존재하는 Cytochrome P450 2E1의 Retropseudogene에 대한 분자유전학적 증거 (Molecular Evidence for the Presence of CYP2E1 Retropseudogene in Human Genome)

  • 유민;신송우
    • 대한의생명과학회지
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    • 제4권2호
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    • pp.129-135
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    • 1998
  • Cytochrome P45O 2El (CYP2El)의 retropseudogene이 사람에 존재하는지 확인하기 위해 혈액에서 분리한 DNA를 주형으로 한 polymerase chain reaction (PCR)을 수행하였다. Primer는 CYP2E1 유전자를 기초하여 여러개 제작하되 적절한 조합에 따라 정상유전자와 retropseudogene이 동시에 증폭될 수 있도록 고안하였다. 본 실험의 결과 그동안 예상은 되었지만 DNA차원에서 미처확인되지 못하였던 CYP2E1의 retropseudogene을 직접 증폭해낼 수 있었다. 세부 구조는 Southern blotting과 DNA 염기서열 결정에서 최종 분석되었다. PCR 반응으로 증폭된 부분에서는 염기서열이 mRNA와 완전히 일치하고 있는 점으로 미루어서 CYP2E1의 retropseudogene은 비교적 최근에 발생했을 것으로 추정되었다.

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A Genetic Marker for the Korean Native Cattle (Hanwoo) Found by an Arbitrarily Primed-Polymerase Chain Reaction (AP-PCR)

  • Lee, Ji-Seon;Lee, Chang-Hee;Nam, Doo-Hyun;Jung, Young-Ja;Yeo, Jung-Sou
    • BMB Reports
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    • 제33권3호
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    • pp.208-212
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    • 2000
  • In order to develop a specific genetic marker for the Korean native cattle (Hanwoo), an arbitrarily-primed polymerase chain reaction (AP-PCR) analysis of 6 different cattle breeds was attempted. Eight different arbitrary primers, each longer than 20-mer nucleotides, were used. In comparison to the AP-PCR patterns, several distinctive DNA bands that are specific for a certain breed were detected. When the primer Kpn-X was employed, a 280bp DNA fragment was found to be specific only for Hanwoo. In an individual analysis of Hanwoo, this AP-PCR marker was observed in 123 head of cattle among the 153 that were tested (80.4%). Nucleotide sequencing revealed that this fragment has a short microsatellite sequence of tandem repeat, $A(G)_{1-2}\;(C)_{1-3}AGAG$. According to the analysis of AP-PCR band patterns, Hanwoo was discovered to be genetically most closely-related with Holstein among the various cattle breeds.

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A highly sensitive molecular diagnosis method for detecting Toxoplasma gondii tachyzoite: a PCR/dot blot hybridization

  • Hong, Sun-Hwa;Lee, Yun-Seong;Kim, Young-Ho;Kim, Ok-Jin
    • 한국동물위생학회지
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    • 제37권1호
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    • pp.29-33
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    • 2014
  • This study aimed at finding a fast, sensitive, and efficient protocol for molecular identification of intracellular protozoa Toxoplasma (T.) gondii. For molecular detection of T. gondii, we developed a polymerase chain reaction coupled with dot blot hybridization assay (PCR/DBH). For DBH analysis, the amplified DNA of T. gondii tachyzoite was labeled by incorporation of digoxigenin. The DBH assay alone was capable of detecting down to $1{\times}10^4$ pg of T. gondii genomic DNA. The PCR alone was capable of detecting down to $1{\times}10^3$ pg of T. gondii genomic DNA, whereas the PCR/DBH assay was capable of detecting down to $1{\times}10^2$ pg of T. gondii genomic DNA, indicating that sensitivity of the PCR/DBH method was approximately 10 to 100 times higher than PCR or DBH alone. Our PCR/DBH assay will be useful for confirming the presence of T. gondii on the samples and differentiating T. gondii infection from other intracellular protozoa infections.

Identification of Aster Yellows Phytoplasma in Dendranthema grandiflorum

  • Chung, Bong-Nam;Park, Gug-Seoun;Kim, Hyun-Ran;Park, Yong-Mun
    • The Plant Pathology Journal
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    • 제17권1호
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    • pp.57-61
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    • 2001
  • Phytoplasmas were identified from two chrysanthemum (Dendranthema grandiflorum) plants showing different symptoms ; one with stusting, rosette, and excessive branching (Ph-ch1), and the other with stunting and chlorosis (Ph-ch2). Electron microscopy of midrib of the plants with the symptoms revealed that numerous phytoplasmas were localized in the phloem cells. The disease was transmitted from infected plants to healthy ones by grafting. Phytoplasma-specific DNA was detected in polymerase chain reaction (PCR) analysis with template DNA extracted from the leaves of Ph-ch1 and Ph-ch2, both of which yielded a same DNA band corresponding to 1.5 kb. Using a specific primer pair (R16F1/R1) synthesized based on aster yellows (AY) phytoplasma, a DNA fragment of 1.1 kb was amplified by PCR. Endonuclease restriction patterns of the 1.1 kb PCR products from Ph-ch1 and Ph-ch2, which were dgeste with each of the restriction endonucleases Sau3A, Hha, Alu and Rsa, were same as those of AY phytoplasma from periwinkle. This suggests that the chrysanthemum plants (Ph-ch1 and Ph-ch2) be infected with a phytoplasma belonging to AY phytoplasma.

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느타리버섯속(屬)의 DNA 다형성분석(多型性分析)에 영향(影響)을 미치는 PCR 조건(條件) (Parameters Affecting Polymerase Chain Reaction in RAPD Analysis of Pleurotus spp.)

  • 김범기;정미정;이창수;이희경;유영복;유진창
    • 한국균학회지
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    • 제23권3호통권74호
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    • pp.202-208
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    • 1995
  • 본 실험결과 느타리버섯속에서의 재현성 있는 최적 RAPD 조건은 $50\;{\mu}l$ 반응액에서 80 ng template DNA, 30 pmole primer, $200\;{\mu}M$ dNTP, 2 mM $MgCl_2$, 50 mM KCl, 10 mM Tris-HCI(pH 9.0), 0.1% Triton X-100, 1.5 unit Taq polymerase(promega)였다. 여섯 개의 primer가 Pleurotus속 8종의 균주에서 RAPD polymorphism을 보임을 알 수 있었으며, 이들의 염기배열은 PR2(GGG GGG AAG C), PR3(GCG GTT GAG G), PR4(CGC ACC GCA C), PR10(CAA TCG CCG T), PR11(CAG CAC CCA C), PR17(TAG GCG TAT CAG GAG GCC CT)이었다.

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Molecular Analysis of HLA-C Using Polymerase Chain Reaction-Sequence Specific Primers

  • Lee, Kyung-Ok;Hong, Sung-Hoi;Kim, Min-Jung;Park, Taek-Kyu;Kim, Yoon-Jung;Lee, Kyu-Pum
    • BMB Reports
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    • 제30권1호
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    • pp.26-32
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    • 1997
  • Of all HLA class I molecules, HLA-C gene products are most poorly understood because they express at a low level on the cell surface compared to HLA-A and -B. In order to identify serologically detectable and undetectable HLA-C antigens, we have established a DNA-based tissue typing method for the HLA-C locus by PCR-SSP (polymerase chain reaction-sequence specific primers). Genomic DNA prepared from Iymphoblastoid 21 B-cell lines and 120 Korean individuals by proteinase K digestion and pheno/chloroform extractions have been typed by PCR-SSP (23 primer mixes were used). The PCR-SSP results of control cell lines were discrepant from serology in 1 case among 21 cases: Cw6 which was negative by serology but positive by PCR-SSP (cell line: MANIKA). Twenty four HLA-Cw "blank" antigens among fifty Korean individuals were completely determined by PCR-SSP DNA typing. HLA-Cw*0101 (15.3%), Cw*1401 (12.3%) and Cw*0701 (11.7%) alleles were frequently found in 120 Korean individual samples. In conclusion. the high level of discrimination for HLA-C alleles may prove useful and informative in the study of transplant survival, and identify the importance of allelic differences, not readily detectable by serology, on host and donor compatibility.

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