• 한국동물생명공학회지
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• 제35권4호
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• pp.323-328
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• 2020

Direct injection of genome editing tools such as CRISPR/Cas9 system into developing embryos has been widely used to generate genetically engineered pigs. The approach allows us to produce pigs carrying targeted modifications at high efficiency without having to apply somatic cell nuclear transfer. However, the targeted modifications during embryogenesis often result in mosaicism, which causes issues in phenotyping founder animals and establishing a group of pigs carrying intended modifications. This study was aimed to establish a genomic PCR and sequencing system of a single blastomere in the four-cell embryos to detect potential mosaicism. We performed genomic PCR in four individual blastomeres from four-cell embryos. We successfully amplified target genomic region from single blastomeres of 4-cell stage embryo by PCR. Sanger sequencing of the PCR amplicons obtained from the blastomeres suggested that PCR-based genotyping of single blastomere was a feasible method to determine mutation type generated by genome editing technology such as CRISPR/Cas9 in early stage embryos. In conclusion, we successfully genotyped single blastomeres in a single 4-cell stage embryo to detect potential mosaicism in porcine embryos. Our approach offers a simple platform that can be used to screen the prevalence of mosaicism from designed CRISPR/Cas9 systems.

• KSBB Journal
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• 제20권4호
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• pp.323-327
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• 2005

조직을 이용한 역전사 (RT)-PCR법을 이용하면 원하는 특정유전자의 발현을 비교적 정확하게 알 수 있지만 조직의 RNA를 이용하므로 세포단위의 정확한 유전자 발현을 알기에는 한계가 있다. 특히 그 기능과 성질이 다른 세포가 무수하게 많이 혼재하는 두뇌와 같은 조직은 신경계의 각종 뉴런(신경세포), 글리어 (glial cell) 등이 서로 얽혀 있다. 대표적인 신경세포의 degeneration 질병으로는 파킨슨병 (Parkinson's disease; PD)이 있다. 파킨슨병은 사람의 신경세포 관련 질병에 있어서 가장 일반적인 질병의 하나이다. PD의 가장 중요한 원인은 도파민 생성 신경세포의 퇴행 혹은 사멸에 기인하여 도파민 (dopamine)이라는 신경전달물질이 감소하는 것이 그 원인이다. 도파민과 같은 카테콜아민의 생합성에 관련된 효소는 타이로신 하이드록실레이스 (TH), 도파 데카르복실레이스 (DDC) 등이 알려져 있다. 그러나 그런 효소들의 생화학적 연구는 많이 되어 있음에도 불구하고 단일 흑질 신경세포에서의 이들 관련 유전자의 발현 양상에 대해서는 알려진 바가 거의 없다. PD와 관련된 유전자의 발현 정도를 밝히기 위하여, 레이저 다이섹터 (laser micro-dissector)에 의한 단일 신경세포의 분리에 착수하였다. 정해진 방법에 따라 정상 대조구 (비PD)와 PD 환자에서 각각 한 개 또는 여러 개를 성공적으로 분리한 흑질 신경세포를 이용하여 유전자 특이적 프라이머를 사용하여 RT-PCR을 행하였다. 그 결과, 단 한 개의 신경세포에서도 여러 개의 세포를 사용한 것과 같은 동일한 결과를 얻는 데 성공하였다. PD환자의 뇌에서 분리한 10개의 독립적인 세포의 예에서는 각 세포간의 발현차이가 인정되었으며, 특히 TH 유전자의 발현은 상당히 높은 확률로 검출되지 않았다. 이 결과로 단일 신경세포에서의 mRNA양을 검출하기 위해서는 본 본문의 RT-PCR법이 효과적인 방법임을 알 수 있다.

• Animal cells and systems
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• 제13권3호
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• pp.351-356
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• 2009

Ciliates are undoubtedly one of the most diverse protozoans that play a significant role in ecology. However, molecular examination, based on comparing the DNA sequences, has been done on a limited number of the species. Because most ciliates are uncultivable and their population sizes are often too small, it is usually difficult to obtain sufficient genomic DNA required for PCR based experiments. In the present study, we evaluated the effectiveness of four commercial DNA extraction procedures that extract high quality genomic DNA from a single ciliate cell. It was discovered that RED Extract-N-$Amp^{TM}$ PCR kit is the best method for removing PCR-inhibiting substances and minimizing DNA loss during purification. This method can also amplify more than 25 reactions of PCR. In addition, this technique was applied to single cells of 19 species belonged to 7 orders under 5 classes that isolated from mixed natural populations. Their small subunit ribosomal DNA (SSU rDNA) was successfully amplified. In summary, we developed a simple technique for the high-yield extraction of purified DNA from a single ciliate cell that may be more useful for rare ciliates, such as tiny and uncultivable marine microbes.

• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2005년도 창립 30주년 및 춘계학술대회
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• pp.18-18
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• 2005

• Asian Pacific Journal of Cancer Prevention
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• 제17권7호
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• pp.3065-3069
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• 2016

Single nucleotide polymorphism (SNP) detection has been used extensively for genetic association studies of diseases including cancer. For mass, yet accurate and more economic SNP detection we have optimized tetra primer amplification refractory mutation system polymerase chain reaction (ARMS PCR) to detect three SNPs in the cytochrome P450 2E1 (CYP2E1) gene locus; i.e. rs3813865, rs2070672 and rs3813867. The optimization system strategies used were (1) designing inner and outer primers; (2) determining of their optimum primer concentration ratios; and (3) determining of the optimum PCR annealing temperature. The tetra primer ARMS PCR result could be directly observed using agarose gel electrophoresis. The method succesfully determined three SNPs in CYP2E1 locus, the results being consistent with validation using DNA sequencing and restriction fragment length polymorphisms (RFLP).

• 농업과학연구
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• 제49권4호
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• pp.847-859
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• 2022

The development and commercialization of industrial genetically modified (GM) organisms is actively progressing worldwide, highlighting an increased need for improved safety management protocols. We sought to establish an environmental monitoring method, using real-time polymerase chain reaction (PCR) and propidium monoazide (PMA) treatment to develop a quantitative detection protocol for living GM microorganisms. We developed a duplex TaqMan quantitative PCR (qPCR) assay to simultaneously detect the selectable antibiotic gene, ampicillin (AmpR), and the single-copy Escherichia coli taxon-specific gene, D-1-deoxyxylulose 5-phosphate synthase (dxs), using a direct cell suspension culture. We identified viable engineered E. coli cells by performing qPCR on PMA-treated cells. The theoretical cell density (true copy numbers) calculated from mean quantification cycle (Cq) values of PMA-qPCR showed a bias of 7.71% from the colony-forming unit (CFU), which was within ±25% of the acceptance criteria of the European Network of GMO Laboratories (ENGL). PMA-qPCR to detect AmpR and dxs was highly sensitive and was able to detect target genes from a 10,000-fold (10^-4) diluted cell suspension, with a limit of detection at 95% confidence (LOD_95%) of 134 viable E. coli cells. Compared to DNA-based qPCR methods, the cell suspension direct PMA-qPCR analysis provides reliable results and is a quick and accurate method to monitor living GM E. coli cells that can potentially be released into the environment.

• 해양환경안전학회지
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• 제24권7호
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• pp.967-972
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• 2018

최근 우리나라 연안에서 출현빈도가 점차 늘어나고 있는 침편모조류에 속하는 Chattonella는 대표적인 유해조류 중 하나로, 이들 종은 세포벽이 없어, 단순히 세포의 형태나 크기 등 광학현미경 관찰만으로는 정확하게 동정하는 것이 어렵다. 따라서 본 연구에서는 2017년 득량만에서 발생한 Chattonella 적조 시료를 대상으로 단일 세포를 분리하고, 이들 시료의 28s rDNA, rbcL, psaA 영역을 대상으로 single-cell PCR 기법을 이용하여 종 동정을 실시하였다. 현미경 관찰 결과 장축은 평균 $74.0{\pm}10.1{\mu}m$이고 단축은 평균 $33.1{\pm}3.6{\mu}m$로 일반적인 Chattonella의 형태적 특징을 보였다. 28s rDNA, rbcL, psaA 영역을 대상으로 한 염기서열 비교 결과에서는 세 영역 모두에서 하나의 종으로 명확히 구분되지는 않았다. 하지만 C. marina, C. marina var. antiqua, C. marina var. ovata 그룹과 99~100 % 높은 서열 유사성을 보였다.

• Animal cells and systems
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• 제15권3호
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• pp.251-258
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• 2011

Ciliates are considered one of the most diverse protozoa and play significant roles in ecology. For successful taxonomic study of these microscopic eukaryotes, a staining procedure is necessary, due mainly to intrinsic difficulties in recognizing characteristics from living cells. Although molecular taxonomy has been used to resolve the ambiguities associated with traditional morphology-based taxonomy, extraction of genomic DNA from stained ciliate cells is not available yet. In the present study, we describe a method to extract genomic DNA from a single protargol-impregnated euplotid cell. By using $HgCl_2$ as a fixative and modulating the exposure time of bleach solution in the protargol impregnation, high-quality genomic DNA can successfully be extracted from a stained single cell with minimal loss of morphological integrity. This technique will contribute to the effectiveness of combined approaches of molecular and morphological taxonomy from single ciliate cells.

• Ocean and Polar Research
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• 제32권3호
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• pp.247-254
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• 2010

Single cell PCR analysis and light and scanning electron microscopic techniques were utilized to identify free living bivalve larvae in the coastal waters of Tae-an, on the west coast of Korea. Through DNA sequencing, venerid clam larvae were isolated and identified as Ruditapes philippinarum (99% similarity) and Meretrix lusoria (99%). Under microscopic observation, the D-veliger stage of R. philippinarum exhibited symmetrical shoulder angles and an elliptical ventral form. In contrast, M. lusoria displayed asymmetrical shoulder angles and a round ventral form in the umbonal stage. Size of the R. philippinarum larvae was $156{\pm}22{\mu}m$ in length, $126{\pm}12{\mu}m$ in height, $92{\pm}14{\mu}m$ in width with a length: height ratio of 1.23. Meretrix lusoria was $202{\pm}44{\mu}m$ in length, $161{\pm}35{\mu}m$ in height, $96{\pm}38{\mu}m$ in width with a length: height ratio of 1.25. Experimental results indicate that morphological and molecular characteristics provide evidence for the larval identification of these two venerid clam larvae species in nature.

• BMB Reports
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• 제32권6호
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• pp.529-534
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• 1999

Asymmetric PCR and single-strand conformation polymorphism (SSCP) methods were combined to analyze human leukocyte antigen (HLA)-DRB allele polymorphism. Asymmetric PCR amplification was applied to generate single-stranded DNA (ssDNA) using the nonradioactive oligonucleotide primers desinged for the polymorphic exon 2 region. The conformational differences of ssDNAs, depending on the allele type, were analyzed by nondenaturing polyacrylamide gel electrophoresis and visualized by ethidium bromide staining. The ssDNAs were clearly separated from double-stranded DNA without interference and obviously migrated depending on their allele type. This method was applied to the genomic DNA either from homozygous or from heterozygous cell lines containing the DR4 allele as template DNA using DR4-specific primers, and satisfying results were obtained. Compared to the standard PCR-SSCP method, this asymmetric PCR-SSCP method has advantages of increased speed, reproducibility, and convenience. Along with PCR-SSP or sequence-based typing, this method will be useful in routine typing of HLA-DRB allele.