• Interdisciplinary Bio Central
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• 제5권2호
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• pp.4.1-4.3
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• 2013

A history of discoveries of a gene and DNA was viewed with respect to people, time and places. It started with G. Mendel and J. Meisher, who discovered a gene in a plant species in 1866 and DNA in animals in 1869, respectively. With recognition that DNA was a chemical substance, A. Kossel identified the four chemical components of DNA without knowing their biological function around the turn of the 19th century. On the other hand F. Griffith found a peculiar activity in a bacterial species in 1928, but victimized by the war before understanding what it was. Those discoveries were made in Europe, but they were still fragmentary. Then, in USA, O. T. Avery, A. Hershey, M. Nirenberg and other scientists organized the European discoveries and elucidated their coordinated biological functions in 1950's and 1960'.

• Journal of Microbiology and Biotechnology
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• 제16권9호
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• pp.1472-1476
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• 2006

Previous study demonstrated that the restriction barrier of Streptomyces griseus is almost completely bypassed by the Streptomyces-E. coli shuttle vectors passed through the E. coli GM161 strain and methylated with AluI and HpaII methyltransferases. The same DNA methylation of the genomic DNA fragments cloned the nonreplicative vectors generated integrative transformation and gene disruption of their chromosomal counterparts at high efficiencies in S. griseus. This result indicated that the efficiency of gene disruption depends on the efficient transfer of the incoming DNA into bacterial hosts.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.869-872
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• 2009

The cyclic undecapeptide cyclosporin A (CyA), one of the most valuable immunosuppressive drugs, is produced nonribosomally by a multifunctional cyclosporin synthetase enzyme complex by the filamentous fungus Tolypocladium niveum. To increase CyA productivity by wild-type T. niveum (ATCC 34921), random mutagenesis was first performed using an antifungal agar-plug colony assay (APCA) selection approach. This generated a mutant strain producing more than 9-fold greater CyA than the wild-type strain. Additionally, a foreign bacterial gene, Vitreoscilla hemoglobin gene (VHb), was transformed via protoplast regeneration and its transcription was confirmed by RT-PCR in the UV-irradiated mutant cell. This led to an additional 33.5% increase of CyA production. Although most protoplast-regenerated T. niveum transformants tend to lose CyA productivity, the optimized combination of random mutagenesis and protoplast transformation described here should be an efficient strategy to generate a commercially valuable, yet metabolite low-producing, fungal species, such as CyA-producing T. niveum.

• Archives of Pharmacal Research
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• 제21권6호
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• pp.621-628
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• 1998

The "evolution" of a thing, a custom, an organ is thus by no means its progressus toward a goal, even less a logical progressus by the shortest route and with the least expendit ure of force, but a succession of more or less profound, mutually independent processes of subduing, plus the resistances they encounter, the attempts at transformation for the purpose of defense and reaction, and the results of successful counteractions. The form is fluid, but the "meaning" is even more so (Friedrich W. Nietzsche).

• 한국약용작물학회지
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• 제15권2호
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• pp.100-104
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• 2007

A protocol for the production of transgenic Panax ginseng C.A. Meyer was established via Agrobacterium tumefaciens-mediated genetic transformation of direct somatic embryos. A number of conditions related to the co-cultivation were tested with respect to maximizing transformation efficiency. The results showed that pH of the co-cultivation medium (5.7), the bacterial growth phase (optical density; $OD_{600}$ = 0.8), co-cultivation period (3 days), and acetosyringone concentration $(100\;{\mu}M)$ had positive effects on transformation. Selected plantlets were cultured on the medium at an elevated hygromycin level(30 mg/l). Integration of the transgenes into the P. ginseng nuclear genome was confirmed by PCR analysis using hpt primers and by Southern hybridization using hpt-specific probe. The transgenic plantlets were obtained after 3-month cultivation and did not show any detectable variation in morphology or growth characteristics compared to wild-type plants.

• 식물조직배양학회지
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• 제28권4호
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• pp.221-225
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• 2001

사과 갈라 품종의 고효율 형질전환 기술체계를 확립하기 위하여 Agobacterium을 이용한 형질전환에 관여하는 상처유도 방법, 배지 고형물, 엽절편체 기원, acetosyringone의 농도와 MES첨가 등 몇 가지 요인이 재분화 및 형질전환에 미치는 영향에 대하여 연구하였다. 엽절편체의 상처유도는 수술용 핀셋 (non-traumatic forcep)의 사용보다는 단순한 절단 후 균접종과 3일 공동배양을 할 경우 재분화와 형질전환율이 더 증가하는 경향을 나타냈다. Agar (A)와 Gelrit $e^{ }$(G)의 조성에 따른 배지 고형물의 처리에서는 Gelrite의 농도가 높을수록 재분화율이 증가하였으나, 형질전환율에 있어서는 2.5 G, 3.5 A+l.2 G 및 7.0 A의 처리 간에 차이가 없었다. 엽신장배지 또는 증식배지 유래가 재분화 및 형질전환율에 유의한 차이를 보이지는 않았으나, 증식배지 유래가 형질전환율을 더 높이는 경향을 나타냈다. Acetosyringone은 0.1 mM 이상의 농도가 첨가할 경우 높은 재분화 및 형질전환을 나타냈고, 0.15 mM의 농도에서 가장 높은 형질전환율을 나타냈다. MES의 재분화와 형질전환에 미치는 영향은 나타나지 않았다.다.

• 한국연초학회지
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• 제20권1호
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• pp.66-70
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• 1998

TMV resistant lines (TRLs) originated from the Blo plant of Nicotiana tabacum cv. NC82 transformed with TMV coat protein cDNA which initially showed delayed disease symptom were selected for increased resistance in each subsequent generation. The result of field experiment of the transgenic tobacco lines in the fifth generation for TMV resistance and their response to other tobacco diseases (black shank, bacterial wilt, and powdery mildew) is described in this report. When fifteen TRLs of the fifth generation were tested for TMV resistance by mechanically inoculating the individual plants, over 95 percent of the plants of 6 lines showed complete resistance even 8 weeks after the inoculation. Average frequency of the resistant plants in TRLs of the fifth generation 8 weeks after the inoculation was 87%. Stable insertion and expression of TMV coat protein cDNA in the fifth generation of the transgenic tobacco plant were confirmed by PCR and immunoblot hybridization, respectively. All TRLs were resistant to the black shank but were susceptible to the bacterial wilt disease and the powdery mildew to the same degree as non-transgenic NC82 was. Therefore, it was indicated that the phenotypes related at least to disease resistance were not changed in the transgenic tobacco. Key words : TMV CP cDNA, TMV resistant tobacco plant, transformation.

• Journal of Microbiology and Biotechnology
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• 제18권2호
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• pp.234-241
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• 2008

Agrobacterum tumefaciens-mediated transformation (ATMT) is becoming an effective system as an insertional mutagenesis tool in filamentous fungi. We developed and optimized ATMT for two Colletotrichum species, C. falcatum and C. acutatum, which are the causal agents of sugarcane red rot and pepper anthracnose, respectively. A. tumefaciens strain SK1044, carrying a hygromycin phosphotransferase gene (hph) and a green fluorescent protein (GFP) gene, was used to transform the conidia of these two Colletotrichum species. Transformation efficiency was correlated with co-cultivation time and bacterial cell concentration and was higher in C. falcatum than in C. acutatum. Southern blot analysis indicated that about 65% of the transformants had a single copy of the T-DNA in both C. falcatum and C. acutatum and that T-DNA integrated randomly in both fungal genomes. T-DNA insertions were identified in transformants through thermal asymmetrical interlaced PCR (TAIL-PCR) followed by sequencing. Our results suggested that ATMT can be used as a molecular tool to identify and characterize pathogenicity-related genes in these two economically important Colletotrichum species.

• Journal of Plant Biotechnology
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• 제32권3호
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• pp.161-165
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• 2005

Agrobacterium과 자엽절편의 공동배양으로 박과작물인 오이의 형질전환체를 생산하였다. 오이 배양재료는 "은침"의 자엽절편을 사용하였으며, reporter유전자로서 gus유전자와 선발표지로서 bar 또는 nptII유전자로 각각 제작된 pPTN289와 pPTN290벡터를 GV3101, LBA4404, EHA101에 형질전환하여 공동배양하였다. 형질전환빈도는 Agrobacterium의 종류에 따라 현저한 차이가 있었으며, 특히 사용한 균주중 EHA101에서 0.35%로 가장 높았다. 선발배지에서 형성된 오이 식물체중 제초제 저항성 (12개체)과 paromomycin 저항성 (3개체)을 얻었고, 이들 모두 gus양성반응 나타냈다. Southern분석에 의하여 오이 형질전환체의 genome에 gus유전자가 도입되어 있음을 확인 하였다.

• 아시안잔디학회지
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• 제18권3호
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• pp.141-148
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• 2004

다양한 Zoysiagrass 4가지 품종들을 식물재료로 사용하여 Agrobacterium만 이용한 방법 그리고 particle bombardment로 배발생캘러스에 상처를 낸 후, Agrobacterium으로 공동배양 시키는 2가지 다른 형질전환 방법을 비교하였다. 예비실험에서 일반적으로 형질전환에 널리 사용되는 kanamycin과 PPT(phospinitricin)의 적적선발농도에 대해서 실험하였는데, kanamycin의 경우 300mg/l 그리고 PPT의 경위 50mg/l의 농도에서 가장 효과적인 선발 효율을 나타내었다. Agrobacterium을 이용한 형질전환은 Agrobacterium을 2일간 배양시킨 다음, 박테리아 농도를 O.D 600nm=1.0-1.2로 맞추고, 배발생캘러스를 30분간 간염 시키는 방법이 효과적이었는데, particle bombardment를 이용하여 캘러스에 상처를 유발시킨 후, Agrobacterium으로 감염시키면 3배 이상 높은 형질전환 수율을 획득할 수 있었다. 이상의 결과는 한국잔디 형질전환에 있어서 particle bombardment과 Agrobacterium을 병행하여 실시한 최초의 보고이고, 이러한 시스템을 기반으로 하여 향후 한국잔디를 포함하여 다른 난지형 및 한지형 잔디의 품종개량에 널리 이용되리라 생각된다.