• 원예과학기술지
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• 제17권4호
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• pp.473-475
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• 1999

본 연구는 antisense 유전자를 이용하여 웅성불임 식물체를 유기하는 웅성불임 유기 유전자의 발현을 억제함으로써 임성을 회복하기 위하여 실시하였다. 약특이 promoter(GBAN215-6 promoter)와 antisense 방향의 diphtheria toxin(DTx-A) 유전자로 제작된 pKDA215b로 담배(cv. petit Havana SR1)를 형질전환시키고 형질전환이 확인된 76개의 $R_0$ 세대를 자가수분하여 $R_1$ 세대를 획득하였다. $R_1$ 세대의 유전 분석후 antisene 유전자가 복수로 존재하는 5개의 $R_1$ 계통 (21505, 21507, 21511, 21522, 21525)을 선발하고 동형접합체를 획득하기 위해 자가수분을 하였다. 임성회복을 유도하고 회복친을 선발하기 위하여 antisense 유전자를 가진 $R_2$ 계통과 웅성불임 식물체를 교배하였다. 그 결과 꽃가루가 완전이 회복된 개체, 부분적으로 회복된 개체, 회복되지 않은 개체 등 3종류의 식물체를 획득하였으며 이들 식물체의 화분 이외의 표현형은 정상식물체와 같았고 그 기작 구명을 위해 선발하고 계속 연구가 진행되고 있다.

• 한국가축번식학회지
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• 제27권2호
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• pp.179-185
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• 2003

본 연구는 생체 내 세포 및 조직배양기로서의 면역결핍동물을 개발할 목적으로 proximal Ick promoter와 DT-A유전자를 이용하여 형질전환생쥐를 생산하였고 형질전환생쥐의 면역기관에서 Di-phteria toxin이 발현되어 T-cell이 결핍되는지를 분석하였다. 총 암수 2마리의 형질전환생쥐를 PCR과 South-ern blotting으로 분석하여 얻었으며 이식유전자의 copy수는 약 2∼3 copy가 정착된 것으로 확인되었다. 형질전환생쥐의 thymus, spleen, liver 조직을 분리한 후 total RNA를 추출하여 poly(dT) primer 와 DT 특이적 primer를 이용하여 RT-PCR수행 결과 형질전환생쥐의 thymus, spleen, liver에서 DT gene이 발현되고 있는 것을 확인할 수 있었다. 형질전환생쥐의 이들 조직간에 DT 발현량에는 큰차이는 없는 것으로 확인되었다. 형질전환생쥐의 혈액에서 적혈구, 백혈구 ,혈소판, 헤모글로빈 등이 정상생쥐보다 감소되었고 특히 백혈구수와 혈소판의 수가 크게 감소되어 있는 것으로 나타났다. 또한 형질전환생쥐의 혈액을 CD3 antibody를 이용하여 FACS 분석을 실시하여 형질전환생쥐의 혈액 중 T-cell이 수가 비정상적으로 줄어든 것을 확인할 수 있었다. 본 연구에서는 Ick-DT 형질전환생쥐에서 DT유전자의 발현에 의한 T-cell 결핍을 유도할 수 있는 것으로 나타나 이를 바탕으로 돼지를 이용한 사람의 이종장기 배양용 형질전환동물을 생산하여 응용될 수 있을 것으로 사료된다.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• 제21권3호
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• pp.141-146
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• 2010

This summary of literature during the past year reviews published studies relating to risk factors for depressive disorders in children and adolescents. Risk factors include environmental toxins, socio-environmental, and genetic factors. As depression has a complex, multifactorial causal mechanism, it is likely that the accumulation and/ or interaction among multiple risk factors lead to depression. Findings related to the result of toxin exposure have been difficult to interpret given that risk factors tend to interact and that higher mental functions are not easily measurable. However, some findings have been consistent. Clinical research data has also shown that the risk for negative outcomes may be modified both by genetic and environmental factors through a gene environment interplay mechanism.

• BMB Reports
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• 제36권5호
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• pp.508-513
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• 2003

The bacterium Bacillus thuringiensis produces toxin inclusions that are deleterious to target insect larvae. These toxins are believed to interact with a specific receptor protein(s) that is present on the gut epithelial cells of the larvae. In various insect species (in particular those belonging to the lepidopteran class), aminopeptidase N (APN) is one of the two receptor proteins that are considered to be involved in toxin-receptor interactions. However, in mosquitoes, the nature and identity of the receptor protein is unknown. Here, using RT-PCR, we identified two isoforms of the APN transcripts in the Aedes aegypti mosquito larval midgut. These results are congruent with a previous report of multiple isoforms of the APN gene expression in lepidopteran larvae. Which of the two isoforms (or other yet unidentified receptor proteins) is involved in the killing of mosquito larvae remains to be elucidated.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 1986년도 추계학술대회
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• pp.515.2-515
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• 1986

B. sphaericus 1593 K-5 synthesize a potent entomicidal toxin against mosquito larvae. B. sphaericus EcoRl DNA fragment carrying the biocidal activity was clonied and expression in E. coli JM83. For the construction of a recombinant plasmid bearing the toxin activity the DNA of B. sphaericus was partially digested by the EcoRl. The EcoRl DNA fragments were ligated to plasmid pUC 8-EcoR1 site. The transformants were selected on LB plates containing X-gall and ampicilline. The transformants were bioassayed against mosquito larvae of which two clones showed biocidal activity. The two clones were redigested with Eco R1 and analyzed by 0.7% agarose gel electrophorsis.

• Journal of Microbiology and Biotechnology
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• 제14권4호
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• pp.772-776
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• 2004

Physiological and molecular characteristics of Bacillus thuringiensis SR6 and SR8 were investigated, and phase contrast and electron microscopies revealed that a large rhomboidal crystal protein was present in the sporulating cells. SDS-PAGE and Western blot analyses showed that B. thuringiensis SR8 produced 70 kDa protein much more than other proteins, and that the 70 kDa protein could bind to the antibody of B. thuringiensis subsp. tenebrionis-crystal toxin protein, indicating that the crystal 70 kDa protein has an immunological homology with B. thuringiensis subsp. tenebrionis-crystal toxin protein. The DNA fragment of B. thuringiensis subsp. tenebrionis-toxin gene was detected in B. thuringiensis SR6 and SR8 by using PCR amplification analysis. Furthermore, the insect bioassay showed the insecticidal activity against Colorado potato beetle larvae. Based on the physiological and molecular similarities to B. thuringiensis subsp. tenebrionis, it is suggested that the B. thuringiensis SR6 and SR8 may be mutants of the B. thuringiensis subsp. tenebrionis strain overexpressing the crystal of 70 kDa toxin protein.

• 미생물학회지
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• 제54권1호
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• pp.1-8
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• 2018

원핵 세포는 핵양체 결합 단백질(NAP)로 알려진 다양한 히스톤 유사 단백질을 가지고 있다. 이들은 DNA의 AT-rich 서열에 결합하여, DNA 자체를 감싸거나, 구부리거나, 떨어져 있는 DNA 가닥을 연결시키는 다리 역할을 하여, 결국에는 원핵 생물의 유전자 발현을 조절한다. NAP는 특히 전사의 억제 기능을 가지고 있기 때문에, 유전자 발현 억제에 있어서 이들의 역할과, 구체적인 메커니즘을 밝히는 것을 매우 중요한 일이다. 본 논문에서는 잘 알려져 있는 NAP인 H-NS와 HU에 대하여 정리하였고, 특히 E. coli와 Salmonella Typhimurium에서 이들의 유전자 발현에 대한 기능을 요약하였다. H-NS는 이들의 올리고머화와 필라멘트 구조 형성을 통하여 Salmonella와 같은 사람에 감염하는 병원성 세균의 독성유전자 발현을 억제할 수 있고, 이런 기능을 수행하였을 때 다른 NAP와 함께 작용할 수 있다. 최근에 H-NS는 사람에게 typhoid fever와 systemic disease를 발생시키는 독성물질인, typhoid toxin의 발현 또한 조절할 수 있음이 밝혀졌다. Salmonella에서 HU 또한 독성 유전자뿐만 아니라, 이들의 생리적 기능에 중요한 유전자들의 발현을 조절할 수 있다. 따라서, H-NS와 HU와 같은 NAP들이 원핵 생물의 독성 유전자 발현의 분자적인 메커니즘을 밝히는데 중요한 요소임을 제시한다.

• 한국동물위생학회지
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• 제39권2호
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• pp.87-92
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• 2016

Porcine edema disease (ED) is a communicable disease of pigs caused by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC) which expresses F18 fimbriae and/or Stx type 2e (Stx2e). While STEC causes a severe illness including hemorrhagic colitis and hemolytic-uremic syndrome in humans, it induces damage to the vascular endothelium, which results in edema, hemorrhage, and microthrombosis, leading in high mortality in pigs. In the present study, we cultured Stx2e-producing E. coli field isolates from conventional pig farms that experienced sudden deaths previously with symptoms similar to porcine edema disease, which were further investigated with Shiga toxin profiles. A total of 43 strains were identified from the collected samples by F18 or Stx2e specific PCR. Based on the PCR, 42 isolates out of 43 isolates were proved to carry one of F18 or Stx2e genes and 14 isolates to carry both F18 and Stx2e genes. All of the 30 isolates that harbored Stx2e gene induced the cytopathic effect (CPE) in vero cells and especially, the isolate 150229 produced the highest level of Shiga toxin. Therefore, we identified the virulence genes (F18 and Stx2e) and demonstrated Shiga toxin-producing abilities from porcine edema disease causing E. coli filed isolates. These results suggested that one of the isolates could be a vaccine antigen candidate against STEC through further investigating to elicit an immune response.

• Journal of Microbiology and Biotechnology
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• 제21권9호
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• pp.937-946
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• 2011

Several isolates of Bacillus thuringiensis (Bt) were screened for the vegetative insecticidal protein (Vip) effective against sap-sucking insect pests. Screening results were based on $LC_{50}$ values against cotton aphid (Aphis gossypii), one of the dangerous pests of various crop plants including cotton. Among the isolates, the Bt#BREF24 showed promising results, and upon purification the aphidicidal protein was recognized as a binary toxin. One of the components of this binary toxin was identified by peptide sequencing to be a homolog of Vip2A that has been reported previously in other Bacillus spp. Vip2 belongs to the binary toxin group Vip1-Vip2, and is responsible for the enzymatic activity; and Vip1 is the translocation and receptor binding protein. The two genes encoding the corresponding proteins of the binary toxin, designated as vip2Ae and vip1Ae, were cloned from the Bt#BREF24, sequenced, and heterologously expressed in Escherichia coli. Aphid feeding assay with the recombinant proteins confirmed that these proteins are indeed the two components of the binary toxins, and the presence of both partners is essential for the activity. Aphid specificity of the binary toxin was further verified by ligand blotting experiment, which identified an ~50 kDa receptor in the brush border membrane vesicles of the cotton aphids only, but not in the lepidopteran insects. Our finding holds a promise of its use in future as a candidate gene for developing transgenic crop plants tolerant against sap-sucking insect pests.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.309.2-309.2
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• 2002

The FimH subunit of type l-fimbriated Escherichia coli has been determined as a major cause of urinary tract infection. To produce a possible vaccine antigen against urinary tract infection, the fimH gene was genetically coupled to the ctxa2b gene, which was then cloned into pMAL -p2E expression vector. The chimaeric construction of pMALfimH/ctxa2b was transformed into Escherichia coli TB1 and its N-terminal amino acid sequence was analyzed. (omitted)