• Journal of Plant Biology
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• 제39권3호
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• pp.179-184
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• 1996

The purpose of this study is to obtain the most efficient combination of Agrobacterium tumefaciens strains and Ti plasmids for the construction of dicotyledonous plant vector system. Ti plasmid-curing A. tumefaciens A136 and KU12C3 were transformed with four kinds of Ti plasmids, pTiBo542, pTiA6, pTiKU12 and pTiAch5, respectively. The stems of 28 species of dicotyledonous plants were then inoculated with these transformants and examined for crown gall formation. The different combination of A. tumefaciens strains and Ti plasmids showed quite a difference in terms of the crown gall formation. Agrobacterium strins A136 and KU12C3 have a same plant host range in case that both strains harour the same kind of Ti plasmid, pTiBo542 or pTiAch5. However, the above-mentioned both strains have quite different host range in the event of containing the same Ti plasmid, pTiKU12 or pTiA6. In case that KU12C3 contains pTiA6 or pTiKU12, this strain has a wider plant host range than A136. The plant host range of pTiBo542 is the widest, followed by pTiA6, pTiKU12 and pTiAch5. Twelve plants among 28 tested plants are not transformed by any virulent Agrobacterium strains used in this study. In conclusion, A. tumefaciens KU12C3 and A136 harboring pTiBo542 showed the widest host range for transforming dicotyledonous plants. Also, it was acertained that the host range of Ti plasmids is affected by chromosomal level.

• 대한바이러스학회지
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• 제27권1호
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• pp.29-37
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• 1997

To use recombinant viruses with wider host range as viral insecticides, we investigated the characteristics and pathogenicity of host range expanded recombinant viruses in insect cells. We compared host range expanded recombinant viruses, RecS-B6 and RecB-8, constructed by cotransfection of Autographa californica nuclear polyhedrosis virus (AcNPV) and Bombyx mori NPV (BmNPV), to host range expanded AcNPV, Ac-BH, by substitution of the 0.6 Kb fragment of the BmNPV helicase gene. Restriction endonuclease profiles of RecS-B6 and RecB-8 DNAs were different from those of parent viruses. Nucleotide sequence analysis of the 0.6 Kb region in the putative helicase gene of RecS-B6 and RecB-8 showed that their structures were identical to the counterpart region of BmNPV. Comparison of viral replication of these recombinant viruses in Sf-21 and BmN-4 cells showed that Ac-BH, compared to wild type viruses, replicated well in BmN-4 cells but poorly in Sf-21 cells. In contrast, RecS-B6 and RecB-8 replicated relatively well in both cells compared to parent viruses. These results may imply that random genomic recombinant viruses, RecS-B6 and RecB-8, possess better potential as viral pesticides than helicase-mediated recombinant virus, Ac-BH.

• 한국응용곤충학회지
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• 제32권4호
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• pp.407-413
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• 1993

숙주범위가 서로 다른 Autographa californica NPV(AcNPV)와 Bombyx mori NPV(BmNPV)를 Spodoptera frugiperda(Sf9) 또는 Bombyx mori(BmN-4)의 세포에 동시감염(coinfection)시킨 후, 숙주범위가 확장된 재조합 바이러스를 Sf9세포에서 10종 BmN-4세포에서 2종씩 플라크 순화하여 선발하였다. 각 재조합 바이러스 DNA의 제한효소 분석결과는 한번 이상의 재조합이 일어났음을 보여주었다. 재조합 바이러스 RecB-8의 전자현미경 관찰결과는 다각체의 모양이 모바이러스인 AcNPV나 BmNPV와는 전혀 다른 정사면체 모양이었으며 또한, 모바이러스와는 달리 virion이 다각체에 거의 매립되어 있지 않은 특징을 보였다.

• 천문학회보
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• 제43권1호
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• pp.62.3-63
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• 2018

Trends of Type Ia supernova (SN Ia) luminosities with the properties of host galaxies are important to study the underlying physics for an SN progenitor system and explosion mechanism. In the YONSEI SN catalog, we have a sample of ~600 SN and host data in the wider redshift range, and two independent light-curve models, SALT2 and MLCS2k2. From this catalog, here we present that SNe Ia in low-mass, globally and locally star-forming environments are fainter than those in high-mass, globally and locally passive environments, after light-curve shape and color or extinction corrections. Our results are then compared to previous studies, and show consistent results.

• The Plant Pathology Journal
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• 제38권4호
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• pp.383-394
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• 2022

In Japan, the P1 protein (S-type) encoded by leek yellow stripe virus (LYSV) isolates detected in Honshu and southward is shorter than the P1 (N-type) of LYSV isolates from garlic grown in Hokkaido due to a large deletion in the N-terminal half. In garlic fields in Hokkaido, two types of LYSV isolate with N- and S-type P1s are sometimes found in mixed infections. In this study, we confirmed that N- and S-type P1 sequences were present in the same plant and that they belong to different evolutionary phylogenetic groups. To investigate how LYSV with S-type P1 (LYSV-S) could have invaded LYSV with N-type P1 (LYSV-N)-infected garlic, we examined wild Allium spp. plants in Hokkaido and found that LYSV was almost undetectable. On the other hand, in Honshu, LYSV-S was detected at a high frequency in Allium spp. other than garlic, suggesting that the LYSV-S can infect a wider host range of Allium spp. compared to LYSV-N. Because P1 proteins of potyviruses have been reported to promote RNA silencing suppressor (RSS) activity of HC-Pro proteins, we analyzed whether the same was true for P1 of LYSV. In onion, contrary to expectation, the P1 protein itself had RSS activity. Moreover, the RSS activity of S-type P1 was considerably stronger than that of N-type P1, suggesting that LYSV P1 may be able to enhance its RSS activity when the deletion is in the N-terminal half and that acquiring S-type P1 may have enabled LYSV to expand its host range.

• 천문학회보
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• 제41권1호
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• pp.32.4-33
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• 2016

Recent studies suggest that the difference between global and local properties of galaxies (the local-global environmental (LoG) bias) might be important in the Type Ia supernova (SN Ia) host galaxy studies. Obtaining local spectroscopic properties of hosts at high redshift, however, is challenging. Here we will introduce a more efficient way to conduct this study by only using photometric data. We find that when we restrict a sample to the hosts whose stellar mass is less than $10^{10}$ $M_{\odot}$, a sample without LoG bias is efficiently selected. From the sample without LoG bias, we confirm that SNe Ia in locally star-forming environment are $0.103{\pm}0.010mag$ and $0.085{\pm}0.012mag$ fainter than those in locally passive region, for MLCS2k2 and SALT2, respectively. Because of ~6 times larger sample that covers much wider redshift range, our results are far more significant statistically, $10.3{\sigma}$ for MLCS2k2 and $7.1{\sigma}$ for SALT2, than previous results.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 영호남 합동 학술대회 및 춘계학술대회 논문집 센서 박막 기술교육
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• pp.55-60
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• 2006

Thermally stable and solution-processable poly(N-arylcarbazole-alt-aniline) copolymers with high structural integrity were synthesized in good yields via palladium-catalyzed polycondensation of aniline with corresponding N-arylcarbazole monomers such as N-(2-ethylhexyloxyphenyl)-3,6-dibromocarbazole,bis[6-bromo-N-(2-ethylhexyloxyphenyl)carbazole-3-yl] and N-(4-(2-ethylhexyl)-3,5-dibromomethylene-phenyl) carbazole, respectively. The optical and electrochemical properties of these copolymers were measured and compared with those of poly(N-alkylcarbazole-alt-aniline) copolymer. All synthesized poly(N-arylcarbazole-alt-aniline) copolymers showed maximum UV-Vis absorption peaks at around 300 nm in THF solution, and exhibited maximum photoluminescence peaks in the blue emission range from 430 to 460 nm. It was also found that poly(N-arylcarbazole-alt-aniline) copolymers had wider band gap energy than poly(N-alkylcarbazole-alt-aniline) copolymer.

• 천문학회보
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• 제35권1호
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• pp.48.1-48.1
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• 2010

Four of nine exoplanets found by microlensing were detected by the resonant caustic, which represents the merging of the planetary and central caustics at the position when the projected separation of a host star and a bounded planet is s~1. One of the resonant caustic lensing events, OGLE-2005-BLG-169, was a caustic-crossing high-magnification event with A_max ~800 and the source star was much smaller than the caustic, nevertheless the perturbation was not obviously apparent on the light curve of the event. In this paper, we investigate the perturbation pattern of the resonant caustic to understand why the perturbations induced by the caustic do not leave strong traces on the light curves of high-magnification events despite a small source/caustic size ratio. From this study, we find that the regions with small magnification excess around the center of the resonant caustic are rather widely formed, and the event passing the small-excess region produces a high-magnification event with a weak perturbation that is small relative to the amplification caused by the star and thus does not noticeably appear on the light curve of the event. We also find that the positive excess of the inside edge of the resonant caustic and the negative excess inside the caustic become stronger and wider as q increases, and thus the resonant caustic-crossing high-magnification events with the weak perturbation occur in the range of q $\leq$ 10-4. We determine the probability of the occurrence of events with the small excess $|\varepsilon|{\leq}3%$ in high-magnification events induced by a resonant caustic. As a result, we find that for the Earth-mass planets with a separation of ~2.5 AU the resonant caustic high-magnification events with the weak perturbation can occur with a significant frequen.

• 한국미생물·생명공학회지
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• 제36권4호
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• pp.260-267
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• 2008

단백질의 산업적 생산을 위해 발현벡터의 선정이 중요하지만 이용 가능한 프로모터가 극히 제한적이며 많은 경우 과발현되는 특성과 함께 불용성 응집체가 형성되는 단점을 지닌다. 따라서 다양한 생물로부터 유래된 잠재성이 큰 유전자원(metagenome)에서의 프로모터 발굴과 한정된 숙주를 해결하려는 노력이 요구된다. 선행연구에서 발굴한 metagenome 유래의 항시발현 프로모터를 이용해 대장균의 일반적인 배양조건에서 세포생리에 영향이 적은 신규 항시발현 벡터를 제작하였다. 이를 위해 예측된 프로모터 서열과 MCS를 포함하는 합성 primer를 제작한 후 PCR로 증폭해 발현벡터를 구성한 후, 프로모터 구동여부와 단백질 발현양상 등을 관찰하였다. 인위적으로 도입된 MCS에 GFP, esterase, $\beta$-glucosidase를 클로닝해 단백질 발현양과 가용성을 분석한 결과, 안정적으로 전체단백질의 $2{\sim}3%$ 정도로 발현되며 80% 이상의 높은 가용성을 지닌 단백질의 발현이 유도되는 것으로 확인되었다. 이와 같은 결과는 잠재적인 생물자원의 보고로서 metagenome의 활용가능성을 제시하고 있다. 따라서 다양한 숙주에서 작동하는 프로모터의 발굴 및 발현벡터의 제작을 시도할 경우 단백질의 생산이나 대사공학에 의한 균주개량에 유용하게 활용할 수 있을 것이다.