• Animal cells and systems
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• 제9권3호
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• pp.139-144
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• 2005

The attractant (orange light) or repellent (white light) signal is transmitted from SRI (Sensory Rhodopsin I) via protein-protein interaction with its transducer Htrl (Halobacterial Transducer for Sensory Rhodopsin I) which in turn controls a cytoplasmic phospho-transfer pathway that modulates flagella motor switching in Halobacterium salinarum. Some mutations in both SRI and Htrl showed an unusual mutant phenotype called inverted signaling, in which the cell produces a repellent response to normally attractant light. Twelve mutations at the Glutamate 56 (E56) position in the second transmembrane helix of Htrl were introduced by site-specific random mutagenesis. Almost all E56 mutants showed orange-light inverted responses in pH and temperature-dependent manners except E56D and E56Y. Except for these two mutants, all mutants accelerated the $S_{373}$ decay compared to wild-type at $18^{\circ}C$. This supported that there is an interaction between SRI and the second transmembrane of Htrl. Also a structural model of Htrl based on the Tar crystal structure and the secondary structure prediction program proposed the E56 residue to be in the middle of the proton channel. The most important observation is that the E56 mutant provides the evidence that this residue is very sensitive for signal relay, which can be explained by the open and closed conformations of the channel (A and R conformations) in SRI, as was postulated by the unified conformational shuttling model for transport and signaling.

• 한국환경농학회지
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• 제42권4호
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• pp.371-381
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• 2023

The effectiveness of plant-based attractants was studied using large traps, which attracted relatively more snails in agricultural water drainage ditches and rice-cultivating environments, although their effectiveness in rice fields and lakes was limited. The rate began to rise after three hours of observation. Watermelon peel exhibited the highest apple snail attraction rate (13.8%), followed by potatoes (10.0%), and apple peel (8.8%). These values significantly differed from the attraction rate attributed to papaya leaves (F=3.84; P=0.0387). After 24 h, watermelon peel and apple peel indicated a higher rate of attraction (23.4% and 21.7%, respectively), which were significantly different compared with those of papaya leaves and potatoes (F=9.94; P=0.00455). Large bait traps outperformed funnel traps in capturing golden apple snails and trapped a significant number of snails measuring over 1 cm in size. Watermelon peel was the most effective attractant for a large bait trap, followed by apple peel, potatoes, and papaya leaves. On average, 110 snails were captured in the lure net. However, potatoes, apple peels, and papaya leaves caught an average of 93, 80, and 79 snails, respectively. Among the attractants, the lure effect of the snails was not significantly different. The efficiency of large bait traps in capturing snails, regardless of the plant attractant employed, followed the order: apple peel > watermelon peel and potatoes > papaya leaves > melon > Korean melon. Watermelon peel is highly recommended for farmer use, as well as apple peel and potatoes. Utilizing these snail attractants may contribute positively to developing a safe and environment-friendly integrated pest management strategy.

• Animal cells and systems
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• 제10권4호
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• pp.237-241
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• 2006

Chemotactic behavior is essential for the survival of animals. However, the mechanism by which animals carry out chemotaxis is poorly understood. To explore the biochemical events underlying chemotaxis, we isolated C. elegans mutants that displayed abnormal chemotactic responses to cAMP, a strong attractant for C. elegans. Based on their responses to other chemoattractants, the mutant animals could be classified into five groups: (1) animals with defective chemotaxis to cAMP only; (2) animals with defective chemotaxis to both cAMP and cGMP; (3) animals with defective chemotaxis to water-soluble attractants; (4) animals with defective chemotaxis to both water-soluble and volatile attractants; and (5) animals with enhanced chemotactic responses. We expect that analyses of these mutants will help understand the molecular mechanisms underlying chemotaxis in C. elegans.

• Animal cells and systems
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• 제6권4호
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• pp.287-292
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• 2002

Functional characterization of sex pheromones in olfactory responses is essential for the study of chemical communications in amphibians. Using Y-maze olfactory preference tests, we have investigated the olfactory res-ponses of male and female red-spotted newts, Notophthalmus viridescens, to the crude extracts of the opposite sex's genial and cloacal pheromones. Both male and female cloacal pheromone extracts caused the opposite sex to initiate olfactory responses by leaving the starting area in the Y-maze, but only subject males exposed to female cloacal pheromone extracts completed olfactory choice by entering the side arm of the Y-maze which received the pheromones. For genial pheromone extracts, only female genial pheromone extracts induced initial olfactory responses from test males. Neither male nor female genial pheromone extracts made the oppo-site sex complete olfactory choice. Pre-exposure of test females to male pheromone extracts increased the likelihood of initial olfactory responses. The latency for initial olfactory responses of test females that were previously exposed to male genial extracts was significantly shorter than that of control females.

• 한국지능시스템학회논문지
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• 제18권3호
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• pp.392-400
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• 2008

This paper proposes a novel optimization algorithm inspired by bacteria behavior patterns for foraging. Most bacteria can trace attractant chemical molecules for foraging. This tracing capability of bacteria called chemotaxis might be optimized for foraging because it has been evolved for few millenniums. From this observation, we developed a new optimization algorithm based on the chemotaxis of bacteria in this paper. We first define behavior and decision rules based on the behavior patterns of bacteria and then devise an optimization algorithm with these behavior and decision rules. Generally bacteria have a quorum sensing mechanism that makes it possible to effectively forage, but we leave its implementation as a further work for simplicity. Thereby, we call our algorithm a simple bacteria cooperative optimization (BCO) algorithm. Our simple BCO is tested with four function optimization problems on various' parameters of the algorithm. It was found from experiments that the simple BCO can be a good framework for optimization.

• Bulletin of the Korean Chemical Society
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• 제6권2호
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• pp.86-90
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• 1985

(Z)-13-Eicosen-10-one, an active component of the sex pheromone of the peach fruit moth was synthesized from 4-oxo-tridecan-1-al and heptylidenetriphenylphosphonium ylide by Wittig reaction. The key intermediate, 4-oxo-tridecan-1-al, was synthesized by three different methods. The biological activity test of the synthetic pheromone as attractant for the male peach fruit moth was tested at several districts in Korea.

• 한국균학회지
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• 제20권2호
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• pp.109-117
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• 1992

운동성을 띠는 5가지 부생균과 1종류의 식물병원세균으로 Agrobacterium radiobacter, Bacillus subtilis, B. polymyxa, Pseudomonas aeruginosa, P. fluorescens 및 Xanthomonas malvacearum을 공시하여 이들 세균이 Cochliobolus sativus 분생포자, Fusarium oxysporum f. sp. ciceri의 후막포자, Macrophomina phaseolina의 균핵 및 Phytophthora drechsleri f. sp. cajani 난포자의 분비물에 미치는 화학주성을 서로 다른 무생물적 조건하에서 실험하였다. 균의 분비물의 농도와 세균세포의 끌리는 유인사이에는 정상관$(r=0.76{\sim}0.89)$이 있었다. 유사한 결과로서 화학주성반응과 배양간격에서도 통계적인 정상관이 있다$(r=0.82{\sim}0.95)$. 세균의 화학주성반응은 온도와 pH에 크게 영향을 받는다. 최적 화학주성을 나타내는 온도로서 A. radiobacter는 $25^{\circ}C$, B. polymyxa, P. aerugionosa, p. fluorescens and X. madracearum은 $30^{\circ}C$이었고, B. subtilis는 $35^{\circ}C$가 최적이었다. 최대 화학주성을 나타내는 분비물의 주성은 pH7이고 pH3과 11에서는 buffer와 같았다. 시험용 모세관에 유인물질이나 buffer 중 어느 종류가 채워져도 유인물질이 있는 시험관에 연결되면 세균은 주성이 나타난다는 것이 증명되었다.

• 한국응용곤충학회지
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• 제29권4호
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• pp.244-251
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• 1990

담배거세미나방 핵다각체병바이러스에 섭식촉진물질, 다각체 침전방지제 및 전착물질과 자외선 차단제를 첨가하여 만든 3종의 바이러스 살충제를 담배거세미나방 유충에 먹여 제제별로 살충 효과를 비교하였다. 바이러스 살충제에 설탕농도 1-5% 첨가로 섭식촉진이 증대되어 살충효과가 높았으며, 바이러스의 불활화 차단효과도 있었다. 살충제 제형에 따른 바이러스 침전방지는 polyvinylalcohoI 0.5%, 식물체 전착성은 Triton X -100 0.1 %에서 효과가 좋았다. 자외선차단제의 양은 white carbon은 100 L 당 800 g, molasses는 30%첨가에서 바이러스의 불활화가 감소되었으며 white carbon-molasses 혼합제는 white carbon 500 g, molasses 10%의 비율에서는 살충효과가 약간 감소하였으나 세 제제 모두 살포 3일후 95%이상의 살충율을 보였다. White carbon 체제는 molasses 제제보다 다각체 포매가 뚜렷하여 잔류효과가 증대되었으나 유충의 섭식은 molasses제제에서 촉진되었다.

• 한국응용곤충학회지
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• 제54권4호
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• pp.443-448
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• 2015

참나무시들음병 매개충인 광릉긴나무좀(Platypus koryoensis (Murayama))(Coleoptera: Platypodidae)의 에탄올과 신갈나무 수피 추출물의 유인효과에 대하여 조사하였다. 유인트랩과 유인목 시험에서는 에탄올과 신갈나무 수피 추출물을 사용한 처리구가 대조구(무처리)보다 높은 유인효과를 나타내었으나, 두 유인제 간의 유의성은 찾지 못하였다. 유인목의 직경별 침입공 수를 비교한 결과, 침입공 수는 직경이 클수록 증가하였다. 유인목의 횡단면 상부와 하부 침입공 수를 비교한 결과, 상부보다 하부에 침입공이 많았고, 통계적으로 유의한 차이(p<0.05)를 나타내었는데, 이는 직사광선에 의한 건조가 적은 하부가 매개충의 먹이가 되는 미생물 번식에 유리하기 때문이라고 추정되었다. 결과적으로 신갈나무 수피 추출물보다 비용 면에서 경제적인 에탄올이 광릉긴나무좀 모니터링 및 방제에 효율적으로 활용될 수 있을 것이며, 신갈나무 수피 추출물은 효율을 높일 수 있는 계속적인 연구의 필요성이 있다.

• 한국응용곤충학회지
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• 제61권4호
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• pp.615-622
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• 2022

본 연구는 콜레마니진디벌의 품질확인장치에 적용할 수 있는 LED 광원을 선발하기 위하여 수행되었다. 4개의 LED 광원(385, 405, 450, 및 660 nm)을 대조구로 5,000k 백색 LED를 사용하여 Y자관 시험에서 선택시험을 수행한 결과, 385 nm LED 광원만 콜레마니진디벌에 대한 유인효과가 있었다. 하지만 3개의 LED 광원(385, 405, 및 450 nm)과 대조구로 5,000k 백색 LED를 사용하여 비선택시험을 수행한 결과, 450 nm > 385 nm > 405 nm 광원 순으로 유인효과가 높았으나 450 nm와 385 nm 광원간 유의차는 없었다. UV-A에 속하는 385 nm LED 광원은 피부질환을 초래할 수 있는 우려가 있어 제외하였고, 최종 450 nm LED 광원을 콜레마니진디벌 품질확인장치에 적용할 광원으로 선발하였다. 450 nm LED 광원을 콜레마니진디벌 우화기구에 적용한 결과, 87.4%의 높은 유인효과를 확인 할 수 있었다. 이러한 결과는 천적 품질관리에 유용하게 활용될 수 있을 것으로 생각된다.