과일이나 농작물의 부패 및 발효 환경에서는 Methanol, Ethanol, Acetic acid을 비롯한 다양한 화학물질들이 생산된다. Drosophila melanogaster는 이러한 발효·부패 환경에 서식하면서 일정 농도 이상의 다양한 화학물질에 지속적으로 노출되어 생존하도록 적응되어온 것으로 생각된다. 다양한 화학물질이 포함한 환경에 안정적으로 서식하기 위해서는 D. melanogaster는 화학물질에 능동적으로 반응하여 해독 유전자나 대사 관련 유전자의 발현량을 변화 시킴으로써 발효·부패 환경에서 생성되는 화학물질에 대한 높은 내성을 가지고 있을 것으로 판단된다. 현재까지 유전자의 발현량 측정을 위해 real-time PCR를 이용하여 reference gene의 발현량을 기준으로 정량화하는 방법이 가장 널리 사용되고 있다. 그러나 조직별, 환경별, 발달단계를 비롯한 다양한 조건에서 안정적으로 발현되는 reference 유전자 선정이 필수적으로 선행되어야 하므로 본 연구에서는 발효·부패 환경에서 생산되는 두 화학물질인 Methanol과 Ethyl Acetate에 노출된 D. melanogaster에서 안정적으로 발현되는 reference gene을 찾는 연구를 실시하였다. 본 연구에서는 다양한 농도의 Methanol과 Ethyl Acetate을 D. melanogaster에 노출시킨 후 RNA 추출과 cDNA 합성을 실시였고, 5가지 후보 reference gene (hsp22, nd, rpL18, tbp and ef-1b)의 안정적 발현 여부를 qRT-PCR을 통해 조사하였으며, 유전자 발현의 안정성을 측정하는 3가지 프로그램(geNorm, NormFinder, BestKeeper)을 이용해 비교·분석하였다. 본 학회에서는 연구의 과정과 그 결과를 발표하고자 한다.

4,4’-dichlorodiphenyltrichloroethane (DDT) has been re-recommended by the World Health Organization for malaria mosquito control in Africa. Previous DDT use has resulted in predisposition of resistance, and with continued use resistance will increase further in terms of level and extent. Drosophila melanogaster is a model dipteran that has many available genetic tools, has been widely used for elucidating insecticide resistance mechanisms, and is related to malaria mosquitoes allowing for extrapolation. The 91-R strain of D. melanogaster is highly resistant to DDT (>1500-fold); however, there is no mechanistic scheme that accounts for this level of resistance. Recently, reduced penetration, increased detoxification, and direct excretion have been identified as resistance mechanisms in the 91-R strain. Their interactions, however, remain unclear. Use of Gal4/UAS-RNAi transgenic lines of D. melanogaster allowed for the targeted knockdown of genes putatively involved in DDT resistance and has identified the role of several cuticular proteins (Cyp4g1 and Lcp1), cytochrome P450 monooxygenases (Cyp6g1 and Cyp12d1), and ATP binding cassette transporters (mdr50, mdr65, and mrp1) in increased sensitivity to DDT. These findings have been further validated in 91-R flies using a nanoparticle-enhanced RNAi strategy, directly implication these genes in DDT resistance in 91-R flies.

The effects of cold storage temperature and exposure duration on immature stages of spotted-wing drosophila (SWD) Drosophila suzukii (Diptera: Drosophilidae) on ‘Campbell Early’ grapes were examined to establish a phytosanitary control method. The immature stages (eggs, larvae and pupae) of SWD were all dead after a 6-day cold treatment at 1°C and 8-day cold treatment at 1.5 and 2°C. Small-scale tests using pupae, which were the most-cold tolerant stage, confirmed the validity of the selected temperature and exposure durations. Conversely, the 8- and 10-day at 1°C treatments showed 100% mortality, suggesting that these treatments can guarantee quarantine security against infestations of SWD on exported ‘Campbell Early’ grapes.

벗초파리는 우리나라에서는 심각한 해충으로 인식되지 않아 발생 기간 및 패턴, 기주 범위 등의 생태적인 연구뿐만 아니라 모니터링을 위한 우수 유인제 및 트랩의 연구도 제한적으로 수행된 실정이다. 본 연구는 기존 연구 결과를 참조하여 사과식초 함유 유인제 2종과 화학적 루어 2종 그리고 트랩 2종에 대한 선발 시험을 수행하였다. 선발 시험은 사육중인 벗초파리를 이용한 choice test와 함께 수목원, 딸기 농장, 블루베리 농장에서의 6반복 유인력 검증 실험을 수행하였다. 유인력 비교 결과 ACV + wine의 포획량이 높았으며, 블루베리 농장 인근 결과값은 전체 조사 항목에서 통계적 유의성을 보였다 (P < 0.05). 트랩 선발 실험 결과 모든 실험 장소에서 Dreves 트랩이 높은 포획량을 보였다. 이상의 결과를 통해 ACV + wine과 Dreves 트랩 조합을 선발하였으며, 이를 이용하여 향후 지속적인 모니터링, 월동 발생 조사 등의 연구에 활용할 수 있을 것으로 생각된다.

Diets influence lifespan and reproduction in insects, but little is known how temperature modulates the impacts of diet on these two key fitness components. Here we examined the interactive effects of temperature and nutrient balance on lifespan and egg production rate in Drosophila melanogaster. Newly emerged adult D. melanogaster were allowed to feed ad libitum on one of eight chemically defined diets differing in P:C ratio (1:16, 1:8, 1:4, 1:2, 1:1, 2:1, 4:1, or 8:1) under one of six ambient temperatures (13, 18, 23, 28, 31, or 33℃). For both males and females, lifespan was longest for D. melanogaster fed on P:C 1:16 diet at 13℃ and shortened as both temperature and P:C ratio increased. As indicated by a significant temperature-by-diet interaction for lifespan, the diet effects on lifespan were more pronounced at lower temperatures than at higher temperatures. Egg production rate was maximized on P:C 4:1 diet at 28℃.

Protein and carbohydrate are two major macronutrients that exert profound influences over fitness in many insects, including Drosophila melanogaster. Until recently, most studies examining the impacts of these macronutrients on various life-history traits in this species have used semi-synthetic diets that are not nutritionally well-defined. Here we used chemically defined diets to examine the patterns of larval and adult traits expressed across 34 diets systematically varying in the ratio and concentration of protein and carbohydrate. The shapes of the nutritional landscapes plotted for all larval and adult traits differed significantly from one another. Diverging nutritional optima identified for these landscapes suggest that D. melanogaster cannot maximize the expression of all life-history traits simultaneously, thus leading them to face a nutrient-dependent life-history trade-off.

Temperature can modulate how insects respond to environmental stressors, such as starvation. In this study, we examine whether and how the effects of temperature on starvation resistance depend on nutritional condition and developmental stages in Drosophila melanogaster. Starvation resistance decreased as the temperature exposed during starvation rose from 18 to 28 ̊C, which was mainly caused by warming-induced increase in energy expenditure. When exposed to warm temperatures during feeding, D. melanogaster accumulated more energy reserves and thus become more starvation resistant. The temperature experienced during the larval stage also had a significant effect on starvation resistance at adult stages, with those larvae raised at cold temperatures developing into adult phenotypes with reduced resistance to starvation. This study suggests that the effects of temperature on starvation resistance are highly complex and context dependent in D. melanogaster.

Drosophila melanogaster and Drosophila suzukii are the species of the family Drosophilidae. Although these two fruit flies are taxonomically close species, D. suzukii is thought to be evolutionally adapted to the flesh or maturing fruits, whereas D. melanogaster is adapted to more fermented environments. According to the previous studies, several environmental toxins, such as acetic acid, ethanol, methanol and phenylacetate, ect., have been identified from rotten fruit and fermentation procedures. Considering the differences of distinct habitat between two flies, D. melanogaster is hypothesized to exhibit higher tolerance to the chemical toxins than D. suzukii. Therefore, in this study, we compared the tolerance and susceptibility of two fruit flies to three chemicals (acetic acid, ethanol, 2-phenlyethano).

Reproduction is essential for the survival of a species and is under the close coordination of the central nerve system (CNS). In Drosophila melanogaster, juvenile hormones (JHs) from the corpora allatum(CA) are essential for egg-production because they promote vitellogenesis and enhance ecdysteroid biosynthesis. JH biosynthesis is under the control of neuropeptides, such as Drosophila insulin-like peptide (dilp) and allatostatin C (AstC). However, how these neuropeptide pathways coordinate JH production remain elusive. Here, we report a small number of neurons in the brain and ventral nerve cord (VNC) neurons that produce a neuropeptide AstC regulate egg-production negatively. The brain neurons seem to act indirectly by inhibiting secretion of dilp that up-regulates JH production, whereas the VNC neurons seem to release AstC into the hemolymph to suppress the CA activity directly. On the CA, the AstC actions appear mediated by two G-protein coupled receptors, AstC-R1 and AstC-R2. We will discuss our recent efforts to identify agonists for either receptor, which will be potential leads for insect reproduction regulators.

Animals must maintain proper balance between energy intake and expenditure. Recently, we descovered the enzymaticco-factor tetrahydrobiopterin (BH4) inhibits feeding in Drosophila. BH4 biosynthesis requires the sequential action of theconserved enzymes Punch, Purple, and Sepiapterin Reductase (Sptr). Although we observe increased feeding upon lossof Punch and Purple in the adult fat body, loss of Sptr must occur in the brain. We found Sptr expression is requiredin four adult brain neurons that express NPF, the fly homologue of the vertebrate appetite regulator NPY. Mechanistically,we found BH4 deficiency reduces NPF levels, while excess BH4 increases NPF accumulation without altering its expression.

The spotted wing drosophila (SWD), Drosophila suzukii, is classified exotic quarantine pest in Australia and EU, soSWD-free must be supported by evidence of surveys and phytosanitary measures in exported host agricultural commoditiesin Korea. From a quarantine control point of view, SWD is importantly considered as model insect pest for exotic fruitflies (Bactrocera dorsalis) in Korea as well because of similarity in ecological cycles. In evaluations of ethyl formate(EF) only and combined cold treatment to kill eggs and larvae of SWD, the combined EF fumigation applied at LCt50%(50% killed lethal concentration X time) and cold treatement (5℃) for > 5 days showed the promise to new conceptfor eradicating quarantine pest and these could be helpful to pre-develop exotic fruit fly management in Korea.

Most insects possess two different acetylcholinesterases (AChEs) loci (ace1 and ace2). In contrast, cyclorrhaphan flies,including Drosophila flies, are known to have only a single ace2 locus according to the previous studies. However, sequenceinformation of two different ace genes of Drosophila suzukii have been reported in GenBank. To identify two ace genes(Dsace-A and Dsace-B) in D. suzukii, therefore, we extracted total RNA from 6 individuals and two ace genes successfullywere amplified using gene-specific primers, suggesting that two Dsace genes are transcribed. According to the amino acidsequence analysis, DsAChE-A possesses typical amino acids for 3D structure and catalytic activity of AChE, while someamino acid residues were not conserved in DsAChE-B, suggesting that DsAChE-A and DsAChE-B may be respectivetrue gene and pseudogene of two ace in D. suzukii.

Temperature can affect the ability of insects to tolerate prolonged period of food deprivation through altering the amountof energy storage, the speed of energy expenditure, or the threshold energy storage for survival. In this study, we examinedthe mechanistic basis of the temperature-dependence of starvation resistance in Drosophila melanogaster. Starvation resistancedecreased as the temperature experienced during starvation rose from 18 to 28 ̊C. This warming-mediated decrease instarvation resistance was due to accelerated energy expenditure. However, the threshold energy storage for survival wasnot affected by starvation temperature. Exposure to warm temperatures during feeding led D. melanogaster to accumulatemore energy reserves and thus to become more starvation resistant. This study highlights the important role played bytemperature in shaping the phenotypic responses of insects to starvation.

벗초파리(Drosophila suzukii)는 아시아가 원산인 파리목 초파리과의 해충이다. 국내에서의 피해사례는 보고되지 않았지만 북미와 유럽에서는 블루베리, 체리, 포도 등의 작물에 많은 피해를 입히는 중요한 해충으로, 알자스의 포도 수확량이 15% 정도 감소되었다는 피해사례가 보고되었다. 미국, 뉴질랜드 등에 수출을 할 때 검역 해충으로 수출포도단지 및 선과장 등에서의 발생이 민감한 해충이다. 본 연구는 효율적인 초파리 모니터링을 위해 식초의 종류, 식초량에 따른 유인량을 알아보고, 수출포도단지에서의 벗초파리 발생시기를 알아보고자 수행하였다. 사과 식초 30, 70, 100ml를 넣고 초파리 유인량을 비교한 결과 유인량에는 차이가 없었다. 양조식초, 현미식초, 사과식초, 백포도식초, 사과식초+와인(5:5) 처리 결과 사과식초+와인(5:5)에서 유인량이 가장 많았다. 수출포도단지 내 재배포장에서 조사한 결과 노랑초파리는 8월에도 발견되었으나, 벗초파리는 9월 중순부터 발견되었다.

Assessments were made of fumigant and contact toxicities of 6 Myrtaceae plant essential oils (EOs) and their components against spotted wing drosophila (SWD), Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Median lethal dose (LD50;mg/L) values of Leptospermum citratum EO for fumigant activity were 2.39 and 3.24 for males and females, respectively. All tested EOs except Kunzea ambigua EO exhibited effective contact toxicity. LD50(μg/fly) values for contact toxicity of manuka and kanuka were 0.60 and 0.71, respectively, for males and 1.10 and 1.23, respectively, for females. β-Triketone fractions, composed of flavesone, isoleptospermone and leptospermone, exhibited efficient activity with the LD50 values of 0.13–0.37and0.22–0.57μg/fly for males and females, respective

애멸구(Laodelphax striatellus Fallén)에서 Drosophila-type AChE 유전자(ace2)의 full-length mRNA 서열 정보를 얻기 위해 RACE PCR 후 클로닝을 하였다. 총 12개의 변이를 얻었으며 아미노산으로 번역된 서열의 사이즈가 304 ~ 681 a.a로 다양하였다. 노랑초파리의 ace2 (X05893.1: 649 a.a)와는 56.9 ~ 62.3%, 근연종인 벼멸구, 흰등멸구와는 90% 이상 유사하였다. 애멸구의 ace1 (KC470080.1: 716 a.a)과는 30.9 ~ 44.6% 유사하였다. 12개 변이중 일부만이 노랑초파리의 ace2 (X05893.1: 649 a.a)와 active site, disulfide bonding site, domain 등을 모두 공유하고 있었다. 한편, 애멸구 발육단계별/부위별(머리, 가슴, 배) ace1과 ace2의 상대적 RNA 발현양을 비교하였다. 이때 ace2의 경우, 참고한 시퀀스 위치가 다른 세 개의 primer set를 사용하였는데 세 개의 primer set 모두 ace1 대비 상이한 결과를 보였다. 특히, ace2의 3′말단에 더 가깝게 제작된 primer (comp34855-3′)는 모든 샘플에서 공통적으로 ace1 (primer: comp33022)의 발현양 보다 2배 이상 낮게 나타났다.

We found a new recorded species, Drosophila subpulchrella Takamori & Watabe from Dopyeong-ri, Idong-myeon, Pocheon-si, Gyeonggi-province. The species of the D. suzukii subgroup in the D. melanogaster species group is reported from Japan and southern China up to now. This species is morphologically very similar to D. suzukii: with spots on the tip of fore-wing(male) and serrated ovipositor(female). The goals of this study are to add a new recorded species, D. subpulchrella to Korean fauna and provide the biological references such as morphological and molecular data using for the species identification

베리류의 주요 해충인 벗초파리(Drosophila suzukii)는 주로 냄새감각을 이용하여 기주식물을 찾아 과실에 산란하는 것으로 알려져 있다. 벗초파리의 안테나에는 수많은 냄새감각기(olfactory sensilla)들이 존재하며, 이들 냄새감각기들이 벗초파리의 기주탐색에 중요한 역할을 하는 것으로 판단된다. 곤충의 안테나에 존재하는 냄새감각세포들의 반응을 측정하는 GC-EAD(gas chromatography–electroantennographic detection) 기술을 사용하여 체리, 딸기, 블루베리 등에서 포집한 추출물로부터 벗초파리에 냄새활성을 나타내는 물질들을 동정하였다. 이 연구를 통하여 2-pentanol, propyl acetate, 2-ethylhexanal을 포함한 18 여개 물질들이 벗초파리의 냄새감각기에 큰 활성을 보이는 것으로 확인되었다. 본 연구 결과는 유인제 등 벗초파리의 방제에 친환경적으로 사용될 수 있는 신호화학물질(semiochemical)의 개발에 유용한 정보가 될 것으로 사료된다

Ryanodine receptors (RyRs) regulate the contractions of insect muscles by altering intracellular Ca2+ concentration and are the targets of chlorantraniliprole. Here we established two resistant strains of Drosophila melanogaster, which were treated with low or high concentrations of chlorantraniliprole, and their resistance levels were determined on the basis of contact and ingestion toxicities. Compared with the wild type, the two resistant strains did not show any significant differences in contact toxicity. However, they showed significantly increased resistance ratios in ingestion toxicity than that by the wild type. The resistant strains had altered expression levels of RyRs and more enhanced Acetylcholinesterase and Glutathione-S-transferase activities than that by the non-selected strain. These results suggested that the resistance development of chlorantraniliprole in the two strains might be mediated by the activation of detoxification pathways in D. melanogaster.

In many insects, female receives a large amount of sperm and ejaculates upon copulation, and keeps them in her uterus for some time, during which she stores sperm. After varying delays, the female removes unused sperm and ejaculates through sperm ejection behavior, which is known as a major mechanism for the post-copulatory sexual selection. In the fruitfly Drosophila melanogaster, timing of sperm ejection behavior is controlled by the diuretic hormone 44 (Dh44) pathway. To identify pathways that regulate Dh44 activities and sperm ejection, here we examine effects of olfactory cues. We will present our recent results suggesting that male odors can be one of upstream signaling pathway that modulates a brain neuropeptide pathway.