The spotted wing drosophila (SWD), Drosophila suzukii, is a severe pest of berry fruits like strawberry, blueberry, sweet cherry and grape in terms of quarantine. For the disinfestation of SWD, methyl bromide (MeBr) is the only option in quarantine practice. However, MeBr's current use will be phased out due to chronic inhalation toxicity to fumigators and related worker as well as ozone depletion properties. To replace MeBr, we evaluated the efficacy of ethyl formate (EF) and phosphine gas (PH3) to all different developmental stages of SWD at practical fumigation condition (>25 ℃). To achieve complete control of all stages of SWD, PH3 required > 6 hr exposure when applied at > 1.0 g m-3. In case of 4hr EF fumigation, the LCt99 (LCt99, 99% lethal concentration × time) of EF to egg, larvae and pupae of SWD was 198.09, 77.42 and 115.55 g·h m-3, respectively.

각종 베리류 과실에 피해를 주는 벗초파리(Drosophila suzukii)에 있는 냄새감각기(Olfactory sensilla)들의 종류와 분포를 알아보기 위해 암, 수컷의 촉각(Antenna)과 작은턱수염(Maxillary Palpi)을 주사전자현미경(Scanning Electron Microscope)으로 관찰하였다. 직경 20–50nm의 작은 구멍(Pore)들이 표면에 존재하는 감각기(Sensilla)들을 냄새감각기 로 구분했을 때, 벗초파리의 촉각과 작은턱수염에 분포하는 많은 감각기들은 대부분이 냄새감각기로 판단되었다. 이들 냄새감각기들은 표면미세구조가 다른 귀모양감각기(Sensilla auricillica), 털감각기(Sensilla trichodea) 및 추상감각 기(Sensilla basiconica)가 대부분을 차지했으며, 감각기 종류와 분포양상은 촉각과 작은턱수염 사이에 뚜렷한 차이를 나타내어 벗초파리의 촉각과 작은턱수염은 서로 다른 냄새감각기능을 가질 것으로 생각되었다. 본 연구 결과는 벗초파리의 냄새통신을 이해하고 유인제를 개발하는데 유용한 정보를 제공할 것으로 사료된다.

We developed a simple molecular detection tool that rapidly and accurately identifies Spotted wing Drosophila (SWD) without sophisticated instruments or expertise. We first identified a gene that is present in the SWD genome but not in that of any other insect species. Then, we developed the loop-mediated isothermal amplification (LAMP) assay, which was designed based on genomic DNA of SWD specific gene. This LAMP assay detected only genomic DNA from SWD—not from Drosophila melanogaster. In addition, this assay could detect genomic DNA in SWD geographical strains collected from 8 different locations in Asia, Europe, Hawaii, and the USA. Our LAMP assay could be a useful detection tool for identifying SWD rapidly in the field. This work was carried out with the support of the Cooperative Research Program for Agriculture Science & Technology Development (Project No: PJ0116302016).

The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is an economically damaging pest that feeds on most thin-skinned fruits. In this study, we sequenced portions of the mitochondrial (mt) COI and ND4 genes from a total of 195 individuals collected mainly from Korea. A total of 139 haplotypes were obtained from the concatenated COI and ND4 sequences. A dataset combining GenBank sequences with our own data identified a total of 94 worldwide COI haplotypes with a maximum sequence divergence of 5.433% (32 bp). A rough estimate of genetic diversity in each country showed higher diversity in ancestral distributional ranges, but the invasion over Asian countries seems to have been substantial because haplotype diversity was only 2.35-3.97-fold lower in the USA, Canada, and Italy than that in the populations ancestral ranges.

Acetylcholinesterase (AChE) is an enzyme for hydrolyzing neurotransmitter acetylcholine. Soluble form of AChE is generated via alternative splicing and functions as a bioscavenger in Dropsophila melanogaster. In this study, effects of ethanol and acetic acid on the soluble AChE expression were investigated. Treatment of ethanol and acetic acid results in over-expression of soluble AChE in the abdomen in a dose-dependent manner. However, no apparent change in AChE expression was observed in the head. Our finding suggests that the soluble AChE is involved in chemical defense against high concentration of ethanol, which is a common by-product from fermented food，and acetic acid, the main metabolite of ethanol. Thus, high level of ethanol and acetic acid resistance in D. melanogaster appears to be evolved via the induction mechanism of soluble AChE expression.

The spotted-wing drosophila Drosophila suzukii (Diptera: Drosophilidae) is an Asian species introduced into North America and Europe. It damages a wide variety of thin-skinned fruits. We sequenced the complete mitochondrial genome (mitogenome) of D. suzukii to better understand the mitogenomic characteristics of this species and understand phylogentic relationships of Drosophila. The 16,230-bp complete mitogenome of the species consists of a typical set of genes, including 13 protein-coding genes (PCGs), two rRNA genes, and 22 tRNA genes, and one major non-coding A+T-rich region, with an arrangement typical of insects. Twelve PCGs began with the typical ATN codon, whereas the COI began with TCG, which has been designated as the start codon for other Drosophila species. The 1,525-bp A+T-rich region is the second longest in Drosophila species for which the whole mitogenome has been sequenced, after D. melanogaster. Phylogenetic analysis with the 13 PCGs of the Drosophila species using Bayesian Inference and Maximum likelihood methods both placed D. suzukii at the basal lineage of the previously defined Melanogaster group, with a strong support.

Repetitive applications of drugs to tumor tissues and animals induced resistance and/or tolerances which caused severe problem in agriculture and medicine. However, we still do not clearly understand the molecular and cellular mechanisms underlying development of resistance and tolerance to chemicals. Drosophila is one of the most widely used model for studying fundamental phenomena in sciences using its available genetic and genomic resources. To investigate unknown molecular and cellular basis of drug resistance development, we applied Drosophila with two different concentrations of a chemical after treating them with Ethyl methanesulfonate mutatgenesis. We found that flies treating with two different concentration of chemicals showed different susceptibility to a chemical. We have established two different lines showing different susceptibility to a chemical. We will use these lines to compare any differences in mRNA expression profiling and enzyme activities. (This work was supported by project title: Investigation on cross drug resistance mechanisms using Drosophila as a model (PJ010821032016) from Rural Development Administration).

We investigated unknown in vivo functions of Torsin by using Drosophila as a model. Downregulation of Drosophila Torsin (DTor) by DTor specific inhibitory double-stranded RNA (RNAi) induced abnormal locomotor behavior and increased susceptibility to H2O2. In addition, altered expression of DTor significantly increased the numbers of synaptic boutons. One of important biochemical consequence of DTor-RNAi expression in fly brains was up-regulation of alcohol dehydrogenase (ADH). Altered expression of ADH has also been reported in Drosophila Fragile-X mental retardation protein (DFMRP) mutant flies. Interestingly, expression of DFMRP was altered in DTor mutant flies, and DTor and DFMRP were present in the same protein complexes. In addition, DTor and DFMRP immunoreactivities were partially colocalized in several cellular organelles in larval muscles. Furthermore, there were no significant differences between synaptic morphologies of dfmrp null mutants and dfmrp mutants expressing DTor-RNAi. Taken together, our evidences suggested that DTor and DFMRP might be present in the same signaling pathway regulating synaptic plasticity. (This work was supported bythe basic science research program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (No. 2015R1D1A3A01018497)

Alzheimer’s disease (AD) is an age-related neurodegenerative disease characterized by extensive loss of synaptic connections, neuronal death, and the presence of extracellular amyloid plaques and intracellular neurofibrillary tangles (iNFTs). The extracellular amlyoid plaques are mainly composed of the amyloid beta (Aβ) peptide which formed by proteolytic processing of the amyloid precursor protein (APP). Aβ42peptide oligomerizes, is neurotoxic and readily forms aggregates that accumulate in the brain to form plaques. These oligomers are thought to cause inflammation, oxidative stress and apoptosis, thereby resulting in synaptic and neuronal loss. Although AD is neurodegenerative disorder, current therapies designed to treat it still demonstrate limited efficacy. Silkworm (Bombyx mori) has long been used as food and medicine in Asian countries which is reputed for the treatment of numerous neurological disorders including AD. In this study, we use Drosophila melanogaster which is expressed the human AD-associated protein APP695, BACE and MAPT as the model and initially investigate whether silkworm powder food has positive effect on flies expressing Alzheimer’s status as well as makes the improvement in disease condition by using this AD fly model (This work was carried out with the support of the Cooperative Research Program for Agriculture Science & Technology Development (Project title: Elucidation the health improvement effects of boiled silk worm larvae, Project No: PJ01082801) Rural Development Administration)

Exposure to several common acting through oxidation stress environmental toxins has been shown to be associated with Parkinson’s disease (PD). One recently identified inherited Parkinson’s disease (PD) gene, DJ-1, may have a role in protection from oxidative stress, thus potentially linking a genetic cause with critical environmental risk factors [1]. In the present study, initially we assessed the antioxidant activity of Silk Worm Powder (SWP) in selected chemical systems and further explored the efficacy of SWP in Drosophila lacking DJ-1 function (This work was carried out with the support of the Cooperative Research Program for Agriculture Science & Technology Development (Project title: Elucidation the health improvement effects of boiled silk worm larvae, Project No: PJ01082801) Rural Development Administration).

Twelve Lamiaceae plant essential oils (EOs) and their components were evaluated for their fumigant and contact toxicities. Inhibition of AChE by the major components of active EOs was also assessed. Strong fumigant toxicity was observed from EOs of Mentha piperita and Perilla frutescens. Menthone and menthol, and perilla aldehyde were identified as major components of the above two EOs, respectively. The LC50 (mg/L) values of M. piperita, P. frutescens, menthone, menthol and perilla aldehyde were 3.87, 2.44, 5.76, 1.88, and 0.99 against male, and 4.10, 3.31, 5.13, 1.94, and 1.15 against female, respectively. Strong contact toxicity was observed from the EOs of Satureja montana and Thymus zygis. Thymol and carvacrol were major components of these two EOs. The LD50 (μg/fly) values for contact toxicity of S. montana, T. zygis, thymol and carvacrol were 2.95, 2.93, 1.63, and 1.30 for male, and 4.59, 5.09, 2.68, and 2.60 for female, respectively. Among the five major components, perilla aldehyde showed most active inhibition activity against AChE of both sexes of SWD.

Drosophila suzukii is an economically important pest of fruit in America and Europe as well as in Asia. Sparassol (1) and methyl orsellinate (2) are produced by Sparassis cripta and S. latifolia during culture. Fumigant and contact toxicities of synthetic sparassol (1) methyl orsellinate (2) and methyl 2,4-dimethoxy-6-methylbenzoate (DMB; 3) were investigated. The possible mode of action of the compounds was pursued by assessing their inhibition activities against acetylcholinesterase (AChE) and glutathione S-transferase (GST). Little or no fumigant activity was observed from tested compounds. In contact toxicity activity, LD50 (μg/fly) values are 5.29, 1.18, 0.02 for male, and 11.14, 2.27, 0.05 for female, respectively. In enzyme inhibition assay, DMB (3) which easily synthesized from sparassol could be an alternative agent for controlling insect pest. In addition, Sparassis species could be an industrial resource of sparassol.

The human β-amyloid (Aβ) cleaving enzyme (BACE-1) is a target for Alzheimer’s disease (AD) treatments. This study was conducted to determine if acacetin extracted from the whole Agastache rugosa plants had anti-BACE-1 and behavioral activities in Drosophila AD models and to determine acacetin’s mechanism of action. Acacetin (100, 300, and 500 μM) rescued amyloid precursor protein (APP)/BACE1-expressing flies and kept them from developing both eye morphology (dark deposits, ommatidial collapse and fusion, and the absence of ommatidial bristles) and behavioral (motor abnormalities) defects. The RT-PCR and Western blot analysis revealed that the protective effect of acacetin on Aβ production is mediated by transcriptional regulation of BACE-1 and APP, resulting in decreased APP protein expression and BACE-1 activity, and reduced Aβ production by interfering with BACE-1 activity and APP synthesis, resulting in a decrease in the levels of the APP carboxy terminal fragments and the APP intracellular domain, and finally, resulting in a decrease in the number of amyloid plaques.

Drosophila has been used as a model for studying various human diseases. Especially, it has been widely used for studying neurological disorders in humans. For example, many progressive neurological disorders such as Alzheimer's diseases, Parkinson’s disease, Amyotrophic lateral sclerosis were recapitulated in Drosophila. We have been studying DYT1 dystonais, an enigmatic movement disorder. We generated several different kinds for Drosophila models by expressing human Torsin1A genes with or without causative mutations. In addition, we employed various Omics tools to identify any genetic, proteomic, and metabolomic alterations. I will summarize our recent progression in using Drosophil as a model for studying molecular and cellular etiologies underlying DYT1 dystonia and in vivo functions of Torsin proteins.

노랑초파리(Drosophila melanogaster)는 가장 연구가 많이 되어져 있는 모델동물로서 다양한 연구에 활용이 되어져 왔다. 하지만, 작물보호제에 대한 약제 저항성 모델로는 활용이 되어지지 않고 있다. 우리는 노랑초파리의 수컷에 Ethylene methane sulfonate를 처리하여 전체염색체에 돌연변이를 유도 한 후에 Chlorantraniliprole을 처리하여 약제에 대하여 저항성을 가지는 초파리 계통을 제작, 확립하였다. 저항성 계통에 대한 전체발현 유전체 분석과 micro-RNA분석을 수행하여 발현이 변화된 유전자를 밝혀내고 돌연변이 유전자를 발굴하는 연구를 수행하고 있다. 이러한 연구는 저항성 관련 기전을 밝혀내는 것과 동시에 내성에 관련된 기전을 밝혀내는데도 커다란 도움을 줄 수 있을 것이다. (본 연구는 농촌진흥청 협동연구사업 “초파리를 이용한 교차저항성 발달 모델 및 기작 구명(PJ01082103)”으로 수행되었음).

Acetylcholinesterase (AChE) is a hydrolase that hydrolyzes the neurotransmitter acetylcholine. Soluble form of AChE is generated via alternative splicing and functions as a bioscavenger in Dropsophila melanogaster. In this study, effects of acetic acid on the soluble AChE expression were investigated. Treatment of acetic acid resulted in over-expression of soluble AChE in the abdomen in a dose-dependent manner. The soluble AChE was determined to be expressed in the fat body. However, no apparent change in AChE expression was observed in the head. Our finding suggests that the soluble AChE is involved in chemical defense against high concentration of acetic acid, which is a common by-product in fermenting foods. The high level of acetic acid resistance in D. melanogaster, thus, appears to have been evolved via the induction mechanism of soluble AChE expression.

The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), originally distributed across a few Asian countries, including South Korea, has invaded North America and Europe, but is absent from Australia. In order to export the South Korean grape cultivar Campbell Early to Australia, its potential to serve as oviposition and development medium for SWD must first be determined. In this study, we determined the oviposition and development potential of SWD on Campbell Early, after elucidating the SWD life cycle and establishing an artificial diet-based mass-culturing system. An investigation of the life cycle under five temperature regimes (16, 19, 22, 25, and 28°C) showed that the durations of the egg, larval, and adult stages were shorten when temperature was increased from 16, 19, 22, 25, and 28°C, but pupal duration was shortest at 25°C and extended again at 28°C. A test of oviposition and development potential of SWD on Campbell Early grape clusters showed oviposition of 30.8 ± 6.8 eggs per cluster of injured grapes and 157.7 ± 16.2 eggs on a culture dish of artificial diet. However, in a similar experiment using uninjured grape clusters, only a single egg was deposited on the grape skin, which soon dried. In light of these results, newly harvested grapes left at vineyards during daily harvests are unlikely to serve as an oviposition and development medium for SWD, as long as the grapes remain uninjured.

Recent studies have shown that mating can alter starvation resistance in female D. melanogaster, but little is known about the behavioral and physiological mechanisms underlying such mating-mediated changes in starvation resistance. In the present study, we first investigated whether the effect of mating on starvation resistance is sex-specific in D. melanogaster. As indicated by a significant sex × mating status interaction, mating increased starvation resistance in females but not in males. In female D. melanogaster, post-mating increase in starvation resistance was mainly attributed to increases in food intake and in the level of lipid storage relative to lean body weight. We then performed quantitative genetic analysis to estimate the proportion of the total phenotypic variance attributable to genetic differences (i.e., heritability) for starvation resistance in mated male and female D. melanogaster. The narrow-sense heritability (h2) of starvation resistance was 0.235 and 0.155 for males and females, respectively. Mated females were generally more resistant to starvation than males, but the degree of such sexual dimorphism varied substantially among genotypes, as indicated by a significant sex × genotype interaction for starvation resistance. Cross-sex genetic correlation was greater than 0 but less than l for starvation resistance, implying that the genetic architecture of this trait was partially shared between the two sexes. For both sexes, starvation resistance was positively correlated with longevity and lipid storage at genetic level. The present study suggests that sex differences in starvation resistance depend on mating status and have a genetic basis in D. melanogaster.

Macronutrient balance has a strong influence on fitness in insects. Previous studies have revealed that altering the concentrations of yeast and sugar in the semi-synthetic diet has a profound impact on lifespan and fecundity in Drosophila melanogaster, indicating the role of dietary protein:carbohydrate (P:C) balance in determining these two key components of fitness. However, since yeast contains not only proteins but also other macro- and micronutrients, this lifespan-determining role of dietary P:C balance needs to be corroborated using a chemically defined diet. In this study, the effects of dietary P:C balance on lifespan and fecundity were investigated in female D. melanogaster flies on one of eight isocaloric synthetic diets differing in P:C ratio (0:1, 1:16, 1:8, 1:4, 1:2, 1:1, 2:1 or 4:1). Lifespan and dietary P:C ratio were related in a convex manner, with lifespan increasing to a peak at the two intermediate P:C ratios (1:2 and 1:4) and falling at the imbalanced ratios (0:1 and 4:1). Ingesting nutritionally imbalanced diets caused flies to start ageing earlier and senesce faster. Egg production increased progressively as the dietary P:C ratio rose from 0:1 to 4:1. Long-lived flies at the intermediate P:C ratios(1:2 and 1:4) stored a greater amount of lipids than those short-lived ones at the two imbalanced ratios (0:1 and 4:1). These findings provide a strong support to the notion that dietary P:C balance is a critical determinant of lifespan and fecundity in D. melanogaster.

Spotted wing drosophila (SWD), Drosophila suzukii, is one of the most harmful pests causing serious damages to blueberries in Northern America and Europe. It is essential to seek alternatives to methyl bromide to ensure dis-infestation of this pest from agricultural products. We investigated the effect of X-ray irradiation (0, 50, 100, 200 and 300 Gy) on development and reproduction of SWD to meet this standard. When eggs were irradiated with the doses, some portion of the eggs hatched even at 300 Gy. The larvae hatched from the irradiated eggs did not pupate at 300 Gy, and they could not develop to adults even at 50 Gy. When larvae were irradiated, they developed up to pupa in some proportion. However above 100 Gy, there was no adult emergence. When pupae were irradiated, some of them emerged to adults. However, the adults could not produce eggs at all above 100 Gy. When adults were irradiated, oviposition occurred normally, but fecundity and hatchability were decreased as irradiation dose went up.