Insect Growth Regulators (IGRs) are insecticides that disrupt the normal development of target insects by inducing symptoms such as premature molting or supernumerary larval stages. Juvenile hormone systems become the targets of two types of IGRs: the Juvenile Hormone Agonists (JHAs) and Juvenile Hormone Antagonists (JHANs). Pyriproxyfen is one of the chemical compounds widely used as JHA to control many kinds of insects while Kanakugiol is a plant-extracted compound which acts as JHAN. The small brown planthopper, Laodelphax striatellus, is one of the most serious pest insects of rice plants because it can transmit the rice stripe virus which often causes significant reduction of yield in the field. In order to analyze the differential gene expressions of L. striatellus upon JHA and JHAN treatment by using next generation sequencing technique, we sprayed Pyriproxyfen and Kanakugiol on 4th instar nymphs of L. striatellus respectively, and extracted total RNA for RNA-seq. The quality-filtered Illumina sequence reads of the control, JHA, and JHAN treated samples were mapped to the reference gene sequences by using the Bowtie2 software. Then the results of mapping by Bowtie2 were analyzed by eXpress software to quantity the differential gene expression.

Recently, Bacillus thuringiensis (Bt) cry genes encoding insecticidal Cry proteins have been widely applied for the construction of transgenic crops resistant to insect pests. This study aimed to construct novel mutant cry1Ac genes for genetically modified crops with enhanced insecticidal activities. Using multi-site directed mutagenesis, 34 mutant cry1Ac genes were synthesized and converted at 24 amino acid residues, located on domain I (8 residues) and domain II (16 residues). These mutant genes were expressed as a fusion protein with polyhedrin using the baculovirus expression system. The expressed proteins were occluded into polyhedra and activated stably to 65 kDa by trypsin. Among these, Mut-N04, N06, and N16 showed high levels of insecticidal activites against larvae of Plutella xylostella, Spodoptera exigua, and Ostrinia furnacalis. Mut-N16, which showed the highest insecticidal activity, is expected to be a desirable cry gene for introduction into transgenic crops. This study could provide useful means to construct mutant cry genes with improved insecticidal activities and expanded host spectrum for transgenic crops.

Bee venom contains a variety of peptide constituents that have various biological, toxicological, and pharmacological actions. However, the biological actions of secapin, a venom peptide in bee venom, remain largely unknown. Here, we provide the first evidence that the Asiatic honeybee (Apis cerana) secapin (AcSecapin-1) exhibits anti-fibrinolytic, anti-elastolytic, and anti-microbial activities. AcSecapin-1 functions as a serine protease inhibitor-like peptide that has inhibitory effects against plasmin, elastases, microbial serine proteases, trypsin, and chymotrypsin. Consistent with these functions, AcSecapin-1 inhibited the plasmin-mediated degradation of fibrin to fibrin degradation products, thus indicating the role of AcSecapin-1 as a clotting factor. AcSecapin-1 also inhibited both human neutrophil and porcine pancreatic elastases. Furthermore, AcSecapin-1 exhibited anti-microbial activity against fungi and Gram-positive and Gram-negative bacteria. Taken together, our data demonstrated that AcSecapin-1 has a multifunctional role as an anti-fibrinolytic agent, an anti-elastolytic agent, and an anti-microbial peptide, and our data suggested novel functions for the biological actions of the bee venom peptide, secapin.

The honeybee inhibitor cysteine knot (ICK) peptide acts as an antifungal peptide and insecticidal venom toxin. However, the ICK peptide from bumblebees has not been characterized. Here, we report the molecular cloning and antifungal activity of a bumblebee (Bombus ignitus) ICK peptide (BiICK). We identified a BiICK that contains an ICK fold. The BiICK was expressed in the epidermis, fat body, and venom gland of B. ignitus worker bees. A 6.7-kDa recombinant BiICK peptide was expressed in baculovirus-infected insect cells. Recombinant BiICK peptides directly bound to Beauveria bassiana, Ascosphaera apis, and Fusarium graminearum, but they did not bind to Escherichia coli, Paenibacillus larvae, or Bacillus thuringiensis. Consistent with this finding, BiICK exhibited antifungal activity against fungi. These results demonstrate that BiICK acts as an antifungal peptide.

Bees of the genus Osmia are cavity-nesting solitary species that play important roles as pollinators. Nest traps are one of the most common methods to study Osmia bees. To elucidate the optimal environmental conditions of nesting sites, we investigated the effects of location, direction, altitude, and sites of nest traps on the rate of trap-nesting Osmia spp. During the collection period, the average rate of trap-nesting Osmia spp. collected within 90 days after the installation of traps was 17.0±20.0%. This percentage was 2.7-fold higher than that of trap-nesting bees in 30 days after the installation of traps. The Jeongseon location exhibited the highest rates of trap-nesting Osmia spp. collected in 30 and 90 days, representing 11.1 ±17.6% and 23.2±22.5%, respectively. The direction of the nest traps did not affect the rate of trap-nesting Osmia spp. The altitude ranges of the traps were 0-199 m, 200-399 m, 400-599 m, 600-799 m and over 800 m. Interestingly, the altitude range of 600-799 m showed the highest rate of trap-nesting bees, which was 40.4±3.9%. Higher altitudes seemed to correspond to higher rates of trap-nesting bees. With regards to the sites where the nests were placed, the rate of trap-nesting bees in a mud wall of an old house was 45.1±25.2%, which was 3-fold higher than that of a nest in an apple orchard. The flowering plants collected at different locations during the trap-nesting activity of Osmia bees belonged to 18 families and 34 species. In conclusion, the rates of trap nests colonized by Osmia spp. were affected by altitude, site, and plant diversity.

Entomopathogenic fungi are facultative microorganisms, dwelling in soil or infecting host insects, and some of the genera have been used as biological control agents worldwide. Collection of fungal isolates should be a platform for the development of highly effective resources, thus in this work we constructed a fungal library using a mealworm pathogenecity-based fungal collection method and further characterized some isolates with high virulence. A phylogenetic three was generated, and of the isolates 17 isolates’ biological features were characterized, such as morphology, spectrum of virulence, cultural characteristics, thermo-stability of fungi, production of biologically active materials, such as enzymes. This work reports an attractive entomopathogenic fungal library including the information of effective isolates in pest management.

The present issue of insect resistance and environmental toxicity of pesticides is triggering deep discussion about the pest management tactics, in which pest monitoring and control activity are mainly involved. Novel control agents, hopefully overcoming the present issues and problems, should be researched and commercially applied to the farm fields. With the monitoring-based research, additionally we have to focus on the control-based, particularly control agent-based research and application. Entomo- pathogenic fungi can used as one of the possible novel control agents once considerations are given to the control of soil- or water-dwelling pests. In our research group, the entomopathogenic fungal library has been constructed using the mealworm-based isolation system, which showed a variety of opportunities of their use in pest control. Important key production technologies including granular formulation have been developed to increase their industrialization. Some entomopathogenic fungal isolates showed high biological performance in the control of rice weevils, western flower thrips and Japanese bettles in field stands. To elucidate the fungal mode of action, a fungal transformation system using AtMT and gene identification tools were established. Recently a more deep study about the relationship between insect and entomopathogenic fungi is be investigated using RNA seq. We suggest that to make the entomopathogenic fungal products be applied to agricultural farm field, R&D of down-stream process should be seriously considered as the key step.

A large-scale neutral hydrogen (H i) ring serendipitously found in the Leo I galaxy group is 200 kpc in diameter with MHi ~ 1:67 X 109M⊙, unique in size in the Local Universe. It is still under debate where this Hi ring originated - whether it has formed out of the gas remaining after the formation of a galaxy group (primordial origin) or been stripped during galaxy-galaxy interactions (tidal origin). We are investigating the optical and Hi gas properties of the dwarf galaxies located within the gas ring in order to probe its formation mechanism. In this work, we present the photometric properties of the dwarfs inside the ring using the CFHT MegaCam u*, g', r' and i'-band data. We discuss the origin of the gas ring based on the stellar age and metal abundance of dwarf galaxies contained within it.

Bone fractures are most often seen in racetrack horses because of the high level of intensity in racing. These issues are the main cause of decreased performance in racehorses. Mesenchymal stem cells (MSCs) have been explored to improve intra-articular therapy in racehorses. MSCs are essential for the repair and regeneration of damaged tissues. In this study, the effect of intra-articular injection of MSCs in racehorses was investigated. Before accessing the MSC therapy, synovial fluids were obtained from the fracture site of racehorses, and adipose tissue was collected for MSC isolation. Using the MSC specific marker, adipose tissue-derived MSCs were identified. The racehorses received intra-articular injection of autologous MSCs (or allogeneic) (3 × 107 cells/3 mL). After 1 or 2 weeks, synovial fluids were collected from racehorses. To test the effect of MSC injection using ELISA, we analyzed inflammatory factors from the untreated samples compared to MSC-treated samples of racehorses. The level of pro-inflammatory factors (interleukin-1β and prostaglandin E2) was significantly decreased in synovial fluids of MSC-injected racehorses, compared to before accessing the MSC therapy, whereas, the level of anti-inflammatory factor (interleukin-10) was higher than prior to accessing the MSC therapy. Further studies are needed to investigate the anti-inflammatory mechanism of MSC in racehorses.

The sintering mechanisms of nanoscale copper powders have been investigated. A molecular dynamics (MD) simulation with the embedded-atom method (EAM) was employed for these simulations. The dimensional changes for initial-stage sintering such as characteristic lengths, neck growth, and neck angle were calculated to understand the densification behavior of copper nano-powders. Factors affecting sintering such as the temperature, powder size, and crystalline misalignment between adjacent powders have also been studied. These results could provide information of setting the processing cycles and material designs applicable to nano-powders. In addition, it is expected that MD simulation will be a foundation for the multi-scale modeling in sintering process.

백두대간 구룡령-약수산 마루금에 22개의 방형구(100m2)를 설정하여 식생을 조사하였다. 식생군집을 분석한 결과 신갈나무-까치박달나무-당단풍나무군집, 신갈나무군집, 층층나무-신갈나무군집 등 3개의 군집으로 분류되었다. 백두대간 구룡령-약수산 마루금은 대부분 신갈나무가 우점하고 있었으며, 일부지역에서 까치박달나무와 층층나무 등이 혼효하고 있었다. 수종간의 상관관계에서 신갈나무와 노린재나무, 철쭉; 피나무와 찰피나무, 노린재나무; 찰피나무와 노린재나무, 철쭉; 거제수나무와 고로쇠나무; 노린재나무와 철쭉 등의 수종 간에는 높은 정의 상관이 인정되었다. 당단풍나무와 노린재나무, 철쭉 등의 수종 간에는 높은 부의 상관이 인정되었다. 조사지의 군집별 종다양성 지수는 0.8170~1.1446범위로 백두대간에 위치한 국립공원들의 능선부 식생구조 보다는 약간 낮게 나타났다.

The objective of this study was to determine the effects of E. coli on boar sperm quality and reproductive performance in sows after artificial insemination. Three different levels of E. coli were artificially inoculated to semen with following concentrations; Control, 500, 5,000 and 50,000 colony forming unit (cfu)/ml. Semen samples were preserved at 17℃ for 5 days. Sperm motility was significantly decreased (p<0.05) on day 3 in the group inoculated with 5,000cfu/ml compared to control groups. In all treatment groups, sperm motility was gradually decreased as storage time increased, but the decline pattern was more drastic in the groups inoculated with 5,000 and 50,000 cfu/ml groups from day 3 (p<0.05) compared to control group. After 3 day of storage at 17℃, sperm viability in sample inoculated with the highest concentration (50,000 cfu/ml) of bacteria was less (p<0.05) than that of control group. The pH of semen sample pH was maintained 7.2～7.5 in all groups during the experimental period. No differences (p>0.05) were found for both storage time and bacterial concentration. The pregnancy rate and live born piglets tend to decrease by increasing the concentration of E. coli in semen. In particular, the rate of pregnancy was lower in the group inoculated with 50,000 cfu/ml (58.3%) compare to the other groups (81.8, 75.0, 76.5%). These results suggest that the contamination of E. coli in boar semen negatively affects fertilizing ability of boar sperm and the reproductive performance obtained from sows after artificial insemination.

Enhanced green fluoresce protein gene (egfp) was expressed in Beauveria bassiana ERL836 based on the Agrobacterium tumefaciens-mediated transformation (AtMT) method in this study. The ERL836 transformants were generated with pCambia-egfp binary vector. Ten transformants were randomly selected and analyzed for the T-DNA insertion and gene expression. The results revealed that 60% of the fungal putative transformants were inserted by the T-DNA fragment. Of these transformants, 33.33% (2 transformants) expressed the egfp gene. The egfp transformants showed strong green fluorescence with different expression levels. The results of this study could provide a reference for foreign protein expression in B. bassiana by using the AtMT method.

Inhibitor cysteine knot (ICK) peptides exhibit ion channel blocking, insecticidal, and antimicrobial activities, but currently, no functional roles for bee-derived ICK peptides have been identified. In this study, a bee (Apis cerana) ICK peptide (AcICK) that acts as an antifungal peptide and as an insecticidal venom toxin was identified. AcICK contains an ICK fold that is expressed in the epidermis, fat body, or venom gland and is present as a 6.6-kDa peptide in bee venom. Recombinant AcICK peptide (expressed in baculovirus-infected insect cells) bound directly to Beauveria bassiana and Fusarium graminearum, but not to Escherichia coli or Bacillus thuringiensis. Consistent with these findings, AcICK showed antifungal activity, indicating that AcICK acts as an antifungal peptide. Furthermore, AcICK expression is induced in the fat body and epidermis after injection with B. bassiana. These results provide insight into the role of AcICK during the innate immune response following fungal infection. Additionally, we show that AcICK has insecticidal activity. Our results demonstrate a functional role for AcICK in bees: AcICK acts as an antifungal peptide in innate immune reactions in the body and as an insecticidal toxin in venom. The finding that the AcICK peptide functions with different mechanisms of action in the body and in venom highlights the two-pronged strategy that is possible with the bee ICK peptide.

Rice stripe virus (RSV) is one of the serious plant pathogenic viruses for rice transmitted by small brown planthopper, SBPH, Laodalphax striatellus. RNA interference (RNAi) is an universal gene-knockdown mechanism in eukaryotic organisms which includes insects，and has been considered as an alternative strategy to control insect pests. Hence, we applied this technique to interfere the translation of target RNA genes to knockdown the virus gene on RSV-viruliferous L. striatellus. Three out of seven RSV genes, RdRp, NS3, and NCP were used as target genes and each dsRNA targeting the viral genes were delivered to the insects indirectly through the rice leaves by irrigation. As a result, not only the relative expression level of target genes decreased but also those of non-target genes and the replication of RSV genome as well. In summary, leaf-mediated dsRNA feeding methods would be useful in the knockdown of target genes on piercing-sucking insects. The genes used in this experiment can be utilized for the development of pest-resistant transgenic plants based on RNAi.

Crystals of proteinaceous insecticidal proteins, Cry proteins, produced by Bacill us thuringiensis (Bt) have been generally used used to control insect pests. In this st udy, through the 3D structure prediction and accompanying mutagenesis study for the Mod-Cry1Ac, 7 and 16 amino acid residues from domain I and II, respectively, responsible for its insecticidal activity against larvae of Plutella xylostella, Spodopt era exigua and Ostrinia furnacalis were identified. To construct novel cry genes wi th enhanced insecticidal activity, we randomly mutated these 24 amino acid sequen ces by in vitro muti site-directed mutagenesis, resulting in totally 34 mutant cry gen es. For further characterization, these mutant cry genes were expressed as a fusion protein with polyhedrin using baculovirus expression system. SDS-PAGE analysis of the recombinant polyhedra revealed that expressed Cry proteins was occluded in to polyhedra and activated stably to 65 kDa by trypsin. When the insecticidal activit ies of these mutant Cry proteins against to larvae of P. xylostella, S. exigua, and O. furnacalis were assayed, they showed higher or similar insecticidal activity compar ed to those of Cry1Ac and Cry1C. Especially, among them Mutant-N16 showed th e highest insecticidal activity against to both of P. xylostella, S. exigua and Ostrinia furnacalis. Therefore, Mutant-N16 is estimated to have the potential for the efficac ious bioagent.

An easy and rapid resistance detection protocol for the Western flower thrips Frankliniella occidentalis was established based on the residual contact vial bioassay (RCV), in which insecticide resistance levels can be estimated at 8 h-post treatment of diagnostic doses. The RDA strain was used as a reference susceptible strain, which has been reared under laboratory conditions over 10 years without exposure to any insecticides. Seven insecticides were tested for the determination of diagnostic dose. Among them, five insecticides (chlorfenapyr, acrinathrin, spinosad, emmamectin benzoate and thiamethoxam, ranged as 0.03 ~ 0.42 μg-1cm2) were applicable to the RCV. However, two insecticides (omethoate and imidacloprid) were not able to be used for the RCV because the treated inner surface of glass vials by these insecticides were too viscous, causing non-specific mortality. The RCV detection kit was employed for the estimation of resistance levels for the five insecticides in five local populations. Almost field-collected populations revealed high levels of resistance to the four insecticides (acrinathrin, spinosad, emmamectin benzoate and thiamethoxam) by showing less than 50% mortality. The baseline resistance detection by RCV method will facilitate the selection of proper insecticides for farmers to manage insecticide resistant-populations of F. occidentalis.

We investigated the insect community along altitudinal gradient to gather basic data for distributional monitoring of insect species in the forest ecosystem. The investigation area was Seon-gaksan (Mt.) in Jinan-gun, Jeollabuk-do province, where the bucket-light trap and pit-fall trap for quantification were installed in Quercus vegetation at altitude of 300m, 600m and 900m. The field collecting was performed on May, July and September 2013 respectively. ANOVA analysis was conducted to analyze the significance between insect species along altitude using the collected insect community data. Analysis of variance (ANOVA) results showed statistically significant differences among ground-beetles and ants abundance with altitude as a response variable. Although we expected a distinct cluster with the difference of altitude at each study site, nonmetric multidimensional scaling (NMS) showed distinct clusters with the moth, ground-beetles, and ant assemblage at altitudinal increase and sampling month. In the result, a total of 309 species in 18 families of nocturnal moths were collected by bucket-light trap. The insects collected in pit-fall trap were ground-beetles with 196 individuals of 26 species and ants with 11,276 individuals of 14 species respectively.