Riptortus pedestris possesses Burkholderia as gut symbiont in a symbiotic organ M4 midgut. To answer why Burkholderia symbionts are not eliminated by Riptortu s immune responses, we developed two hypotheses: (i) Burkholderia symbionts do not activate host innate immunity, or (ii) Burkholderia symbionts are resistant to th e host immune responses. For the first hypothesis, we compared the antimicrobial activities of the cultured Burkholderia-injected hemolymph and symbiotic Burkhol deria-injected hemolymphs. As a result, the symbiotic Burkholderia induced antim icrobial activity like the cultured Burkholderia, indicating the symbiotic cells are st ill immunogentic to host. However, when the activated hemolymph was treated to the Burkholderia cells, the symbiotic Burkholderia showed much higher susceptibi lity than the cultured Burkholderia. To understand molecular basis of these results, we purified antimicrobial peptides (AMPs) from Riptortus hemolymph. Similarly, the symbiotic Burkholderia exhibited the high susceptibility to the purified AMPs, riptocin and rip-defensin. To understand how symbiotic Burkholderia can survive in host in spite of their immuno-susceptibility, we examined the AMP expression i n the M4 midgut. Interestingly, the expression of AMPs is suppressed in the M4 mi dgut in comparison to that of the fat body. Finally, we proposed that the immuno-su sceptibility of Burkholderia symbiont helps them to retain in the symbiotic organ. Our in vivo data showing the rapid clearance of the symbiotic Burkholderia after inj ection to host Riptortus supports our proposal.

Despite many researches related with in-vitro culture of porcine spematogonial stem cells (SSCs), adherent culture system widely used has shown a limitation in the maintenance of porcine SSC self-renewal. Therefore, in order to overcome this obstacle, suspension culture, which is known to have numerous advantage over adherent culture, was applied to the culture of porcine SSCs. Porcine SSCs retrieved from neonatal testes were suspension-cultured for 5 days or 20 days, and characteristics of suspension-cultured porcine SSCs including proliferation, alkaline phosphatase (AP) activity, and self-renewal-specific gene expression were investigated and compared with those of adherent-cul-tured porcine SSCs. As the results, the suspension-cultured porcine SSCs showed entirely non-proliferative and significantly higher rate of AP-positive cells and expression of self-renewal-specific genes than the adherent-cultured porcine SSCs. In addition, long-term culture of porcine SSCs in suspension condition induced significant decrease in the yield of AP staining-positive cells on post-day 10 of culture. These results showed that suspension culture was inappropriate to culture porcine SSCs, because the culture of porcine SSCs in suspension condition didn’t stimulate proliferation and maintain AP activity of porcine SSCs, regardless of culture periods.

The Riptortus-Burkholderia symbiosis is a newly emerging insect-bacterium symbiotic system. This symbiosis system has a good merit as an experimental model system to produce the non-symbiotic (apo) and symbiotic (sym) host insect. In recent reported papers, the symbionts play important biological roles for the host insects. Meanwhile, juvenile hormone (JH) is one of major hormone synthesized corpora allata(CA) to control many physiology of insect. However, the study for cross-talk mechanism between symbionts and host hormones to control important physiological phenomenon of insects is almost none. In this study, we found that Riptortus speed up adult emerging and increase egg laying on presence of symbiont Burkholderia. Also we found that hexamerin proteins, which were controlled the expression by JH, were accumulated in sym-Riptortus hemolymph compare with apo-Riptortus. According as combined results, we hypothesized that the gut symbiont Burkholderia can control JH titer to conclude out beneficial effects such as development and reproduction of R. pedestris. To verify this hypothesis, we examined measurement of JH titer, expression of hexamerins as JH response genes and RNAi for hexamerin protein during whole Riptortus life on presence or absence of symbiont Burkholderia. All results demonstrated that gut symbiont controlled JH titer of Riptortus. Controlled JH amount by symbiont Burkholderia in host midgut regulated hexamerin protein expression for speeding up adult emerging and increasing egg production.

Beet armyworm, Spodoptera exigua is difficult to control using chemical insecticides because of the development of insecticide resistance. Various control agents may use for eco-friendly beet armyworm managements, Entomopathogenic fungus is one of the promising control agents as an alternative to chemical control agent. At previous study we isolated a number of entomopathogenic fungi from soil samples and selected three entomopathogenic fungi, Metarhizium anisopliae FT83, Paecilomyces fumosoroseus FG340 and Metarhizium anisopliae FG344 which had high virulence against larva of beet armyworm. To select an isolate having high virulence at high temperature against S. exigua, thermophilic pest, we conducted bioassay at five different temperatures(15, 20, 25, 30, 35℃). These three isolates showed the high mortality and low LT50 at 30℃. To select substrate for mass production these isolates were inoculated(5×10⁴/㎖, 20㎖) at barley, unpolished rice, wheat bran and rice bran and incubated for 14 days at 25℃. Wheat bran showed highest conidia production of M. anisopliae FT83 and P. funosoroseus FG340 and barley was suitable for M. anisopliae FG344.

Various insect pests infest crops including vegetables and ornamentals during crop production. Chemical pesticides have generally used until recently to control pests. Many pests are very difficult to control using organic pesticides because of the development of insecticide resistance and their rapid population increase. Entomopathogens are the promising alternative control methods. Entomopathogenic fungi are good candidates to control sucking insects such as aphid, whitefly and mite because the fungi can infect without ingestion. Conidia or blastospores of fungal entomopathogens are sprayed onto target plant and/or insect, adhered on insect surfaces, and penetrated into hemocoel through insect cuticle. Then the fungus utilize insect nutrients and kill the host insect. During this process, fungus was influenced by environmental conditions such as temperature, relative humidity and UV light. These are causing slow mortality and preventing wider application and use of mycopescitide using entomopathogenic fungi. In addition, control efficacy with fungal entomopathogen differed fungal isolate and host insect. Therefore, we need to study selection of high virulence isolate, mass production, formulation and application techniques to develop mycopesticide.

The centipede Scolopendra subspinipes mutilans has been a medically important arthropod species by using it as a traditional medicine for the treatment of various diseases. In this study, we derived a novel lactoferricin B like peptide (LBLP) from the whole bodies of adult centipedes, S. s. mutilans, and investigated the antifungal effect of LBLP. LBLP exerted an antifungal and fungicidal activity without hemolysis. To investigate the antifungal mechanism of LBLP, a membrane study with propidium iodide was first conducted against Candida albicans. The result showed that LBLP caused fungal membrane permeabilization. The assays of the three dimensional flow cytometric contour plot and membrane potential further showed cell shrinkage and membrane depolarization by the membrane damage. Finally, we confirmed the membrane-active mechanism of LBLP by synthesizing model membranes, calcein and FITC-dextran loaded large unilamellar vesicles. These results showed that the antifungal effect of LBLP on membrane was due to the formation of pores with radii between 0.74 nm and 1.4 nm. In conclusion, this study suggests that LBLP exerts a potent antifungal activity by pore formation in the membrane, eventually leading to fungal cell death.

Beet armyworm, Spodoptera exigua are difficult to control using chemical insecticides because of the development of insecticide resistance. For eco-friendly beet armyworm managements, various control agents are required. Entomopathogenic fungus is one of promise control agents as an alternative to chemical control agent. We isolated entomopathogenic fungi from soil samples of suwon by insect-bait method using Galleria mellonella and conducted bioassay to larva of beet armyworm. As a result of bioassay isolate FG274, FG340, FG344 had high virulence as 100% against second instar larva of S. exigua. To identify the fungus isolates, their’s morphological characteristic was observed and ITS of 18srRNA was sequenced. ITS sequence of FT274, 340, 344 were highly matched (100%) to that of Beauveria bassiana, Paecilomyces fumosoroseus, Metarhizium anisopliae. To investigate the optimal concentration, three isolates were sprayed at three different concentration(1×106 ,107 and 108 conidia/㎖) in laboratory conditions. 나타내었다.

Use of conidia or spores of entomopathogenic fungi are influenced by environmental conditions such as temperature and relative humidity and caused slow and fluctuation of mortality. In addition, although the fungi have the advantage of a restricted host range, this specificity is one of the limiting factors for their use. These factors are preventing wider application and use of these biocontrol agents. To mitigate such problems we selected an Beauveria bassiana Bb08 which kill green peach aphid with its liquid culture filtrate. In this study we conducted bioassay with the fungal culture filtrate and culture fluid to greenhouse pests such as cotton aphid, whitefly and thrips. Culture fluid showed high mortality against green peach aphid, as well as cotton aphid, sweet potato whitefly, and western flower thrips. However, control effect of culture filtrate varied with pests. Culture filtrate showed high mortality to cotton aphid. Mortality of western flower thrips with culture filtrate was slower than culture fluid including spores and sweet potato whitefly was much lower. These results indicated that the culture fluid of Beauveria bassiana Bb08 has potential to simultaneously control various greenhouse pests.

This study has investigated the effect of isometric contractile force and muscle activity applying sperficial heat according to the time from the biceps brachii muscle. In this study, 20 university students participants without musculoskeletal and neurological disorders. By applying a hot pack 5min, 10min, 20min and 30min respectively. After that measurement are skin temperature, contractile force and muscle activity. Skin temperature of the hot 5 min applied that rapidly changing. Increasing the time it takes to apply a variance has been reduced(p<.001). Isometric contractile force was not statistically significant but highest when applying the hot pack 5 minutes and lowest when applying the hot pack 30 minutes(p<.001). Muscle activity and median frequency was highest when applying the hot pack 5 minutes. To analyze the above results, it was found that isometric contractile force and muscle activity changed according to the applying time. These result lead us to the conclusion that this study will be more evidence for changes in muscle contraction to apply hot pack on clinic.

The purpose of this study is to find out the activity of gluteus medius muscle by the changes of load given to the upper limbs in single support phase. This study was twenty healthy men from A College. The left gluteus medius muscle was measured using SEMG(surface Electromyogram). Only the left foot was supported, and for the right foot, the right upper limbs were abducted while hip joint and the knee joint were bent at a 90° angle. The study was made by giving weight using dumbbells, depending on the RM of the subject(0RM, 1RM, 3RM, 5RM, 7RM). Gluteus medius muscle showed a large activity for those given weight to the upper limbs(1RM, 3RM, 5RM, 7RM) than that without weight(0RM). There was a significant difference in the activity of gluteus medius muscle between each RM. Gluteus medius muscle is high active when weight is given to the upper limbs in single support phase.

Bemisia tabaci, sweetpotato whitefly, has been recognized one of the most destructive insect pests worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We conducted a study of the influence of relative humidity, temperature and different developmental stages on the susceptibility of sweetpotato whitefly to conidia of Isaria javanica isolate, which had been reported high virulence against Q biotype of B. tabaci. The mortality of tobacco whitefly was low at low constant relative humidities, but was high when kept high humidity for first 24 hours and transferred to low humidity. The Isaria isolate had wide range of temperature (15℃ to 35℃) to control sweetpotato whitefly. The isolate has virulence to the egg and all developmental stages of nymph of B. tabaci. These results indicated that the isolate had good control effects at various environmental conditions and is an excellent candidate to develop a microbial pesticide to control sweetpotato whitefly.

Sweetpotato whitefly (Bemisia tabaci), especially Q biotype, has been recognized one of the most destructive insect pests worldwide because of increased resistance to some insecticide groups requiring alternative strategies for its control. We studied the conidia production of entomopathogenic fungus Isaria javanica Pf04, which had been reported high virulence isolate against Q biotype of B. tabaci, using grain. Brown rice was most suitable for conidia mass production of the isolate of I. javanica. Conidia was produced high at 25 ~ 27.5℃. The isolate produced more spores when conidia suspension directly inoculated onto media than two-phase fermentation. When concentration of inoculum was high spore production was high, but increasing rate of conidia production was highest at low inoculum concentration (1×105 conidia/ml) as 6,700 times increase compared with 20 times increase at high inoculum concentration (1×108 conidia/ml). These results indicated that the isolate can produce more conidia with cheap agricultural product and can develop as a microbial pesticide to control sweetpotato whitefly.

The physiology of parasitic wasp control of their lepidopteran hosts' not only includes injecting their egg but also various factors such as symbiotic virus. This study was focused on the investigation of sophisticated interaction between parasitoid (Diadegma fenestrale) and their host (Plutella xylostella) in P. xylostella larva at transcriptome level, to check whether it is parasitized or not. Short-read deep sequencing method (Hiseq2000) was used for the transcriptome analysis. De novo assembly of cDNA sequence data generated 196,081 contigs between 201bp and 15,853bp in length. Some detoxification enzymes such as cytochrome P450 and Immune-related genes such as antimicrobial peptides were up-regulated after parasitism. Expression of symbiotic ichnovirus genes was detected in parasitized larvae with 55 contigs identified from five ichnovirus gene families including vankyrin, viral innexin, repeat elements, a cysteine-rich motif, and polar residue rich protein. This investigation provides a detailed information on differential expression of P. xylostella larval genes and symbiotic ichnovirus genes following parasitization.