Publications by authors named "Yeon Ho Je"

Article Synopsis
  • Polyethylene is durable but doesn't break down easily due to its simple hydrocarbon structure; biodegradation needs oxidation to begin.
  • Galleria mellonella, a type of insect, can oxidize polyethylene on its own, and researchers have identified two candidate enzymes (CYP6B2-GP04 and CYP6B2-13G08) from its midgut that efficiently facilitate this process.
  • The study revealed that the Phe118 residue in CYP6B2-GP04 is crucial for hydrocarbon interaction, and enhanced versions of this enzyme show promise for improving polyethylene biodegradation and reducing plastic waste.
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  • Polymer-based tissue adhesives (TAs) are emerging as alternatives to sutures for closing wounds due to their simplicity, cost-effectiveness, minimal tissue harm, and quick application time.
  • Despite their advantages, TAs struggle with poor mechanical properties and weak adhesion strength, prompting research for improved versions with better performance.
  • This review covers the essential features of polymeric TAs—including properties, assessment methods, mechanisms, applications, and commercial products—while highlighting polysaccharide-based TAs and discussing future developments.
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  • Electroporation is primarily used for transforming Bacillus thuringiensis (Bt) but is not universally applicable to other strains.
  • Polyethylenimine (PEI) serves as a non-viral vector forming polymeric nanoparticles (PNPs) that are efficient, easy to make, and low in toxicity.
  • The study confirmed that PEI-based PNPs can successfully transform Bt strains with efficiency similar to electroporation, indicating a promising alternative method.
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Background: Bacillus thuringiensis (Bt) has been widely used as a biological control agent for lepidopteran pests. However, resistance to Bt is a major concern associated with Spodoptera spp. (Noctuidae) and Plutella xylostella (Plutellidae).

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Soybean is a globally important crop species, which is subject to pressure by insects and weeds causing severe substantially reduce yield and quality. Despite the success of transgenic soybean in terms of () and herbicide tolerance, unforeseen mitigated performances have still been inspected due to climate changes that favor the emergence of insect resistance. Therefore, there is a need to develop a biotech soybean with elaborated gene stacking to improve insect and herbicide tolerance in the field.

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RNA interference (RNAi) has attracted attention as a promising approach to control plant viruses in their insect vectors. In the present study, to suppress replication of the rice stripe virus (RSV) in its vector, , using RNAi, dsRNAs against genes that are strongly upregulated upon RSV infection were delivered through a rice leaf-mediated method. RNAi-based silencing of peroxiredoxin, cathepsin B, and cytochrome P450 resulted in significant down regulation of the NS3 gene of RSV, achieving a transcriptional reduction greater than 73.

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Article Synopsis
  • Insect growth regulators (IGRs) are being explored as safer alternatives to traditional insecticides, with actinomycetes potentially offering new compounds for this purpose.
  • The study screened 363 actinomycetes and identified Streptomyces sp. AN120537 as the most effective, which produced juvenile hormone antagonists (JHANs) and showed strong insecticidal effects.
  • Five active compounds known as antimycins were isolated, demonstrating significant insecticidal activities and causing deformities in treated larvae, indicating their potential application as broad-spectrum IGR insecticides.
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  • - It is commonly believed that the gene ORF1629 is crucial for baculovirus replication in insect cells, leading to the development of recombinant viruses through a baculovirus expression system.
  • - Researchers discovered that a bacmid (a modified baculovirus) could still proliferate in insect cells even when it lacked a complete ORF1629, indicating that the gene is not strictly necessary for replication.
  • - While ORF1629 is not essential, its absence resulted in slower growth rates and lower yields of the virus, along with larger but fewer occlusion bodies, affecting the overall production efficiency of baculoviruses like AcMNPV and BmNPV.
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Insect growth regulators (IGRs) are attractive pest control agents due to their high target specificity and relative safety to the environment. Recently, plants have been shown to synthesize IGRs that affect the insect juvenile hormone (JH) as a part of their defense mechanisms. Using a yeast two-hybrid system transformed with the Aedes aegypti JH receptor as a reporter system, we identified several JH agonists (JHAs) and antagonists (JHANs) causing retardation in the ovarian development of female Asian tiger mosquito, Aedes albopictus, from plant essential oil compounds.

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Calotropis procera R. Br., a traditional medicinal plant in India, is a promising source of commercial proteases, because the cysteine proteases from the plant exhibit high thermo-stability, broad pH optima, and plasma-clotting activity.

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Insects impact human health through vector-borne diseases and cause major economic losses by damaging crops and stored agricultural products. Insect-specific growth regulators represent attractive control agents because of their safety to the environment and humans. We identified plant compounds that serve as juvenile hormone antagonists (PJHANs).

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Efforts are underway to produce antimicrobial peptides in yellow mealworms (Tenebrio molitor), which can be developed as more effective and safer animal feed additives. In this work, we expressed Bombyx mori (Bm) cecropin-A in mealworms by the infection of transformed entomopathogenic Beauveria bassiana ERL1170. The active domain of Bm cecropin A gene was tagged with a signal sequence of B.

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A novel recombinant bacmid, bEasyBm, that enables the easy and fast generation of pure recombinant baculovirus without any purification step was constructed. In bEasyBm, attR recombination sites were introduced to facilitate the generation of a recombinant viral genome by in vitro transposition. Moreover, the extracellular RNase gene from Bacillus amyloliquefaciens, barnase, was expressed under the control of the Cotesia plutellae bracovirus early promoter to negatively select against the nonrecombinant background.

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Unlabelled: ORF11 (ac11) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a highly conserved gene with unknown function. To determine the role of ac11 in the baculovirus life cycle, an ac11 knockout mutant of AcMNPV, Ac11KO, was constructed. Northern blot and 5' rapid amplification of cDNA ends (RACE) analyses revealed that ac11 is an early gene in the life cycle.

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Rice stripe virus (RSV), the type member of the genus Tenuivirus, transmits by the feeding behavior of small brown planthopper (SBPH), Laodelphax striatellus. To investigate the interactions between the virus and vector insect, total RNA was extracted from RSV-viruliferous SBPH (RVLS) and non-viruliferous SBPH (NVLS) adults to construct expressed sequence tag databases for comparative transcriptome analysis. Over 30 million bases were sequenced by 454 pyrosequencing to construct 1,538 and 953 of isotigs from the mRNA of RVLS and NVLS, respectively.

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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.

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We examined the molecular and enzymatic properties of two acetylcholinesterases (AChEs; ClAChE1 and ClAChE2) from the common bed bug, Cimex lectularius. Native polyacrylamide gel electrophoresis followed by activity staining and Western blotting revealed that ClAChE1 is the main catalytic enzyme and is abundantly expressed in various tissues. Both ClAChEs existed in dimeric form connected by a disulfide bridge and were attached to the membrane via a glycophosphatidylinositol anchor.

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Insect-derived Kazal-type serine protease inhibitors exhibit thrombin, elastase, plasmin, proteinase K, or subtilisin A inhibition activity, but so far, no functional roles for bee-derived Kazal-type serine protease inhibitors have been identified. In this study, a bee (Apis cerana) venom Kazal-type serine protease inhibitor (AcKTSPI) that acts as a microbial serine protease inhibitor was identified. AcKTSPI contained a single Kazal domain that displayed six conserved cysteine residues and a P1 threonine residue.

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ORF43 (ac43) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a highly conserved baculovirus gene of unknown function. To investigate the role of ac43 in the baculovirus lifecycle, we constructed an ac43-deleted mutant AcMNPV, Ac43KO. After transfection into Spodoptera frugiperda cells, Ac43KO produced polyhedra much larger in size than those of wild-type AcMNPV.

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Mamestra brassicae nucleopolyhedrovirus-K1 (MabrNPV-K1) was isolated from naturally infected M. brassicae (Lepidoptera: Noctuidae) larvae in Korea. The full genome sequences of MabrNPV-K1 were determined, analysed and compared to those of other baculoviruses.

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Article Synopsis
  • ORF78 (ac78) is a core gene in the AcMNPV virus, but its function was previously unknown.
  • Researchers created a mutant strain, Ac78KO, to study ac78's role, finding that it is a late gene essential for virus production.
  • The study showed that while ac78 is involved in creating infectious viruses, it does not affect viral DNA replication and is crucial for forming occlusion bodies.
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Efforts are underway to develop more effective and safer animal feed additives. Entomopathogenic fungi can be considered practical expression platforms of functional genes within insects which have been used as animal feed additives. In this work, as a model, the enhanced green fluorescent protein (egfp) gene was expressed in yellow mealworms, Tenebrio molitor by highly infective Beauveria bassiana ERL1170.

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We screened the existence of bacteriophages in 67 Bacillus thuringiensis type strains by phage DNA extraction and PCR using phage terminase small subunit (TerS)-specific primers to the supernatants and the precipitated pellets of Bt cultures, and by transmission electron microscopy. The various bacteriophages were observed from the supernatants of 22 type strains. Ten type strains showed the extracted phage DNAs and the amplified fragment by TerS PCR but 12 type strains showed only the phage DNAs.

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Insect-killing (entomopathogenic) fungi have high potential for controlling agriculturally harmful pests. However, their pathogenicity is slow, and this is one reason for their poor acceptance as a fungal insecticide. The expression of bumblebee, Bombus ignitus, venom serine protease (VSP) by Beauveria bassiana (ERL1170) induced melanization of yellow spotted longicorn beetles (Psacothea hilaris) as an over-reactive immune response, and caused substantially earlier mortality in beet armyworm (Spodopetra exigua) larvae when compared to the wild type.

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