This comprehensive study delves into the intricate process of exfoliating and functionalizing boron nitride nanosheets (BNNSs) extracted from hexagonal boron nitride (h-BN), and meticulously explores their potential application within epoxy composites. The extensive research methodology encompasses a sequence of treatments involving hydrothermal and sonication processes aimed at augmenting the dispersion of BNNSs in solvents. Leveraging advanced analytical techniques such as Raman spectroscopy, X-ray diffraction, and FTIR spectroscopy, the study rigorously analyzes a spectrum of changes in the BNNS’s properties, including layer count variations, interlayer interactions, crystal structure modifications, and the introduction of functional groups. The research also rigorously evaluates the impact of integrating BNNSs, specifically glycidyl methacrylate (GMA)-functionalized BNNSs, on the thermal conductivity of epoxy composites. The conclusive findings exhibit notable enhancements in thermal properties, predominantly attributed to the enhanced dispersion of fillers and enhanced interactions within the epoxy matrix. This pioneering work illuminates the wide potential of functionalized BNNSs for significantly enhancing the thermal conductivity of epoxy composites, paving the way for advanced materials engineering and practical applications.
In this study, we developed ten microsatellite markers specific to L. angelina using the Illumina NextSeq 500 platform. Forty-three individuals of L. angelina collected from three localities in South Korea were genotyped to validate these markers and to preliminarily assess population genetic characteristics. The observed number of alleles, observed heterozygosity (HO), and expected heterozygosity (HE) at a locus ranged from 4–13, 0.211–0.950, and 0.659–0.871 in the population with the largest sample size (20 individuals), respectively, thereby validating the suitability of the markers for population analyses. Our preliminarily assessment of the population genetic characteristics indicates the presence of inbreeding in all populations, an isolation of the most geographically distant population (Seocheon), and lower HO than HE. The microsatellite markers developed in this study will be useful for studying the population genetics of L. angelina collected from additional sites in South Korea and from other regions. †These authors contributed equally to this paper.
To control an external parasitic mite, a honey bee line possessing high hygienic behavior (HHB) against an external parasitic mite, Varroa destructor, has been bred in South Korea and an assessment method has been necessitated to diagnose HHB line from the low hygienic behavior (LHB) line. Thus, in this study, we developed single nucleotide polymorphism (SNP) markers from whole genome sequencing of each 20 worker bees from HHB and LHB lines of A. mellifera ligustica (Hymenoptera: Apidae). An average of 319,445,977 sequence reads was mapped to the known A. mellifera reference genome (an average of 87.46%). In 2,316,128 and 3,266,756 SNPs from each HHB and LHB line, an average of 93.6% and was located in the intergenic spacers and introns, whereas, the remaining 6.4% was located in the genic region, respectively. Among them 20 SNPs that were fixed at each line possessing within-individual homozygosity were selected and each four SNPs were used to diagnose the two honey bee lines either by typical PCR-restriction fragment length polymorphism method or allele-specific PCR. The remaining six SNPs had the size difference, enabling relatively easy differentiation between the two honey bee lines on typical agarose gel and another remaining six SNPs only has sequence difference including SNP sites. Thus, these SNP markers can be used to diagnose the honey bee line with HHB from LHB line against V. destructor.
The yellow-legged hornet, Vespa velutina nigrithorax (Hymenoptera: Vespidae), invaded into South Korea in 2003. Currently, V. velutina is distributed throughout South Korean regions,. A genetic trait of invasive species provides important data for environmental risk assessment. In this study, we analysed the genetic variation of the V. velutina among the populations of South Korea and other foreign countries using partial sequences of mitochondrial COI, CytB and 16S rRNA. We further developed intergenic spacers (IGS2 and IGS3) to detect genetic variation among Korean populations. Each single haplotype was recovered from the domestic V. velutina from each coding gene sequence. Korean individuals shared the haplotype with that of Japan and China. Phylogenetic analysis (excluding 16S rRNA) using available sequences and ours showed the presence of two groups: the Indonesia and Malaysia group and another group (Korea, Japan, China, France, Vietnam and Thailand). The newly developed IGS2 and IGS3 markers resulted in each seven and four haplotypes, providing better resolution than coding gene sequences. Analysis of Molecular Variance using the combined sequences of IGS2 and IGS3 showed that the majority of variance was allocated to each population and only minority of variance is allocated to among-populations. This result may indicate that the V. v. nigrithorax invaded in Korea shows a single panmictic population and this possibly suggest that Korean population may have originated from small founder individuals.
동남아시아에 발생하던 등검은말벌은 최근 국내 뿐만 아니라 프랑스와 일본, 유럽 전역으로 확산되어 전 세계 양봉 산업에 극심한 피해를 주고 있다. 등검은말벌을 방제하기 위해 다양한 방제 방법들이 연구되고 있으며, 그 중 말벌 유인제에 대해 국제적으로 많은 연구가 진행되어 왔으나 이 역시 지속적인 개발이 필요한 실정이다. 따라서 본 연구에서는 시판 유인제와 최근 (주)다목에코텍에서 새롭게 개발한 신규 개발 유인제에 대한 효능 검정을 수행하였 고 양봉장에 출현하는 국내 발생 말벌속의 발생양상을 조사하였다. 담양 1개소와 곡성 2개소에 기존 유인제과 신규 유인제를 장착한 포획기를 각 3쌍씩 설치하여 2016년 9월부터 11월말까지 주 1~2회 관찰하였다. 그 결과 국내 발생 말벌속 중 등검은말벌(7,787 개체)이 가장 많이 포획되었고, 다음으로 장수말벌, 말벌, 좀말벌, 꼬마장수말벌, 털보말벌 순으로 포획되었다. 두 유인제의 포획력 검정 결과, 신규 개발 유인제가 통계적으로 유의하게(P < 0.01) 등검은말벌 포획력이 높음을 보였다.
The honey bee, Apis mellifera ligustica (Hymenoptera: Apidae), strain with a high hygienic behavior (HHB) has been bred for several years in Korea, and a diagnosis system to distinguish it from low hygienic behavior (LHB) strain has been necessitated. Thus, complete mitogenome of the two strains were sequenced through Next-Generation Sequencing technique to detect SNPs. Comparison of the mitogenome sequences from the two strains of A. m. ligustica have detected 23 SNPs in 11 PCGs and these were further confirmed the presence of SNPs using each 10 individuals selected randomly from each strain, indicating that these SNP markers might be useful to diagnose the honeybee strains with the HHB. Therefore, mitogenome sequences are promising genome source to detect SNP markers, particularly for inbred female iso-lines.
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.
We developed single nucleotide polymorphism (SNP) markers and are establishing diagnostic systems to distinguish disease resistance- and susceptible-strains of honey bees using the SNPs. For development of SNP markers, whole genome was sequenced each from 20 individuals of “disease resistance-strain” and “susceptible-strain” of Apis mellifera ligustica using the Illumina HiSeq 2000 sequencer. Approximately, 344 and 294 million sequence reads were mapped to the honeybee reference assembly (Amel_4.5) for each strain, respectively. Among the total 2,246,428 SNPs yielded, 33 were found to be fixed between the two strains with all homozygosity. Sixteen of them were casually amplified and sequenced from randomly selected each 10 individual of honey bees from each strain and presented strain specific SNPs. These ten SNPs were used to diagnose the two strains either by original size difference, caused by indel-accompanying SNP, typical PCR-RFLP, or AS PCR.
Despite of a substantial effort, the phylogeny of Lepidoptera still has unstable taxa and unresolved relationships particularly form Apoditrysia to Ditrysia (e.g. phylogenetic position and familial relationships of Gelechioidea, the monophylies of Tineoidea and Zygaenoidea and so on). We performed phylogenetic analysis using ~13,000-bp length of mitogenome sequences form 50 species (with seven species in two superfamilies form this study) representing 13 superfamilies to improve the lepidopteran phylogeny from Apoditrysia to Ditrysia. A close relationship of Gelechioidea to Obtectomera than to apoditrysian taxa was noteworthy, although the nodal support is very weak (ML, 23%; BI, BPP = 0.94). Monophyly of Zygaenoidea without Epipyropidae (Epipomponia nawai) was also noteworthy in spite of weak nodal support (ML, 64%; BI, 1.0). Scrutinized analysis is currently underway.
We sequenced the complete mitochondrial genome (mitogenome) of Vespa velutina nigrithorax and V. ducalis (Hymenoptera: Vespidae). The genomes were 16,475-bp and 15,779-bp long and contained typical sets of genes. The V. velutina and V. ducalis A+T-rich region was 132-bp long and 166-bp long and was the shortest of all sequenced Vespoidea genomes. Start and stop codons in several Vespa species—including V. velutina and V. ducalis—were diversified, despite these species belonging to the same genus. In comparison with the ancestral mitogenomes, Vespa mitogenomes showed substantial gene rearrangement; however, we detected no gene rearrangement among Vespa species. We conducted phylogenetic reconstruction based on concatenated sequences of 13 PCGs and two rRNAs in available species of Vespoidea—22 species in six subfamilies in two families (Vespidae and Formicidae). The Bayesian inference and maximum likelihood (ML) methods revealed that each family formed strong monophyletic groups.
The number of reported mitochondrial genomes (mitogenomes) from the monotypic Lasiocampoidea has been limited until recently. In this study, we sequenced the complete mitogenome of the lappet moth, Kunugia undans (Lepidoptera: Lasiocampidae), and compared it to those of other lasiocampid species and macroheteroceran superfamilies (59 species in six superfamilies). The 15,570-bp long K. undans genome had the typical set of genes found in animal mitogenomes, with the exception of one additional trnR that are located between trnA and trnN loci. Considering that the two trnR copies are located in tandem with proper secondary structures and identical anticodons, a gene duplication event might be responsible for the presence of the two tRNAs. In summary, the general mitogenome characteristics of Lasiocampoidea did not differ greatly from the remaining macroheteroceran superfamilies, but it did exhibit some unique features.
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.
We sequenced complete mitochondrial genomes (mt genomes) of four Apis species, such as A. cerana, A. dorsata, A. laboriosa, and A. mellifera ligustica. The A. m. ligustica used in this study was originated from United States and selected for a high hygienic behavior during several years of breeding program. Considering current phylogenetic hypothesis of Apis the positive relationships between phylogeny and gene rearrangement was not supported. Phylogenetic reconstruction using available Apoidea species has shown the relationships ((Apidae + Colletidae) + Crabronidae). Within Apis, a strong support for three groups was obtained: A. florea and A. andreniformis as a basal group to the other A. cerana and A. mellifera group and A. dorsata and A. laboriosa group. The test to find out suitable single mt gene for the phylogeny at the genus level and below-genus level of Apis provided an identical topology from ND4L and ND6 in the ML analysis and ND3 and NF4L in the BI analysis to that from whole mt genome, with relatively strong support, indicating that these individual genes can potentially be utilized for within-species level phylogeny of Apis.
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.
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.