Since 2007, diamide insecticides have been widely used in Korea to control various types of lepidopteran pests including Spodoptera exigua. For nearly a decade, diamide resistance in field populations of S. exigua across 18 localities has been monitored using bioassays. Based on the LC50 values, some field populations showed a high level of resistance against chlorantraniliprole, although regional and temporal variations were observed. To investigate resistance at a molecular level, mutations (Y4701C, I4790M, and G4946E) were examined in the ryanodine receptor (RyR), which is the primary mechanism underlying diamide insecticide resistance. As a result, only I4790M mutation was found in most of field populations. As resistance levels varied significantly despite the uniform presence of the I4790M mutation, we considered the presence of another resistance factor. Further, the I4790M mutation was also found in S. exigua specimens collected prior to the commercialization of diamide insecticides in Korea as well as in other countries, such as the USA. This finding led us to hypothesize that the I4790M mutation were predisposed in field populations owing to selection factors other than diamide use. For further clarification, we conducted whole-genome sequencing of S. exigua (449.83 Mb) and re-sequencing of 18 individuals. However, no additional non-synonymous mutations were detected in the RyR-coding region. Therefore, the high level of diamide insecticide resistance in Korean S. exigua is not caused by mutations at the target site, RyR, but is attributed to other factors that need to be investigated in future studies.

Gamma irradiation has been used in several ornamental plant species to obtain the desired genetic variability. Commercially, ornamental plants with a rich variety of flower colors and uniform shapes are prized and in high demand. Irradiation technology is widely utilized to generate a high number of mutations, which helps introduce new, improved variants in comparison to the control plant. The main purpose is to promote well-adjusted species by customizing some specific features to expand on the desired parameter. Exposure to an optimum dose of gamma irradiation is crucial to ensure the most beneficial mutation density. The effects of dose rates are species-dependent, thereby affecting the probability of inducing favorable attributes, such that they are either not clearly exhibited or are disoriented during the gradual physical development of the plants. To obtain high-quality species within a very limited period, gamma irradiation may present an alternative method to selective screening with its combined application of molecular-based analysis to contribute to mutational changes in plant physiology. Here we review current literature that focuses on the effect of appropriate doses of gamma irradiation and the morphological, functional, and molecular objectives of such irradiation in ornamental plants.

최근 파밤나방 등 다양한 나비목 해충에서 diamide 계통의 살충제 (IRAC group 28)의 저항성이 많이 보고가 되고 있다. 국내에서도 이미 배추좀나방과 파밤나방의 저항성이 보고되었는데, 본 연구에서 사용된 강릉에서 2018년 채집한 파밤나방의 경우 Chlorantraniliprole에 대하여 감수성 대비 2,500배 이상의 높은 저항성을 나타냈다. 추천 농도 처리 시 30% 이하의 방제가를 나타냈으며 Cyantraniliprole, Cyclaniliprole, Flubendiamide에서 높은 교차저항성을 나타냈다. 이 저항성 집단에서 diamide 계통 살충제의 작용점인 ryanodine receptor에 이미 보고된 G4946E 돌연변이는 발견되지 않았으나 새로운 I4760M 돌연변이를 발견하였는데, 2014년 배추좀나방에서 보고된 돌연변이와 위치가 동일하였다. 따라서 I4760M 돌연변이는 파밤나방에서 diamide 저항성에 관여 할 것으로 판단한다.

Molecular diagnostic markers are necessary for establishing highthroughput screening systems to support insecticide-resistant population management. Here, we identified single amino acid substitution mutations related to carbamate resistance in Laodelphax striatellus Fallén type-1 acetylcholinesterase (Lsace1) using carbofuran-selected strains. The phenotypic resistance profiles of the final selection strain (SEL9) compared to the susceptible strain revealed a 14-fold higher resistance ratio based on topical application, 1.2-fold higher general esterase activity, and 4.3- fold higher acetylcholinesterase insensitivity based on the 50% inhibitory concentration (I50), suggesting that insensitivity of the target site could occur as a resistance factor. Comparison of the nucleotide sequences of Lsace1 of five strains (SUS, SEL0, SEL3, SEL6, and SEL9) revealed two amino acid substitutions (F330Y and F331H). To understand the roles of these mutations, we determined the allele frequency of both point mutations in the selected strains using quantitative sequencing methods. In addition, several quantitative genotypic traits (e.g., gene copy numbers and transcript levels of Lsace1, Lsace2, and LS.CarE1) were assessed. A correlation analysis of genotypic and phenotypic traits revealed strong correlations between resistance level and I50 with F331H allele frequency. Interestingly, the F331H mutation was negatively correlated with transcript levels of Lsace1, suggesting that selection pressure might result in a reduction of the target gene. Overall, the F331H mutation and reduced mRNA are important factors in the development of carbamate resistance. Furthermore, the point mutation can be used to monitor rapid carbofuran resistance in conjunction with molecular diagnostic methods such as quantitative sequencing.

췌장염 환자의 10–30%는 그 원인을 찾지 못하여 특발성 췌장염으로 분류되며, 그중 일부는 유전적 변이가 원인일 것 으로 생각된다. 유전성 췌장염은 소아 때부터 췌장염 관련 증상이 발생하여 대부분 30대 전후로 만성 췌장염으로 진행하기 때문에 췌장암의 발생에 대해 각별한 주의가 필요하다. 췌장염 관련 유전자는 현재까지 30종류 이상 발견되었으며, 대 표적으로 PRSS1, SPINK1, CFTR, CTRC 변이가 있으며, 이는 인종 및 지역에 따라 다양성을 보이고 있다. 따라서, 국내 특발성 췌장염 환자를 대상으로 한 유전자 연구를 통하여 한국인에서의 췌장염 관련 유전자 변이의 양상 및 특징을 파악 하는 것이 중요하겠다. 본고에서는 특발성 췌장염의 병태생리에서 유전적 변이의 역할에 대해 중점적으로 고찰해보고, 국내 문헌을 토대로 특발성 혹은 유전성 췌장염의 국내 연구 결과를 살펴보고자 한다.

서양종 꿀벌의 일벌의 독을 채취하여 정제한 정제봉독에 대한 세균에서의 돌연변이 유발성 검색을 위하여 S. typhimurium의 히스티딘 요구성 균주 TA100, TA1535, TA98, 그리고 TA1537의 균주와 대장균 E. coli의 트립토 판 요구성 균주인 WP2 uvrA를 이용해 복귀돌연변이시험 을 실시하였다. 정제봉독은 부형제로 사용한 멸균생리식 염수에 용해되었으며 모든 농도군의 조제물에서 침전은 관찰되지 않았으며, 정제봉독 조제물을 top agar와 혼합할 때 모든 농도군에서 혼탁이나 침전이 관찰되지 않았다. 대사활성계 적용 TA100, TA1535, TA98 균주에 대해 0, 1.5, 5, 15, 50, 150 및 500 μg/plate의 범위를 설정하고 미 적용시엔 0, 0.15, 0.5, 1.5, 5, 15 및 50 μg/plate의 범위로 설 정하였다. TA1537과 WP2 uvrA균주에 대한 농도 범위은 대사활성계 적용시엔 0, 5, 15, 50, 150, 500 및 1,500를 미 적용시엔 0, 1.5, 5, 15, 50, 150 및 500 μg/plate 범위로 설정하여 시험을 수행하였다. 그 결과 모든 시험균주에서 대사활성계 적용 여부에 상관없이 정제봉독 처리군 의 평균 집락 수는 증가를 나타내지 않았으며, 양성판정 기준을 만족시키지 못하였다. 따라서, 정제봉독은 본 시험 조건 하에 사용한 시험 균주에 복귀돌연변이를 유발하지 않는 것으로 사료되었다.

A series of conserved point mutations in acetylcholinesterase (AChE) confer resistance to organophosphorus and carbamate insecticides in most arthropod pests. However, the mutations associated with reduced sensitivity to insecticides usually results in the reduction of catalytic efficiency and leads to a fitness disadvantage. To compensate for the reduced catalytic activity, overexpression of neuronal AChE appears to be necessary, which is achieved by a relatively recent duplication of the AChE gene (ace) as observed in the two-spotted spider mite and other insects. Unlike the cases with overexpression of neuronal AChE, the extensive generation of soluble AChE is observed in some insects either from a distinct non-neuronal ace locus or from a single ace locus via alternative splicing. The production of soluble AChE in the fruit fly is induced by chemical stress. Soluble AChE acts as a potential bioscavenger and provides tolerance to xenobiotics, suggesting its role in chemical adaptation during evolution.

Control of the vector mosquitoes is critical for implementation of patient’s decrease. Vector mosquito control has been mainly carried out using pesticides in Republic of Korea (ROK), which has developed the resistance against selected insecticides. Voltage-gated sodium channel (VGSC) and Acethylcholine esterase (AchE) are the target of several classes of insecticides. Genetic mutations of VGSC and AchE have been documented to confer resistances to pyrethroids and organophosphates in mosquitoes, respectively. In our studies, the insecticidal resistable level of An. sinensis from four malaria risk areas near Demilitarized Zone (DMZ) was measured. The partial sequence of An. sinensis voltage gated sodium channel (VGSC) IIS6 domain for Kdr gene and ace1 gene for AchE was sequenced. An. sinensis from two areas demonstrated significantly higher resistance to pyrethroids and mutation rates of Kdr gene were comparatively higher. In all tested areas An. sinensis showed high insecticidal resistance to organophosphates and > 70% of mutation rates of ace1 gene ware higher. Understanding the mechanisms of insecticide resistance among vector mosquitoes populations is very important to efficient and effective vector control.

The two-spotted spider (Tetranychus urticae) is one of the most serious pests worldwide and has developed resistance to almost all types of acaricides. Various mutations on acaricide target and detoxification genes and their duplication (including overexpression) have been identified since the completion of T. urticae genome analysis. The mutations are mainly observed in functionally important domains (i.e. transmembrane, cellular loops and catalytic triad, etc.), which likely confer acaricide resistance directly or indirectly. Gene duplication was found on major detoxification and insecticide target enzymes, such as cytochrome P450, glutathione S-transferase, ABC-transporter, UDP-glycosyltranferase and acetylcholinesterase (AChE). Interestingly, co-occurrence of both mutation and gene duplication (especially, single gene amplification) was found in AChE, which possibly explains the compensatory role of gene duplication to minimize the fitness cost mediated by point mutations. Such mutation and duplication traits associated with resistance can be utilized as molecular markers for the determination of resistance levels based on the quantitative sequencing and real-time PCR.

The cotton aphid, Aphis gossypii (Glover), is one of the main pests in various vegetable crops due to insecticide resistance in Korea. Some insect pests noticed neonicotinoid insecticide resistance such as Nilaparvata lugens, Bemisia tabaci and Myzus persicae etc. and the major player which contributed for developing the resistance was over-expression of P450, particularly CPY6 family. However, A. gossypii was a unique case that they developed non-P450 dependent resistant mechanism. Previously we reported that two point mutations (RtoT in nicotinic acetylcholine receptor, nAChR, beta 1 subunit and RtoT with LtoS in a transcript variant) contribute to develop the imidacolprid resistance in A. gossypii. Moreover we surveyed the mutation(s) in various local field populations. Based on the 3D modeling, we hypothesize that RtoT mutation can reduce the imidacloprid sensitivity. A stretch of 33 amino acid was deleted in the N-terminal region of original transcript of nAChR beta 1 subunit that contained RtoT with LtoS mutations in resistant strain. Among the two transcripts, only original transcript differently expressed between imidacloprid susceptible and resistant strain (resistant ratio = 3,800). Six alpha subunit (1∼5, 7) transcript levels were not significantly different between two strains. Therefore mutation and down-regulation of nAChR beta 1 subunit is also associated with imidacloprid resistance in the A. gossypii.

The melon and cotton aphid Aphis gossypii Glover (Hemiptera; Aphididae) is one of the most serious pests worldwide. We surveyed insecticide susceptibility in A. gossypii field populations to 12 insecticides (6 neonicotinoids, 3 pyrethroids and 3 others) to examine resistance ratios. The levels of insecticide resistance were extremely high, especially to neonicotinoids, such as acetamiprid, clothianidin, thiacloprid and imidacloprid. To identify the neonicotinoid resistance mechanisms, we used an imidacloprid-resistant (IMI-R) strain as a model strain. IMI-R showed an extremely high resistance ratio and also cross-resistance to all the test neonicotinoids. However, there was little or no cross-resistance to the other insecticides, including sulfoxaflor. Synergist tests and enzyme activity assays suggested the absence of resistance mechanisms based on enhanced detoxification enzymes, such as cytochrome P450, esterase and glutathione S-transferase. One point mutation was found in the beta1 subunit loop D region of the nicotinic acetylcholine receptor (nAChR) of the IMI-R strain. This R81T point mutation was also found in field populations collected from 5 regions. Therefore, the R81T point mutation was identified as an important mechanism of imidacloprid resistance in A. gossypii.

Bovine coat color is decided by the melanocortin receptor 1 (MC1R) genotype mutation and melanogenesis. Specially, in the various cattle breeds, dominant black coat color is expressed by dominant genotype of ED, red or brown is expressed in the frame shift mutation of recessive homozygous e by base pair deletion and wild type of E+ is expressed in various coat colors. However, not very well known about the effected of MC1R genotype mutation on the coat color through family lines in KBC. Therefore, this study were to investigate effect of MC1R genotype mutation on the coat color, and to suggest mating breed system in accordance with of MC1R genotype for increased on brindle coat color appearance. Parents (sire 2 heads and dam 3 heads) and offspring (total : 54 heads) from crossbreeding in KBC family line with the MC1R genotype and phenotype records were selected as experimental animals. The relationship between melanocortin 1 receptor (MC1R) genotypes expression verified by PCR-RFLP, and brindle coat color appearance to the family line of the cross mating breed from MC1R genotype pattern was determined. As a result, 4MC1R genetic variations, E+/E+ (sire 1), E+/e (sire 2 and dam 3), E+/e with 4 bands of 174, 207 and 328 bp (dam 1) and E+/e with 3 bands of 174, 207, 328 and 535 bp (dam 2) from parents (sire and dam) of KBC. However, 3 genetic variations, e/e (24%), E+/E+ (22%) and E+/e (56%) were identified in offspring. Also, brindle coat color expressrated was the e/e with the 0%, E+/E+ with 67% and E+/e with 77% from MC1R genotype in offspring on the cross mating of KBC. Furthermore, when the sire had E+/e genotype and the dam had E+/E+ with the 3 bands or E+/e genotype, and both had whole body-brindle coat color, 62% of the offspring had whole body-brindle coat color. Therefore, the seresults, the mating system from MC1R genotype patterns of the sires (E+/e) and dams (E+/E+ with the 3 bands or E+/e) with brindle coat color may have the highest whole body-brindle coat color expression in their offspring.

The cotton aphid, Aphis gossypii (Glover), is one of the most serious pests in various vegetable crops. In Korea, some field populations of A. gossypii especially in greenhouse showed high resistance against neonicotinoids. The imidaclopridresistant strain (IR) selected from one of the greenhouse strains was found to be about 3,800 folds more resistant to imidacloprid, compared to the susceptible strain (S), as judged by LC50 values. To identify differentially expressed genes in IR, an isogenic strain, reverse susceptible strain (IRS) was generated from IR and comparative transcriptome analyses based on GS-FLX were conducted using total RNAs extracted from both IR and IRS. Also we confirmed protein expression patterns by 2DE and detoxification enzyme over-expression by synergist test. However there was no significant variation among IR, IRS and S. Comparison of the nucleotide sequence of seven nicotinic acetylcholine receptor (nAChR) subunit (alpha 1-5,7 and beta 1) genes from S and IR strain revealed a point mutation causing an arginine to threonine substitution (R81T) in the loop D region of the nAChR beta 1 subunit of the IR. These mechanisms were also reported in M. persicae and this amino acid change confers a vertebrate-like character to the insect nAChR and results in reduced sensitivity to neonicotinoids. Moreover an extra point mutation, L80S (leucine to serine substitution) was also detected nearby R81T mutation in nAChR beta 1 subunit variant. These mutations can be an additive factor in imidacloprid resistance in A. gossypii. This is the first report of imidacloprid resistance mechanism in A.gossypii. Further, this would be helpful in managing A. gossypii resistant populations in field.