Search

BACKGROUND: Long non‐coding RNAs (lncRNAs) play important roles in the regulation of biological processes and have been identified in many species including insects. However, the association between lncRNAs and pesticide resistance in insect species such as Bactrocera dorsalis is unknown. RESULTS: RNA‐seq was performed on malathion resistant (MR1) and susceptible (MS) strains of B. dorsalis and a total of 6171 lncRNAs transcripts were identified. These included 3728 lincRNAs, 653 antisense lncRNAs, 1402 intronic lncRNAs, and 388 sense lncRNAs. A total of 40 and 52 upregulated lncRNAs were found in females and males of the MR1 strain compared to 54 and 49 in the same sexes of the MS strain, respectively. Twenty‐seven of these lncRNAs showed the same trend of expression in both females and males in the MR1 strain, in which 15 lncRNAs were upregulated and 12 were downregulated. RT‐qPCR results indicated that the differentially expressed lncRNAs were associated with malathion resistance. The lnc15010.10 and lnc3774.2 were highly expressed in the cuticle of the MR1 strain, indicating that these two lncRNAs may be related to malathion resistance. RNAi of lnc3774.2 and a bioassay showed that malathion resistance was possibly influenced by changes in the B. dorsalis cuticle. CONCLUSION: LncRNAs of B. dorsalis potentially related to the malathion resistance were identified. Two lncRNAs appear to influence malathion resistance via modulating the structure, or components, of the cuticle. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

BACKGROUND Bactrocera dorsalis (Hendel) is a notorious agricultural pest worldwide, and its resistance to insecticides is a major obstacle in successful control. Cytochrome P450s (P450s) are major metabolic enzymes associated with insecticide resistance. The genome of B. dorsalis was sequenced recently, allowing an integrated genome‐wide analysis of P450 genes (P450s) and the analysis of correlations between these genes and insecticide resistance in this pest. RESULTS: Totally, 101 P450s were identified in the B. dorsalis genome and classified into four clans, 25 families and 57 subfamilies. Quantitative reverse transcription polymerase chain reaction results showed that most of these genes were highly expressed in adults (46) and in metabolic tissues, including the fatbody (63), midgut (61) and Malphagian tubules (66). In a malathion‐resistant strain, 13 and 9 genes were significantly upregulated and downregulated, respectively, compared with a susceptible strain, and these genes were screened as candidate genes associated with malathion resistance. CONCLUSION: This study provides useful information for understanding the evolution and potential functions of P450s in B. dorsalis, and the results lay the foundation for further studies on the correlations between P450s and malathion resistance in B. dorsalis. © 2020 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Background: The oriental fruit fly, Bactrocera dorsalis (Hendel) is a worldwide pest damaging a wide range of hosts. Due to the long-term indiscriminate use of insecticides, B. dorsalis has developed serious resistance to several insecticides. UDP-glycosyltransferases (UGTs) are secondary metabolic enzymes involved in biotransformation and play an important role in the metabolism of plant secondary metabolites and synthetic insecticides in insects. Thus, we suspect that UGTs in B. dorsalis play an important role in insecticide tolerance., Results: In this study, 31 UGT genes were identified in the genome of B. dorsalis, belonging to 13 subfamilies. Real-time quantitative polymerase chain reaction (RT-qPCR) results revealed that 12 UGT genes were highly expressed in the antennae, midgut, Malpighian tubule and fat body. The mRNA expressions of 17 UGT genes were up-regulated upon exposure to λ-cyhalothrin, imidacloprid, abamectin and chlorpyrifos. Knockdown of the selected five UGT genes (BdUGT301D2, BdUGT35F2, BdUGT36K2, BdUGT49D2, BdUGT50B5) by RNA interference increased the mortality of B. dorsalis from 9.29% to 27.22% upon exposure to four insecticides., Conclusion: The abundance of UGTs in B. dorsalis is similar to other insect species, and 12 out of 31 UGTs were specifically expressed in metabolic tissues, suggesting a key role in detoxification. Down-regulation of five selected UGT genes increased the susceptibility of B. dorsalis to various insecticides, indicating that UGTs may play an important role in tolerance of B. dorsalis to multiple insecticides. © 2022 Society of Chemical Industry., (© 2022 Society of Chemical Industry.)

Objective: To study the diagnoses and treatments of small thyroid nodules (maximum diameter < 1 cm) with contralateral papillary thyroid microcarcinoma (PTMC)., Methods: A total of 253 patients with unilateral PTMC and contralateral thyroid benign nodules identified by ultrasound before thyroidectomy was retrospectively analysed. All patients underwent near-total or total thyroidectomy. Chi-square test was used for univariate analysis and logistic regression test for multivariate analysis., Results: In 53 (20.9%) of 253 patients with unilateral PTMC, the contralateral thyroid benign nodules identified by ultrasound were confirmed pathologically as PTMC. Univariate analysis showed multifocality of the primary tumor and Hashimoto's thyroiditis were correlated with contralateral PTMC (χ(2) = 24.834, χ(2) = 5.182, P < 0.05). However, there were no significant differences for the existence of contralateral PTMC in age, sex, tumor size, capsule invasion, lymph node metastasis, the number of nodules and Tg-level. Multivariate analysis showed only multifocal PTMC was an independent predictive factor for contralateral PTMC (OR = 5.352, P < 0.05)., Conclusions: The patients with unilateral multifocal PTMC have a high rate of PTMC in contralateral small thyroid nodules. However, it is very difficulty to define by ultrasonography preoperatively. The total thyroidectomy maybe serve as a useful treatment.