Overexpression of a nuclear receptor HR96 contributes to spirodiclofen susceptibility in Panonychus citri (McGregor).

The citrus red mite, Panonychus citri, is one of the most notorious and devastating citrus pests around the world that has developed resistance to multiple chemical acaricides. In previous research, we found that spirodiclofen-resistant is related to overexpression of P450, CCE, and ABC transporter genes in P. citri. However, the regulatory mechanisms of these detoxification genes are still elusive. This study identified all hormone receptor 96 genes of P. citri. 8 PcHR96 genes contained highly conserved domains. The expression profiles showed that PcHR96h was significantly upregulated in spirodiclofen resistant strain and after exposure to spirodiclofen. RNA interference of PcHR96h decreased expression of detoxification genes and increased spirodiclofen susceptibility in P. citri. Furthermore, molecular docking, heterologous expression, and drug affinity responsive target stability demonstrated that PcHR96h can interact with spirodiclofen in vitro. Our research results indicate that PcHR96h plays an important role in regulating spirodiclofen susceptibility and provides theoretical support for the resistance management of P. citri.

A UDP-glycosyltransferase gene PcUGT202A9 was associated with abamectin resistance in Panonychus citri (McGregor).

Panonychus citri (McGregor) strains have developed a high level of resistance to abamectin, but the underlying molecular mechanism is unknown. Uridine diphosphate (UDP)-glycosyltransferases (UGTs) are critical for the removal of a variety of exogenous and endogenous substances. In this study, an enzyme activity assay revealed that UGTs potentially contribute to P. citri abamectin resistance. Spatiotemporal expression profiles showed that only PcUGT202A9 was significantly overexpressed in the abamectin-resistant strain (AbR) at all developmental stages. Moreover, UGT activity decreased significantly, whereas abamectin susceptibility increased significantly, in AbR after PcUGT202A9 was silenced. Three-dimensional modeling and molecular docking analyses revealed that PcUGT202A9 can bind stably to abamectin. Recombinant PcUGT202A9 activity was detected when α-naphthol was used, but the enzymatic activity was inhibited by abamectin (50 % inhibitory concentration: 803.3 ±â€¯14.20 µmol/L). High-performance liquid chromatography and mass spectrometry analyses indicated that recombinant PcUGT202A9 can effectively degrade abamectin and catalyze the conjugation of UDP-glucose to abamectin. These results imply PcUGT202A9 contributes to P. citri abamectin resistance.

Evaluation of marketing authorization and labels of medicines in 2021 WHO Model List of Essential Medicines for Children in China, the Russian Federation and Brazil.

OBJECTIVE: This work compares the marketing authorization, labels and dosage forms of medicines in the WHO Model List of Essential Medicines for Children (EMLc) in China, the Russian Federation and Brazil to urge policymakers to pay more attention to paediatric medication. METHODS: Medicines were selected from the 8th EMLc. By searching relevant databases, which include different types of medical information in China, the Russian Federation and Brazil, the marketing authorization, labels and dosage forms of paediatric medicines in the three countries were evaluated. RESULTS: A total of 485 drug products containing 312 active pharmaceutical ingredients listed in the WHO EMLc were evaluated. Among them, 344 products were approved for use in China, 286 in the Russian Federation and 264 in Brazil. Out of the 344 approved medicines, 317 (92.15%) were authorized for paediatric use in China, 224 (78.32%) in the Russian Federation and 218 (82.58%) in Brazil. In terms of guidance information labelling on drug labels, 75.08%, 83.04% and 88.07% of paediatric drugs approved in China, the Russian Federation and Brazil, respectively, clearly indicated the usage and dosage for paediatric use. Additionally, injections and tablets were the most prevalent dosage forms in these three countries. CONCLUSION: There is still scope for enhancing the marketing authorization and development of dosage forms for paediatric medicines in the three countries. Furthermore, additional measures are being implemented to enhance the information provided on drug labels for children, particularly in China.

Chromosome-level genome assembly of the Asian citrus psyllid, Diaphorina citri.

Diaphorina citri is a global citrus pest. As a vector insect, it can transmit the causative agents of citrus huanglongbing, causing irreversible losses to the citrus industry. The acquisition of genomic information can provide a molecular genetic basis for effective control of D. citri. Here, the DNBSEQ™ , Oxford Nanopore Technologies, and Hi-C technologies are applied to generate a high-quality chromosome-level genome of D. citri. The genome size of D. citri was 523.78 Mb with a scaffold N50 of 47.05 Mb distributed on 13 chromosomes. A total of 250.64 Mb (47.85%) repeat sequences and 24 048 protein-coding genes were predicted. Genome resequencing of female and male individuals indicated that the sex chromosome system of D. citri is XO. Phylogenetic analysis demonstrated that D. citri and Pachypsylla venusta, which separated from their most recent common ancestor about 336.62 million years ago, were the most closely related. Additionally, we identified genes potentially involved in detoxification metabolism, pathogen transmission, and honeydew secretion for further investigation. The high-quality genome provides an important reference for developing effective management strategies of D. citri.

Effects of Candidatus Liberibacter asiaticus infection on metagenome of Diaphorina citri gut endosymbiont.

Asian citrus psyllid (Diaphorina citri, D. citri) is the important vector of "Candidatus Liberibacter asiaticus" (CLas), associated with Huanglongbing, the most devastating citrus disease worldwide. CLas can affect endosymbiont abundance of D. citri. Here, we generated the high-quality gut endosymbiont metagenomes of Diaphorina citri on the condition of CLas infected and uninfected. The dataset comprised 6616.74 M and 6586.04 M raw reads, on overage, from CLas uninfected and infected psyllid strains, respectively. Taxonomic analysis revealed that a total of 1046 species were annotated with 10 Archaea, 733 Bacteria, 234 Eukaryota, and 69 Viruses. 80 unique genera in CLas infected D. citri were identified. DIAMOND software was used for complement function research against various functional databases, including Nr, KEGG, eggNOG, and CAZy, which annotated 84543 protein-coding genes. These datasets provided an avenue for further study of the interaction mechanism between CLas and D. citri.

Biochemical and Molecular Analysis of Field Resistance to Spirodiclofen in Panonychus citri (McGregor).

Spirodiclofen is one of the most widely used acaricides in China. The citrus red mite, Panonychus citri (McGregor) (Acari: Tetranychidae), is one of the most destructive citrus pests worldwide and has developed a high resistance to spirodiclofen. However, the molecular mechanism of spirodiclofen resistance in P. citri is still unknown. In this study, we identified a field spirodiclofen-resistant strain (DL-SC) that showed 712-fold resistance to spirodiclofen by egg bioassay compared to the susceptible strain. Target-site resistance was not detected as non-synonymous mutations were not found by amplification and sequencing of the ACCase gene of resistant and susceptible strains; in addition, the mRNA expression levels of ACCase were similar in both resistant and susceptible strains. The activity of detoxifying enzymes P450s and CCEs in the resistant strain was significantly higher than in the susceptible strain. The transcriptome expression data showed 19 xenobiotic metabolisms genes that were upregulated. Stage-specific expression profiling revealed that the most prominent upregulated gene, CYP385C10, in transcriptome data was significantly higher in resistant strains in all stages. Furthermore, functional analysis by RNAi indicated that the mortality caused by spirodiclofen was significantly increased by silencing the P450 gene CYP385C10. The current results suggest that overexpression of the P450 gene, CYP385C10, may be involved in spirodiclofen resistance in P. citri.

Degarelix vs. leuprorelin for the treatment of prostate cancer in China: A cost-utility analysis.

Objective: To explore the cost-effectiveness of degarelix acetate for injection (degarelix) compared to leuprorelin in prostate cancer (Pca) castration treatment from Chinese healthcare system perspective. Methods: A Markov model, adapted from the one established in Finland was conducted for the cost-effectiveness analysis of degarelix and leuprorelin for Pca treatment. The main data were derived from global phase III clinical trials of degarelix (CS21), published study and expert surveys. Outcomes, utility and costs of prostate cancer patients were calculated on a 30-year time horizon. The CS21 study based population of intention-to-treat (ITT) population and three scenarios were modeled. Taking three times of the Gross domestic product (GDP) per capita (242,928 yuan, 2021) as the acceptable threshold for cost-effectiveness. One-way and probabilistic sensitivity analyses were performed on key parameters, including transition probabilities, costs, utility, and discount rate to test the robustness of the model. Results: Base case analysis for ITT population revealed that total costs of degarelix and leuprorelin were 566,226 yuan and 489,693 yuan, while the total quality-adjusted life years (QALYs) were 5.19 and 4.51 during the 30-year time horizon, resulting an incremental cost effectiveness ratio (ICER) of 112,674 yuan/QALY which was 1.39 times the GDP per capita, lower than willingness-to-pay level of three times the GDP per capita. The results for scenario analyses revealed that compared to leuprorelin, degarelix for Pca treatment in China was cost-effective. One-way sensitivity analysis showed that the model was most sensitive to price of 80 mg degarelix, utility of 1st-line therapy, hazard ratio of PSA recurrence, price of 3.75 mg leuprorelin, response rate of docetaxel per cycle, and discount rate of cost. In probabilistic sensitivity analysis, compared to leuprorelin, the probability of degarelix to be cost-effective was 53 and 81% for willingness-to-pay threshold of one and three times the GDP per capita. Conclusion: Compared to leuprorelin, degarelix for prostate cancer treatment is cost-effective. Moreover, scenario, one-way, and probabilistic sensitivity analyses revealed that the model was robust.

The Consistency Between the Chinese Essential Medicines List and Treatment Guidelines-Taking Oncology Medicines as an Example.

The concepts of "essential medicine" and "national medicine policy" were first put forward for the first time at the World Health Assembly in 1975 in an effort to alleviate the problem of medicine unavailability in developing and poor countries. The essential medicine system in China has experienced three development stages since 1979, when the concept of essential medicines was first introduced, to actively respond to the call of the World Health Organization. Currently, the essential medicines list published in China is the national essential medicines list (2018 Edition). In this study, we examined the consistency between the essential medicines for treating seven cancers (liver cancer, breast cancer, esophageal cancer, lung cancer, colorectal cancer, gastric cancer, and leukemia) and the recommended medicines by cancer treatment guidelines to determine whether the essential medicines are of high quality for clinical needs. The results indicated that the degree of similarity between oncology medicines on the essential medicines list and oncology medicines recommended by guidelines was low, with the majority falling between 30 and 60%. Therefore, to improve the quality of essential medicines, it is necessary to further improve the matching degree. In addition, to further improve the consistency between the essential medicines list and treatment guidelines, the following suggestions are put forward in this paper: (1). Formulate universal treatment guidelines; (2). When selecting essential medicines, greater consideration should be given to those recommended in the guidelines; (3). The essential medicines list and treatment guidelines should be concurrently updated; (4). The cycle for updating the essential medicines list and treatment guidelines should be shortened.

Whole genome sequencing and bulked segregant analysis suggest a new mechanism of amitraz resistance in the citrus red mite, Panonychus citri (Acari: Tetranychidae).

BACKGROUND: Amitraz is a broad-spectrum insecticide/acaricide for the control of aphids, psyllids, ticks and mites. Current evidence suggests that ticks and phytophagous mites have developed strong resistance to amitraz. Previous studies have shown that multiple mechanisms are associated with amitraz resistance in ticks, but very few reports have involved Panonychus citri. We therefore used whole genome sequencing and bulked segregant analysis (BSA) to identify the mechanism underlying P. citri's resistance to amitraz. RESULTS: High-quality assembly of the whole P. citri genome was completed, resulting in a genome of approximately 83.97 Mb and a contig N50 of approximately 1.81 Mb. Gene structure predictions revealed 11 577 genes, of which 10 940 genes were annotated. Trait-associated regions in the genome were mapped with bulked segregant analysis and 38 candidate SNPs were obtained, of which T752C had the strongest correlation with the resistant trait, located at the 5' untranslated region (UTR) of the ß-2R adrenergic-like octopamine receptor gene. The mutation resulted in the formation of a short hairpin loop structure in mRNA and gene expression was down-regulated by more than 50% in the amitraz-resistant strain. Validation of the T752C mutation in field populations of P. citri found that the correlation between the resistance ratio and the base mutation was 94.40%. CONCLUSION: Our results suggest that this 5' UTR mutation of the ß-2R octopamine receptor gene, confers amitraz resistance in P. citri. This discovery provides a new explanation for the mechanism of pest resistance: base mutations in the 5' untranslated region of target gene may regulate the susceptibility of pests to pesticides.

Expression of exogenous dsRNA by Lecanicillium attenuatum enhances its virulence to Dialeurodes citri.

BACKGROUND: Dialeurodes citri is an important pest in citrus-producing areas of the world. Lecanicillium attenuatum parasitizes D. citri and kills it, suggesting a potential approach for the biological control of pests. However, the low virulence of the fungus and its slow rate of killing have limited its commercial competitiveness. The objective reason for these disadvantages is immunological rejection by the host. Our strategy was to use fungi to express the double-stranded RNA (dsRNA) of the host immune genes. The fungal hyphae release siRNA at the time of infection, thus interfering with the expression of immune genes in the host and facilitating fungal invasion. RESULTS: We selected prophenoloxidase (DcPPO), prophenoloxidase-activating factor (DcPPO-AF), and lysozyme (DcLZM) as target genes to construct intron-splicing hairpin RNA expression vectors and to successfully obtain transgenic fungi. Two days after infection, the immune genes of D. citri showed varying degrees of silencing compared with those in the positive control group. The median lethal concentration (LC50 ; spores mL-1 ) values of La::GFP, La::DcPPO, La::DcPPO-AF, and La::DcLZM were 9.63 × 104 , 2.66 × 104 , 1.21 × 105 , and 3.31 × 104 , respectively. The 50% lethal time (LT50 ) values of these fungi were 5.15, 3.60, 5.34, and 4.04 days, respectively. The virulence of La::DcPPO and La::DcLZM increased 3.62- and 2.91-fold, respectively, and their LT50 decreased by 30.10% and 21.55%, respectively. CONCLUSIONS: The results indicate that this method, which uses tens of thousands of hyphae to inject dsRNA to improve the virulence of transgenic fungi, can play a greater role in the prevention and control of pests in the future. © 2018 Society of Chemical Industry.