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We searched for evidence of knockdown resistance (kdr) mutations in the voltage-gated sodium channel gene of Aedes aegypti (Linnaeus) (Diptera: Culicidae) and Aedes albopictus (Skuse) (Diptera: Culicidae) mosquitoes from Panama. Conventional PCR was performed on 469 Ae. aegypti and 349 Ae. albopictus. We did not discover kdr mutations in Ae. albopictus, but 2 nonsynonymous kdr mutations, V1016I (found in 101 mosquitoes) and F1534C (found in 29 of the mosquitoes with the V1016I), were detected in Ae. aegypti. These kdr mutations were present in all specimens that were successfully sequenced for both IIS5-S6 and IIIS6 regions, which included samples collected from 8 of the 10 provinces of Panama. No other kdr mutations were found in Ae. aegypti, including V1016G, which has already been reported in Panama. Findings suggest that the V1016I-F1534C variant is prevalent in Panama, which might be related to the introduction and passive movement of mosquitoes as part of the used-tire trade. However, we cannot rule out the possibility that selection on de novo replacement of kdr mutations also partially explains the widespread distribution pattern of these mutations. These 2 ecological and evolutionary processes are not mutually exclusive, though, as they can occur in tandem. Research in Panama needs to calculate the genotypic and allelic frequencies of kdr alleles in local Ae. aegypti populations and to test whether some combinations confer phenotypic resistance or not. Finally, future studies will have to track the introduction and spreading of new kdr mutations in both Aedes species.

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This study identified genetic mutations linked to resistance to pyrethroid insecticides in the plant pest Lygus pratensis. The voltage-gated sodium channel (VGSC) gene was cloned, revealing two mutations (Met918Thr and Leu1014Phe) in laboratory strains and field populations from Inner Mongolia, resulting in variable pyrethroid resistance. A 3D model of LpVGSC was created using homology modeling, and pyrethroid binding patterns were analyzed via molecular docking. Molecular dynamics simulations confirmed structural stability changes and binding stability of pyrethroids to VGSC sites. Mutation frequencies of homozygous and heterozygous genotypes did not exceed 40 and 20%, respectively. Toxicity tests showed high resistance to λ-cyhalothrin (LC50:401.31 ng/cm2). The kdr (L1014F) and superkdr (M918T) mutations weakened interaction forces, reducing pyrethroid binding. M918T and L1014F mutations are predicted to reduce Type I pyrethroid affinity, suggesting Type II pyrethroids may be more effective against resistant strains. These findings aid in resistance management and insecticide design.

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The complex interplay between vascular signaling and neurogenesis in the adult brain remains a subject of intense research. By exploiting the unique advantages of the zebrafish model, in particular the persistent activity of neural stem cells (NSCs) and the remarkable ability to repair brain lesions, we investigated the links between NSCs and cerebral blood vessels. In this study, we first examined the gene expression profiles of vascular endothelial growth factors aa and bb (vegfaa and vegfbb), under physiological and regenerative conditions. Employing fluorescence in situ hybridization combined with immunostaining and histology techniques, we demonstrated the widespread expression of vegfaa and vegfbb across the brain, and showed their presence in neurons, microglia/immune cells, endothelial cells and NSCs. At 1 day post-lesion (dpl), both vegfaa and vegfbb were up-regulated in neurons and microglia/peripheral immune cells (macrophages). Analysis of vegf receptors (vegfr) revealed high expression throughout the brain under homeostatic conditions, with vegfr predominantly expressed in neurons and NSCs and to a lower extent in microglia/immune cells and endothelial cells. These findings were further validated by Vegfr3 and Vegfr4 immunostainings, which showed significant expression in neurogenic radial glial cells.Following brain lesion (1 dpl), while vegfr gene expression remained stable, vegfr transcripts were detected in proliferative cells within the injured parenchyma. Collectively, our results provide a first overview of Vegf/Vegfr signaling in the brain and suggest important roles for Vegf in neurogenesis and regenerative processes.

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INTRODUCTION: This study delved into the role of Kinase Insert Domain Receptor (KDR) and its associated miRNAs in renal cell carcinoma through an extensive computational analysis. The potential of our findings to guide future research in this area is significant. METHODS: Our methods, which included the use of UALCAN and GEPIA2 databases, as well as miRDB, MirDIP, miRNet v2.0, miRTargetLink, MiEAA v2.1, TarBase v8.0, INTERNET, and miRTarBass, were instrumental in identifying the regulation of miRNA associated with KDR expression. The predicted miRNA was validated with the TCGA-KIRC patients' samples by implementing CancerMIRNome. The TargetScanHuman v8.0 was implemented to identify the associations between human miRNAs and KDR. A Patch Dock server analyzed the interactions between hsa-miR-200b-3p-KDR and hsa-miR-200b-3p with KDR. RESULTS: The KDR expression rate was investigated in the Kidney Renal Cell Carcinoma (KIRC) samples, and adjacent normal tissues revealed that the expression rate was significantly higher than the normal samples, which was evident from the strong statistical significance (P = 1.63e-12). Likely, the KDR ex-pression rate was estimated as high at tumor grade 1 and gradually decreased till the metastasis grade, reducing the survival rate of the KIRC patients. To identify these signals early, we predicted a miRNA that could trigger the expression of KDR. Furthermore, we uncovered the potential associations between miR-200c-3p expressions by regulating KDR towards the progression of KIRC. DISCUSSION: Upon examining the outcome, it became evident that miR-200c-3p was significantly down-regulated in KIRC compared to the normal samples. Moreover, the negative correlation was obtained for hsa-miR-200c-3p (R = - 0.276) along with the KDR expression describing that the increased rate of hsa-miR-200c-3p might reduce the KDR expression rate, which may suppress the KIRC initiation or progres-sion. CONCLUSION: The in-silico analysis indicated that the significant increase in KDR expression during the initiation of KIRC could serve as an early diagnostic marker. Moreover, KDR could be utilized to identify advancements in KIRC stages. Additionally, hsa-miR-200c-3p was identified as a potential regulator capable of downregulating and upregulating KDR expression among the 24 miRNAs screened. This find-ing holds promise for future research endeavors. Concurrent administration of the FDA-approved 5-fluor-ouracil with KIRC drugs, such as sorafenib, zidovudine, and everolimus, may have the potential to en-hance the therapeutic efficacy in downregulating hsa-miR-200c-3p. However, further in vitro studies are imperative to validate these findings and gain a comprehensive understanding of the intricate regulatory interplay involving hsa-miR-200c-3p, KDR, 5-fluorouracil, and other FDA-approved drugs for the treat-ment of KIRC. This will facilitate the identification of KIRC stage progression and its underlying pre-ventative mechanisms.

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The aim of our study was to investigate an association between polymorphisms of either the VEGF (vascular endothelial growth factor) gene (rs6921438) or the KDR (kinase insert domain receptor) gene (rs2071559, rs2305948) and DN (diabetic nephropathy) in Caucasians with T2DM (type 2 diabetes mellitus). The second aim was to investigate the effect of either the VEGF gene (rs6921438) or the KDR gene (rs2071559, rs2305948) on the immune expression of either VEGF or KDR in the renal tissues of T2DM subjects (to test the functional significance of tested polymorphisms). The study included 897 Caucasians with T2DM for at least ten years (344 patients with DN and 553 patients without DN). Each subject was genotyped and analyzed for KDR (rs1617640, rs2305948) and VEGF (rs6921438) polymorphisms. Kidney tissue samples taken from 15 subjects with T2DM (autopsy material) were immunohistochemically stained for the expression of VEGF and KDR. We found that the rs2071559 KDR gene was associated with an increased risk of DN. In addition, the GG genotype of the rs6921438 VEGF gene had a protective effect. We found a significantly higher numerical area density of VEGF-positive cells in T2DM subjects with the A allele of the rs6921438-VEGF compared to the homozygotes for wild type G allele (7.0 ± 2.4/0.1 mm2 vs. 1.24 ± 0.5/0.1 mm2, respectively; p < 0.001). Moreover, a significantly higher numerical area density of KDR-positive cells was found in T2DM subjects with the C allele of rs2071559 (CC + CT genotypes) compared to the homozygotes for wild type T allele (9.7± 3.2/0.1 mm2 vs. 1.14 ± 0.5/0.1 mm2, respectively; p < 0.001) To conclude, our study showed that the presence of the C allele of the rs2071559 KDR gene was associated with a higher risk of DN, while the G allele of the rs6921438-VEGF conferred protection against DN in Slovenian T2DM subjects.

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BACKGROUND: Pyrethroid resistance is one of the major threats for effectiveness of insecticide-treated bed nets (ITNs) in malaria vector control. Genotyping of mutations in the voltage gated sodium channel (VGSC) gene is widely used to easily assess the evolution and spread of pyrethroid target-site resistance among malaria vectors. L1014F and L1014S substitutions are the most common and best characterized VGSC mutations in major African malaria vector species of the Anopheles gambiae complex. Recently, an additional substitution involved in pyrethroid resistance, i.e. V402L, has been detected in Anopheles coluzzii from West Africa lacking any other resistance alleles at locus 1014. The evolution of target-site resistance mutations L1014F/S and V402L was monitored in An. coluzzii and Anopheles arabiensis specimens from a Burkina Faso village over a 10-year range after the massive ITN scale-up started in 2010. METHODS: Anopheles coluzzii (N = 300) and An. arabiensis (N = 362) specimens collected both indoors and outdoors by different methods (pyrethrum spray catch, sticky resting box and human landing collections) in 2011, 2015 and 2020 at Goden village were genotyped by TaqMan assays and sequencing for the three target site resistance mutations; allele frequencies were statistically investigated over the years. RESULTS: A divergent trend in resistant allele frequencies was observed in the two species: 1014F decreased in An. coluzzii (from 0.76 to 0.52) but increased in An. arabiensis (from 0.18 to 0.70); 1014S occurred only in An. arabiensis and slightly decreased over time (from 0.33 to 0.23); 402L increased in An. coluzzii (from 0.15 to 0.48) and was found for the first time in one An. arabiensis specimen. In 2020 the co-occurrence of different resistance alleles reached 43% in An. coluzzii (alleles 410L and 1014F) and 32% in An. arabiensis (alleles 1014F and 1014S). CONCLUSIONS: Overall, an increasing level of target-site resistance was observed among the populations with only 1% of the two malaria vector species being wild type at both loci, 1014 and 402, in 2020. This, together with the co-occurrence of different mutations in the same specimens, calls for future investigations on the possible synergism between resistance alleles and their phenotype to implement local tailored intervention strategies.

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OBJECTIVE: The objective of this research was to investigate the part played by KDR and miRNAs in the development and prognosis of oral squamous cell carcinoma (OSCC). METHODS: The gene and protein expression of KDR in OSCC cell lines and a normal human oral epithelial keratinocyte cell line were detected using real-time PCR and western blot analysis. We evaluated the impact of KDR on the proliferation, metastasis, and migration of OSCC cells using the MTT assay and colony formation assay in the CAL27 cell line. Data on OSCC were retrieved from the TCGA-HNSC and GEO databases, and we identified miRNAs that were differentially expressed between OSCC and normal tissue samples. Furthermore, we predicted their potential target mRNAs. miR-424-5p was identified as a regulator upstream of KDR expression, and dual luciferase reporter assays confirmed binding between KDR and miR-424-5p. RESULTS: KDR overexpression was observed in OSCC samples from various databases. These findings were further validated through in vitro experiments, which established that elevated KDR levels enhance the proliferative potential of OSCC cells. Moreover, miR-424-5p was found to counteract the tumorigenic effects of KDR in OSCC cells, suppressing their proliferation, invasion, and metastasis capabilities. CONCLUSIONS: Our research suggests that miR-424-5p and KDR might serve as valuable diagnostic and prognostic markers, as well as potential therapeutic targets, in OSCC.

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BACKGROUND: Vector control based on indoor residual spraying (IRS) is one of the main components of the visceral leishmaniasis (VL) elimination programme in India. Dichlorodiphenyltrichloroethane (DDT) was used for IRS until 2015 and was later replaced by the synthetic pyrethroid alpha-cypermethrin. Both classes of insecticides share the same target site, the voltage-gated sodium channel (Vgsc). As high levels of resistance to DDT have been documented in the local sand fly vector, Phlebotomus argentipes, it is possible that mutations in the Vgsc gene could provide resistance to alpha-cypermethrin, affecting current IRS pyrethroid-based vector control. METHODS: This study aimed to compare frequencies of knockdown resistance (kdr) mutations in Vgsc between two sprayed and two unsprayed villages in Bihar state, India, which had the highest VL burden of the four endemic states. Across four villages, 350 female P. argentipes were collected as part of a 2019 molecular xenomonitoring study. DNA was extracted and used for sequence analysis of the IIS6 fragment of the Vgsc gene to assess the presence of kdr mutations. RESULTS: Mutations were identified at various positions, most frequently at codon 1014, a common site known to be associated with insecticide resistance in mosquitoes and sand flies. Significant inter-village variation was observed, with sand flies from Dharampur, an unsprayed village, showing a significantly higher proportion of wild-type alleles (55.8%) compared with the three other villages (8.5-14.3%). The allele differences observed across the four villages may result from selection pressure caused by previous exposure to DDT. CONCLUSIONS: While DDT resistance has been reported in Bihar, P. argentipes is still susceptible to pyrethroids. However, the presence of kdr mutations in sand flies could present a threat to IRS used for VL control in endemic villages in India. Continuous surveillance of vector bionomics and insecticide resistance, using bioassays and target genotyping, is required to inform India's vector control strategies and to ensure the VL elimination target is reached and sustained.

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BACKGROUND: Knockdown resistance (kdr) is one of the primary resistance mechanisms present in anopheline species. Although this mutation is largely spread across the Anopheles gambiae s.l. members, its prevalence in other species is still not well documented. METHODS: The present study investigated the distribution and allelic frequencies of kdr in An. gambiae s.l., An. pharoensis, and An. ziemanni samples collected in 2022 and 2023 in nine sites spread across five ecogeographical settings in Cameroon. Members of the An. gambiae complex were identified molecularly by polymerase chain reaction (PCR). kdr L1014F and L1014S alleles were screened by PCR and confirmed by sequencing. RESULTS: An. gambiae (49.9%), An. coluzzii (36.5%), and An. arabiensis (13%) were identified, and the frequency of the kdr L1014F was high in both An. gambiae and An. coluzzii in all sites. The kdr L1014F allele was detected for the first time in 8 out of 14 An. ziemanni samples examined and in 5 out of 22 An. pharoensis samples examined. The kdr L1014S allele was scarce and found only in the heterozygote "RS" state in An. arabiensis and An. gambiae in Yangah and Santchou. CONCLUSIONS: The present study sheds light on the rapid expansion of the kdr L1014F allele in malaria vectors in Cameroon and stresses the need for surveillance activities also targeting secondary malaria vectors to improve the control of malaria transmission.

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Cells of various organs and systems perform their functions and intercellular interactions not in an inert environment, but in the microenvironment of tissue fluids. Violations of the normal drainage of tissue fluids accompany lymphedema. An important mechanism of angiogenesis and vasculogenesis regulation in tissue fluids is the production and reception of vascular endothelial growth factors in combination with the regulation of matrix metalloproteinases. The aim of the work was to perform: a comparative analysis of some polymorphisms of vascular endothelial growth factor and their receptors and the genes encoding matrix metalloproteinases in two forms of lymphedema; an analysis of the relationship of these genes' polymorphisms with the levels of vascular endothelial growth factor and matrix metalloproteinases and their inhibitors in serum and affected tissues. Polymorphism of VEGF (rs699947, rs3025039), KDR (rs10020464, rs11133360), NRP2 (rs849530, rs849563, rs16837641), matrix metalloproteinases MMP2 (rs2438650), MMP3 (rs3025058), MMP9 (rs3918242), Timp1 (rs6609533) and their combinations were analyzed by the Restriction Fragment Length Polymorphism method and TaqMan RT-PCR. The serum and tissue fluid levels were determined using the ELISA test system. Changes in the frequency distribution of MMP2 genotypes in primary and MMP3 in secondary lymphedema are shown. Significant frequency differences in NRP2 genotypes were revealed by comparing primary and secondary lymphedema. Features of the distribution of complex genotypes in primary and secondary lymphedema were revealed. The correlation analysis revealed the interdependence of the concentrations of the MMP, TIMP and VEGF products and differences in the structure of the correlation matrices of patients with both forms of lymphedema. It was shown that, in primary lymphedema, genotypes associated with low MMP2 and TIMP2 in serum and tissue fluid are detected, while in secondary lymphedema, other associations of the production levels with combined genetic traits are observed.

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BACKGROUND: Anopheles stephensi is recognized as the main malaria vector in Iran. In recent years, resistance to several insecticide classes, including organochlorine, pyrethroids, and carbamate compounds, has been reported for this medically important malaria vector. The main objective of the present study was to evaluate the insecticide susceptibility status of An. stephensi collected from the southern part of Iran, and to clarify the mechanism of resistance, using bioassay tests and molecular methods comparing the sequence of susceptible and resistant mosquitoes. METHODS: Mosquito larvae were collected from various larval habitats across six different districts (Gabrik, Sardasht, Tidar, Dehbarez, Kishi and Bandar Abbas) in Hormozgan Provine, located in the southern part of Iran. From each district standing water areas with the highest densities of Anopheles larvae were selected for sampling, and adult mosquitoes were reared from them. Finally, the collected mosquito species were identified using valid keys. Insecticide susceptibility of An. stephensi was tested using permethrin 0.75%, lambdacyhalothrin 0.05%, deltamethrin 0.05%, and DDT 4%, following the World Health Organization (WHO) test procedures for insecticide resistance monitoring. Additionally, knockdown resistance (kdr) mutation in the voltage-gated sodium channel (vgsc) gene was sequenced and analysed among resistant populations to detect possible molecular mechanisms of observed resistance phenotypes. RESULTS: The susceptibility status of An. stephensi revealed that resistance to DDT and permethrin was found in all districts. Furthermore, resistance to all tested insecticides in An. stephensi was detected in Gabrik, Sardasht, Tidar, and Dehbarez. Analysis of knockdown resistance (kdr) mutations at the vgsc did not show evidence for the presence of this mutation in An. stephensi. CONCLUSION: Based on the results of the current study, it appears that in An. stephensi from Hormozgan Province (Iran), other resistance mechanisms such as biochemical resistance due to detoxification enzymes may be involved due to the absence of the kdr mutation or non-target site resistance. Further investigation is warranted in the future to identify the exact resistance mechanisms in this main malaria vector across the country.

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Elevated resistance to pyrethroids in major malaria vectors has led to the introduction of novel insecticides including neonicotinoids. There is a fear that efficacy of these new insecticides could be impacted by cross-resistance mechanisms from metabolic resistance to pyrethroids. In this study, after evaluating the resistance to deltamethrin, clothianidin and mixture of clothianidin + deltamethrin in the lab using CDC bottle assays, the efficacy of the new IRS formulation Fludora® Fusion was tested in comparison to clothianidin and deltamethrin applied alone using experimental hut trials against wild free-flying pyrethroid-resistant Anopheles funestus from Elende and field An. gambiae collected from Nkolondom reared in the lab and released in the huts. Additionally, cone tests on the treated walls were performed each month for a period of twelve months to evaluate the residual efficacy of the sprayed products. Furthermore, the L1014F-kdr target-site mutation and the L119F-GSTe2 mediated metabolic resistance to pyrethroids were genotyped on a subset of mosquitoes from the EHT to assess the potential cross-resistance. All Anopheles species tested were fully susceptible to clothianidin and clothianidin + deltamethrin mixture in CDC bottle assay while resistance was noted to deltamethrin. Accordingly, Fludora® Fusion (62.83% vs 42.42%) and clothianidin (64.42% vs 42.42%) induced significantly higher mortality rates in EHT than deltamethrin (42.42%) against free flying An. funestus from Elende in month 1 (M1) and no significant difference in mortality was observed between the first (M1) and sixth (M6) months of the evaluation (P > 0.05). However, lower mortality rates were recorded against An. gambiae s.s from Nkolondom (mortality rates 50%, 45.56% and 26.68%). In-situ cone test on the wall showed a high residual efficacy of Fludora® Fusion and clothianidin on the susceptible strain KISUMU (> 12 months) and moderately on the highly pyrethroid-resistant An. gambiae strain from Nkolondom (6 months). Interestingly, no association was observed between the L119F-GSTe2 mutation and the ability of mosquitoes to survive exposure to Fludora® Fusion, whereas a trend was observed with the L1014F-kdr mutation. This study highlights that Fludora® Fusion, through its clothianidin component, has good potential of controlling pyrethroid-resistant mosquitoes with prolonged residual efficacy. This could be therefore an appropriate tool for vector control in several malaria endemic regions.

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It is acknowledged that conventional renal cell carcinoma (cRCC), which makes up 85% of renal malignancies, is a highly vascular tumor. Humanized monoclonal antibodies were developed to inhibit tumor neo-angiogenesis, which is driven by VEGFA/KDR signaling. The results largely met our expectations, and in several cases, adverse events occurred. Our study aimed to analyze the expression of VEGFA and its receptor KDR by immunohistochemistry in tissue multi-array containing 811 cRCC and find a correlation between VEGFA/KDR signaling and new vessel formation. None of the 811 cRCC displayed VEGFA-positive immunostaining. However, each glomerulus in normal kidney showed VEGFA-positive endothelial cells. KDR expression in endothelial meshwork was found in only 9% of cRCC, whereas 2% of the cRCC displayed positive KDR reaction in the cytoplasm of tumor cells. Our results disclose the involvement of VEGFA/KDR signaling in the neo-vascularization of cRCC and explain the frequent resistance to drugs targeting the VEGFA/KDR signaling and the high frequency of adverse events.

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BACKGROUND: The Aedes albopictus mosquito is of medical concern due to its ability to transmit viral diseases, such as dengue and chikungunya. Aedes albopictus originated in Asia and is now present on all continents, with the exception of Antarctica. In Mozambique, Ae. albopictus was first reported in 2015 within the capital city of Maputo, and by 2019, it had become established in the surrounding area. It was suspected that the mosquito population originated in Madagascar or islands of the Western Indian Ocean (IWIO). The aim of this study was to determine its origin. Given the risk of spreading insecticide resistance, we also examined relevant mutations in the voltage-sensitive sodium channel (VSSC). METHODS: Eggs of Ae. albopictus were collected in Matola-Rio, a municipality adjacent to Maputo, and reared to adults in the laboratory. Cytochrome c oxidase subunit I (COI) sequences and microsatellite loci were analyzed to estimate origins. The presence of knockdown resistance (kdr) mutations within domain II and III of the VSSC were examined using Sanger sequencing. RESULTS: The COI network analysis denied the hypothesis that the Ae. albopictus population originated in Madagascar or IWIO; rather both the COI network and microsatellites analyses showed that the population was genetically similar to those in continental Southeast Asia and Hangzhou, China. Sanger sequencing determined the presence of the F1534C knockdown mutation, which is widely distributed among Asian populations, with a high allele frequency (46%). CONCLUSIONS: These results do not support the hypothesis that the Mozambique Ae. albopictus population originated in Madagascar or IWIO. Instead, they suggest that the origin is continental Southeast Asia or a coastal town in China.

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BACKGROUND: Aedes albopictus is an important vector of chikungunya, dengue, yellow fever and Zika viruses. Insecticides are often the most effective tools for rapidly decreasing the density of vector populations, especially during arbovirus disease outbreaks. However, the intense use of insecticides, particularly pyrethroids, has led to the selection of resistant mosquito populations worldwide. Mutations in the voltage-gated sodium channel (VGSC) gene are one of the main drivers of insecticide resistance in Ae. albopictus and are also known as "knockdown resistance" (kdr) mutations. Knowledge about genetic mutations associated with insecticide resistance is a prerequisite for developing techniques for rapid resistance diagnosis. Here, we report studies on the origin and dispersion of kdr haplotypes in samples of Ae. albopictus from the Yangtze River Basin, China; METHODS: Here, we report the results of PCR genotyping of kdr mutations in 541 Ae. albopictus specimens from 22 sampling sites in 7 provinces and municipalities in the Yangtze River Basin. Partial DNA sequences of domain II and domain III of the VGSC gene were amplified. These DNA fragments were subsequently sequenced to discover the possible genetic mutations mediating knockdown resistance (kdr) to pyrethroids. The frequency and distribution of kdr mutations were assessed in 22 Ae. albopictus populations. Phylogenetic relationships among the haplotypes were used to infer whether the kdr mutations had a single or multiple origins; RESULTS: The kdr mutation at the 1016 locus had 2 alleles with 3 genotypes: V/V (73.38%), V/G (26.43%) and G/G (0.18%). The 1016G homozygous mutation was found in only one case in the CQSL strain in Chongqing, and no 1016G mutations were detected in the SHJD (Shanghai), NJDX (Jiangsu) or HBQN (Hubei) strains. A total of 1532 locus had two alleles and three genotypes, I/I (88.35%), I/T (8.50%) and T/T (3.14%). A total of 1534 locus had four alleles and six genotypes: F/F (49.35%), F/S (19.96%), F/C (1.48%) and F/L (0.18%); S/S (23.66%); and C/C (5.36%). Haplotypes with the F1534C mutation were found only in Ae. albopictus populations in Chongqing and Hubei, and C1534C was found only in three geographic strains in Chongqing. Haplotypes with the 1534S mutation were found only in Ae. albopictus populations in Sichuan and Shanghai. F1534L was found only in HBYC. The Ae. albopictus populations in Shanghai were more genetically differentiated from those in the other regions (except Sichuan), and the genetic differentiation between the populations in Chongqing and those in the middle-lower reaches of the Yangtze River (Huber, Jiangsu, Jiangxi, and Anhui) was lower. Shanghai and Sichuan displayed low haplotype diversity and low nucleotide diversity. Phylogenetic analysis and sequence comparison revealed that the 1016 locus was divided into three branches, with the Clade A and Clade B branches bearing the 1016 mutation occurring mostly in Jiangsu and the Clade C branch bearing the 1016 mutation occurring mostly in Chongqing, suggesting at least two origins for 1016G. IIIS6 phylogenetic analysis and sequence comparison revealed that F1534S, F1534C and I1532T can be divided into two branches, indicating that IIIS6 has two origins; CONCLUSIONS: Combined with the distribution of kdr mutations and the analysis of population genetics, we infer that besides the local selection of pyrethroid resistance mutations, dispersal and colonization of Ae. albopictus from other regions may explain why kdr mutations are present in some Ae. albopictus populations in the Yangtze River Basin.

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Indoor cases of Tetranychus cinnabarinus displaying resistance have been documented, but the resistance level in field populations remains unexplored in China. This study delves into the resistance dynamics of T. cinnabarinus to fenpropathrin in various field populations across China, a pressing concern in contemporary agricultural pest control. The conventional bioassay and amplicon sequencing reveal a notable absence of significant fenpropathrin resistance in field populations, contrasting with known resistance in indoor cases. Current study highlights the limitations of traditional bioassays in detecting early-stage resistance and underscores the nuanced capabilities and constraints of amplicon sequencing in resistance gene frequency analysis. By employing an integrated approach, we combined dose-response bioassays, amplicon sequencing, and statistical modeling to assess resistance levels and investigate underlying genetic factors. The model with empirical data indicates that a 5% mutation frequency represents the threshold before resistance emerges. However, the detection of the kdr mutation in certain populations ranging from 0 to 1.2%, signals an early looming threat of future resistance emergence. Additionally, we further assessed a specific dsRNA targeting VGSC genes at two concentrations (10 ng/µL and 100 ng/µL), both inducing substantial mortality by silencing target genes effectively. The exploration of RNA interference (RNAi) as a novel, more environmentally friendly pest control measure opens new avenues, despite the ongoing challenge of resistance evolution. Overall, this study underscores the necessity for evolving pest management strategies, integrating advanced biotechnological approaches with traditional methods, to effectively counter pesticide resistance and ensure sustainable agricultural productivity.

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BACKGROUND: This study aimed to investigate the relationship between the physicochemical characteristics of An. gambiae s.s. and An. coluzzii breeding sites, the susceptibility profiles to commonly used insecticides in public health, and the underlying insecticide resistance mechanisms. METHODS: Anopheles breeding sites surveys were conducted in Cotonou and Natitingou in September 2020, January and August 2021. Physicochemical properties and bacterial loads were determined in individual breeding sites. The WHO susceptibility assays were carried out using the female of the emerging adult mosquitoes. Anopheles species were identified through PCR techniques. Kdr L1014F/S, N1575Y and G119S mutations were investigated using TaqMan genotyping assays. RESULTS: Molecular analysis showed that all mosquitoes analyzed in Cotonou were Anopheles coluzzii, while those of Natitingou were Anopheles gambiae s.s. Fecal coliforms were identified as playing a role in this distribution through their significant influence on the presence of An. coluzzii larvae. WHO susceptibility assay indicated a high level of resistance to deltamethrin in the two cities. The resistance levels to deltamethrin were higher in Cotonou (X2 = 31.689; DF = 1; P < 0.0001). There was a suspected resistance to bendiocarb in Cotonou, whereas the mosquito population in Natitingou was resistant. The kdr L1014F mutation was highly observed in both mosquito populations (frequence: 86-91%), while the Ace-1 mutation was found in a small proportion of mosquitoes. In Cotonou, salinity was the only recorded physicochemical parameter that significantly correlated with the resistance of Anopheles mosquitoes to deltamethrin (P < 0.05). In Natitingou, significant correlations were observed between the allelic frequencies of the kdr L1014F mutation and pH, conductivity, and TDS. CONCLUSION: These results indicate a high level of pyrethroid resistance in the anopheles populations of both Cotonou and Natitingou. Moreover, this study report the involvement of abiotic factors influencing Anopheles susceptibility profile.

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Mosquito coil is commonly used in many African households for protection against mosquito bites. The coil usually has semi-volatile pyrethroids as an active ingredient, which usually diffuse across open space, and the cloud either kills mosquitoes that are exposed, or mosquitoes can be exposed to sublethal doses of the insecticides. This study was conducted to assess the impact of sublethal doses of mosquito coil on the development of insecticide resistance in Aedes aegypti, a major vector for dengue fever and several other arboviral diseases. A laboratory colony of Ae. aegypti was exposed to sublethal doses of a meperfluthrin-based mosquito coil in a Peet-Grady chamber once per generation for 16 generations. The susceptibility of the exposed colony to a diagnostic dose of the mosquito coil as well as to three other insecticides was determined. Three different kdr mutations and five enzyme activities were evaluated in both the exposed and control colonies. After 16 generations of sublethal exposure to mosquito coils, the full diagnostic dose of the coil caused 68% mortality to the exposed colony compared to 100% mortality in the control colony. Mortality caused by deltamethrin (0.05%) was also significantly lower in the exposed colony. The frequency of 1016I kdr mutation as well as MFO and alpha esterase activities were higher in the exposed colony compared to the control colony. This study provides evidence of the development of pyrethroid resistance in an Ae. aegypti population due to sublethal exposure to mosquito coil for 16 generations. Given the large-scale use of mosquito coils in many African households, its role as a pyrethroid resistance selection source should be taken into consideration when designing resistance management strategies.

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(1) Background: In Cambodia, Aedes albopictus is an important vector of the dengue virus. Vector control using insecticides is a major strategy implemented in managing mosquito-borne diseases. Resistance, however, threatens to undermine the use of insecticides. In this study, we present the levels of insecticide resistance of Ae. albopictus in Cambodia and the mechanisms involved. (2) Methods: Two Ae. albopictus populations were collected from the capital, Phnom Penh city, and from rural Pailin province. Adults were tested with diagnostic doses of malathion (0.8%), deltamethrin (0.03%), permethrin (0.25%), and DDT (4%) using WHO tube assays. Synergist assays using piperonyl butoxide (PBO) were implemented before the pyrethroid assays to detect the potential involvement of metabolic resistance mechanisms. Adult female mosquitoes collected from Phnom Penh and Pailin were tested for voltage-gated sodium channel (VGSC) kdr (knockdown resistance) mutations commonly found in Aedes sp.-resistant populations throughout Asia (S989P, V1016G, and F1534C), as well as for other mutations (V410L, L982W, A1007G, I1011M, T1520I, and D1763Y). (3) Results: The two populations showed resistance against all the insecticides tested (<90% mortality). The use of PBO (an inhibitor of P450s) strongly restored the efficacy of deltamethrin and permethrin against the two resistant populations. Sequences of regions of the vgsc gene showed a lack of kdr mutations known to be associated with pyrethroid resistance. However, four novel non-synonymous mutations (L412P/S, C983S, Q1554STOP, and R1718L) and twenty-nine synonymous mutations were detected. It remains to be determined whether these mutations contribute to pyrethroid resistance. (4) Conclusions: Pyrethroid resistance is occurring in two Ae. albopictus populations originating from urban and rural areas of Cambodia. The resistance is likely due to metabolic resistance specifically involving P450s monooxygenases. The levels of resistance against different insecticide classes are a cause for concern in Cambodia. Alternative tools and insecticides for controlling dengue vectors should be used to minimize disease prevalence in the country.

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BACKGROUND: Age-related macular degeneration (AMD) is a major global health problem as it is the leading cause of irreversible loss of central vision in the aging population. Av-vascular endothelial growth factor (anti-VEGF) therapies have been shown to be effective, but they do not respond optimally to all patients. OBJECTIVE: This study investigates the genetic factors associated with susceptibility to AMD and response to treatment, focusing on key polymorphisms in the CFH (rs1061170, rs1410996) and KDR (rs2071559, rs1870377) genes and the association of CFH and KDR serum levels in patients with AMD. RESULTS: A cohort of 255 patients with early AMD, 252 patients with exudative AMD, and 349 healthy controls underwent genotyping analysis, which revealed significant associations between CFH polymorphisms and the risk of exudative AMD. The CFH rs1061170 CC genotype was associated with an increased risk of early AMD (p = 0.046). For exudative AMD, the CFH rs1061170 TC + CC genotype increased odds (p < 0.001), while the rs1410996 GA + AA genotype decreased odds (p < 0.001). Haplotypes of CFH SNPs were associated with decreased odds of AMD. In terms of response to treatment, none of the SNPs were associated with the response to anti-VEGF treatment. We also found that both early and exudative AMD patients had lower CFH serum levels compared to the control group (p = 0.038 and p = 0.006, respectively). Exudative AMD patients with the CT genotype of CFH rs1061170 had lower CFH serum levels compared to the control group (p = 0.035). Exudative AMD patients with the GG genotype of CFH rs1410996 also had lower CFH serum levels compared to the control group (p = 0.021). CONCLUSIONS: CFH polymorphisms influence susceptibility to AMD but do not correlate with a response to anti-VEGF therapy. Further research is imperative to fully evaluate the developmental significance, treatment efficacy, and predictive role in influencing susceptibility to anti-VEGF therapy for KDR and CFH.