Skip to main content

Key gene modules and hub genes associated with pyrethroid and organophosphate resistance in Anopheles mosquitoes: a systems biology approach

Abstract

Indoor residual spraying (IRS) and insecticide-treated nets (ITNs) are the main methods used to control mosquito populations for malaria prevention. The efficacy of these strategies is threatened by the spread of insecticide resistance (IR), limiting the success of malaria control. Studies of the genetic evolution leading to insecticide resistance could enable the identification of molecular markers that can be used for IR surveillance and an improved understanding of the molecular mechanisms associated with IR. This study used a weighted gene co-expression network analysis (WGCNA) algorithm, a systems biology approach, to identify genes with similar co-expression patterns (modules) and hub genes that are potential molecular markers for insecticide resistance surveillance in Kenya and Benin. A total of 20 and 26 gene co-expression modules were identified via average linkage hierarchical clustering from Anopheles arabiensis and An. gambiae, respectively, and hub genes (highly connected genes) were identified within each module. Three specific genes stood out: serine protease, E3 ubiquitin-protein ligase, and cuticular proteins, which were top hub genes in both species and could serve as potential markers and targets for monitoring IR in these malaria vectors. In addition to the identified markers, we explored molecular mechanisms using enrichment maps that revealed a complex process involving multiple steps, from odorant binding and neuronal signaling to cellular responses, immune modulation, cellular metabolism, and gene regulation. Incorporation of these dynamics into the development of new insecticides and the tracking of insecticide resistance could improve the sustainable and cost-effective deployment of interventions.

Peer Review reports

Introduction

Malaria remains a significant problem in many African countries, including Benin and Kenya, where it causes a significant public health burden [1]. In Western Benin, the prevalence of malaria is exceptionally high due to favorable mosquito breeding conditions and a dense population of Anopheles gambiae s.s. as the main malaria vector in this region. Similarly, malaria is endemic in Kenya, with transmission occurring throughout the year, especially in the western and coastal areas [2]. The primary malaria vectors in Kenya are An. gambiae s.l., An. arabiensis, and An. funestus [3]. Anopheles stephensi and An. coluzzii have recently been reported in Northern Kenya, but their contribution to malaria transmission in Kenya is yet to be described [4, 5].

Insecticide-treated nets (ITNs) and indoor residual spraying (IRS) are key components of malaria control strategies that have been effective in reducing malaria transmission, particularly between the years 2000 and 2015 [6]. However, these measures are now threatened by insecticide resistance in mosquitoes, especially to pyrethroids. Target site mutations [7,8,9,10], over-expression of metabolic enzymes [11,12,13,14,15,16,17,18], cuticular thickening [19, 20], and changes in microbiota compositions [21, 22] have been described as mechanisms involved in conferring insecticide-resistant phenotypes. These mechanisms work synergistically to cause resistance [23].

Networks are interconnected systems of genes within an organism that interact with each other. A gene that significantly regulates other genes' activities in a network and is densely interconnected is commonly known as a hub gene [24]. Based on gene expression data, weighted gene co-expression network analysis (WGCNA) can be used to identify co-expressed modules associated with phenotypes, conditions, or traits [25]. The resulting hub genes can be identified based on the connectivity of an organism’s whole transcriptomic data. It groups genes into modules based on their expression patterns across samples and identifies hub genes that are highly connected within each module. These hub genes serve as molecular markers for the trait being studied, representing the overall characteristics of their respective modules [25]. The co-expression and similar molecular functions within modules suggest that these genes work together in response to a specific trait.

In this study, we hypothesized that genetic markers often associated with insecticide resistance are linked with additional genes in networks and that those networks are centered around hub genes. The typical differential gene expression analysis approach assumes that every gene acts as an isolated unit in the cell but does not capture gene co-expression and correlation patterns, which could provide a more holistic picture of the gene expression landscape by identifying sets of genes that regulate together to modulate the insecticide resistance phenotypes observed. WGCNA could be a beneficial approach for linking genes to insecticide-resistance phenotypes. This study applied the WGCNA approach to whole transcriptomic data to identify potential molecular markers for insecticide resistance. Anopheles gambiae and An. arabiensis samples were collected from Benin and Kenya, respectively, and the insecticide resistance phenotypes for alphacypermethrin, deltamethrin, and pirimiphos-methyl were determined in preceding studies [26, 27]. The RNA of the resistant and susceptible mosquitoes was sequenced, and the corresponding gene counts were used for WGCNA analysis to identify potential markers (hub genes) associated with insecticide resistance. After identifying the hub genes, differential gene expression analysis was performed for hub gene validation as potential IR markers.

Results

Data pre-processing before WGCNA

The dataset initially contained a total of 17 samples from An. gambiae and 18 samples from An. arabiensis. However, we excluded two samples (DA and DA2) from An. gambiae and one sample (MD0_1.1) from An. arabiensis during the normalization process because these samples were outliers, as identified on a dendrogram plot of the total read counts at a height threshold of 80 for An. gambiae and 500 for An. arabiensis (Fig. 1).

Fig. 1
figure 1

Representation plots of the total read counts for An. gambiae (A) and An. arabiensis (B). Fig 1A represents a dendrogram plot for An. gambiae normalized read counts. DA = Djougou Alphacypermethrin, DD = Djougou Deltamethrin, BP = Bassila Permethrin, BA = Bassila Alphacypermethrin, and BP = Bassila Primiphos-methyl. Fig. 1B represents a dendrogram plot for An. arabiensis normalized read counts. MA0 = Migori Alphacypermethrin, MP0 = Migori Primiphos-methyl, MD = Migori Deltamethrin, SA0 = Siaya Alphacypermethrin, SD0 = Siaya Deltamethrin, SP0 = Siaya Primiphos-methyl,KIS = Kisumu strain An. gambiae, and DON = Dongola strain An. arabiensis

After filtering these low abundance reads, the dataset contained a total of 10,871 and 10,908 genes from An. gambiae and An. arabiensis, respectively, which we utilized to construct weighted gene co-expression networks. This careful sample selection and noise reduction approach improved the reliability and quality of the subsequent weighted gene co-expression analysis for both An. gambiae and An. arabiensis, providing a solid foundation for the interpretation of the results in the study.

Modules associated with insecticide resistance

As a result, we obtained 26 gene co-expression modules for An. gambiae and 20 gene co-expression modules for An. arabiensis (Fig. 2). Module trait relationship results showed that 12 and 9 modules in An. gambiae and An. arabiensis, respectively, were positively correlated with resistance. Based on correlation with percentage survival in the bioassays, the top modules in An. gambiae were blue (p = 0.06, cor = 0.8), darkslateblue (p = 0.2, cor = 0.65), and bisque4 (p = 0.2, cor = 0.59), whereas the top three co-expression modules correlated with resistance in An. arabiensis were pink (p = 0.01, cor = 0.8), floralwhite (p = 0.02, cor = 0.77), and mediumpurple3 (p = 0.1, cor = 0.56) (Fig. 3).

Fig. 2
figure 2

Scale-free topology fitting index (R2) versus a soft threshold power plots and hierarchical clustering dendrogram plots for both An. gambiae and An. arabiensis

Fig. 3
figure 3

Module trait relationship heat map plots and module preservation summary plots in An. gambiae and An. arabiensis.Each point represents a module labeled by color.The dashed lines indicate thresholds Z = 2 (no preservation) and Z = 10 (highly preserved modules)

We then calculated module preservation in the resistant Anopheles network compared to the susceptible network. This analysis aided in identifying preserved modules in the resistant network and visualizing their differential expression in the two conditions. The higher the z summary score, the higher the preservation and differential expression of the two conditions. In An. gambiae, the top four preserved modules included greenyellow, black, salmon, and cyan (z score > 5), as shown in Fig. 3. An. arabiensis most preserved modules included yellow, brown, yellowgreen, and darkmagenta, which had the same z summary score as An. gambiae (Fig. 3). The differential expression of the top preserved modules in susceptible and resistant samples in the two species validated their role in resistance, and further investigation is recommended for the specific modules (Fig. 4). A list of all the genes in the specific modules is provided as supplementary File 2. Further analysis to explore if the number of genes in a module affected module preservation was performed using medium rank scores, and interestingly, there was no correlation between the two (Fig. 3). Further, we visualized the constructed weighted gene co-expression networks for the two species to gain insights into the relationships and interactions among various modules within the network and comprehend the interactions between genes better (Fig. 5).

Fig. 4
figure 4

An. gambiae and An. arabiensis preserved module expression plots in resistant and susceptible anopheles populations.Higher values are represented with reds of increasing intensity, and lower values are represented with greens of increasing intensity

Fig. 5
figure 5

Resistant anopheles gene co-expression networks generated using weighted gene co-expression network analysis based on TOM > 0.1 for visualization. This figure illustrates gene co-expression networks; each node (point) represents a gene and genes of the same color form modules. The edges (lines) connecting the nodes represent gene-to-gene relationships. Fig. 5A represents the An. gambiae gene co-expression network, whereas Fig. 5B illustrates the An. arabiensis gene co-expression network

Functional enrichment of the identified modules

To explore the functional relevance of the positively correlated modules from the module trait relationship, we performed gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) term enrichment analysis using the DAVID database. The enrichment analysis revealed significant enrichment of GO terms and KEGG pathways associated with genes in these modules. Enriched GO terms in all categories were analyzed. Similarly, the enriched KEGG pathways provided insights into the functional pathways involved in insecticide resistance for both An. gambiae and An. arabiensis. To visualize and explore these enrichment results, we used the EnrichmentMap plugin in Cytoscape to create an enrichment map. The enrichment map revealed multiple clusters of enriched terms for An. gambiae and An. arabiensis. The enriched terms in An. gambiae included transmembrane processes, immunity pathways, metabolic pathways, cytoplasm, fatty acid degradation pathways, signal transduction, and DNA replication (Supplementary 1). The enriched terms in An. arabiensis include the nucleus, metabolic pathways, signal transduction, ATP binding, and immune pathways (Supplementary 2). The enrichment map indicated several enriched insecticide targets, including voltage-gated sodium channels, acetylcholine-gated channels, and nervous system receptors. Furthermore, fundamental insecticide response mechanisms, such as immune response and metabolic pathways, were also enriched, as depicted in the maps. We constructed a detailed illustration at the cellular level that shows the molecular pathways and mechanisms in pyrethroid-resistant Anopheles mosquitoes using Biorender software (Fig. 6).

Fig. 6
figure 6

Panoramic view of molecular interactions in insecticide-resistant Anopheles mosquitoes. OBP-Odorant Binding Proteins; ORN-Olfactory Receptor Neurons; GPCRs-G coupled protein receptors; PKA-Protein Kinase A

Hub genes are associated with insecticide resistance

The hub genes for An. gambiae modules encoded 3.4 kDa salivary protein, angiotensin-converting enzyme, cuticular protein RR-2, putative serotonin 5HT-7 receptor, calcium/calmodulin-dependent serine protein kinase, ubiquinol-cytochrome c reductase subunit 8, protein disulfide isomerase family A, ceramide synthetase, cuticular protein 1 in the CPLCA family, otopetrin, zinc finger protein, CTL-like protein 2, cytosolic carboxypeptidase 6, solute carrier family 19 (thiamine transporter), RING-type domain-containing protein, E3 ubiquitin-protein ligase TRIP12, glucosylgalactosylhydroxylysine glucosidase, Cytidine deaminase, ubiquitin-conjugating enzyme E2, and 2 unspecified products (Table 1).

Table 1 Hub Genes and Gene Descriptions of Anopheles gambiae Modules. The table presents the hub genes identified from each module of Anopheles gambiae, along with their corresponding gene descriptions

The hub genes identified in the modules for An. arabiensis encode CLIP serine protease, protein chiffon, Importin subunit alpha, glutathione S-transferase zeta class, cuticular protein RR-2, E3 ubiquitin-protein ligase RNF19A, neurexin, putative muscarinic acetylcholine receptor 1, an inhibitor of apoptosis, protein wings apart-like, coronin, sortilin-related receptor, slit protein, single-stranded DNA-binding protein 3, and six unspecified products (Table 2). Notably, serine protease, E3 ubiquitin-protein ligase, cuticular protein RR2, and leucine-rich immune protein were identified as hub genes in both species. We then conducted pairwise comparisons between resistant mosquitoes in Benin and Kenya and susceptible mosquito strains to assess the differential gene expression status of the identified hub genes (Fig. 7).

Table 2 Hub Genes and Gene Descriptions of Anopheles arabiensis Modules. The table presents the hub genes identified from each module of Anopheles arabiensis, along with their corresponding gene descriptions
Fig. 7
figure 7

Gene expression profiles of resistant An. arabiensis and An. gambiae from (A) Kenya and (B) Benin exposed to deltamethrin, primiphos-methyl and alphacypermethrin compared to the susceptible An. arabiensis Dongola strain and An. gambiae Kisumu strain, respectively. The horizontal dotted line on the volcano plot denotes a P-value of 0.01, while the vertical dotted lines indicate twofold expression differences

In An. gambiae populations, we conducted pairwise comparisons from two sites (Bassila and Djongou) in Benin. In Bassila, the BD vs. KIS comparison yielded 5207 differentially expressed genes, with 6 of the 24 hub genes {Cytidine deaminase (AGAP009489), Ubiquinol cytochrome c reductase (AGAP010337), Glyco_hydro_65m domain-containing protein (AGAP008548), Cuticular protein (AGAP006145), angiotensin-converting enzyme 9 (AGAP004563), and Serine/Threonine protein kinase (AGAP009784)} being significantly differentially expressed. Similarly, in the BP vs. KIS comparison, 5207 genes were differentially expressed, with the same hub genes differentially expressed in BD vs. KIS and 2 other hub genes [cuticular protein RR-2 (AGAP006369), 23.4 kDa salivary protein (AGAP008782)]. In Djougou, DD vs. KIS had 4107 DEGs, with five differentially expressed hub genes: {Cytidine deaminase (AGAP009489), Ubiquinol cytochrome c reductase (AGAP010337), Glyco_hydro_65m domain containing protein (AGAP008548), Cuticular protein (AGAP006145), and Cuticular protein (AGAP006369)}, and lastly, in DP vs. KIS comparison, we identified 5480 differentially expressed genes, with five differentially expressed hub genes: {Cuticular protein (AGAP006369), Ubiquinol cytochrome c reductase (AGAP010337), Glyco_hydro_65m domain-containing protein (AGAP008548), Ceramide synthetase (AGAP001761), and unspecified product (AGAP004444)}. In all An. gambiae groups, AGAP010337 and AGAP006369, encoding ubiquinol-cytochrome c reductase and cuticular protein RR-2, respectively, were significantly downregulated. Serine/Threonine Protein Kinase (AGAP009784) was upregulated in all Bassila groups.

Additionally, we did comparisons for An. arabiensis between two different sites: Siaya and Migori in Kenya. In the first set of comparisons, alphacypermethrin-resistant mosquitoes versus the Dongola susceptible strain (MA vs. DO), deltamethrin-resistant mosquitoes versus Dongola (MD vs. DO), and pirimiphos-methyl resistant mosquitoes versus Dongola (MP vs. DO) were compared in Migori. In the MP vs. DO comparison, we identified 6887 differentially expressed genes (DEGs) at FDR < 0.05, and among the 20 hub genes, 6 hub genes were downregulated with no upregulated hub gene. In the MA vs. DO comparison, we found 6512 DEGs, with only one unspecified protein (AARA016867) being upregulated and 6 downregulated hub genes, including protein chiffon (AARA000810), protein wings apart-like (AARA010271), Importin (AARA003983), cuticular protein RR-2 (AARA009171), and 2 unspecified products (AARA009424, AARA006322). In the MD vs. DO comparison, there were 4568 significantly differentially expressed genes; only unspecified protein (AARA006893) was upregulated, with 5 downregulated genes: {protein chiffon (AARA000810), protein wings apart-like (AARA010271), Importin (AARA003983), unspecified product (AARA009424), and cuticular protein RR-2 (AARA009171)}. Similarly, in Siaya, four hub genes {protein chiffon (AARA000810), protein wings apart-like (AARA010271), Importin (AARA003983), and unspecified product (AARA009424)} were downregulated in all Siaya comparisons, with no upregulation in SA vs. DO and SD vs. DO. The SP vs. DO comparison revealed two upregulated hub genes (serine protease (AARA015714) and unspecified protein (AARA006893)). Notably, AARA015848, encoding serine protease, and AARA001131, encoding cuticular protein, were significantly differentially expressed in most of the group comparisons.

Discussion

This study used a systems biology method, WCGNA, to identify hub genes associated with insecticide resistance in An. gambiae from Benin and An. arabiensis from Kenya. Overall, serine protease (AARA015848), cuticular protein (AARA001131), and serine/threonine-protein kinase (AGAP009784) genes were the most upregulated hub genes. Interestingly, chitin-binding protein (AGAP008548), cuticular protein (AGAP006369), carbonic anhydrase (AGAP010337), serine/threonine protein kinase (AGAP009784), serine protease (AARA015848), and cuticular protein (AARA001131) were differentially expressed in multiple group comparisons, indicating that they play an important role in insecticide resistance and are potential molecular markers for resistant phenotypes. This analysis allows the comprehension of the “coordinative” role of the hub genes in mediating insecticide resistance, pointing these to be potentially excellent markers for monitoring insecticide resistance or targets for insecticide delivery. Further functional validation needs to be conducted to confirm their role in conferring insecticide resistance. This study provides novel insights into the differential gene expression patterns of hub genes in resistant mosquito populations, highlighting them as potential molecular markers for insecticide resistance in two main species of malaria vectors.

Understanding the genetic basis and molecular mechanisms involved in insecticide resistance is crucial for developing effective vector control strategies by identifying the most relevant targets that can be exploited to increase the efficacy of malaria control and monitor insecticide resistance development. In this study, we took a novel approach by conducting weighted gene co-expression network analysis (WGCNA) on transcriptomic data to gain insights into the connectivity of the genetic determinants and molecular processes associated with insecticide resistance in An. gambiae and An. arabiensis. To our knowledge, this is the first time a WGCNA has been applied to insecticide resistance data to identify hub genes associated with insecticide resistance.

The hub genes identified in An. gambiae encode ras-related and estrogen-like proteins, Cyt c reductase, cuticular protein RR-2, sodium/hydrogen exchanger, synaptotagmin-1, and leucine-rich immune proteins. These proteins have been previously implicated in various biological processes and may play essential roles in insecticide resistance. Ras-related proteins are involved in signal transduction pathways, and their dysregulation and function in oxidative stress are associated with insect insecticide resistance mechanisms [28]. Estrogen-like proteins are implicated in insect development and reproduction, and their involvement in resistance may be attributed to dysregulated hormonal signaling [29]. Cytochrome C reductase plays a vital role in the electron transport chain and the generation of reactive oxygen species during stress, potentially affecting insecticide resistance mechanisms by modulating detoxification processes [30]. Cuticular proteins form the insect cuticle, and their upregulation promotes resistance by altering insecticide penetration [31,32,33]. Sodium/hydrogen exchangers and synaptotagmin-1 are associated with neuronal functions and synaptic vesicle release, indicating their potential involvement in neurophysiological changes associated with resistance [34, 35]. Synaptotagmin-1 is used as a target in a yeast-interfering RNA larvicide for controlling disease vector mosquitoes, indicating that it plays a role in resistance [36]. Leucine-rich immune proteins are involved in immune response, and their upregulation may be linked to immune-related resistance mechanisms [37].

The hub genes identified in An. arabiensis encode CLIP serine protease, RIMS-binding protein 2, GST zeta class, slit protein, E3 ubiquitin-protein ligase RNF19B-like, cysteine desulfurase, cuticular protein RR-2, and leucine-rich melanocyte differentiation-associated protein-like. CLIP serine protease is involved in the immune response and the formation of melanin in insects [38, 39], and its role in resistance can be attributed to altered immune mechanisms. RIMS-binding protein 2 is involved in neurotransmitter release and synaptic function [40], implying that it plays a potential role in neurophysiological changes associated with resistance. Glutathione S transferases, class Zeta, are part of the GST family, and several studies have demonstrated their role not only in insecticide detoxification processes but also in plasmodium infection in Anopheles and Aedes species [13, 41,42,43,44]. Slit protein is involved in axon guidance and may play a role in resistance-related neuronal adaptations. E3 ubiquitin-protein ligase RNF19B-like is involved in protein degradation pathways and may modulate the turnover of proteins associated with resistance mechanisms [45]. Transcriptomic analysis has shown that cuticular proteins and salivary gland proteins are implicated in insecticide resistance [26, 27, 46, 47]. Notably, we identified four hub genes, namely serine protease, E3 ubiquitin-protein ligase, cuticular protein RR2, and leucine-rich immune protein, shared between the two resistant Anopheles species, indicating the possibility of common resistance mechanisms across the two species.

The identified preserved modules in both An. gambiae and An. arabiensis, showing differential expression between susceptible and resistant samples, highlight the significant role of these modules in resistance. This emphasizes the need for deeper investigation into the specific genes within these modules to understand their functional contributions to resistance mechanisms. The hub genes within these preserved modules included zinc finger proteins, E3 ubiquitin protein ligase, angiotensin, calcium-dependent serine protein kinase, protein shifon, glutathione S transferase, and unspecified protein. Further, KEGG and GO analyses were conducted to provide insights into the functional relevance of these genes and molecular mechanisms associated with insecticide resistance in resistant Anopheles, as illustrated in Supplementary File 1. This integration of enrichment analysis with network analysis provided a comprehensive overview of the biological processes, cell organelles, and pathways associated with insecticide resistance in An. gambiae and An. arabiensis.

Enriched GO terms related to transmembrane processes indicate the importance of membrane transporters and channels in these resistant anopheles, especially with their role as pyrethroid targets [48]. The enrichment of immune response-related terms highlighted the involvement of immune pathways in resistant mosquitoes, indicating the activation of immune defense mechanisms in resistant species. Upregulation of immune genes in field mosquitoes due to exposure to different environmental bacteria, parasites, and viruses. To reduce this environmental effect on gene expression, these samples were reared in the laboratory to F0 generation and then exposed to insecticides. Therefore, we are still convinced that their overrepresentation in the network may be due to the insecticide exposure. Metabolic pathways were also enriched in the analyzed dataset, implying the potential role of metabolic adaptations in detoxification and resistance. The top enriched pathways included fatty acid degradation, signal transduction, DNA replication, ATP binding, and oxidative phosphorylation. This enrichment analysis, in conjunction with the existing literature, enabled us to get a step-by-step molecular mechanism of resistance at a cellular level, as illustrated in Fig. 5.

The intake of insecticides by mosquitoes involves several interconnected processes. First, odorants present in the environment permeate the mosquito cuticle and bind to Odorant Binding Proteins (OBPs). Odorant Receptor Neurons (ORNs) within the mosquito's sensory system recognize the bound odorants and trigger specific cellular responses [49]. These responses involve the activation of various receptors, including GPCRs, GABA receptors, and ion channels on the cell membrane, leading to activating signaling pathways. For example, the GABA receptor pathway involves the production of gamma-aminobutyric acid (GABA) and its subsequent signaling to the central nervous system [50]. Cellular gates and receptors facilitate the movement of ions in and out of the cell, regulating neuronal activity. The proteasome plays a significant role in insect resistance to insecticides by facilitating the breakdown and removal of insecticide-targeted proteins, enabling some insects to develop resistance mechanisms. Insects with increased proteasome activity can more efficiently degrade or detoxify insecticides, reducing their toxic effects and contributing to the development of insecticide resistance [51]. Mitochondria play a vital role in cellular energy production through the tricarboxylic acid (TCA) cycle and oxidative phosphorylation. The mosquito immune response can also be influenced by odorants, which can be captured by antigen-presenting cells (APCs) to induce an immune reaction. In summary, the intake of insecticides by mosquitoes involves a complex series of steps, including odorant binding, neuronal signaling, cellular responses, immune modulation, cellular metabolism, and gene regulation, which are crucial in the activity or detoxification of insecticides. These findings can provide a reference for developing new insecticides with higher efficacy and specificity and monitoring the emergence of resistance via key biological targets.

Conclusion

We performed weighted gene co-expression network analysis (WGCNA) and differential expression analysis to unravel the genetic determinants and molecular processes driving insecticide resistance in An. gambiae and An. arabiensis, providing key insights into the multifactorial nature of insecticide resistance. The identified hub genes can be used to understand the mechanisms that could be targeted to improve mosquito control. These genes are implicated in various biological functions, including signaling pathways and oxidative stress responses to immune defenses and nervous system adaptations, showing the complexity of the development of insecticide resistance at the molecular level. The discovery of shared hub genes between the two Anopheles species indicates that they may share some common mechanisms for resistance and can be used to develop strategies targeting both species. These findings provide a novel basis for analyzing and interpreting transcriptomic data associated with insecticide resistance.

Methods

Data acquisition

We retrieved RNA-Seq data on insecticide-resistant An. gambiae s.s. and An. arabiensis from the NCBI repository (SRA PRJNA986474 and PRJNA98270). The Genomics of African Vectors for NMCP Management of Insecticide Resistance (G-AVENIR) project generated the two datasets that aimed to identify molecular markers associated with insecticide resistance. The first dataset consisted of 17 resistant samples of An. gambiae collected from Benin {Djougou (9° 42′ 29.1312″ N and 1° 39′ 58.8672″ E) and Bassila (9° 0′ 23.0148″ N and 1° 39′ 50.1264″ E)} collected in August and October 2019 respectively, with each sample comprising a pool of 10 mosquitoes. These mosquitoes were phenotyped for resistance using CDC bottle bioassays to different insecticides (alphacypermethrin, deltamethrin, and pirimiphos methyl [52]. The second dataset consisted of 18 resistant samples of An. arabiensis collected from Kenya {Migori (1.0707° S, 34.4753° E) and Siaya (0.0626° N, 34.2878° E)} in August and October 2019, respectively, with each sample also comprising a pool of 10 mosquitoes. The mosquitoes in the second dataset were also phenotyped for resistance to the same insecticides as the Benin samples [53].The CDC bottle bioassay, sample processing, RNA extraction, and library preparation of the data utilized in this study are described in [26, 27]. We also added susceptible laboratory population data from the An. gambiae Kisumu strain and An. arabiensis Dongola datasets (SRA PRJNA986474 and PRJNA98270) for WGCNA and differential gene expression analysis.

Transcriptomic data processing and filtering

We initiated the RNA Pipeline as used by [52, 53] to assess the quality of the RNA-Seq raw reads using the FastQC (v0.11.5, [54]) software. To ensure the reliability of our data, we then used fastp (-l50,-q20,v0.20.1, [55]) software to eliminate low-quality reads and adaptor sequences. We then aligned the trimmed sequences to their respective reference genomes (An. gambiae (release 48), An. arabiensis Dongola (release 57)) from the Vectorbase database [56] using subjunc (v1.6.0, [57]). Subsequently, we subjected the resulting BAM files to post-alignment processing steps using samtools (v1.17, [58]) to remove duplicates, low mapping quality reads (-q 10), and unmapped reads (-F4) to have accurate and reliable results for downstream analysis. Next, we quantified the filtered and sorted mapped reads using FeatureCounts (v1.6.0, [59]) software. We excluded read counts that were below 10 and were present in over 80% of the dataset to minimize noise during correlation analysis. This step was essential for maintaining the robustness of our downstream analysis. We were interested in coding genes and their functional analysis, so we eliminated non-coding genes from the annotated gene count list.

Read count normalization

We normalized the An. gambiae and An. arabiensis read counts separately because they were from distinct investigations. We used the CalcNormFactors function in EdgeR (v3.14.0) [60] to compute normalization factors using the Trimmed Mean of M-Values (TMM) normalization method. After normalization, we constructed a dendrogram plot for the counts using hclust in R (v1.2.3) to identify outliers based on the distance matrix [61]. Only samples below cut heights of 500 and 80 for An. arabiensis and An. gambiae, respectively, were used for the WGCNA.

Construction of gene co-expression network

The normalized counts were utilized to construct a weighted gene co-expression network using the WGCNA R package version 1.72–1 (Langfelder & Horvath, [25]). We used the pickSoftThreshold function to determine the soft-thresholding power (β) and created a weighted adjacency matrix for a signed network type based on the β using the adjacency function. The matrix was then transformed into the Topological Overlap Matrix (TOM) using the TOM similarity function, and the TOM measure between gene pairs was utilized for average linkage hierarchical clustering (soft-power 18/20, mergeCutheight 0.25, minModuleSize 30, networktype signed). We then calculated the module-trait relationships by evaluating Pearson’s correlation between the eigengene of each module and the specific phenotype data (concentration of the insecticides, percent mortality, and percent survival, Supplementary 3) for the samples. Module eigengenes were calculated separately in each network using the moduleEigengenes functions in WGCNA. Module preservation statistics were calculated using the modulePreservation function in the WGCNA R package (nPermutations = 100, random seed = 1) by comparing the resistant sample network with the susceptible network [62]. Lastly, we identified the hub genes using the chooseTopHubInEachModule function (with a power of 4 and signed type) in WGCNA.

Differential gene expression analysis

To evaluate the differential expression status of the identified hub genes within the An. arabiensis and An. gambiae networks, we conducted a comprehensive differential gene expression analysis. This analysis involved a direct comparison between the expression levels of these hub genes in the resistant population (survivors after insecticide exposure) versus the susceptible population (Kisumu strain and Dongola for An. gambiae and An. arabiensis, respectively). We statistically assessed differential expression using the Likelihood-Ratios (LR) test implemented in edgeR. Genes were classified as differentially expressed if they exhibited a significant change in expression with a false discovery rate (FDR)-adjusted p-value less than 0.05, indicating a high confidence level in the results. Our particular focus was on hub genes that demonstrated a fold change exceeding two and satisfied the strict FDR criteria, as these genes were the most likely potential insecticide resistance markers.

Functional enrichment analysis and visualization

We conducted GO and KEGG pathway analysis using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) database [63] to understand the biological functions of the modules. We utilized Cytoscape to visualize the weighted gene co-expression networks for An. gambiae and An. arabiensis with default settings. An enrichment map, a Cytoscape [64] plug-in, was used to identify the enriched terms in a network. The molecular pathways associated with insecticide resistance phenotypes were illustrated using Bio-Render software [65].

Availability of data and materials

Sequence data used by this study is available at Sequence Read Archive (SRA) under the Bio Project accession number  PRJNA986474 and PRJNA98270. Custom scripts used for all the analysis are available from the primary author on request.Email:cynthiaawuor18@gmail.com.

References

  1. Malaria eradication: benefits, future scenarios & feasibility - World | ReliefWeb. 2020. https://reliefweb.int/report/world/malaria-eradication-benefits-future-scenarios-feasibility. Accessed 25 May 2023.

  2. Kenya - Malaria Indicator Survey 2020. https://microdata.worldbank.org/index.php/catalog/4188. Accessed 12 Oct 2023.

  3. Nicholas K, Bernard G, Bryson N, Mukabane K, Kilongosi M, Ayuya S, et al. Abundance and distribution of malaria vectors in various aquatic habitats and land use types in Kakamega County, Highlands of Western Kenya. Ethiop J Health Sci. 2021;31:247–56.

    PubMed  PubMed Central  Google Scholar 

  4. Kamau L, Bennett KL, Ochomo E, Herren J, Agumba S, Otieno S, et al. The Anopheles coluzzii range extends into Kenya: Detection, insecticide resistance profiles and population genetic structure in relation to conspecific populations in West and Central Africa. Res Sq. 2024;:rs.3.rs-3953608.

  5. First detection of Anopheles stephensi Liston. 1901 (Diptera: culicidae) in Ethiopia using molecular and morphological approaches. Acta Trop. 2018;188:180–6.

    Article  Google Scholar 

  6. Bhatt S, Weiss DJ, Cameron E, Bisanzio D, Mappin B, Dalrymple U, et al. The effect of malaria control on Plasmodium falciparum in Africa between 2000 and 2015. Nature. 2015;526:207–11.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  7. Ochomo E, Subramaniam K, Kemei B, Rippon E, Bayoh NM, Kamau L, et al. Presence of the knockdown resistance mutation, Vgsc-1014F in Anopheles gambiae and An. arabiensis in western Kenya. Parasit Vectors. 2015;8:616.

    Article  PubMed  PubMed Central  Google Scholar 

  8. Ondeto BM, Nyundo C, Kamau L, Muriu SM, Mwangangi JM, Njagi K, et al. Current status of insecticide resistance among malaria vectors in Kenya. Parasit Vectors. 2017;10:429.

    Article  PubMed  PubMed Central  Google Scholar 

  9. Salako AS, Ahogni I, Aïkpon R, Sidick A, Dagnon F, Sovi A, et al. Insecticide resistance status, frequency of L1014F Kdr and G119S Ace-1 mutations, and expression of detoxification enzymes in Anopheles gambiae (s.l.) in two regions of northern Benin in preparation for indoor residual spraying. Parasit Vectors. 2018;11:618.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  10. Silva APB, Santos JMM, Martins AJ. Mutations in the voltage-gated sodium channel gene of anophelines and their association with resistance to pyrethroids – a review. Parasit Vectors. 2014;7:450.

    Article  PubMed  PubMed Central  Google Scholar 

  11. Al-Yazeedi T, Muhammad A, Irving H, Ahn S-J, Hearn J, Wondji C. Overexpression and nonsynonymous mutations of UDP-glycosyltransferases potentially associated with pyrethroid resistance in Anopheles funestus. 2023.

    Google Scholar 

  12. Clarkson CS, Temple HJ, Miles A. The genomics of insecticide resistance: insights from recent studies in African malaria vectors. Curr Opin Insect Sci. 2018;27:111–5.

    Article  PubMed  PubMed Central  Google Scholar 

  13. Enayati AA, Ranson H, Hemingway J. Insect glutathione transferases and insecticide resistance. Insect Mol Biol. 2005;14:3–8.

    Article  CAS  PubMed  Google Scholar 

  14. Kusimo M, Mackenzie-Impoinvil L, Ibrahim S, Muhammad A, Irving H, Hearn J, et al. Pyrethroid resistance in the new world malaria vector Anopheles albimanus is mediated by cytochrome P450 CYP6P5. Pestic Biochem Physiol. 2022;183:105061.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  15. Menze B, Tchouakui M, Mugenzi L, Tchapga Kamga W, Tchoupo M, Wondji M, et al. Marked aggravation of pyrethroid resistance in major malaria vectors in Malawi between 2014 and 2021 is partly linked with increased expression of P450 alleles. BMC Infect Dis. 2022;22(1):660.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  16. Ochomo E, Bayoh MN, Brogdon WG, Gimnig JE, Ouma C, Vulule JM, et al. Pyrethroid resistance in Anopheles gambiae s.s. and Anopheles arabiensis in western Kenya: phenotypic, metabolic and target site characterizations of three populations. Med Vet Entomol. 2013;27:156–64.

    Article  CAS  PubMed  Google Scholar 

  17. Wondji C, Hearn J, Irving H, Wondji M, Weedall G. RNAseq-based gene expression profiling of the Anopheles funestus pyrethroid resistant strain FUMOZ highlights the predominant role of the duplicated CYP6P9a/b cytochrome P450s. G3-Genes Genomes Genet. 2021;12:12.

    Google Scholar 

  18. Yvan Gaëtan F, TENE B, Mugenzi L, Wondji M, Njiokou F, Ranson H, et al. Genetic diversity of cytochrome P450s CYP6M2 and CYP6P4 associated with pyrethroid resistance in the major malaria vectors Anopheles coluzzii and Anopheles gambiae from Yaoundé, Cameroon. 2022.

    Google Scholar 

  19. Balabanidou V, Grigoraki L, Vontas J. Insect cuticle: a critical determinant of insecticide resistance. Curr Opin Insect Sci. 2018;27:68–74.

    Article  PubMed  Google Scholar 

  20. Wood OR, Hanrahan S, Coetzee M, Koekemoer LL, Brooke BD. Cuticle thickening associated with pyrethroid resistance in the major malaria vector Anopheles funestus. Parasit Vectors. 2010;3:67.

    Article  PubMed  PubMed Central  Google Scholar 

  21. Dada N, Sheth M, Liebman K, Pinto J, Lenhart A. Whole metagenome sequencing reveals links between mosquito microbiota and insecticide resistance in malaria vectors. Sci Rep. 2018;8:2084.

    Article  PubMed  PubMed Central  Google Scholar 

  22. Omoke D, Kipsum M, Otieno S, Esalimba E, Sheth M, Lenhart A, et al. Western Kenyan Anopheles gambiae showing intense permethrin resistance harbour distinct microbiota. Malar J. 2021;20:77.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  23. Lucas ER, Nagi SC, Egyir-Yawson A, Essandoh J, Dadzie S, Chabi J, et al. Genome-wide association studies reveal novel loci associated with pyrethroid and organophosphate resistance in Anopheles gambiae and Anopheles coluzzii. Nat Commun. 2023;14:4946.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  24. Yu D, Lim J, Wang X, Liang F, Xiao G. Enhanced construction of gene regulatory networks using hub gene information. BMC Bioinformatics. 2017;18:186.

    Article  PubMed  PubMed Central  Google Scholar 

  25. Langfelder P, Horvath S. WGCNA: an R package for weighted correlation network analysis. BMC Bioinformatics. 2008;9:559.

    Article  PubMed  PubMed Central  Google Scholar 

  26. Omoke D, Impoinvil LM, Derilus D, Okeyo S, Saizonou H, Mulder N, et al. Whole transcriptomic analysis reveals overexpression of salivary gland and cuticular proteins genes in insecticide-resistant Anopheles arabiensis from Western Kenya. BMC Genomics. 2024;25:313.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  27. Saizonou H, Impoinvil LM, Derilus D, Omoke D, Okeyo S, Dada N, et al. Transcriptomic analysis of Anopheles gambiae from Benin reveals overexpression of salivary and cuticular proteins associated with cross-resistance to pyrethroids and organophosphates. BMC Genomics. 2024;25:348.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  28. Olson MF, Marais R. Ras protein signalling. Semin Immunol. 2000;12:63–73.

    Article  CAS  PubMed  Google Scholar 

  29. Insect - Social Behavior, Colonies, Communication | Britannica. https://www.britannica.com/animal/insect/Role-of-hormones. Accessed 16 Jul 2023.

  30. Zhao R-Z, Jiang S, Zhang L, Yu Z-B. Mitochondrial electron transport chain, ROS generation and uncoupling (Review). Int J Mol Med. 2019;44:3–15.

    CAS  PubMed  PubMed Central  Google Scholar 

  31. Xu Y, Xu J, Zhou Y, Li X, Meng Y, Ma L, et al. CPR63 promotes pyrethroid resistance by increasing cuticle thickness in Culex pipiens pallens. Parasit Vectors. 2022;15:54.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Yahouédo GA, Chandre F, Rossignol M, Ginibre C, Balabanidou V, Mendez NGA, et al. Contributions of cuticle permeability and enzyme detoxification to pyrethroid resistance in the major malaria vector Anopheles gambiae. Sci Rep. 2017;7:11091.

    Article  PubMed  PubMed Central  Google Scholar 

  33. Zhu J-Y, Li L, Xiao K-R, He S-Q, Gui F-R. Genomic and transcriptomic analysis reveals cuticular protein genes responding to different insecticides in fall armyworm spodoptera frugiperda. Insects. 2021;12:997.

    Article  PubMed  PubMed Central  Google Scholar 

  34. Bacaj T, Wu D, Burré J, Malenka RC, Liu X, Südhof TC. Synaptotagmin-1 and -7 are redundantly essential for maintaining the capacity of the readily-releasable pool of synaptic vesicles. PLOS Biol. 2015;13:e1002267.

    Article  PubMed  PubMed Central  Google Scholar 

  35. Moffett DF, Onken H. The cellular basis of extreme alkali secretion in insects: a tale of two tissues. In: Gerencser GA, editor. Epithelial transport physiology. Totowa, NJ: Humana Press; 2010. p. 91–112.

    Chapter  Google Scholar 

  36. Mysore K, Li P, Wang C-W, Hapairai LK, Scheel ND, Realey JS, et al. Characterization of a yeast interfering RNA larvicide with a target site conserved in the synaptotagmin gene of multiple disease vector mosquitoes. PLoS Negl Trop Dis. 2019;13:e0007422.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  37. Ng A, Xavier RJ. Leucine-rich repeat (LRR) proteins. Autophagy. 2011;7:1082–4.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  38. Kanost MR, Jiang H. Clip-domain serine proteases as immune factors in insect hemolymph. Curr Opin Insect Sci. 2015;11:47–55.

    Article  PubMed  PubMed Central  Google Scholar 

  39. Moussawi LE, Nakhleh J, Kamareddine L, Osta MA. The mosquito melanization response requires hierarchical activation of non-catalytic clip domain serine protease homologs. PLOS Pathog. 2019;15:e1008194.

    Article  PubMed  PubMed Central  Google Scholar 

  40. Mittelstaedt T, Alvarez-Baron E. RIM proteins and their role in synapse function. Biol Chem. 2010;391:599–606.

    Article  CAS  PubMed  Google Scholar 

  41. Nouage L, Elanga-Ndille E, Binyang A, Tchouakui M, Atsatse T, Ndo C, et al. Influence of GST- and P450-based metabolic resistance to pyrethroids on blood feeding in the major African malaria vector Anopheles funestus. PLoS ONE. 2020;15:e0230984.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  42. Tchouakui M, Chiang M-C, Ndo C, Kuicheu CK, Amvongo-Adjia N, Wondji MJ, et al. A marker of glutathione S-transferase-mediated resistance to insecticides is associated with higher Plasmodium infection in the African malaria vector Anopheles funestus. Sci Rep. 2019;9:5772.

    Article  PubMed  PubMed Central  Google Scholar 

  43. Muleya V, Hayeshi R, Ranson H, Abegaz B, Bezabih M-T, Robert M, et al. Modulation of Anopheles gambiae Epsilon glutathione transferase activity by plant natural products in vitro. J Enzyme Inhib Med Chem. 2008;23:391–9.

    Article  CAS  PubMed  Google Scholar 

  44. Tao F, Si F-L, Hong R, He X, Li X-Y, Qiao L, et al. Glutathione S-transferase (GST) genes and their function associated with pyrethroid resistance in the malaria vector Anopheles sinensis. Pest Manag Sci. 2022;78:4127–39.

    Article  CAS  PubMed  Google Scholar 

  45. de Bie P, Ciechanover A. Ubiquitination of E3 ligases: self-regulation of the ubiquitin system via proteolytic and non-proteolytic mechanisms. Cell Death Differ. 2011;18:1393–402.

    Article  PubMed  PubMed Central  Google Scholar 

  46. Messenger LA, Impoinvil LM, Derilus D, Yewhalaw D, Irish S, Lenhart A. A whole transcriptomic approach provides novel insights into the molecular basis of organophosphate and pyrethroid resistance in Anopheles arabiensis from Ethiopia. Insect Biochem Mol Biol. 2021;139:103655.

    Article  CAS  PubMed  Google Scholar 

  47. Vijay S, Rawal R, Kadian K, Raghavendra K, Sharma A. Annotated differentially expressed salivary proteins of susceptible and insecticide-resistant mosquitoes of anopheles stephensi. PLoS ONE. 2015;10:e0119666.

    Article  PubMed  PubMed Central  Google Scholar 

  48. Silver KS, Du Y, Nomura Y, Oliveira EE, Salgado VL, Zhorov BS, et al. Voltage-gated sodium channels as insecticide targets. Adv Insect Physiol. 2014;46:389–433.

    Article  Google Scholar 

  49. Venthur H, Zhou J-J. Odorant receptors and odorant-binding proteins as insect pest control targets: a comparative analysis. Front Physiol. 2018;9:1163.

    Article  PubMed  PubMed Central  Google Scholar 

  50. Allen MJ, Sabir S, Sharma S. GABA receptor. In: StatPearls. Treasure island (FL): StatPearls Publishing; 2023.

  51. Amezian D, Nauen R, Le Goff G. Transcriptional regulation of xenobiotic detoxification genes in insects - an overview. Pestic Biochem Physiol. 2021;174:104822.

    Article  CAS  PubMed  Google Scholar 

  52. Transcriptomic analysis of Anopheles gambiae from Benin reveals overexpression of salivary and cuticular proteins associated with cross-resistance to pyrethroids and organophosphates. 2023. https://www.researchsquare.com. Accessed 15 Oct 2023.

  53. Whole transcriptomic analysis reveals overexpression of salivary gland and cuticular proteins genes in insecticide-resistant Anopheles arabiensis from Western Kenya. 2023. https://www.researchsquare.com. Accessed 15 Oct 2023.

  54. Andrew S. Babraham Bioinformatics - FastQC A Quality Control tool for High Throughput Sequence Data. 2010. https://www.bioinformatics.babraham.ac.uk/projects/fastqc/. Accessed 7 Nov 2023.

  55. Chen S, Zhou Y, Chen Y, Gu J. fastp: an ultra-fast all-in-one FASTQ preprocessor. Bioinformatics. 2018;34:i884–90.

    Article  PubMed  PubMed Central  Google Scholar 

  56. Giraldo-Calderón GI, Emrich SJ, MacCallum RM, Maslen G, Dialynas E, Topalis P, et al. VectorBase: an updated bioinformatics resource for invertebrate vectors and other organisms related with human diseases. Nucleic Acids Res. 2015;43:D707–13.

    Article  PubMed  Google Scholar 

  57. Liao Y, Smyth GK, Shi W. The Subread aligner: fast, accurate and scalable read mapping by seed-and-vote. Nucleic Acids Res. 2013;41:e108.

    Article  PubMed  PubMed Central  Google Scholar 

  58. Li H, Handsaker B, Wysoker A, Fennell T, Ruan J, Homer N, et al. The sequence alignment/map format and SAMtools. Bioinforma Oxf Engl. 2009;25:2078–9.

    Article  Google Scholar 

  59. Liao Y, Smyth GK, Shi W. featureCounts: an efficient general purpose program for assigning sequence reads to genomic features. Bioinforma Oxf Engl. 2014;30:923–30.

    Article  CAS  Google Scholar 

  60. Robinson MD, McCarthy DJ, Smyth GK. edgeR: a Bioconductor package for differential expression analysis of digital gene expression data. Bioinformatics. 2010;26:139–40.

    Article  CAS  PubMed  Google Scholar 

  61. Müllner D. fastcluster: fast hierarchical, agglomerative clustering routines for R and python. J Stat Softw. 2013;53:1–18.

    Article  Google Scholar 

  62. Langfelder P, Luo R, Oldham MC, Horvath S. Is my network module preserved and reproducible? PLOS Comput Biol. 2011;7:e1001057.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  63. Sherman BT, Hao M, Qiu J, Jiao X, Baseler MW, Lane HC, et al. DAVID: a web server for functional enrichment analysis and functional annotation of gene lists (2021 update). Nucleic Acids Res. 2022;50:W216–21.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  64. Shannon P, Markiel A, Ozier O, Baliga NS, Wang JT, Ramage D, et al. Cytoscape: a software environment for integrated models of biomolecular interaction networks. Genome Res. 2003;13:2498–504.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  65. BioRender. https://app.biorender.com/biorender-templates. Accessed 10 Aug 2023.

Download references

Acknowledgements

We would like to express our heartfelt gratitude to all individuals and organizations whose contributions and support have been invaluable in successfully completing this research. Our profound gratitude goes to the Kenya and Benin teams for their invaluable assistance in sharing their data with us for the analysis.Additionally,we gratefully acknowledge the KEMRI Director General for his permission to publish this work.

Disclaimer

The findings and conclusions in this paper are those of the authors and do not necessarily represent the official position of the CDC.

Funding

This work was supported by the Bill and Melinda Gates Foundation, Grand Challenges Grant No. INV024969, and Investment Grant OPP1210769.

Author information

Authors and Affiliations

Authors

Contributions

EO, LD, AL, ND, LI, NM, SN,DN and CAO: conceptualization of the study, methodology design, data analysis, as well as drafting and revising the manuscript. CAO, DO, DD, DN, SN, HS and SO: development of RNAseq pipeline, data analysis, interpretation and validation as well as drafting and revising the manuscript.

Corresponding author

Correspondence to Cynthia Awuor Odhiambo.

Ethics declarations

Ethics approval and consent to participate

Approval for this study was granted by the Kenya Medical Research Institute (KEMRI) Scientific Ethics Review Unit Steering Committee (SERU).

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Odhiambo, C.A., Derilus, D., Impoinvil, L.M. et al. Key gene modules and hub genes associated with pyrethroid and organophosphate resistance in Anopheles mosquitoes: a systems biology approach. BMC Genomics 25, 665 (2024). https://doi.org/10.1186/s12864-024-10572-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1186/s12864-024-10572-z

Keywords