Genome-Wide Transcriptional Analysis and Functional Validation Linked a Cluster of Epsilon Glutathione S-Transferases with Insecticide Resistance in the Major Malaria Vector Anopheles funestus across Africa

Resistance is threatening the effectiveness of insecticide-based interventions in use for malaria control. Pinpointing genes associated with resistance crucial evidence-based management targeting major vectors. Here, a combination RNA-seq based genome-wide transcriptional analysis and RNA-silencing vivo functional validation were used to identify key insecticide DDT DDT/permethrin cross-resistance across Africa. A cluster glutathione-S-transferase from epsilon group found be overexpressed resistant populations Anopheles funestus Africa including GSTe1 [Cameroon (fold change, FC: 2.54), Ghana (4.20), Malawi (2.51)], GSTe2 (4.47), (7.52), (2.13)], GSTe3 (2.49), Uganda (2.60)], GSTe4 (3.47), GSTe5 [Ghana (2.94), (2.26)], GSTe6 [Cameroun (3.0), (3.11), (3.07), (3.78)] GSTe7 (2.39) Ghana. Validation GSTe expression profiles by qPCR confirmed that are differentially expressed greater overexpression DDT-resistant mosquitoes. RNAi-based knock-down analyses supported five playing role pyrethroids (permethrin deltamethrin) An. funestus, significant recovery susceptibility observed when GSTe2, 3, 4, 5 silenced. These findings established GSTe3, 6 contribute should further characterized their specific genetic variants, help design DNA-based diagnostic assays, as previously done 119F-GSTe2 mutation. This study highlights GSTes development insecticides vectors calls actions mitigate this resistance.