D3203: Transcriptomic and functional genomic analysis identifies mosquito genes modulating Plasmodium falciparum development

Malaria remains a global health challenge, with transmission of malaria parasites to humans primarily mediated by Anopheles mosquitoes infected with Plasmodium falciparum. Understanding the molecular interactions between the parasite and its mosquito vector is critical for developing innovative control strategies. We performed RNA-seq–based whole-transcriptome profiling of Anopheles gambiae midguts and carcasses 24 h post-infection with P. falciparum (human malaria parasite) or P. berghei (rodent malaria). Comparative R-based analysis revealed mosquito transcripts with both conserved and species-specific responses. Upregulated genes in the mosquito midgut displayed broadly similar functional profiles for P. falciparum and P. berghei, indicating shared early midgut epithelial responses to invasion by both parasites. Among them, 18 genes — either strongly regulated specifically by P. falciparum or commonly by both parasite species — were selected for functional validation. Functional genomics studies were performed by RNAi-mediated gene silencing: gene-specific primers were designed for dsRNA synthesis, the resulting dsRNAs were injected into 3-d-old adult A. gambiae, followed by P. falciparum infection using standard membrane feeding assays and oocyst quantification at 8 days post-infection. Results showed that silencing four genes, including the gene ACYL,Tsf1,ABCC, and TEP15, significantly reduced P. falciparum oocyst load, whereas silencing two genes, HPX8 and STER, significantly increased oocyst numbers, consistent with host-restrictive and host-facilitative roles, respectively. These results provide functional evidence that infection-responsive mosquito genes modulate parasite development in the vector. Furthermore, they highlight novel candidate genes that may serve as targets for transmission-blocking interventions, offering promising opportunities for innovative vector control strategies.