Transcripts of the malaria vector Anopheles gambiae that are differentially regulated in the midgut upon exposure to invasive stages of Plasmodium falciparum

Understanding the interactions between the most deadly malaria parasite, Pl asmodium falciparum, and its main vector, Anopheles gambiae, would be of gr eat help in developing new malaria control strategies. The malaria parasite undergoes several developmental transitions in the mosquito midgut and suf fers population losses to which mosquito factors presumably contribute. To identify such factors, we analysed An. gambiae midgut transcripts whose exp ression is regulated upon ingestion of invasive or non-invasive forms of P. falciparum using a differential display approach. Sixteen cDNA were studie d in detail; 12 represent novel genes of An. gambiae including a gene encod ing profilin. Four transcripts were specifically regulated by P. falciparum gametocytes (invasive forms), whereas the others were regulated by either non-invasive or both non-invasive and invasive forms of the parasite. This differential regulation of some genes may reflect the adaptation of P. falc iparum to its natural vector. These genes may be involved in the developmen t of P. falciparum in An. gambiae or in the defence reaction of the mosquit o midgut towards the parasite.