Cloning and analysis of a cecropin gene from the malaria vector mosquito, Anopheles gambiae

Parasites of the genus Plasmodium are transmitted to mammalian hosts by ano pheline mosquitoes. Within the insect vector, parasite growth and developme nt are potentially limited by antimicrobial defence molecules. Here, we des cribe the isolation of cDNA and genomic clones encoding a cecropin antibact erial peptide from the malaria vector mosquito Anopheles gambiae. The locus was mapped to polytene division 1C of the X chromosome. Cecropin RNA was i nduced by infection with bacteria and Plasmodium. RNA levels varied in diff erent body parts of the adult mosquito. During development, cecropin expres sion was limited to the early pupal stage. The peptide was purified from bo th adult mosquitoes and cell culture supernatants. Anopheles gambiae synthe tic cecropins displayed activity against Gram-negative and Gram-positive ba cteria, filamentous fungi and yeasts.