Promoter sequences of the putative Anopheles gambiae apyrase confer salivary gland expression in Drosophila melanogaster

The saliva of blood-feeding arthropods contains an apyrase that facilitates hematophagy by inhibiting the ADP-induced aggregation of the host platelet s, We report here the isolation of a salivary gland-specific cDNA encoding a secreted protein that likely represents the Anopheles grambiae apyrase, W e describe also two additional members of the apyrase/5'-nucleotidase famil y, The cDNA corresponding to the AgApyL1 gene encodes a secreted protein th at is closely related in sequence to the apyrase of the yellow fever mosqui to, Aedes aegypti, and whose expression appears enriched in, but not restri cted to, female salivary glands, The AgApyL2 gene was found searching an A. gambiae data base, and its expression is restricted to larval stages. We i solated the gene encoding the presumed A. gambiae apyrase (AgApy) and we te sted its putative promoter for the tissue-specific expression of the LacZ g ene from Escherichia coli in transgenic Drosophila melanogaster. All the tr ansgenic lines analyzed showed a weak but unambiguous staining of the adult glands, indicating that some of the salivary gland-specific transcriptiona l regulatory elements: are conserved between the malaria mosquito and the f ruit fly. The availability of salivary gland-specific promoters may be usef ul both for studies on vector-parasite interactions and, potentially, for t he targeted tissue-specific expression of anti-parasite genes in the mosqui to.