Expression and evolution of the Drosophila Attacin/Diptericin gene family

We describe the genes for three new glycine-rich antimicrobial peptides in Drosophila, two attacins (AttC and AttD) and one diptericin (DptB). Their s tructures support the proposal that these glycine-rich antimicrobial peptid es evolved from a common ancestor and are probably also related to proline- rich peptides such as drosocin. AttC is similar to the nearby AttA and AttB genes. AttD is more divergent and located on a different chromosome. intri guingly, AttD may encode an intracellular attacin. DptB is linked in tandem to the closely related Diptericin. However, the DptB gene product contains a furin-like cleavage site and may be processed in an attacin-like fashion . All attacin and diptericin genes are induced after bacterial challenge. T his induction is reduced in imd mutants, and unexpectedly also in Tl- mutan ts. The 18w mutation particularly affects the induction of AttC, which may be a useful marker for 18w signaling. (C) 2000 Academic Press.