Supplementary Material for: Short-Form Bomanins Mediate Humoral Immunity in <b><i>Drosophila</i></b>

2018-06-19T09:13:21Z (GMT) by Lindsay S.A. Lin S.J.H. Wasserman S.A.
The Bomanins (Boms) are a family of a dozen secreted peptides that mediate the innate immune response governed by the <i>Drosophila</i> Toll receptor. We recently showed that deleting a cluster of 10 <i>Bom</i> genes blocks Toll-mediated defenses against a range of fungi and gram-positive bacteria. Here, we characterize the activity of individual Bom family members. We provide evidence that the Boms overlap in function and that a single <i>Bom</i> gene encoding a mature peptide of just 16 amino acids can act largely or entirely independent of other family members to provide phenotypic rescue in vivo. We further demonstrate that the <i>Boms</i> function in <i>Drosophila</i> humoral immunity, mediating the killing of the fungal pathogen <i>Candida glabrata</i> in an in vitro assay of cell-free hemolymph. In addition, we find that the level of antifungal activity both in vivo and in vitro is linked to the level of <i>Bom</i> gene expression. Although Toll dictates expression of the antimicrobial peptides (AMPs) drosomycin and metchnikowin, we find no evidence that Boms act by modifying the expression of the mature forms of these antifungal AMPs.