Effector specificity and function in Drosophila innate immunity: Getting AMPed and dropping Boms

[...]researchers have characterized novel and essential effectors, rewritten the individual and collective roles of antimicrobial peptides, and identified stochastic variation and persistent infection as common features of microbial infection. [...]many belong to gene families, potentially minimizing the loss-of-function phenotype for an individual gene mutation. [...]immune mutant screens have typically assayed for loss of reporter gene activation and thus identified lesions only in genes upstream of effector induction [see, e.g., 11,12]. In the case of the Imd pathway, flies simultaneously deleted for the majority of induced AMP genes are as susceptible to gram-negative bacteria as those lacking all pathway function [14]. [...]for many gram-negative bacteria, individual gene disruption is without consequence, supporting the idea that organisms express sets of AMPs that overlap in specificity and function (Fig 1C).