Recent genomic analyses of arthropod defense mechanisms suggest conservation of key elements
underlying responses to pathogens, parasites and stresses. At the center of pathogen-induced immune responses
are signaling pathways triggered by the recognition of fungal, bacterial and viral signatures. These pathways result
in the production of response molecules, such as antimicrobial peptides and lysozymes, which degrade or destroy
invaders. Using the recently sequenced genome of the pea aphid (Acyrthosiphon pisum), we conducted the first
extensive annotation of the immune and stress gene repertoire of a hemipterous insect, which is phylogenetically
distantly related to previously characterized insects models.