The Genetic Basis of Natural Variation in Drosophila melanogaster Immune Defense against Enterococcus faecalis

Dissecting the genetic basis of natural variation in disease response in hosts provides insights into the coevolutionary dynamics of host-pathogen interactions. Here, a genome-wide association study of survival after infection with the Gram-positive entomopathogenic bacterium is reported. There was considerable variation in defense against infection among inbred lines of the Genetics Reference Panel. We identified single nucleotide polymorphisms associated with six genes with a significant ( < 10 , corresponding to a false discovery rate of 2.4%) association with survival, none of which were canonical immune genes. To validate the role of these genes in immune defense, their expression was knocked-down using RNAi and survival of infected hosts was followed, which confirmed a role for the genes and in immune defense. We further identified a putative role for the Bomanin gene (also known as ), in infection response. This study adds to the growing set of association studies for infection in and suggests that the genetic causes of variation in immune defense differ for different pathogens.