The role of Drosophila antifungal immune response genes in intestinal homeostasis

The signaling pathways that control intestinal development, regeneration and disease show a high degree of conservation between Drosophila and mammals. The gut epithelia of Drosophila provide protection against invasion of microorganisms through production of reactive oxygen species (ROS) and antimicrobial peptides (AMPs). Although Drosophila gut immunity has been extensively studied, the specific responses to Gram-positive bacteria, fungi and toxic compounds are not fully understood. To identify the physiological role of genes involved in host defense we studied Drosophila mutants in antifungal genes identified previously and tested their survival upon feeding with various pathogens and toxic compounds. The results showed that several mutants displayed decreased viability compared with wild-type flies, and the lower survival rates were attributed to morphological change and excessive cell death in mutant guts. Thus, we identified several new Drosophila genes (spen, jumeau, inv, DDB1 and shg) required for intestinal homeostasis or stress responses