Figure 3
From: Molecular architecture of the fruit fly's airway epithelial immune system
Signal transduction pathways in the airway epithelia. Among the 4 signal transduction pathways relevant for the innate immune response of the fly, only the Toll-pathway is not represented by all vital members (A, E). In opposite, the other pathway that terminates into activation of NF-kB factors, the IMD-pathway, is functional, because all corresponding genes are expressed (B, E). The JNK-pathway should also be functional because all relevant members are present (C). JAK/STAT signalling depends only on a very limited number of genes. The complete set of genes required for its activation is expressed in the airways (D). In addition, JAK/STAT-signalling can be visualized in the terminal tracheal structures using a STAT::gfp reporter system (F, 19).