Meeting Abstract
The EGF pathway is a conserved and ubiquitously used cell signaling cascade in animal development. In the highly studied insect Drosophila melanogaster, four ligands (Vein, Gurken, Spitz and Keren) are used to activate the pathway, and the protein Argos represses activation of the EGF pathway by binding to the EGF receptor. An arthropod-centered phylogenetic analysis showed that the genes encoding the ligands Vein and Argos were present in the last common ancestor of all arthropods. However, this analysis showed the genes encoding Gurken evolved in the last common ancestor of the Diptera, the clade including flies. Our analysis also provides evidence that spitz and Keren are the result of a gene duplication event in the Tephritid flies. In an attempt to determine the ancestral role of the spitz/Keren gene in the context of insect development, we used RNA interference targeting the orthologues of the genes in two separate lineages, Orthoptera and Hemiptera. These lineages are represented by the cricket Gryllus bimaculatus and the milkweed bug Oncopeltus fasciatus respectively.
