Abstract
ABSTRACTDrosophila homologue of the EGF receptor (DER) is like mammalian epidermal growth factor (EGF) receptor. It is a member of receptor tyrosine kinase (RTK) family. DER signal pathway plays an important role in eye development and wing development. P line stock are mutants by P element inserted in special genes. To identify novel components in the DER pathway, we used a gain-of-function allele, ElpB1, to carry out genetic modifier screen in P line stock. Several dominant enhancers were isolated, and then genetic tests were used to distinguish these dominant enhancers. Some of these mutant genes appear to be participated in eye development, four (gsb, CG2162, ppl, and an unknown gene)seem to be more specific for photoreceptor development. When Gsb protein is ectopic expressed in the third laval stage, it interacts genetically with Egfr, Ras,MAPK .These results are expected to have the opposite effect on gsb01155 ； the coding sequence of Gsb contains one consensus MAPK phosphorylated sites. CG2162 interacts genetically with Argos, Egfr, Ras,Raf, MEK, MAPK . The sequence of CG2162 protein contains two consensus MAPK phosphorylation sites and an NLS domain. Based on these data, we suggest that gsb and CG2162 might be directing phosphorylated in response to activation of the Ras 1/MAPK or parallel of it.