Abstract
Epidermal growth factor (EGF) receptor plays an important role to the differentiation of cells in the Drosophila development, DER including eye development and wing vein formation. To identify novel components in the DER pathway, we use a gain-of-function DER allele, ElpB1, to carry out genetic modifier screen. We found that Df(2L)H20/C(36A8-36E2) enhance the rough eye and extra vein phenotypes of ElpB1. Two P elements, P754 and P769, are included in this deficiency. P754 and p769 homozygotes are viable with WT eye, but exhibit extra wing vein in the CV-P. P754 can suppress the rough eye phenotype caused by HS-argos, and enhances the R7 production in sevE4/Y；Sos Jc2/＋ background. Together, this indicates that P754 is involved in eye development. In addition, P754 enhances the extra vein phenotype of rlsem, indicating that P754 is involved in wing vein specification. According to our genetic epistasis, P754 and P769 are downstream of Ras, Raf, MEK or in a parallel pathway. P754 has vague genetic interactions with MAPK, yan, pnt, ed, and sina. We perform inverse PCR to clone the flanking genomic DNA of P754, and use it to search EST clone. We got three clones with 3.4Kb. It encodes a protein of 809 amino acids, with a Leucine-rich repeat at the N terminal, and a calponin homology (CH) domain at the C terminal.