Human epidermal growth factor receptor (EGFR) has been implicated in multiple cancers of epithelial derivation. EGFR is a transmembrane receptor kinase that spans the cell membrane and is activated by a number of external ligands, including EGF and transforming growth factor α. Activation of EGFR initiates several signal transduction cascades, leading to DNA synthesis and cell proliferation. There is one orthologous gene in flies, Dmel\Egfr, for which classical amorphic and hypomorphic alleles, constitutively active alleles, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated. Dmel\Egfr is orthologous to three additional human genes, ERBB4, ERBB3 and ERBB2; ERBB2 has also been implicated in multiple cancers.
Amorphic mutations of Dmel\Egfr act as recessive embryonic lethals; they also act as cell lethals in somatic clones. Hypermorphic (gain-of-function) alleles exhibit dominant visible phenotypes. Egfr overexpression in imaginal disc epithelial cells leads to mild overproliferation phenotypes; the mild phenotype has been exploited to screen for enhancement by interacting genes. A transgenic allele that is constitutively active (FBal0065871) has also been used in this disease model. Extensive physical and genetic interactions have been described; see below and in the gene report for Egfr.
The human gene Hsap\EGFR has been introduced into flies, using a mutant form that displays constitutive kinase activity and can be expressed in specific tissues using the GAL4-UAS system. Constructs of Hsap\EGFR have been used for human disease models of malignant glioma (FBhh0000399, FBhh0000401, FBhh0000403).
[updated Dec. 2018 by FlyBase; FBrf0222196]