The Mdm2 proto-oncogene is amplified and over-expressed in a variety of tumors. 
One of the major functions of Mdm2 described to date is its ability to modulate 
the levels and activity of the tumor suppressor protein p53. Mdm2 binds to the 
N-terminus of p53 and, through its action as an E3 ubiquitin ligase, targets p53 
for rapid proteasomal degradation. Mdm2 can also bind to other cellular proteins 
such as hNumb, E2F1, Rb and Akt; however, the biological significance of these 
interactions is less clear. To gain insight into the function of Mdm2 in vivo, 
we have generated a transgenic Drosophila strain bearing the mouse Mdm2 gene. 
Ectopic expression of Mdm2, using the UAS/GAL4 system, causes eye and wing 
phenotypes in the fly. Analysis of wing imaginal discs from third instar larvae 
showed that expression of Mdm2 induces apoptosis. Crosses did not reveal genetic 
interactions between Mdm2 and the Drosophila homolog of E2F, Numb and Akt. These 
transgenic flies may provide a unique experimental model for exploring the 
molecular interactions of Mdm2 in a developmental context.