In wild type flies, the imaginal discs, which are folded epithelial monolayer structures, differentiate during metamorphosis at the pupal stage into their respective adult structures of the head, thorax and genitalia.
Drosophila tumors share several characteristics with malignant neoplasms in vertebrates.
These include cellular hyperproliferation and defects in differentiation, but most strikingly they form invasive, lethal tumors when transplanted in an unaffected animal. The prototypical DnaK and DnaJ proteins were identified in E. coli where their mutations caused defective replication of bacteriophage lambda. Once bound, they then recruit the DnaK component, activate its ATPase activity and transfer the substrate to form a functional chaperone complex. Apoptosis is a tightly controlled, energy dependent process, and mitochondrial function which provides the bulk of the cellular energy in the form of ATP, is maintained during apoptosis . Under conditions of high ATP levels, cells undergo apoptosis, while at low ATP levels, cells undergo necrosis, an alternative form of cell death.