It is interpreted as an altruistic behaviour of the cells towards development and defence of the entire organism. Previous studies have emphasized its role in embryogenesis, tissue homeostasis and immuno response. The far-reaching significance of this genetically coded cell death has become clear only recently. Due to these changes on the surface, apoptotic cells are taken up and digested by macrophages.
Many cells involved in apoptosis have the capacity to induce apoptosis by overexpression.
It seemd impossible to use this dominant effect for isolating genes because their activity leads to cell death instead of amplification of the cells as in the case of oncogenes. However, we have been able to isolate such dominant, apoptosis-inducing genes. For that purpose, we developed a genetic screen based on the iterative transfection of small expression plasmid pools from a normalized gene library and the subsequent microscopic determination of programmed cell death based on the phenotype of the cells. Significance of apoptosis for different physiological and pathological processes. Apoptosis plays an important role in the balance of proliferation and cell death in tissues that are constantly renewed, e.g. in the intestines or the skin.