Modification of cell growth and longevity using an in vivo assay in Drosophila melanogaster

Beadex is a mutation in Drosophila melanogaster that causes premature cell death in the growing wing blade. The extent of cell loss can be modified by environmental conditions and by other genes. By strictly controlling the genotype, therefore, we can use phenotypic variation in the amount of cell death as an in vivo screen of the action that selected drugs have upon cell longevity and replacement in the growing wing. We found that drugs that modify membrane stability or lysosome activity often, but not always, had similar effects upon cell and organism longevity. Thus, the processes important to cell stability in a growing organ are partially separable from those acting upon the organism as a whole. Furthermore, Minute mutations that reduce the efficiency of protein synthesis and extend developmental time allow Beadex -related cell death to be compensated for by additional cell replacement or increased cell lifespan. Both time-span of developmental activity and the stability of cell membranes and organelles are therefore important variables affecting the makeup of the cell populations in an adult organ.