Translational control of mRNAs regulates the spatio- temporal production of the proteins they encode. Further refinement of mRNA and protein distribution patterns is brought about by regulation of transcript stability. Genetic and molecular analyses in Drosophila can provide unparalleled insight into the developmental functions of the modulation of mRNA translation and stability. These mechanisms play a key role in regulating the production of cell fate determinants, cell cycle regulators and molecular chaperones.Copyright 1997 Academic Press