Modification of nuclear gene expression by inhibition of mitochondrial translation during sporulation in MATa/Mata diploids of Saccharomyces cerevisiae.

Sporulation of S. cerevisiae MAT alpha-/MATa was accompanied by a novel pattern of protein synthesis as shown by the disappearance of some "mitotic" polypeptides and by the appearance of a new set of "meiotic" polypeptides. Inhibition of mitochondrial protein synthesis by erythromycin within the 1st h caused the disappearance of several "meiotic" polypeptides. These meiotic polypeptides were also sensitive to cycloheximide and were localized in the cytosol, demonstrating that they were not mitochondrial translational products. Since erythromycin affected neither protein synthesis nor sporulation in a mitochondrially inherited eryr mutant, we conclude that mitochondrial protein synthesis is needed for the expression of some nuclear genes during sporulation.