Figure 1.

A microarray analysis to study the subcellular localization of mRNAs encoding mitochondrial proteins. (a) After cycloheximide blocking of translation, polysomes associated with mitochondria (MP) and free cytoplasmic polysomes (FP) were purified and the corresponding mRNA species were purified and treated for analysis (b) using high-density oligonucleotide microarrays. The total mRNA population from spheroplasts (TOT) was extracted in parallel with the two other fractions and used as a reference. (c) After normalization and signal treatment, a synthetic localization value called MFI (membrane versus free index) was calculated as indicated for each mRNA. Ninety-seven percent of the probe sets, corresponding to 96% of the genes and 94% of the mitochondrial genes, have MFI values assigned to them.