Figure 3

Mitochondrial compartmentalization. (a): Cytoplasmic vs. mitochondrial splicing, ribosomal (small and large subunits are lumped together) and ribosomal translational complexes. All genes are nuclear-encoded. Black profiles represent mRNAs classified as periodic. Within each of the two compartments, the time courses of gene expression are similar and fairly coordinated. Even the amount of correlation among the complexes subunits is similar, with e.g. ribosomal mRNAs in both compartments being more tightly coordinated than the corresponding translational machineries. The bursts for the cytoplasmic localizations are much sharper, higher and shorter than in the mitochondria. These last accumulate an average phase lag of ~90^°, or around 50 minutes of delay (recall that the phase is computed by autocorrelation with a train of sinusoids, hence the value for the phase represents the "center" of the pulse). The cytoplasmic ribosomal complex substantially overlaps with cluster 9 of Fig. 1(a), while the mitochondrial ribosomal complex is contained in cluster 8 of the same Figure. (b): Mitochondrial translocases across outer and inner membranes, and mRNAs having Puf3p as a RBP (220 genes, 134 periodic). Of the 236 mRNAs belonging to at least one of the mitochondrial categories shown in the Figure, 62 have Puf3p as RBP. This tells us that in this case the "localization" constraint is stronger than co-sharing a single RBP, but that the two conditions are coupled and induce a similar pattern of dynamical regulation.