Mitochondrial mRNA localization and mRNA length. The MFI values of 358 genes known to have mitochondrially localized products are plotted against the corresponding mRNA length (semi-log scale). The Pearson correlation coefficient between MFIs and log mRNA length is 0.67. The red dots correspond to genes of prokaryotic origin (ABE in Figure 5). The higher number of nascent polypeptide-chain-associated complexes (NAC) found on the longer mRNAs could attract the corresponding polysomes to the vicinity of mitochondria (see text for details).