The long and winding road to RNA editing in plant mitochondria: the Tübingen-Berlin chapter.

It took several independent observations of C-to-T differences between genomic mtDNA sequences and corresponding complementary DNA (cDNA) sequences before RNA editing in plant mitochondria was accepted as a fact by the group at Tübingen and later Berlin (Hiesel et al., Science246 (1989) 1632-1634). The first such deviating sequence runs were critically viewed in the lab as being errors of some kind, most likely cloning artifacts, which occur only too frequently. Several such cDNA-mtDNA differences identified in independent cDNA clones in different libraries and finally CGG to TGG codon changes dispelled the skeptical view, and this phenomenon was finally recognized as plant mitochondrial RNA editing of a type similar to the apolipoprotein B RNA editing in mammals.