Personal reflections on RNA: an emphasis on trypanosomes

I was drawn into the field of RNA biology as a graduate student interested in the regulation of cellular processes in pathogenic protozoa. I thought that the mechanisms that African Trypanosomes use to control the differential expression of their mitochondrial (mt) genes during their life cycle must be fundamentally important and critical to this lethal pathogen. This is because these pathogens generate energy generation by oxidative phosphorylation in the insect vector but by glycolysis in the mammalian host. My naïve expectation was that this would entail conventional mechanisms such as regulation of transcription initiation to switch between the different modes of energy generation. I was surprised when it turned out to be the novel process of RNA editing, by which the coding sequences of primary mitochondrial transcripts are changed by the insertion and deletion of Us. When sequencing the unusual mt genome of T. brucei we found a frameshift in …