MITOCHONDRIAL GENOME REPOSITIONING DURING THE DIFFERENTIATION OF THE AFRICAN TRYPANOSOME BETWEEN LIFE-CYCLE FORMS IS MICROTUBULE MEDIATED

The cell cycle of the African trypanosome requires a precise orchestra tion of nuclear and mitochondrial genome (kinetoplast) positioning to ensure faithful segregation during division. The controls underlying t hese events must be subject to modulation, however, as the respective positioning of these organelles changes during the parasite's complex life cycle. We have studied mitochondrial DNA repositioning during dif ferentiation between the trypanosome's bloodstream and procyclic form. We have found that repositioning occurs simultaneously with the DNA r eplication phase of the cell cycle of the differentiating parasite. Fu rthermore, we demonstrate, at the cell and individual microtubule leve l, that this organelle repositioning is achieved via microtubule-depen dent processes. Our results have implications for the control of cell differentiation and division in African trypanosomes.