Chromosome segregation is modified in TbAGO1-/- cells. Wild-type (A-C) and TbAGO1-/- (D-F) cells were fixed and processed for FISH using a probe for the 5S tandem repeats, localised on chromosome I and stained with DAPI. Left, phase-contrast image merged to DAPI (blue), middle, chromosome I signal (yellow) and right, merged DAPI-FISH signals. A. G1 cell; B-F. Mitotic cells. Defects in chromosome segregation are frequently observed in mutant cells.