Fig. 7. Silencing Cenp-F weakens centromeric cohesion. HeLa cells were transfected with siRNA duplexes designed to repress lamin B1, Cenp-F and Sgo1. (A) Immunoblot showing repression of Cenp-F and Sgo1. (B) Metaphase spreads showing loss of centromere cohesion following repression of Cenp-F and Sgo1. Dashed line in panel (vi) separates chromosomes from two spreads. (C) Images of chromosomes stained with anti-Bub1 and anti-ACA antibodies confirming the presence of separated chromatids. (D) Bar graph quantitating the number of metaphase spreads with separated chromatids. At least 117 cells scored in each group. (E) Bar graph quantitating the number of MPM-2-positive cells in asynchronous populations, showing that repression of Cenp-F and Sgo1 activate the spindle checkpoint. (F) Bar graph quantitating the number of cells with DNA contents greater than 4N, showing that repression of Sgo1, but not Cenp-F, enhances endoreduplication.