Which is activated for nuclear fragmentation in apoptosis?

Mitochondria contain several proteins that are capable of inducing apoptosis; these proteins include cytochrome c and other proteins that neutralize endogenous inhibitors ofapoptosis. Cytochrome c, together with some cofactors, activates caspase-9. Other proteins that leak out of mitochondria block the activities of caspase antagonists that function as physiologic inhibitors of apoptosis.The net result is the activation of the caspase cascade, ultimately leading to nuclear fragmentation.( Robbins Basic Pathology, 9th edition, page 19 )