Ultrastructural traits of apoptosis

Abstract This review summarizes original and literature data on changes in the ultrastructure of major cell organelles during apoptosis obtained by transmission electron microscopy. Organelles that make the most crucial contribution to the initiation of apoptosis: plasma membrane, mitochondria, proteasomes, Golgi apparatus, and endoplasmic reticulum, were of our prime attention. The nucleus and cytoskeleton that undergo essential changes, were considered as well. Special attention was paid to the data on ultrastructural changes in the cell organelles observed recently by electron microscopic tomography and correlative microscopy, in particular, to remodeling of mitochondrial crista junctions and microtubules during the execution phase of apoptosis.