No abstract

The mitochondria are dynamic organelles that constantly fuse and divide. These mitochondrial dynamics play a role in mitochondrial and cellular functions. In the last 10 years, the technique of electron tomography (ET) employing high voltage electron microscopes and rapid freezing fixation methods has revealed new information about mitochondrial membrane structure [1]. For example, Mannella and co-workers have shown that the commonly accepted concept that mitochondria have cristae composed of extended sheet-like, parallel involutions of the inner membrane is incorrect [2]. Instead Perkin and coworkers discovered that the inner membrane invaginates to form cristae only through narrow, tubular openings, crista junctions [3].