Abstract
The survival of parasites is dependent on that of the host. It is considered that parasites originated from nonparasitic ancestors and adapted to the environment in the host during the evolutional process, and developed host-and organ-specificities. Regarding energy metabolism, which is an essential factor for the survival, parasites adapt to the environment under a low oxygen tension in the host using metabolic systems which are very different from that of the host mammals. In such systems, parasite mitochondria play diverse roles. Especially, marked changes in the morphology and components of the mitochondria in the life cycle are very interesting in biological aspects such as developmental control and environmental adaptation. Such unique properties of parasite mitochondria could be promising targets for chemotherapy.
