ABSTRACT

The field of mitochondrial genetic research is an emerging and rapidly expanding area of interest. A recent OVID (Medline) search revealed 300 references between 1975-1979 citing mitochondria as a keyword in some format (mitochondria, mitochondrial or mtDNA), but by 2000-2004 this number has increased to 14,000. Mitochondria are essential intracellular organelles that are the primary source of adenosine triphosphate (ATP), the high energy molecule required for all active intracellular processes. ATP is generated by oxidative phosphorylation which is carried out by the respiratory chain on the inner mitochondrial membrane. The respiratory chain is composed from over 100 different polypeptides, making up five enzyme complexes, some of which are synthesized within the mitochondria from their own DNA (the mitochondrial genome, mtDNA). In addition to their fundamental role in energy metabolism, mitochondria are involved in intracellular calcium signaling and apoptosis. It therefore comes as no surprise that diverse disciplines have developed an interest in mitochondria, from inherited neurological disorders to cancer and the ageing process. The mtDNA molecule forms the focus of this chapter.