Nucleoid autonomy: An underlying mechanism of mitochondrial genetics with therapeutic potential.

Emerging research shows that the packaging of mitochondrial DNA (mtDNA) into protein-DNA assemblies called nucleoids confers higher-order organization to the mitochondrial genome. Studies of nucleoid composition, structure and dynamics reveal the mitochondrial nucleoid to be tightly regulated in its genetic autonomy, macromolecular organization and distribution throughout the cell. Our recent research shows that mitochondrial nucleoids are self-contained genetic entities that do not exchange mtDNAs with each other frequently. This suggests that the genetic composition of a cell's nucleoids will be the key determinant of the cell's mtDNA dynamics, and provides a mechanistic basis for therapeutic methods to rescue dysfunction due to mutations in mtDNA.