How is mitochondrial DNA inherited?

1 Answer
Oct 14, 2014

In humans and other mammals, mitochondrial DNA, or mtDNA is inherited from the mother's ovum. Since the father's mtDNA is located in the mitochondrial sheath of the sperm, which is lost at fertilization, all children of the same mother have the same maternal mtDNA, and therefore their mtDNA is identical to each other and to their mother.

Mitochondrial DNA testing is a very powerful and accurate way to test for biological siblings. Mitochondrial testing is currently used by military DNA laboratories to identify skeletons discovered in old war zones, by tracing the mitochondrial DNA back to living relatives.

The US military is still using mitochondria DNA testing to identify bone fragments from world war II, Vietnam and Korean wars, and many other conflicts.

mtDNA can play an important role in missing persons investigations, mass disasters, and other forensic investigations involving samples with limited biological material. Additionally, mtDNA is maternally inherited. Therefore, barring a mutation, an individual's mother, siblings, as well as all other maternally-related family members will have identical mtDNA sequences. As a result, forensic comparisons can be made using a reference sample from any maternal relative, even if the unknown and reference sample are separated by many generations.