A New Route to Evolution: How DNA from Our Mitochondria Works Its Way Into Our Genomes
Published:19 Oct.2022 Source:University of Cambridge
Mitochondria are tiny ‘organelles’ that sit within our cells, where they act like batteries, providing energy in the form of the molecule ATP to power the cells. Mitochondrial DNA is passed down the maternal line -- that is, we inherit it from our mothers, not our fathers. However, a study published in PNAS in 2018 from researchers at the Cincinnati Children's Hospital Medical Center in the USA reported evidence that suggested some mitochondrial DNA had been passed down the paternal line.
To investigate these claims, the Cambridge team looked at the DNA from over 11,000 families recruited to Genomics England’s 100,000 Genomes Project, searching for patterns that looked like paternal inheritance. The Cambridge team found mitochondrial DNA ‘inserts’ in the nuclear DNA of some children that were not present in that of their parents. This meant that the US team had probably reached the wrong conclusions: what they had observed were not paternally-inherited mitochondrial DNA, but rather these inserts. Now, extending this work to over 66,000 people, the team showed that the new inserts are actually happening all the time, showing a new way our genome evolves.