From ‘science fiction’ to ‘just hard’: Mitochondrial DNA editing inches closer to reality

Aubrey De Grey used to talk about moving mitochondrial DNA into the nucleus as an anti-aging strategy (Not sure he’s still thinking about this)… but interesting:

From ‘science fiction’ to ‘just hard’: Mitochondrial DNA editing inches closer to reality

Over a billion years ago, a single-celled archaean engulfed an overachieving bacterium. The bacterium didn’t perish but instead struck an agreement with its host. For shelter, the bacterium would pay rent by doing what it did best—churn out energy molecules to power both itself and the host cell.

This pivotal event in Earth’s history, according to the endosymbiosis theory, allowed the nested cells to harvest energy from the environment like never before, thus starting the march toward complex life. From such simple prokaryotic life forms came nucleus-toting eukaryotes and then their multicellular counterparts, eventually giving rise to the organismic richness across the planet today. With a few exceptions, most modern eukaryotic cells harbor these once-free-roaming bacteria. We call them mitochondria.

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Over the eons, mitochondria coevolved with their hosts as organelles, but the former bacteria never fully jettisoned their genes. In a last-ditch streak of independence, mitochondria retained 37 genes to code for 13 proteins, leaving the remaining 99% of the proteins it needs to the nuclear genome. But where there are genes, there is replication—and errors are bound to arise. Mutations in mitochondria- associated genes lead to mitochondrial diseases. These multisystemic disorders can impact any organ, though those with the highest energy demands, such as the brain and heart, tend to be the most affected.

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I watched a video on mitochondria that talked about why the genes moved. What I remember from it is that it is more efficient for the cell to make the proteins in the cell itself, hence the moving. The remaining genes remain with the mitochondria to avoid recombination, because it is important for functioning that they stay as a group.

It is also true, apparently, that the mitochondrial genes that come from the cell need to be compatible with each other & with the mitochondria capsule.

FWIW, there are also errors in replication in the nuclear dna, so moving to the cell ‘city’ doesn’t stop it, though it might slow down the rate.