WIKIMEDIA, LOUISA HOWARDMice bred such that their nuclear and mitochondrial DNAs derive from different strains tend to grow old in better health than mice whose mitochondrial and nuclear DNAs are ancestrally matched, according to a study published today (July 6) in Nature. These apparent health benefits occur despite signs of oxidative stress in the mismatched animals, researchers from the Spanish National Center for Cardiac Research in Madrid and their colleagues have found.
“This paper is very exciting because it is putting an emphasis on the impact of the match between mitochondrial DNA and nuclear DNA,” said mitochondrial biologist Orian Shirihai of Boston University who was not involved with the work.
Mitochondria, the energy-producing power stations of cells, have their own small genomes. And, compared with the human nuclear genome, these mitochondrial genomes are highly variable, said José Antonio Enríquez of the Spanish National Center for Cardiac Research, who led the new study. But with the exception of known disease-causing mitochondrial DNA (mtDNA) mutations, he noted, “we always considered this variability just not relevant—silent.” The idea was that if the variants did somehow alter metabolic physiology, they would likely have been lost during evolution, he explained.
But growing ...
