Will three-parent genes increase life expectancy?

Posted Jul 14, 2016 by Tim Sandle
Studies using mice, where pups have been born with genes from three parents, have shown that the mice live longer. Scientists are discussing whether such a longevity effect would be seen with people.
Greg Wood, AFP/File
The studies on mice relate to the procedure ‘mitochondrial donation’. With this offspring are produced with DNA from three people: a mother, a father and a female donor. The second female supplies mitochondria.
In cells, mitochondria convert the energy from food into a form that cells can use. It is known that many genetic diseases are the result of defective mitochondria. One of the reasons why some countries have passed legislation allowing experiments in ‘three person IVF’ (or ‘mitochondrial donation’) is to overcome genetic diseases. One country allowing such experiments is the U.K.
With the process:
A child born through mitochondrial donation inherits maternal nuclear DNA, paternal nuclear DNA and a dash of mitochondrial DNA from the second female donor.
While the main focus of the research is genetic diseases, according to The Economist, Spanish researchers have detected a general, potential benefit: increased life expectancy.
This is based on research conducted by Dr. José Antonio Enríquez of the Carlos III Centre for Cardiovascular Research. The study has shown modified mice live longer than control mice. This is because the modified mice gain less weight and have more stable blood-insulin levels. Moreover, their muscles deteriorate at a slower rate. This makes sense, given the role mitochondria play in modifying the metabolic rate.
Understandably the news has sparked interest on social media. InterestingNews (@UpdateNewsLive), for example, tweeted: "We're born with 2 parents. Could 3 be life-saving?" And school teacher Brenda Flick (@HLHSBrendaFlick) messaged: "This could be an interesting class discussion. Mitochondrial donation: Three’s company."
While very interesting, further study is required to confirm the effect to see if the same effects occur in other animals. The research has been published in the journal Nature. The paper is titled “Mitochondrial and nuclear DNA matching shapes metabolism and healthy ageing.”
In related news, mitochondria may be more complex than previously thought. In a Nature editorial, Garry Hamilton writes: “A growing body of evidence suggests that mitochondria do not just produce energy, but also influence a wide range of cellular processes, from cell death to immune responses.” In inference is that such variations could be more complex than previously thought and that this could make the ‘three parent’ concept could carry additional risks.