Three’s company

Elixir of life

GENETICALLY speaking, everyone has two parents. But that could soon change. Several countries, led by Britain—whose legislators approved the idea last year—are working on a procedure called mitochondrial donation, which would result in a child with DNA from three people: its mother, its father and a female donor sometimes dubbed a mitomum.

The mitomum supplies the child’s mitochondria. These are tiny structures (one is pictured below), present in most cells, that liberate usable energy from food and oxygen. People with defective mitochondria suffer debilitating illness and often die young because the tissues of their bodies are starved of the energy they need to work. Mitochondrial diseases are hereditary, and at the moment incurable. Mitochondrial donation is designed to prevent them by replacing faulty mitochondria with healthy ones.

But mitochondria are, or used to be, creatures in their own right. They are the descendants of ancient bacteria that once lived free, but then entered into a symbiotic union with other cells. As such they have their own tiny genomes, separate from the main…Continue reading
Source: Economist