And lately the manipulation of DNA has been driving the fascinating, if controversial, business of genetically modifying the animals and plants on our farms; even changes to human DNA are now up for discussion as the recent debates around mitochondrial transfer and genome editing have shown.
These help a mitochondrial enzyme called carnitine acetyltransferase to do its job.
What they found was that there is a lot of variability in the mitochondrial DNA, and much less in the Y-chromosome DNA.The most plausible explanation for this is that a few men in each generation contribute the bulk of the Y-chromosomes to the next.
And that, as they describe in Science, is what Dr Thalmann, Dr Wayne and the rest of the team did.In this section Face the facts The company of wolves Aerosniff Thyme to touch ReprintsThey extracted mitochondrial DNA from 18 fossil canids, making sure to include the earliest doglike creatures that show skeletal signs of domestication.
Because each cell has lots of mitochondria, but only one nucleus, there is a better chance of getting mitochondrial genes than nuclear genes from a fossil.
Using estimates of how often mutations appear in mitochondrial DNA (the so-called molecular clock), she and Wilson did some matridendrochronology.
That was all but certain from their previous study of the creature's mitochondrial DNA (an abundant form of the molecule found in cells' powerpacks), released in March.
Similarly, part of the Y chromosome (which carries the genes that determine maleness) is passed intact from fathers to sons, but not to daughters.In this section Hale and healthy Talk is cheap Screening for screams Marching backwards ReprintsAll this means that mitochondrial DNA and non-mixing Y-chromosome DNA change only as a result of mutation, and such mutations are infrequent.
So the small slice of mitochondrial DNA from the donor should not affect things like eye colour, height or personality, which will be influenced by the child's parents in the usual way.
African cattle have features of both Bos taurus and Bos indicus, but their mitochondrial DNA suggests that, despite this apparently intermediate nature, they all belong to Bos taurus.
But the separateness of mitochondrial genes means that by moving the nucleus from an afflicted egg into a healthy one, the mutated, disease-causing genes can be left behind.
