Chromosome painting

Here is a view of my chromosomes 1 through 22 (actually, each bar represents the two copies of each of my chromosome, one inherited from my father and the other from my mother). There are two more chromosomes (the 23rd pair), which are not drawn here, and which determine the person’s sex. In my case, since I’m a woman, I got an X chromosome from each of my parents and I am XX.

This functionality of the 23andme website, called “ancestry painting”, allows me to see the origin of my chromosomes in terms of large geographical regions.




In my case, the image shows that 99 percent of my chromosomes 1 through 22 are of European origin (they are painted black). The rest of my genome, less than 1 percent, is painted orange and is of Asiatic origin. This encompasses a small fragment on chromosome 8 (inherited from just one of my parents, as seen from the fact that only the lower half of that fragment is painted orange); and a slightly larger fragment on chromosome 18, that seems to have derived from the same geographic origin in both my parents, as it is completely painted orange. Chromosome painting has another very interesting application, which I will explain on some other occasion.