Mary F. Lyon

In mammals in particular, the strategy is this process of X chromosome inactivation.

It was discovered by Mary Lyon, a British geneticist, many decades ago.

And when I arrived in the lab of Phil Avner at the Pasteur Institute, we really didn't know very much other than that one of the two X chromosomes is shut down.

My project was to understand how do you switch off a whole chromosome? I was lucky enough that when I arrived, one gene had just been discovered.