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Bluma Lesch, a geneticist at Yale University, was in the midst of a study on epigenetics and development when her subjects starting dying inexplicably. A year before, she had bred mice to examine how epigenetic alterations in their fathers’ sperm might affect them, but had not noticed any abnormalities before. At first, she couldn’t believe it.
“I kept showing that data to different people, kind of asking them to point out what was wrong with the experiment,” she says.
She had knocked out the gene Kdm6a, also known as Utx, only in the fathers’ sperm. The gene encodes an enzyme that removes methyl groups from histones—epigenetic marks that can activate or inactivate portions of DNA.
The enzyme is thought to play an important role in development. It also happens to be located on the X chromosome, meaning that if she inactivated it in the sperm of ...
