Fertility treatment, not maternal age, causes epigenetic changes in mouse offspring

After fertilization, cells within a newly-formed mouse embryo divide and multiply. The cells all have the same DNA, but gene expression patterns diverge as they start to take on different roles. Once there are a few dozen cells, a fluid-filled cavity appears in the center of the embryo. Cells on the surface will become the placenta and the clump of cells nestled to one side will become the fetus. With epigenetic disorders, the gene expression instructions aren't passed down or maintained properly. In Beckwith-Wiedemann syndrome, for example, the loss of epigenetic marks causes an overgrowth of the placenta and certain parts of the fetus.
Credit: Audrey Kindsfather / University of Pittsburgh