Figure 1.

Transgenerational epigenetic inheritance. According to the classical definition of transgenerational epigenetic inheritance, environmental triggers that hit pregnant female individuals (F0) can affect “directly” not only the first new generation (F1), but also its germ cells that represent the second generation (F2). For this reason, only changes in F3 can be due “purely” to epigenetic inheritance. The male germline, instead, can be affected only for one generation, allowing observing epigenetic inheritance already at F2.