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epigenetic Describing heritable changes that are not the result of changes in DNA sequence. An example of an epigenetic phenomenon is molecular imprinting, in which expression of a gene varies depending on whether it is inherited from the mother or father. Another example is paramutation, which has been described in several plant species. Certain genes behave as if they have undergone mutation after being in the same genome as other, so-called paramutagenic alleles. The change persists in subsequent generations of plants, even when the paramutagenic alleles are no longer present.