Hurley said adaptation to salt is likely affecting Daphnia at the epigenetic level, a heritable change
in gene levels rather than genetic code.
But another approach -- "germ line gene therapy" (GLGT), which, by modifying sperm, eggs, or embryos, creates a heritable change
that affects future generations -- is now also approaching practicability.
Up to now, gene therapy has been of a type that affects only the patient being treated but does not create a heritable change
and affect future generations; that is, it does not modify sperm, eggs, or embryos in a way that would constitute "germline gene therapy" (GLGT).
An heritable change
in the sensitivity of a pest population reflected in the repeated failure of a product to achieve the expected level of control when used according to the label recommendation for that pest species.
These changes appear to be targeted, and allow significant heritable change
to take place within a generation.
It is an interaction between two alleles of a single locus that results in a heritable change
of one allele.
Fourth, all scientists should refrain, for the time being, from "attempting to make heritable changes
in the human genome.
Thus, owing to their role in shaping gene expression, and the potential for heritable changes
, epigenetic factors are of great interest for plant breeders, in their quest for adaptable, high yielding phenotypes.
Editing the DNA of such cells, or of the embryo itself, would pass heritable changes
to future generations.
Epigenetics refers to the study of heritable changes
in gene expression, caused by environmental modifications in a chromosome.
The idea that heritable changes
can result from environmental effects and cellular experiences is a radical one for biologists, who rejected the Lamarckian model of evolution in favor of a gene-based, Darwinian view in the 1930s and '40s.
Epigenetic: Heritable changes
in phenotype or gene expression caused by mechanisms other than changes in the underlying DNA sequence.