The experimenter modified human genes to displace certain emotional facilities for improved mental abilities, and the success of the experiment eventually led to the development of near-emotionless humans with high levels of intelligence that became the Observers.

On the same basis, the escape of Monsanto modified genes into the wild should be charged back for cleaning them all up.

Occasionally, mutations can modify genes, but many mutations are either silent or lethal.

Many coat color modifying genes affect the skin and eyes as well as the coat color.

Environmental factors and additional, modifying genes and are also likely to play major roles.

Using ZFNs to modify endogenous genes has traditionally been a difficult task due mainly to the challenge of generating zinc finger domains that target the desired sequence with sufficient specificity.

"We have the tools to modify genes within crops of major food interest," said Norman A. Jacobs, president of Biotechnica, which is based in Cambridge, Mass. "The time is now to begin applying that technology."

This strongly suggests the presence of modifying genes that affect the phenotypic expression of this mutation, or possibly the interaction of the BRCA2 mutation with environmental factors.

Maybe the first thing that happens when species diverge is that they start modifying genes - imprinting them - and eventually, as a consequence, they cannot mate.

Genome editing using ZFN provides a new strategy for genetic manipulation in plants and is likely to assist engineering desired plant traits by modifying endogenous genes.