Scientists map silenced genes to study effects

Remember biology class where you learned that children inherit one copy of a gene...

Remember biology class where you learned that children inherit one copy of a gene from mom and a second from dad? There’s a twist, some of those genes arrive switched-off, so there is no back-up if the other copy goes bad, making you more vulnerable to disorders from obesity to cancer.

Duke University scientists now have identified these “silenced genes”, creating the first map of this unique group of about 200 genes believed to play a profound role in people’s health.

More intriguing, the work marks an important step in studying how our environment food, stress, pollution interacts with genes to help determine why some people get sick and others do not.

“What we have is a bag of gold nuggets,” lead researcher Dr Randy Jirtle said about the collection of “imprinted” genes. The team’s findings were published online on Thursday by the Genome Research.

Next comes work to prove exactly what role these genes play. “Some will be real gold and some will be fool’s gold,” Jirtle added.

Usually, people inherit a copy of each gene from each parent and both copies are active, programmed to do their jobs whenever needed. If one copy of a gene becomes mutated and quits working properly, often the other copy can compensate.

Genetic imprinting knocks out that backup. It means that for some genes, people inherit an active copy only from the mother or only from the father. Molecular signals tell, or “imprint”, the copy from the other parent to be silent.