BIOLOGICAL MECHANISM PASSES ON LONG-TERM EPIGENETIC 'MEMORIES'

According to epigenetics, the study of inheritable changes in gene expression not directly coded in our DNA, our life experiences may be passed on to our children and our children's children. Studies on survivors of traumatic events have suggested that exposure to stress may indeed have lasting effects on subsequent generations. But how exactly are these genetic "memories" passed on?

Researchers have been preoccupied with how the effects of stress, trauma, and other environmental exposures are passed from one generation to the next for years. Small RNA molecules, short sequences of RNA that regulate the expression of genes, are among the key factors involved in mediating this kind of inheritance.

"We previously showed that worms inherited small RNAs following the starvation and viral infections of their parents. These small RNAs helped prepare their offspring for similar hardships," Dr. Rechavi said. "We also identified a mechanism that amplified heritable small RNAs across generations, so the response was not diluted. We found that enzymes called RdRPs are required for re-creating new small RNAs to keep the response going in subsequent generations."

Scientists discovered that specific genes, which they named "MOTEK" (Modified Transgenerational Epigenetic Kinetics), were involved in turning on and off epigenetic transmissions.

"We discovered how to manipulate the transgenerational duration of epigenetic inheritance in worms by switching 'on' and 'off' the small RNAs that worms use to regulate genes," said Dr. Rechavi.

"The feedback determines whether epigenetic memory will continue to the progeny or not, and how long each epigenetic response will last."

Thanks to: sciencedaily.com