Mice can 'warn' progeny of dangers via sperm: study
By Mariette Le Roux, AFP
December 3, 2013, 12:08 am TWN
PARIS -- Lab mice trained to fear a particular smell can transfer the impulse to their unborn sons and grandsons through a mechanism in their sperm, a study said Sunday.
The research claims to provide evidence for the concept of animals “inheriting” a memory of their ancestors' traumas, and responding as if they had lived the events themselves.
It is the latest find in the study of epigenetics, in which environmental factors are said to cause genes to start behaving differently without any change to their underlying DNA encoding.
“Knowing how ancestral experiences influence descendant generations will allow us to understand more about the development of neuropsychiatric disorders that have a transgenerational basis,” said study co-author Brian Dias of the Emory University School of Medicine in Atlanta, Georgia.
And it may one day lead to therapies that can soften the memory “inheritance.”
For the study, Dias and co-author Kerry Ressler trained mice, using foot shocks, to fear an odor that resembles cherry blossoms.
Later, they tested the extent to which the animals' offspring startled when exposed to the same smell. The younger generation had not even been conceived when their fathers underwent the training, and had never smelt the odor before the experiment.
The offspring of trained mice were “able to detect and respond to far less amounts of odor ... suggesting they are more sensitive” to it, Ressler told AFP of the findings published in the journal Nature Neuroscience.
They did not react the same way to other odors, and compared to the offspring of non-trained mice, their reaction to the cherry blossom whiff was about 200-percent stronger, he said.
The scientists then looked at a gene, M71, that governs the functioning of an odor receptor in the nose that responds specifically to the cherry blossom smell.