Obese? Your grandfather could be blamed for it

Toronto: If you are obese, diabetic or have cancer, do not just blame the DNA for it. There could be other mechanisms involved which play a key role in transferring environmental memories down generations, a new study says.

Before his offspring are even conceived, a father's life experiences involving food, drugs, exposure to toxic products and even stress can affect the development and health not only of his children, but even of his grandchildren.

Now, McGill University researchers have an explanation why this happens. They have found that proteins known as histones - which have attracted relatively little attention until now - may play a crucial role in the process.

Histones are distinct from our DNA, although they combine with it during cell formation.

The researchers created mice in which they slightly altered the biochemical information on the histones during sperm cell formation and then measured the results.

They found that there were dire consequences for the offspring both in terms of their development and in terms of their surviving at all.

Moreover, what was most surprising, was that these effects could still be seen two generations later.

"When we saw the decreased survivability across generations and the developmental abnormalities we were really blown away as it was never thought that altering something outside the DNA, that is, a protein, could be involved in inheritance," said lead author Sarah Kimmins.

"These findings are remarkable because they indicate that information other than DNA is involved in heritability. The study highlights the critical role that fathers play in the health of their children and even grandchildren," Kimmins added.

Since chemical modifications on histones are susceptible to environmental exposures, the work opens new avenues of investigation for the possible prevention and treatment of diseases of various kinds, affecting health across generations, she said.

The study was published in the journal Science.