Epigenitics and what is passed on to our children

[Lance]

From new scientist magazine

http://www.newscientist.com/article/mg22630254.400-first-evidence-of-how-parents-lives-could-change-childrens-dna.html

FOR the first time, we have a mechanism that could explain how your lifestyle choices may impact the genes of your children and grandchildren.

Mounting evidence suggests that environmental factors such as smoking, diet and stress can leave their mark on the genes of future generations. For example, girls born to Dutch women who were pregnant during a long famine at the end of the second world war had twice the usual risk of developing schizophrenia.

This is puzzling – although we know that the environment can alter how our genes are expressed through structural changes to our DNA, classical genetics says such epigenetic markers are stripped from our genomes when we are early embryos.

But now researchers have observed some human genes evading this clean-up process. Azim Surani at the University of Cambridge and colleagues found that about 2 to 5 per cent of DNA methylation, a form of epigenetic tag that makes genes less active, escapes the reset process that happens during early embryonic development (Cell, doi.org/438).

Because this is only a small proportion of the genome, Surani says most epigenetic changes caused by our environment are very unlikely to affect future generations, but that there may be a small window of opportunity for some to be passed on.

They found that these "escapees" were mostly genes implicated in brain conditions such as bipolar disorder and schizophrenia, as well as metabolic disorders like obesity.

Edited July 15, 2015 by TheDoorGuy

[kejedo]

Some experiences such as x-rays can change the DNA for future generations. Stressful or malnourished pregnancies can have a direct result on the developing fetus. It seems logical to conclude, as does Surani, that the tiny proportion of epigenetic material (escapees) is unlikely to carry on to future generations.  The hypothesis that "there may be a small window of opportunity for some to be passed on,but it is VERY unlikely." is fascinating, but early and not substantiated by this small piece of data, imho. That being written, we should monitor our behaviors and health choices during pregnancy for our sons and daughters. Whether our good choices will have an effect on our grandchildren is questionable. My personal example: I quit smoking during my first pregnancy (but not immediately).MY first son was the smallest and the only natural delivery and had ear infections as a child (never needed tubes.) I never smoked (again) at all during my next two pregnancies, who were both large and c-sections. My second son had a bad cold when only a few days old and we were snowed in, but my doc titrated down a dose of reg cough meds, and he did fine,  My third son had pneumonia and tonsillitis. If they get married and have children, it is a stretch to think my nutritional choices during my pregnancies will matter to my potential grandchildren. If they marry women who smoke throughout pregnancy and have bad nutrition, it seems this would trump any of my behavior choices. For the Dutch women in the study, there is no followup of the next gen, so one could conclude an emaciating event during development of the fetus could deprive the developing brain and result in abnormality. It should not have been too difficult to track offspring of these women. Interesting,though. I believe scientists are earning grants or focusing research in their race to crack the double helix.